600176023
  SCIENTIFIC AND TECHNICAL DATA BASE

                FOR

   CRITERIA AND HAZARDOUS POLLUTANTS



         1975 ERC/RTP REVIEW
U.S.  ENVIRONMENTAL PROTECTION AGENCY
 OFFICE OF RESEARCH AND MONITORING
 HEALTH EFFECTS RESEARCH LABORATORY
 RESEARCH TRIANGLE PARK, N.C. 27711
       u.

-------
                              DISCLAIMER
     This report has been reviewed by the Health Effects Research
Laboratory, U.S. Environmental Protection Agency, and approved for
publication.  Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
                                  11

-------
                            TABLE OF CONTENTS
                                                                    Page

LIST OF FIGURES	   v-vi

LIST OF TABLES	vii-ix

PREFACE	    x

1.  SUMMARY	    1

    1.1  GENERAL DISCUSSION 	    1

    1.2  INSTRUMENTATION	    2

         1.2.1   Nitrogen Oxides	    2
         1.2.2   Carbon Monoxide	    3
         1.2.3   Hydrocarbons	    3
         1.2.4   Photochemical Oxidants	    4
         1.2.5   Particulate Matter	    5
         1.2.6   Sulfur Oxides	    6
         1.2.7   Asbestos	    6
         1.2.8   Beryllixm	    7
         1.2.9   Mercury	    7
         1.2.10  Methods Standardization and Performance
                   Evaluation	    7

    1.3  ENVIRONMENTAL APPRAISAL	    7

         1.3.1   Emissions	    8
         1.3.2   Ambient Concentrations	    9

    1.4  TRANSFORMATION AND TRANSPORT	   10

    1.5  EFFECTS	   13

         1.5.1   Human and Animal	   13
         1.5.2   Materials	   27
         1.5.3   Ecology	   29

    1.6  CONTROL TECHNOLOGY 	   29

         1.6.1   Stationary Sources	   29

2.  INTRODUCTION	   35

3.  MEASUREMENT	   37

    3.1  INTRODUCTION	   37

    3.2  PRODUCTION OF TEST ATMOSPHERES	   45
                                111

-------
11


TABLE OF CONTENTS (continued)

                                                                  Page

         3.3  OXIDES OF NITROGEN MEAStJREMENTS	   47

              3.3.1  Ambient Air	   47
              3.3.2  Stationary Sources	   58
              3.3.3  Mobile Sources	   60

         3.4  CARBON MONOXIDE MEASUREMENT	   60

              3.4.1  Ambient Air	   60
              3.4.2  Stationary Sources 	   72

         3.5  HYDKX&KBCNS	   72

              3.5.1  Ambient Air	   72
              3.5.2  Stationary Sources 	   80
              3.5.3  Mobile Sources	   81

         3.6  PHOTOCHEMICAL OXIDANTS	   84

              3.6.1  Ambient Air	   84
              3.6.2  Stationary Sources	   99

         3.7  SUSPENDED PARTICUIATE	102

              3.7.1  Calibration	102
              3.7.2  Ambient Air	103

         3.8  SULFUR OXIDES	105

              3.8.1  Ambient Air	105
              3.8.2  Stationary Sources 	  106
              3.8.3  Mobile Sources	107

         3.9  ASBESTOS	112

              3.9.1  Stationary Sources 	  112

         3.10 BERYLLIUM	113

         3.11 MERCURY	115

         3.12 METHODS STANDARDIZATION AND PERFORMANCE
                EVALUATION	117

              3.12.1 General Discussion 	  118
              3.12.2 Particulates 	  118
              3.12.3 Sulfur  Dioxide 	  118
                                      IV

-------
                                                                     Ill
TABLE OF CONTENTS (continued)

                                                                    Page

          3.12.4  Carbon Monoxide	119
          3.12.5  Nitrogen Dioxide	.* . .  .  120
          3.12.6  Stationary Sources	121

    3.13  REFERENCES	123

4.  ENVIRONMENTAL APPRAISAL	126

    4.1   SOURCES	126

          4.1.1   National Emissions Report	126
          4.1.2   Nitrogen Oxides Emissions (NO )	129
          4.1.3   Carbon Monoxide	x	137

    4.2   TRANSFORMATION AND TRANSPORT	142

          4.2.1   Oxides of Nitrogen	142
          4.2.2   Carbon Monoxide	151
          4.2.3   Hydrocarbons	152
          4.2.4   Oxidant	153
          4.2.5   Particulate	154
          4.2.6   Sulfur Oxides and Aerosols	163
          4.2.7   Mathematical Modeling	174


    4.3   REFERENCES	184

5.  Et'ttXJlS	191

    5.1   HEALTH	191

          5.1.1   General Discussion	191
          5.1.2   Nitrogen Oxides	191
          5.1.3   Carbon Monoxide	229
          5.1.4   Hydrocarbons	237
          5.1.5   Oxidants	244
          5.1.6   Total Suspended Particulates	275
          5.1.7   Sulfur Oxides	299
          5.1.8   Mercury	314
          5.1.9   Beryllium	324
          5.1.10  Asbestos	327

    5.2   MATERIALS	343

          5.2.1   Nitrogen Oxide	343
          5.2.2   Sulfur Dioxide (SO,)  	345
          5.2.3   Ozone (O3)  ... 7	346

-------
IV


TABLE OF CONTENTS (continued)

                                                                  Page

    5.3   WEATHER, VISIBILITY AND CLIMATE	348

          5.3.1   Air Quality Trends Analysis	348
          5.3.2   Atmospheric Turbidity	349
          5.3.3   Visibility	349

    5.4   ECOLOGICAL	350

          5.4.1   Introduction	350

    5.5   REFERENCES	360

6.  CONTROL TECHNOLOGY	391

    6.1   STATIONARY SOURCES VS., POLLUTANTS	391

          6.1.1   Particulate Control	391
          6.1.2   Sulfur Oxides Control	392
          6.1.3   Nitrogen Oxides Control 	  394
          6.1.4   Hazardous and Other Control	395

    6.2   STATIONARY SOURCES VS. CONTROL	396

          6.2.1   Combustion	396
          6.2.2   Industrial Processes	425
          6.2.3   Particulate Control Technology	442

    6.3   REFERENCES	449
                                     VI

-------
                             LIST OF FIGURES

                                                                    Page

3.1   Oxides of nitrogen chemluminesoent analyzer	    55

3.2   Flow scheme for calibration of NO, N02, and NO  and
        O_ monitors by gas phase titration   . . . .x	    57

3.3   NDIR analyzer	    66

3.4   Dual isotope fluorescence analyzer 	    70

3.5   Block diagram of dual hydrogen flame detector	    78

3.6   Electronic diagram of dual flame detector  	    79

3.7   Typical ozone source, dilution and manifold system	    86

3.8   All-glass midget impinger	    89

3.9   Schematic of colorimetric oxidant analyzer	    94

3.10  Automated gas phase chemiluminescent ozone monitor	    97

3.11  Ultraviolet absorption ozone analyzer	   100

4.1   Emissions by categories - United States	   128

4.2   Seasonal diurnal patterns of nitric oxide concentrations . .   135

4.3   Seasonal diurnal patterns of nitrogen dioxide
        concentratioris	   135

4.4   Seasonal pattern of nitrogen dioxide concentration
        levels, composite graph of the six CAMP sites  	   136

4.5   Long-term trend line for nitrogen dioxide concentration
        levels composite graph of the six CAMP sites	   136

4.6   Maximum 1-hour NO- as a function of initial NO  at
        various initialTMIC levels (Snog chamber data)	   145

4.7   Nitrogen dioxide dosage as a function of initial NO
        at various initial NMHC levels (Smog chamber data* ....   146

4.8   Correlation of aerometric data on NO  (6-9 am)  and
        maximum - 1-hour-NO,, (8 am - 5 pm)X(Data from all
        CAMP sites)	   148
                                vii

-------
VI


LIST OF FIGURES

                                                                   Page

4.1   Maximum daily 1-hour-average oxidants as a function of
        6-to-9-a.m. averages of. nonmethane hydrocarbons at
        CftMP stations, June through September, 1966 through
        1968, Los Angeles, May through October, 1967	    150

4.10  Number, surface area, and volume distributions of a
        hypothetical smog.  The linear ordinate normalized
        by total number, area, or volume is used so that the
        apparent area under the curves is proportional to
        the quantity in that size range	    158

4.11  National and regional trends in sulfur dioxide, 1970-
        1973	    171
                                               64
5.1   % difference in mortality (N02 - control)    	    228

5.2   Difference in % mortality versus length of exposure to
        .5 or 3.5 ppm N026    . ,	    228

5.3   The difference in mean survival time between control  ,.
        of N0~ mice versus length of exposure to 3.5 ppm N0?   .    230

5.4   Effect of particle size on. regional respiratory
        particle deposition in nan 	    291

5.5   Deposition vs. particle size of inhaled particles
        in the upper respiratory tract and lungs of guinea
        pigs and monkeys compared to people	    292

5.6   Effects of inhalation of asbestos in rats	    335
                                               314
5.7   Effects of inhalation of asbestos in rats    	    336
                                    Vlll

-------
                             LIST OF TABLES

                                                                   Page

3.1   APPROXIMATION OF THE GASEOUS COMPOSITION OF DRY
        UNPOLLUTED AIR	     38

3.2   PRIMARY GASES AND VAPORS PRODUCED BY HUMAN ACTIVITIES  . .     39

3.3   SECONDARY ATMOSPHERIC POLLUTANTS 	     39

3.4   ATMOSPHERIC PARTICULATES AND MAJOR PRIMARY AND SECONDARY
        AIR POLLUTANTS FORMED BY PARTICLE PARTICIPATION  ....   40-41

3.5   NATIONAL AIR QUALITY STANDARD3a	   42-43

4.1   EMISSIONS BY CATEGORIES - UNITED STATES	    128

4.2   EMISSION FROM MISCELLANEOUS SOURCES	    129

4.3   ESTIMATED 1972 NO  EMISSIONS FROM STATIONARY SOURCES
        (Partial Listing of Equipment Type and Fuel Burned
        Accounting for Approximately 70% of Total Emissions) . .    131

4.4   RECLASSIFICATION STUDY - 24-HOUR DATA	    137

4.5   ESTIMATED CC»O!NTRATIONS OF LOS ANGELES AEROSOL
        PARTICLES BY SOURCE18 (Annual Average, 1966) 	    160

4.6   PARTICULATE POLLUTION INCLUDING CONSTITUENTS LARGELY
        OF SECONDARY ORIGIN	    161
                                                    ?Q
4.7   AEROSOL AND OXLDANT REACTIVITY OF HYDROCARBONS   	    164
                                                      44
4.8   SURVEILLANCE CATEGORIES FOR SULFUR DIOXIDE SITES
        (Nutrter of Sites)  	    170

4.9   SO2 DEPOSITION VELOCITIES	    174

5.1   ESTIMATED AVERAGE ANNUAL POLLUTANT EXPOSURE LEVELS IN
        THREE STUDY AREAS Ii! CHATTANOOGA, TENNESSEE, 1968-
        19724	    195

5.2   DAILY NITROGEN DIOXIDE CCNCEOTRATIONS OBSERVED AT
        CHATTANOOGA AIR MONITORING STATIONS4	196-197

5.3   MAXIMUM HOURLY NO., OONCENTRATICNS BY COMMUNITY AND
        STATION O^TIANOOGA, TENNESSEE, 1970-734
        (Micrograins per Cubic Mater)	    199
                                 IX

-------
VL11
LIST OF TABLES (continued)

                                                                  Page

5.4   THREE-YEAR FREQUENCY OF "ANY LOWER RESPIRATORY DISEASE"
        AND BRONCHITIS:  MODEL PREDICTED RATES FOR CHILDREN
        AGED ONE TO 12 YEARS FROM HOUSEHOLDS WITH A HIGH
        SCHOOL EDUCATION OR GREATER (1969-1971)	     200

5.5   RELATIVE RISK FOR TWO STUDY PERIODS OF ACUTE RESPIRATORY
        ILLNESS FOR STABLE FAMILIES LIVING IN COMMUNITIES
        EXPOSED TO DIFFERING LEVELS OF AIR POLLUTION38  ....     202

5.6   HOURLY NITROGEN DIOXIDE OMENTRATIONS OBSERVED AT
        CHATTANOOGA AIR MONITORING STATIONS8	204-205

5.7   SUMMARY OF DATA FOR RATS IN MORPHOMETRIC STUDY36  ....     215

5.8   NUMBER OF PARENCHYMAL AIR-SPACE UNITS (ALVEOLAR AND
        DUCTAL) , RATES OF FORMATION, AND '   IVIDUAL VOLUMES
        IN THE MATURING CONTROL AND NO -E*.  -6ED RAT LUNGS35 . .     216

5.9   RELEASE OF HISTAMENE FROM LUNG FRAGMENTS IN THE
        PRESENCE OF 100 nW SALT SOLUTIONS49'52  .	     223

5.10  AMBIENT AIR QUALITY STANDARD FOR CARBON MONOXIDE  ....     232

5.11  JUDGMENT THRESHOLD ESTIMATES FOR HEALTH JSbMsSUlS FOR CO  .     233

5.12  SIZE OF POPULATION AT POTENTIAL RISK OF POiLLUTANT
        INDUCED EFFECT	     234

5.13  SOME CLINICAL HEMATOLOGIC AND PATHOLOGIC FINDINGS IN
        SIX PATIENTS WITH HODGKBJ'S DISEASE	     240

5.14  LEUKEMIA EPIDEMIOLOGICAL STUDY	     241

5.15  EXPECTED VS. OBSERVED DEATHS FROM LEUKEMIA IN EIGHT
        EUROPEAN AFFILIATES 1962-1971	     241

5.16  PATHOLOGICAL CHANGES CAUSED BY OZONE	     266

5.17  EFFEC1S OF OZONE ON INFECTIVITY	     267

5.18  OZCNE INDUCED TOLERANCE	     268

5.19  EXTRA-PULMONARY EFFECTS OF OZONE	     269

5.20  EFFECTS OF SMOG	     270

5.21  EFFECT OF OZONE ON PULMONARY FUNCTION	     271

-------
                                                                      IX


LIST OF TABLES (continued)

                                                                    Page

5.22  BIOCHEMICAL EFFECTS	    272-273

5.23  BEHAVIORAL EFFECTS	       274

5.24  U.S. NATIONAL PRIMARY STANDARD FOR TOTAL SUSPENDED
        PARTICIPATES	       276

5.25  SCIENTIFIC EVIDENCE FOR THE U.S. NATIONAL PRIMARY
        TOTAL SUSPENEED PARTICIPATE STANDARD	       276

5.26  SUBSEQUENT SCIENTIFIC EVIDENCE RELATING TO THE U.S.
        NATIONAL PRIMARY TOTAL SUSPENDED PARTICULATE
        STANDARD	       279

5.27  BEST JUDGMENT THRESHOLD ESTIMATES FOR HEALTH EFFECTS
        OF TOTAL SUSPENDED PARTICULATES	       280

5.28  BEST JUDGMENT THRESHOLD ESTIMATES FOR HEALTH EFFECT
        SUSPENDED PARTICULATES BASED ON NEW EVIDENCE	       285

5.29  ESTIMATED POPULATION AT POTENTIAL RISK TO POLLUTANT-
        INDUCED EFFECT	       286

5.30  PRIMARY NATIONAL AMBIENT AIR QUALITY STANDARDS FOR
        SULFUR OXIDE	       301

5.31  INFORMATION BASE FOR ESTABLISHMENT OF NATIONAL
        PRIMARY AMBIENT AIR QUALITY STANDARD FOR SULFUR
        DIOXIDE	       302

5.32  ADDITIONAL SCIENTIFIC EVIDENCE	       304

5.33  BEST JUDGMENT THRESHOLD ESTIMATES FOR HEALTH EFFECTS
        OF SULFUR OXIDES	       309

5.34  SAFETY MARGIN INCLUDED IN SULFUR OXIDE STANDARD	       310

5.35  SIZE OF POPULATION AT POTENTIAL RISK OF POLLUTANT-
        INDUCED EFFECT	       311

5.36  CORRELATION OF INORGANIC FIBERS WITH ASBESTOS BODIES
        IN LUNGS OF 3,000 CONSECUTIVE AUTOPSIES IN NEW
        YORK CITY, 1966 to 1968   	       333

5.37  CHRYSOTILE IN 28 CASES STUDIED BY ELECTRON MICROSCOPY .  .       333

5.38  NUMBER OF ANIMALS WITH LUNG TUMOURS OR MESOTHELIOMATA .  .    339-340
                               XI

-------
                                  PREFACE


       This report was prepared by Environmental Research Center,

Research Triangle Park (ERC/RTP) staff.  The report's objective is

to review results of research by and under the sponsorship of ERC/

RTP, related to criteria and hazardous pollutants since publication

of the criteria and background documents.  Recent reviews are also

included in a series of documents by the Conmittee on Challenges to

Modern Society, NATO; and by the National Academy of Science.

       This report does not duplicate those other reviews.  Primary

emphasis here is on results of the ERC/RTP research program.  Sig-

nificant results of still other investigators known to the authors,

however, are included.  But it is not a complete review and evalua-

tion of all current literature.

       Contributing authors from the ERC/RTP include the following:

                  D. L. Coffin           C. Kommineni
                  J. H. B. Garner        J. Elder
                  T. Ripberger           R. Smizlowicz
                  D. I. Hammer           J. Graham
                  J. G. French           A. H. Ellison
                  M. D. Waters           P. Brubaker
                  K. Bridbord            G. Ortman
                  J. R. Smith            0. Stopinski
                  J. B. Clements         J. Nader
                  W. Galke               W. Stein
                  F. Benson              T. Hauser
                  Paul Humphrey          J. Upham
                  D. Cahill              G. Fairchild
                                XII

-------
                                1.  SIM4ARY


1.1  GENERAL DISCUSSION

     The best scientific data base was unavailable for six air pollu-

tants when National Ambient Air Quality Standards (NAAQS) were set.

This data base is still inadequate.  However, evidence gathered since

the NAAQS were set support the standards.

     A recent in-depth review by the National Academy of Sciences (MAS)*

indicated that there was no good reason relative to health and welfare

effects to change the standards.  In some cases, for example, safety

factors were minimal compared to those factors used to control pollu-

tants such as radiation.

     The National Academy of Sciences' report comprehensively reviews

the scientific data base for NAAQS.  The details of material included

in the MAS reports will not be duplicated here.  Summary material will

be included, however, when appropriate for completeness.

     In this review, primary emphasis is on results achieved from the

ERC/RTP  research and development program since publication of cri-

teria and background documents.

     Air pollutants include complex combinations of reactive sulfur,

nitrogen, inorganic and organic compounds from man-made and natural

sources.  Man and other species and materials are exposed to varying
*Air Quality and Automobile Emissions Control, A Report by the Coordi-
 nating Committee on Air Quality Studies, National Academy of Sciences,
 National Academy of Engineering (4 Volumes), dated September 1, 1974.
 Prepared for the Committee on Public Works, U.S. Senate.

-------
amounts of this mixture of pollutants at different times.  The biologi-



cal response to exposure is different for different species and pollu-



tion combinations.  Physical properties of the environment such as



temperature and humidity may also influence the response.



     Parts of this review consider things such as atmospheric transport,



certain analytical techniques and control technology common to each



classification of pollutants.  Material on specific pollutants is also



presented with awareness that such pollutants contribute to the total



pollution burden in the atmosphere.  A brief general discussion is



included in each section of the report.



1.2  INSTRUMENTATION



     Since NAAQS were set, significant progress has been made in devel-



opment of sampling, analytical and instrumental methods to measure



ambient and source concentrations of air pollutants--particularly in



areas of chromatography, spectroscopy and chemiluminescence.  Programs



in method calibration, interlaboratory comparison, quality assurance



and station siting have been developed and are being implemented.



Although the over-all monitoring program is still inadequate, the above



efforts have added much to the quality of aerometric data.



1.2.1  Nitrogen Oxides



     An improved 24-hour wet chemical method of sampling and analysis



(TGS method) for ambient NO-, and an instrumental method (Chemilumi-



nescent) for NO, N09, NO , has been developed over the past three years.
                   If    A-


The chemiluminescent method is now widely used for continuous monitoring



of ambient oxides of nitrogen along with the TGS and other methods and



is being considered as a replacement for the current Federal Reference



method.

-------
     Guidelines have been proposed for selection and use of continuous
monitoring systems for NO  emissions from chosen stationary sources.
                         J\,
     The criteria and procedures for determining acceptability of a
candidate ambient air-monitoring method, equivalent to the prescribed
reference method, have been proposed.
     Chemiluminescence is widely accepted as the most selective, accu-
rate and rapid means of NO  analysis of mobile source emissions.
                          JC
1.2.2  Carbon Monoxide
     Automated gas-chromatography instruments capable of semi-continu-
ously monitoring ambient air CO concentrations over a range of 0.1 to
1000 ppm are now  commercially available.  Improvements in methods for
generation of known concentrations of CO are under development.
     The EPA reference method for measurement of CO from stationary
sources (continuous sampling coupled with a Non-Dispersive Infrared
analysis) is considered the most reliable of available methods.  Pri-
mary problems involve particulates, water vapor  and CO-.  But recent
advances in NDIR technology have minimized these problems.
     Gas correlation spectroscopy has been developed as an improved
method to measure CO emissions from mobile sources.  The technique can
measure the expected low concentrations from light-duty vehicles of
FY 1976 and later.
1.2.3  Hydrocarbons
     A commercial non-methane reactive hydrocarbon analyzer is now
available.  The system converts all hydrocarbons except methane to FLO
and CO.-,--the methane is continuously monitored with a flame ionization
detector  (FID) and total hydrocarbons are monitored with a second

-------
detector.  A chemiluminescent method to monitor reactive hydrocarbons



and olefinic organics (such as ethylene and vinyl chloride) has been



partially developed.  EPA has not yet required the states to monitor



hydrocarbons in support of the State Instrumentation Plans (SIP).



     Emission standards for hydrocarbons from stationary sources have



not been set.  No measurements are therefore required.  Both total hydro-



carbons and non-methane hydrocarbon instrumentation developed for ambient



air measurements have been used to measure emissions from stationary



sources.  These systems do not settle the question of their applicabil-



ity to emission standard settings.  The present research and development



effort involves grab-sampling systems for class fractions that are then



analyzed in the laboratory using chromatographic methods.  The analyti-



cal methods for polynuclear aromatics are not completely satisfactory.



The procedures are complicated and reproducibility and sensitivity are



problems.



     Current Federal regulations of total hydrocarbon emissions from



mobile sources utilize flame ionization analysis.  Techniques have been



developed to measure detailed composition, total non-reactive hydro-



carbons and methane.  Work is in progress to develop methods to measure



other reactive components such as osygenates.



1.2.4  Photochemical Oxidants



     The Federal Reference method for ozone measurements in ambient air



is based on the chemiluminescent reaction of 0_ with ethylene.  A number



of chemiluminescent methods are now available commercially.  These ozone



monitors are calibrated with ozone generators whose output has been



determined using the neutral buffered KI method.  The calibration

-------
procedure is not completely satisfactory, but work is underway to improve



the procedure.



1.2.5  Particulate Matter



     New procedures to collect aerosols in the fine and coarse particle



size-ranges are in final stages of development and will be tested in



CY 1975.  With these collection procedures, sample deposit profiles are



well suited for rapid mass analysis by the beta gauge for mass and by



x-ray flourescence for elements with atomic numbers above 12.



     Methods to determine the rate of particulate matter emissions, mass



concentrations, visible emission (opacity) selection of sampling ports,



stack gas velocity, stack gas molecular weight and stack gas moisture



from certain types of stationary sources have been published.  To date,



most measurements methods have been concerned with mass emissions and



valid sampling techniques.  Work is underway to develop satisfactory



methods to determine size distribution using inertial and optical tech-



niques .



     Methods to determine the composition of particulates emitted from



stationary sources are being studied.  The most attractive method cur-



rently for routine multielemental analysis of particulate matter from



stationary sources is x-ray fluorescence (XRF) spectroscopy.  A wave-



length dispersion multispectrometer instrument, recently set up at



ERC/RTP,  permits rapid analysis of all elements higher than oxygen in



atomic number with the high degree of spectral resolution needed for



airborne particulate samples.



     Particulate measurement techniques have been developed for light-



duty mobile sources using a dilution technique.  Measurements are

-------
currently made gravmetrically.  Instruments to do that measuring are



being developed.



1.2.6  Sulfur Oxides



     Several major improvements in methods to measure ambient air con-



centrations of sulfur dioxide and sulfate have been developed over the



past three years.  Sensitivity, specificity and stability of field



monitoring systems for SCL offered commercially during the 1970's have



been greatly improved over those available in the 1960's.  Improved



methods to measure sulfate and sulfuric acid in ambient air are being



developed.



     Specifications for SO--continuous-monitoring systems for stationary



sources and ambient air have been published or proposed.



     Sulfuric acid emissions from vehicles with exhaust oxidation cata-



lyst systems for CD and hydrocarbon control have stimulated work to



develop measurement techniques for sulfur in fuel and for sulfur oxides,



sulfuric acid and sulfates in exhaust emissions.  Techniques have been



developed and are in use.  Work is in progress to develop real-time



methods.



1.2.7  Asbestos



     The present National Emissions Standards for Hazardous Pollutant



(NESHAP) regulation for asbestos emissions is based upon prescribed con-



trol practices.  The most common measurement technique involves electron



microscopy to identify, count and size fibers.  Development of a new and



more rapid measurement method is under way using the x-ray diffraction



technique on a. sample pretreated for fiber alignment.

-------
1.2.8  Beryl Hum



     A measurement method for beryllium emissions involving isokinetically



sampling with a participate sampling train and analyzing the sample by



atomic absorption technique is described in the Federal Register.   A



continuous monitoring technique is not available as a proven method



applicable to emission sources.



1.2.9  Mercury



     The measurement method for mercury prescribed in the Federal  Register



involves isokinetically sampling emissions in a solution of iodine mono-



chloride with analysis by spectrophotometry.  A continuous monitoring



system can be developed through use of available analytical systems in



conjunction with an appropriate automated sampling interface system.



Development of such an interface system is under way.



1.2.10  Methods Standardization and Performance Evaluation



     EPA is standardizing reference methods for individual air pollu-



tants in ambient air and stationary and mobile sources.  The program



includes in-house methods evaluation and ruggedness testing, method



inter-relatability studies and collaborative testing.  All criteria pol-



lutants are under study and some results have been published for all six



criteria pollutants.



1.3  ENVIRONMENTAL APPRAISAL



     Essentially all man-made atmospheric matter classified as pollu-



tants are also produced by natural sources.  Emissions produced by man-



made sources are superimposed on the "natural background."  Trace gases



are naturally emitted from geophysical and biological sources.  Natural



sources produce a major portion of particulate matter found in the
                                7

-------
atmosphere.  Crude models for sulfur and nitrogen cycles are available,



but they are not sufficiently accurate to determine the contribution of



air pollutants from man-made activities to atmospheric loading.  At



present, only limited attention is given to problems relating to natural



sources and removal mechanisms that impact on global or regional bal-



ances of air pollutants.



     Limited data are available on emissions from selected classes of



stationary and mobile sources.  They only permit crude estimates of the



contribution to atmospheric loading.  An effort is under way to get



improved emission factors for both stationary and mobile sources.



1.3.1  Emissions



1.3.1.1  Oxides of Nitrogen Emissions--It is estimated that stationary



sources contribute at least half of the NO  emissions of man-made
                                          X.


sources in the U.S.  The 1972 estimate was over eleven-million tons.



About 98% of total emissions were produced by combustion of fossil fuels.



The remainder was from industrial processes such as manufacture of nitric



acid, sulfuric acid  and explosives.



     Nationwide, mobile sources contribute about 50% of the total man-



made emissions of NO .  In some urban areas such as Los Angeles, however,
                    x


the percentage is much higher.  Oxides of nitrogen are formed in mobile



sources primarily by the fixation of atmospheric nitrogen in the combus-



tion process.  Exhaust gas recirculation (EGR) and water injection



schemes reduce the peak temperature attained and this reduces the NO
                                                                    J\.



emissions.  Use of these methods on light-duty vehicles have reduced NO
                                                                       A.



emissions significantly (50% between 1968 and 1973 models).



1.3.1.2  Carbon Monoxide Emissions--Preliminary results of tests on 1975



prototype light-duty vehicles equipped with oxidation catalyst-converters



                                    8

-------
indicate that these vehicles will meet the 1975 standard of 15 gm/mi.  In
some cases, the results were better than the 1976 standard of 3.4 gm/mi.
Reported values of CO emissions from the only commercially available car
equipped with the stratified charge engine (Honda CVCC) was 2 gm/mi.
1.3.1.3  Hydrocarbon Emissions--The Clean Air Act requires a 901 roll-
back from the 1970 levels of hydrocarbon emissions from light-duty
vehicles.  The standard for 1976 models will be 0.41 gm/mi.  Preliminary
tests indicate that this standard is being achieved in. prototype vehi-
cles.  Tests indicate that the relative percentage of methane in emis-
sions from vehicles equipped with catalytic controls is increased--
approximately 801 of the hydrocarbon emissions with catalytic controls
may be methane.  Ford Company has asked that emission standards be
changed to exempt methane.  This proposal is currently under review.
1.3.1.4  Sulfur Oxides Emissions--Trace qualities of sulfur primarily
in the form of organic sulfur compounds are present in gasoline.  Dur-
ing normal combustion processes, this sulfur is converted to SO- and
S03 (about 98% S02).  The S03 reacts rapidly with water in the exhaust
and is emitted as sulfuric acid or sulfate particulate.  The amount of
SO- and SO, emitted from mobile sources is negligible  (less than II)
compared to that of stationary sources.  Light-duty vehicles equipped
with catalytic converters emit higher concentrations of sulfuric acid
and sulfates than those vehicles without these devices.  This may
result in significant concentrations of sulfur oxide emissions in high
traffic density areas.
1.3.2  Ambient Concentrations
     Because of uncertainties in emission and air quality data, it is
difficult to establish a quantitative relationship between trends.
                                9

-------
However, some qualitative estimates can be made.  Since the national



ambient air quality standards were set and control strategies imple-



mented, air quality data indicates a downward trend in CO and particu-



late matter pollutants.  Oxides of nitrogen concentrations have increased,



but urban concentrations have decreased.  No significant change in sulfate



concentrations is evident despite reduction in urban SO- levels.  There is



some evidence that non-urban sulfate concentrations may have increased.



     Ambient CO trends should directly reflect exhaust emissions from



motor vehicles.  Since introduction of CO emissions controls, the average



CO emission rate has decreased.  The annual average CO concentration for



selected urban areas appears to have decreased.  Instrumentation problems



and operating procedures have biased the data in some areas.



     The annual average concentration of nitric oxide (NO) has increased.



The pattern is less consistent for N02 and total oxides of nitrogen.



This increase is attributed to increase in fuel combustion and introduc-



tion of control systems for CO and hydrocarbons on mobile sources that



in some cases produced increased emissions of nitrogen oxides.



     Trends for photochemical oxidants are not well established.  The



data in general suggest a decrease in urban concentrations.  However,



there is now much evidence that ozone concentration in certain non-urban



regions is increasing (Northeast U.S.).



     There are few data available on ambient concentrations of mercury,



asbestos and beryllium.



1.4  TRANSFORMATION AND TRANSPORT



     The relationship between emissions and atmospheric loading or air



quality is dependent on transformation, transport and removal processes
                                  10

-------
in the ambient atmosphere.  These processes are greatly affected by



meteorology and terrain.  The extent that these processes contribute



to chemical characteristics and temporal and spatial distribution of



criteria and hazardous pollutants is often not well known.



     Once pollutants are emitted into the atmosphere, they are subject



to various chemical reactions.  A polluted atmosphere is a very



dynamic mixture of reactive gases and aerosols.  It is this mixture



that man and materials are exposed to.



     Although the photochemistry of nitrogen oxides has been widely



studied, only about 501 of the nitrogen emitted into the atmosphere has



been accounted for.  Recent investigation suggests that nitric acid is



produced in the atmosphere by photolytic processes.  Nitrous acid is



not formed in as great a quantity as nitric acid, but is important in



photochemical smog production because of the highly reactive radicals



produced.  Many questions remain to be answered about quantitative



relationship between NO , oxidant and hydrocarbons in urban and non-
                       .X


urban atmosphere.



     New findings on pollutant transport and conditions of hydrocarbon



oxidation have led to a new reactivity classification for organic com-



pounds,  under the prolonged irradiation conditions of transported air



masses, organic compounds formerly classified as "less reactive" can



yield as much oxidant as some classified "more reactive."  Recent smog



chamber experiments have produced quantitative oxidant-HC-NO  relation-
                                                            J\.


ships.  The applicability of these findings to the real atmosphere,



however, remains questionable.  These results suggest coordinated con-



trol of HC and NO  as the most effective means of oxidant reduction.
                 .A.




                               11

-------
     Major advances have been made in understanding the sources, proper-



ties, chemical composition and dynamics of atmospheric aerosols.



Effective control techniques must consider particle size and particle



composition as well as precursors (S09, NO  and certain organics).
                                     Li    Jv


Research work has identified a multimodal distribution of the atmo-



spheric aerosol.



     Secondary sulfate, nitrate and organic aerosols comprise the major



part of fine particulate (one mode)  matter.  Road dust, tire debris and



other materials generated by vehicular traffic are a major source of



coarse particles in urban areas.  Organic material is a major primary



and secondary component of fine particulate matter.



     The transformation that converts S02 to sulfate is better under-



stood and measurements of transformation rates in power plant plumes and



urban atmosphere have been made.  Progress has been made in chemical



characterization of atmospheric aerosols and further work is under way.



     A solution to regional sulfate pollution problems will require an



understanding of how sulfates are formed in the atmosphere.  Chemical



mechanisms for the transformation are not well known.  Chemical oxida-



tion by photochemically generated intermediates and catalytic oxidation



are currently being emphasized as the most likely mechanisms.  Both



laboratory and field studies are under way.



     No significant oxidation reaction of CO has been found for urban



air.



     Models have been developed to estimate pollutant concentrations



over an urban area.  A User's Network for Applied Modeling of Air Pol-



lution (UNAMAP) was put into operation in May 1973.  This program gives
                                   12

-------
interested agencies current air-quality simulation models via a teletype-



processing network.  A fluid modeling facility is being established to



study the flow and diffusing of pollutants around buildings, highway



configurations and complex terrain.  A regional air pollution study



is now under way in St. Louis, Missouri that provides data for valida-



tion and improvement of pollution simulation models.



1.5  EFFECTS



     National ambient air quality standards were established in refer-



ence to an incomplete data base.  The standards were designed, based



upon available information, to include a margin of safety sufficient to



protect the health of the most sensitive segments of our society.



Since setting the standards, a continuing research effort has provided



additional effects information.  Although the data base is still inade-



quate, recent reviews by the National Academy of Sciences (MAS) and the



National Institute for Environmental Health Sciences (NIEHS) have con-



cluded that the standards should not be changed at this time.  However,



the NAS suggested that consideration be given to establishment of an



hourly standard for NCL.



     Recent evidence suggests that secondary aerosols or combinations



of aerosols and gases are better correlated with adverse health effects



than are gaseous pollutants.  The size distribution and chemical compo-



sition of the aerosols appear to significantly influence the biological



response.



1.5.1  Human and Animal



1.5.1.1  Nitrogen Dioxide and Suspended Nitrates--The limited number of



studies on human health effects of NCL reveal many gaps in the information
                                 13

-------
base for the primary national standard.  The few studies that have been



conducted are confounded by the presence of high levels of other pollu-



tants that have not been appropriately disentangled.  Measurement data



used in these studies was also limited either by use of too few sampl-



ing stations or use of an unreliable measurement method for NCL or both.



     A continuous monitoring instrument using the chemiluminescence



reaction between ozone and nitrogen oxide is considered more reliable



than either the Jacobs Hochheiser or the Saltzman method for measuring



nitrogen dioxide (that can be reproducibly converted to nitric oxide).



The chemiluminescent reaction is currently being used in new health



studies but information from such studies is not yet available.



     In the Chattanooga study £>nwhi.chthe NCL standard was based), the



high NCL levels also were accompanied by relatively high levels of



suspended nitrates.  The recent linking of asthma attacks to suspended



nitrates raises the question as to whether or not suspended nitrates may



have contributed to the observed adverse health effects in the Chatta-



nooga study.  The observed human effects support reasonably well the



biological effects observed in experimental animal studies using NCL as



a single pollutant.



     However, it has been reported that in some NCL rich atmospheres of



animal exposure chambers, aramonum nitrate may be generated in fairly



large quantities.  This suggests that in some instances suspended



nitrates as well as NCL may have been contributing to atmospheric expo-



sure in animal studies.  In any study involving exposure of animals to



NCL, the extent of reduction of NCL must be considered.



     Five categories of human health effects have been identified in



association with NCL; acute toxic, often fatal reactions; diminished




                                   14

-------
lung function; structural and biochemical changes in lungs that are most



likely to promote development of chronic respiratory disease; suscep-



tibility to infection; and systemic effects.



      There is enough information from both human and animal studies to



determine the levels of N09 that may contribute to toxic reactions.
                          £


However, there are very few points on the lower part of the dose-response



curve to provide information on the levels of NCL that may contribute to



susceptibility to infection and development of chronic respiratory



disease.  Further human studies are necessary that address the contribu-



tion of N02 and its degradation products to insidious chronic disease.



Until such information is available, it seems appropriate to maintain the



present standard.  It provides a reasonable margin of safety based on



both animal and human studies to date.



      In the New York-New Jersey metropolitan area, a study of 373



asthmatics followed daily for eight months showed that increased asth-



matic attacks were significantly associated with ambient suspended



nitrates.  The observed increased risk of asthmatic attacks related to



increased concentrations of nitrates occurred only at a temperature of



10° centigrade or above.  In another study in two southeast communi-



ties there was evidence of excess risk of asthmatic attacks with ele-



vated levels of suspended nitrates at higher temperatures.  But the



findings were less consistent than those observed in the New York-New



Jersey area.



      Preliminary findings of a study of 512 asthmatics in seven communi-



ties in the Los Angeles Basin also show significant association of



asthmatic attacks with suspended nitrates.  But the full data analyses
                                  15

-------
of this study has not yet been completed.  Nitrogen dioxide was not



significantly associated with asthma attack rates in any of these



studies.



     Very little is known about inhalation toxiciology of inorganic



nitrates.  If the associations between airborne nitrates and asth-



matic attacks are causal, airborne nitrates may be an important



respiratory irritant.



     Pathologic effects of NCL on the respiratory tract have been



induced in experimental animals at concentrations at and above 2 PPM.



Exposure to concentrations of 10-25 ppm on a continuous basis has pro-



duced pulmonary emphysema-like disease in rats, mice, dogs, and



rabbits.  The biological response appears to be different when the



experimental animal is exposed to oxidant and NCL, although the results



are not yet conclusive.



     The NCL effect was obscured when equal parts of NCL and 0, were



used.  The physical appearance of emphysema varied with the species



studied and was possibly influenced by differences in the size and



frequency of inter-alveolar pores.



     The biochemical mechanisms by which NCL reacts with tissue resem-



bles CL to some degree because of their common oxidizing properties.



A biochemical study is being done to examine the prospect that toxicity



of NCL and CL may be an "ultimate" toxicant produced by a reaction



between the oxidant and unsaturated fatty acid.  Ozone is known to



react with unsaturated fatty acids to produce fatty acid ozonides.  NO
                                                                      t+


similarly can react with unsaturated fatty acids to produce nitroxide



fatty acids that are likely to be very reactive.
                                   16

-------
     A second biochemical study is being done to examine the mechanism
of action to nitrates and sulfates.  The results of these studies should
provide additional insight into comparative toxicity of these pollutants.
     Studies are being conducted that employ interaction of pathogenic
organisms and air pollutants to demonstrate increased susceptibility to
infectious pneumonia.  The model has been used effectively in environ-
mental toxicological studies of ozone, NCL, radiated automobile smog and
exposure to some trace metals.  The results have shown that the role of
infectivity can be enhanced in certain species of animals studied.
     The model has also been used to study mechanisms of action of pol-
lutants.  An important problem in NCL and CL toxicity involves relative
toxicity of mode of dose-concentration or a function of time over given
time periods.  The results of these preliminary studies show greater
mortality in experimental animals from pulmonary infection produced by
the same concentration multiplied by time for different time periods
(for example:  14 ppm x 0.5 hr. versus 1 ppm x 7 hr.).  The study indi-
cates that actual concentration has more influence than duration of
exposure.  An inverse relationship was found between survival and length
of exposure at constant concentrations,
1.5.1.2  Carbon  Monoxide--Both the present ambient air quality standard
for carbon monoxide of 10 mg/m  (9 ppm) averaged over eight hours and of
the 40 mg/m  (35 ppm) one-hour average coincide with carboxyhemoglobin
levels of approximately 1.51.  Since the standard was established, new
evidence has appeared supporting the current standard in three areas.
These areas include:
     (1) Effects on individuals with arteriosclerotic vascular disease
(2.5-3.01 range during exercise);  (2) effects on exercise capacity in
                                  17

-------
healthy individuals (diminished exercise performance at COHb levels of



approximately 5-6%); and (3) additional evidence on alertness effects



(impairments on vigilance tasks at COHb levels ranging from 3.0-6.5%).



1.5.1.3  Oxidants_--The oxidant thresholds for cough and chest discomfort



were found in one study to be 500-600 yg/m  as a maximum one-hour



average.  These levels are similar to those observed in studies of



occupational exposure of men.  These thresholds should be generally



applicable to healthy adults and would probably represent an upper



bound for persons with pre-existing cardiovascular disease or asthma.



     The synergistic effect of ozone and sulfur dioxide on human pul-



monary function has been reported in the past two years.  There is also



concern that interaction of these two pollutants on lung function is



impaired in a non-linear fashion to any stimulus.  The "extra" decre-



ment attributed to the combination of SCL and ozone could be an additive



effect in the non-linear part of lung-function curves.



     Chromosome breaks in hamsters following ozone exposure have been



observed.  But this may only be a peripheral and not a stem cell effect.



If so, it is not properly described as a mutagenic effect, but more data



are needed to clarify this point.



     There is much evidence that exposure to ozone at concentrations 
-------
number of studies have shown that ozone exposure induces changes in



pulmonary function.



     Studies have consistently shown deleterious effects (decrease in



pulmonary function, chest discomfort, cough and eye discomfort) in



people exposed to less than 1 ppm (0.05 to 0.75 ppm).  Healthy adult



males exposed to 0.50 ppm of ozone for two hours during intermitten



light exercise developed measurable physiological and biochemical



changes.



1.5.1.4  Particulates--The theoretical definition of suspended fine



particles as they relate to health are necessarily broad and somewhat



arbitrary.  Deposition of particles anywhere in the respiratory tract,



from nose to alveoli, may be harmful to health.  There appears, how-



ever, that non-viable particles deposited below the trachea may be



more harmful than those deposited in the nasal cavity.  Whether parti-



cles must reach the alveoli to exert harmful effects is a more contro-



versial issue.  It is likely that particles deposited in the bronchi



or bronchioles are more important in producing bronchitis than those



deposited in the alveoli.  At present, there is little value in con-



fining the category of suspended fine particles only to those parti-



cles that reach the alveoli.



     The Task Group on Lung .Dynamics has calculated that up to 10% of



inhaled particles of diameter 2-5 ym are deposited in the alveolar



compartment and up to 30% are deposited in the alveolar compartment.



Most of the particles of diameter above 5 urn are deposited in the



nasal cavity.  So a size range of fine particulates, up to 2-5 ym



diameter, measured aerodynamically, is of principal interest from a



health standpoint.




                                19

-------
     The toxicological properties of inhaled particles are related to a



complex of factors that include the specific physical-chemical proper-



ties of the particles themselves and host conditions that affect response



to exposure to these particles.  As for toxicity of certain specific



particulates that may exist in the atmosphere, moderate amounts of infor-



mation are known.  But such information is not usually available in a



form suitable for accurate assessment of minimum time-concentrates for



exposure that will lead to adverse health effects.



     Even less information is known about how physical environmental



variables (weather conditions) may interact with suspended particulate



matter and alter its chemical composition and affect its toxicity.



Weather conditions per se may affect people in such a way as to alter



their exposure to inhaled particulates.  The information that is avail-



able, however, provides a basis for estimating the relative toxicity of



certain substances and provide insight into problem areas where our



information is inadequate.



     The main way air particulates affect health is presumably through



breathing and consequent effects on the respiratory system.  This pre-



sumption is acceptable in determining short-term effects of irritant



aerosols, but may be less tenable in considering long-term exposure



effects where such responses are carcinogenesis, mutagenesis and subtle



metabolic effects result from whole body burdens.  In these cases, routes



of entry besides breathing may be important in establishing dose-response



relationships,  However, inhaled particles may become non-respiratory



toxicants where substances are translocated to the gastro-intestinal



system by muco-ciliary transport and swallowing.  There they may exert
                                   20

-------
a primary toxic effect or be absorbed through the lung into the blood



stream and translocated to other tissues, eliciting an adverse health



effect.



     Deposition rates and retention time of inhaled particles are sepa-



rate phenomena with overlapping biologic effects.  Particle retention



time is dependent upon:  (1) the site of initial deposition in the



respiratory tract, and (2) the chemical composition and properties of



the particles.



     If particles are deposited in the ciliated epithelium of airways,



particle clearance is reasonably rapid.  Toxicity then depends on



solubility of particles in mucus while in transit up the muco-ciliary



escalator.  If the particle is highly soluble, toxic inflammation in



the airway epithelium may occur.



     Particles deposited in the alveoli of the lung may only slowly



clear from this location.  The extent to which alveoli are cleared



reflects their solubility and subsequent translocation via lymphatic



drainage or macrophage phagocytosis and clearance via the muco-ciliary



transport mechanisms.



     In some cases, especially with fine suspended particle material,



numbers of particles may be more relevant than particle mass.  To



relate the number of particles to the mass size distribution requires



determination of frequency distribution.  Particle number can be



toxicologically important since the large surface area may promote gas-



particle or volatile-substance particle interaction.  Coupled with



small size, these interactions may result in deeper penetration of



gaseous or volatile substances in the respiratory tract and more rapid
                               21

-------
dissolution.  Surface area is also important for highly insoluble parti-



cles that express their toxic potential only at the surface.



     Another important factor in the regional deposition of inhaled



particles is hygroscopic!ty.  Particles, as usually measured externally,



are not saturated with water.  The growth of sodium chloride particles



is a function of relative humidity, with particle size increasing when



relative humidity exceeds 75%.  The respiratory tract, with its satu-



rated atmosphere, may considerably increase effective particle size over



and above that measured in ambient air.  However, hygroscopicity is of



less significance with particles of high density.



1.5.1.5  Sulfur Oxides, Sulf uric Acid and Sulfate--0ne of the primary



problems in determining health effects of SO- continues to be develop-



ment of an understanding of the way this gas interacts with other sub-



stances in the atmosphere.  Laboratory studies have demonstrated that,



in an experimental situation, the levels of SO- found in ambient air



are innocuous until combined with other substances.



     Similar studies with animals demonstrated increased toxicities of



sulfuric acid mists and various sulfate compounds that are products of



atmospheric transformation of S0?.  The importance of high relative



humidity (580%) to enhancement of the effect of sulfur dioxide and



sodium chloride aerosol is demonstrated through sensitive respiratory



physiologic responses.  Observed initial associations of adverse health



effects with ambient levels of suspended sulfates in epidemiologic



studies tend to support these laboratory studies.



     Studies of three New York neighborhoods showed that cold tempera-



tures were directly related to increased symptom rates in people with
                                  22

-------
combined heart and lung disease.  Elevated suspended sulfates were the



only pollutant consistently associated with symptom aggravation.  Daily



sulfur dioxide and total suspended particulate concentrations could not



be associated with symptom aggravation in the "heart and lung" panel,



the most sensitive to variations in daily pollutant concentrations.



     Also, asthma attack rates were more consistently associated with



daily suspended sulfate levels than with either sulfur dioxide or



total suspended particulates.



     Studies of daily asthma attack rates in the Salt Lake Basin showed



that attacks were more consistently correlated with colder outdoor



temperature than with any measured pollutant.  So an analysis of asthma



attack rates measured against daily pollutant concentrations was car-



ried out within two ranges of minimum temperature, 30 to 50°F and



greater than 50°F.  Virtually no relationship between sulfur dioxide



and attack rates appeared, but total suspended particulates and sus-



pended sulfates were positively correlated with daily asthma attack



rates.  A higher frequency cf asthma attacks was observed at the same



daily total suspended particulate concentration when a high sulfate



fraction was present in the atmosphere so that it appeared sulfate



levels were a stronger determinant of asthma attack rates than total



suspended particulates.



     The breathing ability of elementary school children in New York



City was affected in areas with high levels of SCL.  In Cincinnati,



this same indicator was associated with sulfate exposure.



     The pattern of chronic bronchitis rates is consistently higher



among residents of more polluted communities.
                              23

-------
1.5.1.6  Hydrocarbons - -The National Ambient Air Quality Standard for



hydrocarbons was established as a guide in regulating oxidant standards.



The reference method measures gas-phase hydrocarbons corrected for



methane.  Particulate hydrocarbons, especially polynuclear hydrocarbons,



were not considered in establishment of the standard.  Current ambient



air data are limited primarily to non-methane gaseous hydrocarbons and



benzo-a-pyrene.



     When the criteria document of hydrocarbons was published (March



1970), there was insufficient evidence to demonstrate any bad health



effects from gaseous hydrocarbons at levels found in the ambient air.



No new evidence to the contrary is available.  However, little research



has been done on the question.



     Many gaseous hydrocarbons are directly involved in atmospheric for-



maldehyde, other aldehydes, ketones, peroxyacetyl nitrate (PAN) and



other oxidants.  Some of these products produce adverse health effects.



A limited amount of study in cases of occupational exposure has been



devoted to some of these compounds.  In reported studies Hodgkin's



disease has been associated with exposure to benzene at concentrations



of 150 to 210 ppm in the work place.  Toxic effects attributed to for-



maldehyde concentrations of 2 to 10 ppm have been reported.  A study of



the incidence of leukemia involving petroleum and chemical products in



the work population produced no conclusive increased risks.  The limi-



tations inherent in each of these studies are such that results should



be viewed with caution--particularly for quantitative results.



     Occupational evidence and laboratory experiments for other classes



of hydrocarbons such as PVC/VC, PCB's and polynuclear hydrocarbons show
                                    24

-------
that some of these compounds are carcinogenic.  The dose response data,



however, are incomplete.



1.5.1.7  Mercury--Several recent animal exposure studies using methyl



mercury given in repeated oral doses over relatively long time-periods



show that a "no-effect" level for neurological sign development and/or



histopathological evidence of mercury poisoning is from 0.03 mg/kg body



weight (monkeys, cats) to 0.1 mg/kg body weight (calves).



     Daily oral doses of alkyl-mercury compounds as small as 0.4 mg/kg



body weight produce neurological disorders in rabbits, cats and dogs.



Daily oral doses of 0.25 mg/kg body weight of methyl mercuric chloride



given throughout most of the gestational period have caused increased



abortions and fetal abnormalities in cats.  Levels above 0.3 mg/kg



given during gestation also increased fetal abnormalities in rat fetuses.



     Most animal experiments were carried out with daily dose levels



much higher than the foregoing experiments.  The most chronic exposure



found was that of monkeys exposed for two years.  Low level, long-term



exposures were notably absent.



     Behavioral changes have been produced in rodents where no histo-



logical lesions were found from single oral doses of methylmercuric



chloride.  A relatively high 25 mg/kg dose level was required since



doses at 20 mg/kg level did not produce significant changes.



1.5.1.8  EeryIlium--A long latent period of 15 or more years has been



observed between the onset of disease and the last exposure to beryl-



lium, with evidence indicating that beryllium may accumulate in a



latent form in lyosome.  A latent period could persist for years until



declining adrenal stress, reserve and output with age caused lyosomal
                                25

-------
instability and the onset of beryllium disease.  Under these conditions,



especially if the adrenal reserve was also low, the adrenal output may



not be adequate to meet the needs.



     In recent experiments, the biological half-life of  Be in mice was



found to be about twice the value cited by the ICRP (540 days).  There



is now some evidence of auto-immune response subsequent to beryllium



exposure.



1.5.1.9  Asbestos--The association of impaired health with industrial



exposure to asbestos, principally asbestosis and pulmonary cancer is



well known.  There is little evidence that exposures to low levels of



asbestos and asbestos-like fibers that may be present in ambient air



have resulted in either asbestosis or pulmonary cancer in people.  How-



ever, the discovery of mesiothelioma of the pleura associated with low



exposure or casual contact with chrysotile asbestos has raised suspi-



cion about possible health hazards of air pollution.



     Evidence indicates that all major types of asbestos may cause lung



cancer.  There are clear differences in risk with type of filter and



the nature of exposure, however.  All commercial types of asbestos,



except anthophylite, may cause induction of mesathelioma.  However, the



risk is greatest with crocidalite, less with amosite and apparently



less with chrysotile.



     Some cases of mesothelioma have no known association with exposure



to asbestos.  There is some evidence of association of mesothelioma



development with air pollution near croidalite mines and factories work-



ing with mixed fibers.  There appears to be no extra risk from air



pollution near chrysotile and amosite mines.





                                     26

-------
     At present, there is no evidence of extra cancer risk to the general
public from asbestos in air, water or food.  Cigarette smoking enhances
the risk of developing bronchogenic cancer in workers exposed to asbes-
tos.  There is evidence that health effects associated with exposure to
asbestos may not be unique to commercial forms, but may also be associ-
with asbestos-like fibers found in other rocks and possibly man-made
fibers.
1.5.2  Materials
     The soiling effects of particulate matter and most cause-effect
relationships for common gaseous pollutants have long been known.  What
has been lacking is information on dose-response relationships to use in
cost-benefit studies, support for primary air quality standards and set-
ting of secondary standards.
     In past years, EPA scientists have conducted both laboratory and
field studies to better define cause-and-effect.  Recently they used
specially-designed controlled environment chambers to generate needed
dose-response data for economically vulnerable materials.  Although some
preliminary information was produced, all (materials) research for FY-75
and after, including dose-response studies, was terminated because of
budget limitations.
1.5.2.1  Nitrogen Oxides--The damaging effects of atmospheric nitrogen
oxides mainly concern the textile industry.  Nitrogen dioxide (N07) is
                                                                 LJ
the troublesome pollutant; nitric oxide (NO) appears harmless.  Atmo-
spheric N0~ can react with a number of textile dyes and produce
noticeable color change or faiding, causing a problem to the textile
industry for decades.  Concerning the yellow discoloration of undyed-
                                 27

-------
white and pastel-colored fabrics, chemists have traced this problem to



the action of NCL on additives used to enhance fabric marketing proper-



ties.  In the United States, annual gross damage to materials by N0~ is



estimated at three-quarters of a billion dollars.



1.5.2.2  Sulfur Oxide--The fact that SO- speeds deterioration of many



materials has long been recognized.  Both field and laboratory studies



have shown that SCL-polluted environments (1) increase the corrosion



rates of most metals, especially iron, steel and zinc; (2) damage build-



ing materials such as limestone, marble, roofing slate  and mortar; (3)



discolor and cause deterioration of statuary and other works of art;



(4) increase erosion rates of oil base paints; (5) degrade textile



fibers, especially cotton and nylon and fade-dyed fabrics; (6) embrittle



and discolor paper and (7) weaken leather.



1.5.2.3  Ozone--Damage by atmospheric ozone occurs mainly to elastomers



and textile dyes.  Not all elastomers, however, are subject to ozone



damage; synthetic elastomers with saturated chemical structures have



inherent resistance, although they are relatively expensive and account



for only a fraction of the market.  The great bulk of elastomers, includ-



ing natural rubber and synthetic polymers of styrerebutadiene, poly-



butadiene and polyisoprene, contain double bonds prone to oxidation and



thus sensitive to ozone.  Researchers have developed antiozone additives



capable of protecting elastomers, but such protection is not permanent.



For certain items, such as tires, it usually lasts for the life of the



item.



     Some important textile dyes are susceptible to fading from ozone



exposure.  Blue dyes used on acetate and polyester/cotton fabrics and
                                    28

-------
nylon carpets have been particularly troublesome.  To prevent or mitigate



ozone fading, the textile industry must use more resistant dyes and/or



inhibitors, increasing the cost of finished goods.



1.5.3  Ecology



1.5.3.1  Nitrogen Compound:;--The effect of nitrogen oxides on vegetation



has been noticed only near industrial sources, as in the effect of nitric



acid on plants where ambient levels of nitrogen dioxide have been high.



Effects have been identified chiefly through laboratory experiments.



Indirect damage to vegetation has occurred from formation of acid rain



and photochemical reactions.



     Photochemical reactions result in the formation of peroxyacyl



nitrate, the most abundant of the compounds formed, and responsible for



serious plant damage.



1.6  CONTROL TECHNOLOGY



1.6.1  Stationary Sources



     Stationary combustion sources contribute more to the ambient atmo-



spheric loading of SO , NO  and total suspended particulates (TSP) than
                     ,X    j\.


any other anthropogenic category, causing approximately 80% of SO
                                                                 .A.


emissions, 501 of NO  emissions, and 50% of ambient fine particulates.
                    .X


     Advances in the development of technology to control SO, NO  and
                                                            .A.    .A.


primary particulates have been, achieved, and additional improvements  are



expected in coining years.



     Industrial processes and open sources (e.g., open burning, mining,



incineration, fugitive emissions) account for approximately 16% of SO
                                                                      J\.


emissions, 44% of hydrocarbon emissions, 22% of  CO emissions and 25%  of



ambient fine particulates.  They are also responsible for most hazardous
                                  29

-------
air pollutant emissions (i.e., asbestos, beryllium,and mercury) as well



as vinyl chloride and other potentially hazardous carcinogenic pollu-



tants.



1.6.1.1  Particulate Control--Most pressing is the development of commer-



cially available and widely applicable fine particle (less than 3 microns)



control technology.  It is currently in very early development under EPA



sponsorship.  This technology is also needed to control detrimental trace



metals.



     Scrubbers, electrostatic precipitators and fabric filter collectors



are the principal particulate collection devices.  They are being



improved by attention to lowering costs, increasing their applicability



and extending the range of collection to smaller particle sizes.  In



addition, entirely new concepts of particle collection are being



investigated.



     System studies have been completed for each conventional device to



define areas for improvement and show new applications.  Long-range



projects include:  development of models for existing collectors; iden-



tification and laboratory testing of new concepts in particle technology



and new work in small particle detection and generation equipment.



1.6.1.2  Sulfur Oxides Control--In the area of sulfur oxides control,



achievement of Ambient Air Quality Standards demands control of indus-



trial combustion, industrial processes and area sources as well as



utility combustion.  Natural low-sulfur fuels are only sufficient for



about 40% of the demand of State Implementation Plans.  The remainder



must be supplied by technology in the form of effluent desulfurization,



fuel cleaning or process modification.  Although the currently defined
                                    30

-------
sulfur oxides control technology program contains projects diverse enough



to ensure achievement of Ambient Air Quality Standards, substantial EPA



research and development investment will be required to bring this



technology to commercial fruition.  Only effluent desulfurization tech-



nology for electric utilitlies should achieve widespread commercializa-



tion within the next few years.



     Although the program has emphasized stack gas cleaning systems, with



five or six such processes to be demonstrated before 1976, it has also



included work in areas of fuel modification and desulfurization, indus-



trial process modification and advanced combustion processes.



     Most of EPA's early coal desulfurization work was to evaluate and



improve physical cleaning methods for coal.  These methods should now



have moderate applicability in reducing sulfur by 30 to 701 in certain



coals.  Ongoing work here includes washability testing, coal desulfuri-



zation and cleaning and pollutant control evaluation and optimization.



Most recent work is aimed at chemical desulfurization and the problems



of pollutants in fossil fue].



     Laboratory-scale work is under way on processes to remove sulfur



totally from coal.  The two processes under development are unique



since one is completely selective to inorganic sulfur in coal and the



other is preferential organic sulfur removal, but both produce a solid



fuel retaining the basic physical characteristics of coal.  The tech-



nical feasibility of the inorganic sulfur removal system has been



proven on the laboratory and bench scale and is undergoing design to a



pilot-plant-size operation, with construction of this plant planned for



early 1974.  The degree of sulfur removal from the organic process is
                                 31

-------
currently being studied in a laboratory apparatus and should be ade-



quately developed by mid-1974 to start scale-up design to continuous



pilot operation by September  1974.  The two systems will be examined



in detail as to possible integration into one scheme for complete



removal of sulfur from coal.  After successful pilot plant operation,



plans call for scale-up to a demonstration-size plant.



     Two factors—the major contribution of small coal-and-oil-burning



sources (area sources) to the pollution of ambient air and severely



limited supplies of low-sulfur fuels--indicate a need for clean fuel



or coal conversion processes.  EPA has provided funds to both the



bureau of Mines and the Office of Coal Research to help develop conver-



sion and gasification processes for providing clean fuels and help



determine the environmental controls these techniques will require.



     Work on advanced processes involves primarily the development of



fluidized-bed combustion.   Fluidized-bed combustion options include:



pressurized coal combustion, coal gasification for the production of



low-sulfur, low-Btu gas and oil gasification.  EPA also has conducted



systems studies for the development of advanced power cycles.



     Work is also under way to control emissions from smelters, iron



and steel operations, Kraft wood pulping, iron foundries, secondary



aluminum furnaces and other industrial sources.



1.6.1.3  Nitrogen Oxides Control--On a national basis, 98% of the nitro-



gen oxides (NO ) from stationary sources are from combustion processes.
              A.


Combustion control technologies under EPA investigation include:  com-



bustion modifications such as flue gas recirculation, off-stoichiometric



combustion and low excess air operation; identification of alternate or
                                    32

-------
novel combustion systems with inherently low NO  emission levels; changes
                                               -X
in burner design and use of alternate fuels.  Although flue gas cleaning
processes and advanced power cycles are also being investigated, they
may offer only longer-term solutions to the problem.  Major emphasis has
been on coal combustion in utility and industrial boilers, since this
poses the most difficult problem.
     The main approach has been modification of the combustion process
to reduce NO  formation, with bench-scale and field work indicating
            A.
that control for the immediate future can be achieved.  In addition,
promising stack gas cleaning processes are being investigated on a
small scale.  Results in this area are not too encouraging to date,
however.
     A complicating factor is that NO  are formed during combustion
                                     jC
through two separate mechanisms--the fixation of nitrogen in combus-
tion air, and the conversion of fuel-bound nitrogren contained in the
fuels.  Although some control of both mechanisms has been achieved by
combustion modifications, it remains to be determined whether or not
combustion modification alone will adequately control the NO  from
                                                            .A
fuel nitrogen.
1.6.1.4  Hazardous and Other Control--The number of pollutants requiring
control has expanded to include more than 30 potentially harmful and
annoying air pollutants.  Since most of them are likely to be emitted as
particulate matter, there is strong interaction between these two pro-
grams.  Hazardous and other pollutants under consideration include:
asbestos, beryllium, cadmium,, carbon monoxide, fluorides, hydrocarbons,
lead, mercury, and odorous materials from rendering plants, pulp mills,

                                 33

-------
sewage treatment plants and chemical process industries.  Because of the
paucity of data now available, many problem definition and source
characterization studies are required.
                                      34

-------
                            2.  INTRODUCTION





     National Ambient Air Quality Standards established under the pro-



visions of the Clean Air Act amendments of 1970 were designed on the



basis of the best available information.  Since this information was



incomplete, the Environmental Protection Agency began a continuing



research program to improve the data base and assess its adequacy.  This



document is the first in a series of annual reviews by the Environmental



Research Center/RTF, as to results of its research efforts.  It is not



intended to be a update of the criteria documents, which will be accom-



plished under the Pollutant Characterization  Program.



     Since this is the first of a series of reviews, it must cover new



information attained by ERC/RTP since promulgation of the Standards.  A



review of the basis for the National Ambient Air Quality Standards and



automobile emission controls has recently been completed by the National



Academy of Sciences (MAS).  For convenience, some material presented



here duplicates that presented by NAS.



     Maintaining air quality and the consequences for human health and



welfare involves understanding many scientific, economic and social



variables.  Since our present understanding is extremely limited, stan-



dard-setting and environmental control must be based in large measure



on judgment.  Man-made environmental pollution is a consequence of our



unwillingness or inability to control human population and the products



of our natural resources, so that decisions on control are compromises



with impact on all of society's values.  There is an important element



of risk resulting from incomplete information and understanding.





                                    35

-------
     Material presented here represents only a small part of the problem.



It is limited by our ability to:  (1) measure gaseous and aerosol com-



pounds which have been classified as deleterious or hazardous; (2) quan-



tify and characterize emissions of pollutants from stationary and mobile



sources; (3) monitor and characterize atmospheric loading; (4) determine



the effects of a polluted atmosphere on human health and welfare and (5)



control man-made emissions necessary to maintain a given air quality.
                                      36

-------
                              3.  MEASUREMENT



3.1  INTRODUCTION


     Measurement of an air pollutant begins with isolation and identifi-


cation.  This is the qualitative step.  Technique is developed to


generate the known substance in a controlled atmosphere free of unknown


substances.  The quality of a sensor is then judged based on freedom


from response to other substances, sensitivity to the substance to be
                  i

measured and other characteristics.


     Equally important is how well the measuring method reflects con-


centrations of the substance sensed.  This is the quantitative step.


Before assessing the quantitative capability of a method, it is essen-


tial to generate a substance in known concentrations.  Determining the


response of a sensor to a series of known concentrations constitutes


the calibration of the sensor.  The degree to which the sensor repro-


duces the calibration reflects the stability of the methods.


     The scope of the measurement problem is shown in discussion


following.


     The composition of unpolluted air is not known precisely, but


Table 3.1 represents an approximation.
                                 37

-------
          Table 3.1.  APPROXIMATION OF THE GASEOUS COMPOSITION OF
                                  DRY UNPOLLUTED AIR
Constituent
Nitrogen
Oxygen
Water
Argon
Carbon Dioxide
Neon
Helira
Methane
Krypton
Nitrous Oxide
Hydrogen
Carbon Monoxide
Xenon
Ozone
Organic Vapors
Sulfur Dioxide
Nitrogen Dioxide
Ammonia
Molecular
Formula
N2
°2
H2°
Ar
co2
Ne
He
CH4
Kr
N20
H2
CO
Xe
°3
--
S02
N02
NH,
Volume
Fraction
78.09%
20.94%
—
0.93%
0.0318%
18 ppm
5 . 2 ppm
1.0-1.2 ppm
1.1 ppm
0.5 ppm
0.5 ppm
0.1 ppm
0.09 ppm
0.02 ppm
-0.02 ppm
-0.001 ppm
-0.001 ppm
-0.001 ppm
Major gases and vapors produced by man are shown in Table 3.2.
                                  38

-------
            Table 3.2.  PRIMARY GASES AND VAPORS PRODUCED BY

                                 HUMAN ACTIVITIES
                         Compound	Formula



                     Carbon dioxide             CO-



                     Carbon monoxide            CO



                     Sulfur dioxide             S09
                                                  Li


                     Nitric oxide               NO



                     Hydrogen sulfide           H2S



                     Ammonia                    NH.,



                     Hydrogen chloride          HC1



                     Hydrogen fluoride          HF



                     Paraffins



                     Olefins



                     Aromatics





     Principal secondary pollutants produced in the atmosphere are shown



in Table 3.3.





              Table 3.3.  SECONDARY ATM3SPHERIC POLLUTANTS





                	Compound	Formula



                Nitrogen dioxide             NO-



                Ozone                        0,



                Peroxyacetyl nitrate         H3C-C-0-0-N02



                Aldehydes                    RCHO



                Sulfuric acid                H2S04
                                   39

-------
     Organic or inorganic particles found in the atmosphere frequently

are participants in the formation of gaseous or particulate secondary

pollutants shown in Table 3.4.
       Table 3.4.  ATMOSPHERIC PARTICULARS AND MAJOR PRIMARY AND
                    SECONDARY AIR POLLUTANTS FORMED BY PARTICLE
                                    PARTICIPATION
         Suspended Particulate Matter

           Inorganics

             Metals, (Pb, Cd, Be, Hg, etc)

             Fluorides

             Nitrates, Sulfates, Phosphates

             Asbestos

             Mineral Dusts (Silicates, Silica, etc)

           Organics

             Polycyclic Organics (Benzo [a] pyrene, etc)

             Oxygenated Compounds

             Pesticides

             Aeroallergens

           Gases

             Inorganics

               Sulfur Oxides (S02, S03)

               Nitrogen Oxides (NO, N02)

               °3
               CO

               H2S
               HC1, C12, Fluorides, etc
                                       40

-------
         Table 3.4 (continued)


             Ammonium Compounds (NH,, etc)


             W2

           Organics

             Hydrocarbons (Paraffins, Olefins, Aromatics)

             Oxygenated Compounds (Aldehydes, Ketones)

             Sulfur Containing Compounds (Mercaptans, etc)

             Nitrogen Containing Compounds (Peroxyacetyl Nitrate
                 (PAN), etc)

             Halogenated Compounds


     Table 3.5 shows pollutants for which the federal government has

established National Ambient Air Quality Standards
                               41

-------
                    Table 3.5.  NATIONAL AIR QUALITY STANDARDS
                Averaging   Primary     Secondary       Reference0
   Pollutant      Time      Standards   Standards        Method


Sulfur Dioxide

Particulate
Matter

Carbon
Monoxide
Annual
Arithmetic
Mean
24 hours
3 hours
Annual
Geometric
Mean
24 hours
8 hours
1 hour
80 iio/m
(0.03 ppm)
365 yg/m
(0.14 ppm)
--
75 yg/m3
260 yg/m3
10 mg/m3
(9 ppm)
40 mg/m
(35 ppm)


--
1300 yg/m3
(0.5 ppm)
60 yg/m
150 yg/m3
Same as
Primary
Standards


Pararos aniline
Method

High Volume
Sampling Method

Non- Dispersive
Infrared
Spectroscopy
Photochemical
Qxidants

(corrected for
N0~, and S0~)
                1 hour
160 ^/m    PrUS
(0.08 ppm)   J™2*
                                        Standard
                                    Gas Phase
                                    Chemi luminescent
                                    Method
Hydrocarbons                ,6Q   /      Same as      Flame  lonization
(corrected for  3 hours     ff] -$'   ->   Primary      Detection Using
methane)                    ^     pp J   Standard    Gas  Chromatography
Nitrogen
Dioxide
  Annual    ,nn   / 3   Same as
Arithmetic  ^°nf/l.   Primary
   Mean     (0-05 ppm)   Standa;d
                                                   New Reference
                                                   Method Under Study
                                    42

-------
Table 3.5 (continued)
a.  National standards other than those based on annual arithmetic means
    or annual geometric means are not to be exceeded more than once per
    year.
b.  National Primary Standards:  The levels of air quality necessary,
    with an adequate margin of safety, to protect the public health.
c.  National Secondary Standards:  The levels of air quality necessary
    to protect the public welfare from any known or anticipated adverse
    effects of a pollutant.
d.  Reference method as described by the EPA.  An "equivalent method"
    means any method of sampling and analysis which can be demonstrated
    to the EPA to have a "consistent relationship to the reference
    method."
e.  For use as a guideline in assessing implementation plans.
     EPA plans to examine emissions from industrial categories that may
lead to additional standards.  Stationary sources under consideration
are:
   *Alurainum Reduction Plants
    Animal Feed Defluorination Plants
    Automobile Assembly Plants
    Chlorine and Caustic Plants
   *Coal Cleaning Plants
    Coke Plants
   *Copper Smelters
    Cotton Gins
   *Ferro-Alloy Plants
    Gas Turbines
    Grain Millins and Handling
    Graphic Arts Plants
    Grey Iron Foundries
    Hydrochloric Acid Plants
 Lime Plants
 Paint and Varnish Plants
 Petrochemical Plants
*Phosphate Fertilizer Plants
*Phosphoric Acid Plants
*Phosphorous Reduction Plants
 Pulp and Paper Mills
 Rendering Plants
*Sewage Sludge Incinerators
 Soap and Detergent Manufacturing
   Facilities
 Sulfur Recovery Units
 Vinyl Chloride Plants
*Zinc Smelters
*Promulgated or proposed.
                                 43

-------
     Emission standards for asbestos, beryllium and mercury are contained



in Federal Register  ^>8_  (6) 8820, April 6, 1973.  These substances have



been identified as hazardous air pollutants under the Clean Air Act as



amended.



     In 1970 Congress passed legislation requiring 1975 automobiles to



show a 90% reduction in hydrocarbon and carbon monoxide emissions over



1970 models and a reduction in nitrogen oxide emissions by 1976 of 90%



from that in 1971 models.  Regulations covering 1972-1975 light duty



vehicles and heavy duty engines were published in Federal Register 37



(22) 24250, November 15, 1972, and amended in Federal Register 3£ (124),



June 28, 1973.  The Administrator granted a one-year extension for the



1975 standard in Federal Register 38_ (126) 17441, July 2, 1973, and a



one-year extension for the 1976 NO  standard in Federal Register 38 (161)
                                  ,x


22474, August 21, 1973.



     Additional regulations for special engine types beginning with 1973



model year are contained in Federal Register 37_ (221) 24250, November 15,



1972, and interim standards for specific truck types in Federal Register



38^ (151) 21398, August 7, 1973.



     Standards for control of air pollution from aircraft and aircraft



engines were promulgated by EPA in Federal Register_38 (136) 19088,



July 17, 1973.



     Thus far EPA has promulgated methods for measuring six ambient air



pollutants, one of which (NO) has been rescinded for further study; five



pollutants for five sources under standards for new stationary sources,



two hazardous pollutants and four pollutants from mobile sources.
                                    44

-------
     The objective of the Clean Air Act is ensuring air quality.  Since



knowledge of atmospheric loading is important to air quality, it is to



this subject that the rest of this section will be largely devoted.



Generation of a controlled atmosphere for purposes of studying perfor-



mance characteristics and establishing calibration of a manual or



instrumental method will be covered.  Measurement methods in common use



as well as those having promise will be discussed as well as EPA efforts



to upgrade measurement methods by promulgating performance criteria for



reference and equivalent methods.  Validation techniques, auditing and



interlaboratory and intralaboratory evaluation methods will be discussed.



3.2  PRODUCTION OF TEST ATMOSPHERES



     The adequacy of a manual or instrumental method designed to measure



a gaseous pollutant is proven by the manner in which it respons to a



test atmosphere artifically produced by introducing into clean air a



known amount of the pollutant.  Knowing the volume of clean air (diluent



gas) and the volume of the pollutant, the volume-to-volume relationship



can be calculated.  In ambient air measurements this is commonly refer-



red to in terms of parts per million (ppm), parts per hundred million



(pphm) or parts per billion (ppb) by volume.  Air pollution technolo-



gists assume the "by volume."



     The reading obtained as a result of the signal (the pollutant) is



then a measure of the sensitivity of the method.



     The same procedure is used for generating a test atmosphere that



contains an interferent sepai-ately or in addition to the pollutant to



be measured.
                                 45

-------
     There is no technique for providing an optimal test atmosphere for



all measurement methods used in ambient monitoring.



     The permeation technique as originally reported described how a



condensible gas (in its liquid state) would be sealed in a section of



inert plastic tubing.  Following an initiation period of a few hours to



several weeks, permeation of the substance through the tubing proceeds



at a constant rate until the enclosed gas is nearly exhausted.  The rate



of permeation is calculated by gravimetric determinations of weight loss



in a unit of time.  Using apparatus to control the temperature of the



permeation tube and regulate the flow of the diluent gas stream over the



tube, a wide range of known concentrations are obtainable from parts per



billion to parts per million with achievable accuracies of within plus



or minus 2%.  The concept has been extended to include the controlled



dispensing of non-liquifiable gases, and some instrument suppliers are



including permeation dispensing devices as a self-contained calibration



source or an optional ancillary module.



     There are installations where gas mixtures pressurized in metal



cylinders have advantages.  Methane in air is an example of convenience



dictating the use of a certified concentration of the gas for calibra-



tion of hydrocarbon analyzers.  While not long ago the reliability of



such specialized gas mixtures left much to be desired, recently spe-



cialty gases from industrial suppliers have improved greatly.  Nonethe-



less EPA plans a quality control program for these mixtures.



     The National Bureau of Standards (NBS) is more and more supplying



standard gases for use in air pollution laboratories.  Currently it sup-



plies nitric oxide, carbon monoxide and methane in nitrogen at one or
                                    46

-------
more concentrations.  These concentrations are considerably higher than



those found in the average atmosphere.  The use of nitrogen rather than



air as the diluent gas renders the mixture unusable for certain applica-



tions.  NBS is cooperating with EPA in exploring the feasibility of sup-



plying a greater variety of gases and concentrations and the use of air



as a diluent.



     Very promising is the use of   aluminum cylinders for pressurized



gases.  Preliminary evidence indicates that changes to a contained gas



due to wall effects occur at a much slower rate (if at all) in aluminum



rather than steel cylinders.  It has been established that aluminum



cylinders are superior for storage of ultrapure air, a supply of which



becomes increasingly important as measurement technology progresses.



Having a pollutant-free gas for use as a diluent to provide step con-



centrations of a pollutant is useful in producing a calibration curve



characterizing the response of any manual or automated method.



3.3  OXIDES OF NITROGEN MEASUREMENTS



3.3.1  Ambient Air



     This section discusses the measurement of nitric oxide (NO),



nitrogen dioxide (N09) and total oxides of nitrogen (NO ).  Most man-
                    ^                                  X


made nitrogen oxides are in the form of NO.  In the atmosphere, NO



reacts to form the more irritating and toxic N0~.  Other oxides of



nitrogen, nitrogen pentoxide (N^Or), nitrogen tetroxide (N^O-^)  and



nitrogen trioxide (N-O?) are present in the atmosphere in extremely



low concentrations if at all.  Their involvement in photochemical



reaction is possible.  Laughing gas, nitrous oxide  (N~0), if present



in the atmosphere, is harmless.  NO and N09, referred together as NO  ,
                                          L*                         -X


are the compounds of primary interest.



                                 47

-------
3.3.1.1  Calibration--Permeation tubes are the preferred source for



calibration of NCL analyzers.  NO is supplied in nitrogen, typically



at concentrations of 50 or 100 ppm, in pressurized cylinders.  The con-



centration in the cylinders remains stable for months.



     The calibration accuracy of NO  analyzers is dependent upon a true
                                   ,A-


zero.  Residual NO and N02 are removed by converting the NO to N02 using



ozone to oxidize the NO and then removing the N02 by an N02 absorbent



like activated charcoal.



3.3.1.2  Manual Measurement--Manual N02 analytical techniques usually



are performed in a laboratory remote from the sampling site; hence the



requirement for a method to efficiently collect and retain the N02 sam-



ples.  The sampling time is generally 24 hours.  Variables are sampling



rates, duration of sampling period, collection efficiency and analytical



method.  Absorption in liquids is the most common method of sampling.



3.3.1.2.1  Jacobs Hochheiser Method--This method, contained in Federal



Register 36_ (84) 8186, April 30, 1971, is a procedure where an ambient



sample containing NO- is drawn through an aqueous sodium hydroxide solu-
                    LJ


tion producing a nitrite ion from N02-  The resulting alkaline solution



is treated in the laboratory to produce a color proportional to the N02



sampled so that optical absorbance is linearly proportional to the con-



centration of the colored species and is measured spectrophotometrically.



     This method, declared the reference method for measurement of N02,



was used in the National Air Sampling Network (NASN).  However, in 1972,



EPA studies of the procedure showed nonlinearity of collection efficiency



varying from approximately 15 to 70%, depending on the concentration of



N02 sampled.  It was also found that NO in the presence of N02 caused a



positive interference in the measurement.



                                      48

-------
     EPA published the following remarks on June 8, 1973:

         "	EPA's analysis indicates that the reference
         method is deficient in two respects.  First, the
         method overestimates nitrogen dioxide concentra-
         tions at low levels and underestimates them at
         high levels because the collection efficiency of
         the abosrbing reagent is dependent upon nitrogen
         dioxide concentration being measured.  Second,
         the method is subject to positive interference by
         nitric oxide.  Since the variable collection
         efficiency problem cannot be resolved, this
         method can no longer serve as the reference
         method."

3.3.1.2.2  Saltzman Method—One of the most widely used chemical methods

for determining NCL in ambient air is also known as the Greiss-Saltzman

method.  This coloriraetric method is based on the reaction of NO- with

sulfanilic acid to form a diazonium salt which couples with N-(l-naph-

thyl)-ethylene-diamine dihydrochloride to give a red dye.  The color is

measured spectrophotometrically at 550 nm and the value obtained is

proportional to the NO- concentration.
                      Li

     This method is sensitive from 0.005 ppm to about 5 ppm when sam-

pling is conducted with bubblers.  Sampling time is usually 10 to 30

minutes.

     The Intersociety Committee (ISC) has adopted the Saltzman method

as the tentative manual method of analysis for NO,,.  The American

Society for Testing and Materials (ASTM) has also selected the Saltzman

method as the standard method of test for nitrogen dioxide content of

the atmosphere.

     Ordinarily interferences are not a problem.  A tenfold ratio of

S02 to NO- produces no effect.  A 30-fold ratio bleaches the color to

a slight extent.  Interferences from other oxides of nitrogen and ozone

at typical ambient levels are negligible.  Peroxyacetylnitrate (PAN)


                                 49

-------
can give a response of up to 35% of an equivalent molar concentration of



NCL, but in ordinary ambient air, PAN concentrations are too low to



cause any significant error.



     The Saltzman method for NCL measurement cannot be used successfully



when the delay between sample collection and color measurement is more



than four to six hours or when sampling periods of longer than one hour



are required because of color fading.



3.3.1.2.3  Tentative Method for the Determination of Nitrogen--Dioxide



TGS ANSA--This method has its basis in the Levaggi (TEA) Method.  It is



currently one of several prime candidates for a reference method.



     NCL is drawn through a solution of triethanolamine, o-methoxyphenol



and sodium metabisulfite.  The nitrite ion produced during sampling is



determined coloriraetrically by reacting the exposed absorbing reagent



with sulfanilomide and 8-anilino-l-naphthralenesulfonic acid.  The method



is applicable to collections of 24-hour samples in the field followed by



analysis within three weeks in the laboratory.  The range of analysis is



about 0.01 to 2 ppm.  Beer'slaw is obeyed throughout this range.  The



method has a predictable collection efficiency of between 92-94% from



20-740 yg/m5 NCL and virtually no interference from NO, SC>2, 03 and C02.



3.3.1.2.4  Tentative method for the determination of nitrogen dioxide



in the atmosphere (Sodium arsenite procedure) - -This method has its basis



in the Christie (arsenite) Method.  It is also under investigation and



is a prime candidate for the reference method.



     NCL is drawn through a solution of sodium hydoxide sodium arsenite



to form a stable solution of sodium nitrite.  The nitrite ion produced



during sampling is reacted with phosphoric acid, sulfanilamide and




                                  50

-------
N-l-(naphthyl) ethylenediamine dihydrochloride to form an azo dye.  The



method is applicable to collection of 24-hour samples in the field fol-



lowed by analysis in the laboratory within six weeks.  The range of



analysis is about 0.015 to 1.0 ppm.  Beer's law is obeyed through this



range.




3.3.1.3  Automated Analyses--Commercially available instruments for the



automatic analysis of NO  are based on perhaps a dozen principles.  Some
                        J\.


of these are colorimetric, amperometric, ion-selective electrode,



electrochemical, chemiluminescence and a variety of spectrometric tech-



niques.  The cost range is from about $1,000 to more than $10,000, with



a size range from a portable 7 kilogram module to a room-sized, stationary



450 kilogram system.  Skill required to operate an analyzer varies



greatly.  Selected analyzers suitable for ambient air field monitoring



applications are discussed here.  Complex techniques limited to the



laboratory or special field applications are not included even though



they may have superior performance characteristics.  Also, certain



promising field techniques such as second derivative spectrometers are



excluded here owing to insufficient performance information, too rigor-



ous operational requirements or too few instruments sold.



     Analyzers representing breakthroughs in the art of measurement are



coming to the forefront but have not been proven.



3.3.1.3.1  Colorimetric analyzers--Colorimetric analyzers usually



represent automating of a manual technique.  As with manual methods,



such analyzers measure the optical absorbance of a solution following



reaction with NCL in an air sample.  The absorbance is linearly propor-



tional to concentration of the colored species.
                                51

-------
     This type of anlayzer has been in use for nearly 20 years; improve-



ment lately has been in the area of modifications to reagents, improved



electronics, updated optics and so on.



     Ten or more manufacturers are selling these analyzers, and an auto-



mated colorimetric method is under consideration for a reference method.



Currently colorimetric analyzers are the most prevalent instrument for



measuring NCL, NO and NO  although the chemiluminescent method is
            LI           X.


rapidly growing in usage.  Advantages of colorimetric analyzers are



simplicity, high sensitivity, and with effect controls, specificity.



Problems include reagents leaking at fittings, temperature and pH sensi-



tivity, long response time, reagent purity and interferents in the



sampled air.



     Analyzers almost exclusively use a modified Saltzman absorbing



reagent.



     Colorimetric NO  anlayzers are designed to operate in one of three
                    J\.


modes:  series, parallel and simultaneous.



3.3.1.3.1.1  Series mode--The air sample is drawn through the reagent



wherein N02 reacts to form the azo-dye which is measured and recorded



as NO-.  The sample stream still containing NO passes through an oxi-



dizer (e.g., acid permanganate bubbler) becoming N0~ and is then



measured.  If the analyzer is properly calibrated, an accurate reading



of N0? and NO is recorded.  Summing the two readings provides the NO
     LI                                                              X.


value.



3.3.1.3.1.2  Parallel mode--The air sample is drawn into the analyzer



where it is split.  One flow is passed through the reagent where the



NO- reacts to form the azo-dye which is measured and recorded.  The
                                    52

-------
other stream is drawn through an oxidizer where the NO is converted to



N02.  The N02 present in the sample stream plus the NO (now N02) reacts



to form the azo-dye which is measured and recorded.  This reading is the



NO^ value (N02 + NO).  By subtracting the N02 reading the NO value is



obtained.  Again, the best results are obtained by a dynamically cali-



brated analyzer.



3.3.1.3.1.3  Simultaneous node--The air stream is split into two por-



tions as it is drawn through the anlyzer.  One stream is scrubbed of its



N02 content by drawing it through a filter containing triethanlomine



(TEA) impregnated on firebrick for the removal of NO,, which reacts with



the azo-dye which is measured for the NO reading.  The other stream is



drawn through the reagent where the N02 reacts and the azo-dye developed



is measured and recorded as N02.  Combining the two readings gives the



NO  value.
  J\.


     Each of three modes has certain advantages and disadvantages.



Generally an instrument using one of the modes, properly attended,



maintained and most important, carefully calibrated, will provide



creditable data.  Electronic modules can be added to the systems for a



variety of signal presentation such as direct digital readings of NO,



N07 and NO .
  £       J\.


3.3.1.3.2  Chemiluminescent analyzers--EPA has under consideration the



chemiluminescent method as a reference method for N02.  Approximately



seven years ago, EPA inaugurated in-house and contract investigations



into measuring oxides of nitrogen by application of chemiluminescent



technology.  Light energy—with or without flames--of specific wave-



lengths can be generated by bringing into a chamber a given substance





                                  53

-------
that burns or reacts with another substance to emit light energy detected
by a photomultiplier tube.  Application of the principle of measurement
for oxides of nitrogent has passed through several stages.
     Today about ten manufacturers are selling oxides of nitrogen analy-
zers using the chemiluminescent principle.  They operate over a wide
range of ambient temperature and humidity with minimal effect on accuracy.
     The oxides of nitrogen analyzer is designed to measure NO, NCL and
NO  in a continuously exchanged ambient air sample.  The system reacts
  A.
quickly to quantitative changes in NO, N09 and NO  content of the sample,
                                         I*       X.
while providing a highly stabilized measurement capability for extended
periods without repeated adjustments.  An output signal proportional to
the measurement is produced for recording.
     The oxides of nitrogen analyzer uses the principle of photometric
detection of chemiluminescence resulting from the flameless gas phase
reaction of NO with ozone (0,).  Since this reaction only occurs between
NO and 0,, the amount of NO., is shown by the difference between NO  and
        o                  Z                                      .Jt
NO, accomplished by dividing the input sample into two flow streams.
One stream goes directly into the reaction chamber and results in a
measurement of NO.  The other stream, defined as NO , goes through a
                                                   JO.
catalytic converter changing N02 to NO but having no effect on incoming
NO, and then into the reaction chamber for measurement.  The amount of
N09 is determined by subtracting the NO from the NO  measurement.  The
  b                                                X.
analyzer provides automatic cycling through the NO and NO  measurements
                                                         J\.
with the output difference (N0?) up-dated after each cycle.  The normal
cycle time is one or two minutes.
                                       54

-------
         Analyzers generally have several ranges.   In most  cases a range is



    0-0.5 ppm full scale with a minimum detectable  sensitivity of 5 ppb.



    Zero and span drift usually do not exceed one percent in 24 hours.



    Nominal weight of the instrument is 25 kg.



         The variation produced by one manufacturer is shown in Figure  3.1.



    This analyzer measures NO and NO  simultaneously  by using two cells,
                                    .A.


    negating the necessity for cycling between measurements.   The manu-



    facturer claims improved stability with use of  the optical chopper  for



    automated drift compensation and an improved NO,.,  to NO  converter.   The



    EPA St. Louis Regional Air Pollution Study (RAPS) has 25 such analyzers



    in the Regional Air Monitoring Stations (RAMS).   As of  November  1974



    they are undergoing the Systems Acceptance Test (SAT).
Air
Air
                                        r
Opficol

chopper
Photo -
multiplier
tube
Slgnol
Phase-
sensitive
amplifier
Phose sensing freq. -Tl-ri-n_


NOX


                                   Flow   '

                                   constrictors
                                                                  Diff
                                                                  amp

Photo -
multiplier
tube
Signal


Phase -
sensitive
amplifier

1^
NO

                                                                           °NO.
                                 >N09
                                                                           oNO
            Figure  3.1.   Oxides of nitrogen   chemiluminescent analyzer


                                      55

-------
3.3.1.3.3.1  Tentative method for the calibration of nitric oxide,



Nitrogen Dioxide and Ozone analyzers by gas phase titration--This tech-



nique developed by EPA for calibration of chemi luminescent oxides of



nitrogen and ozone analyzers is a milestone in ambient air quality



measurement.  Reported in the Environmental Protection Technology



Series, March 1974 (EPA-R2-75 246), its application substantially



improves rapid calibration ability in the field.  Integrity of the



technique can be affirmed in the laboratory by certification using NO-



primary standard permeation tubes.



     The gas phase titration (GPT) technique uses the rapid gas phase



reaction between nitric oxide and ozone so that with concentration of



one of the three gases known, the concentration of the other two may be



determined.  Cylinder nitric oxide at 50 to 100 ppm in nitrogen is used



as a secondary standard for routine field calibrations.  Ozone is added



to excess nitric oxide in the dynamic calibration system, and a chemi -



luminescent nitric oxide monitor indicates changes in concentration.



The decrease observed on the spanned nitric oxide analyzer with addition



of ozone is equivalent to the concentration of nitric oxide consumed,



the concentration of ozone added and the nitrogen dioxide concentration



produced.  The advantages of the procedure are that a primary standard



for only one gas is required and that rapid and routine calibrations of



ozone, nitric oxide and nitrogen dioxide monitors may be performed at a



common manifold as shown in Figure 3.2.
                                      56

-------
      NEEDLE
      VALVE
JLEAN AIR
 SOURCE
       VENT


AIR FLOWMETER
0 TO 10 LITERS MIN







"A



t
Pll 1 tLRvJ



1/3 SOURCE
-£&»•













QJ
^








                             RESTRICTION
                            STANDARD
                              NO
                            CYLINDER
                       REACTION
                       CHAMBER
                                                            FLOWMETER
SAMPLE MANIFOLD-^
MIXING BULB
                                                J




CHEMILUMI-
NESCENT N02
MONITOR




CHEMILUMI-
NESCENT 03
MONITOR




CHEMILUMI-
NESCENT NO
MONITOR

                     Figure 3.2.   Flow scheme for calibration of NO, MX,,
                                   and NO  and 0,, monitors by gas phase
                                   titration


           3.3.1.3.3  Electrochemical NO and N00 analyzer--Fjiergetics Science,  Inc.
                       " "' ---«-" ~ ~~ --"--•-!  i      T •"' —      -jT, -'-— - -i—rj-i- J-~ -•

           has  produced a fully protable analyzer to measure NO and N02 separately


           and  simultaneously.

                The detection principle used is an advanced electrochemical  method


           whereby NO is measured by oxidation and N02 is measured by reduction.

           The  analyzer has dual  ranges for both NO and N02 with the high  sensi-

           tivity range for N02 being 0-1.0 ppm and for NO, 0-10 ppm full  scale.
                                             57

-------
Prototypes with a full-scale sensitivity of 0.5 ppm are being engineered.



Limitations include pronounced temperature sensitivity; the principal



advantage of the analyzer is that it is portable and can be operated with



a minimum of training.



3.3.1.3.4  N0? Fluorescence monitor—A laser-induced fluorescence monitor



for NO- has been developed for EPA.  A recent 30-day field study in St.



Louis, Mo. comparing the fluorescent and chemiluminescent methods for



NO,, showed almost no difference between the two procedures.  EPA is work-



ing on a system to induce NO- fluorescence with a pulsed high energy



broad bank xeon source.  Such a system would be simpler to operate and



considerably less expensive than  the laser  method.



3.3.1.3.5  Nitrates--An automated instrument for nitrates has been devel-



oped.  The system couples a wet microelectrostatic precipitator (Leap



sampler) with a nitrate ion selective electrode.  The solution from the



Leap sampler is automatically pumped into a cell containing the ion



selective electrode where the nitrate ion concentration is measured.



The system is capable of measuring 1 yg/m  of NO, for a one-hour collec-



tion period.  EPA is conducting field and laboratory tests on interfer-



ences and general performance characteristics.



3.3.2  Stationary Sources



     The prescribed reference method for NO  uses the EPA sample train
                                           J\.


to collect a sample from the stack source and the phenoldisulfonic


                         1 2
acid method for analysis. '   The method is time-consuming (with respect



to sample analysis) and needs improvement to increase rep  ducibility.



Regulations allow for equivalent and alternative methods, but criteria



and procedures for determining equivalency and acceptable alternative



methods have not yet been proposed.

                                     58

-------
     Guidelines have been developed for continuous NO  monitoring
                                                     .X


systems and performance specifications proposed based on evaluation



of commercially available systems. ' '   Commercial systems are avail-



able using various sampling and analytical techniques.  Both extractive



and in-situ techniques are available.  Analytical methods include:



electronchemical, coulometric, UV, IR and visible absorption spectres-



copy, colorimetric and chemiluminescent.



     The reference method procedure is being evaluated to improve its



reproducibility, minimize executive time and delineate critical per-



formance parameters to be used as criteria for equivalent and alterna-



tive methods.



     The lead dioxide method for NO  developed on contract  is being
                                   X.


evaluated as an alternative reference method for power plant emissions



and will be evaluated also for application to other NO  sources.
                                                      JC


     Evaluation studies have been done comparing various sampling



approaches to continuous monitoring of NO  emissions, namely, extrac-
                                         -A.


tive, in-situ and remote sensing.  A report on these studies is under



way.  A study has been completed on delineation and evaluation of



criterical design and performance parameters of interface systems

                                                     7

required in the use of extractive monitoring systems.   The study



considered various pollutant gases including NO .  An in-situ gas
                                               A.


filter correlation NO  monitor has been developed as a field proto-
                     JL
                                        Q

type and is undergoing field evaluation.   Contract effort has been



started to evaluate the application of the same technique to remote



sensing of NO  by IR emission compared with IR absorption in the in-situ
             J\*
       g

device.   An inexpensive, simple NO  monitor is being developed in-house.
                                   -A.



                                  59

-------
     Within a year or two enough data will be available to allow



reassessment of research and development activities.  At this time



no additional activities are advised beyond completion of ongoing



tasks and two tasks in future plans.  One is development and evalua-



tion of a myoglobin method as an alternative method for NO; the other



is the evaluation of conversion efficiency of N0? in the chemilumi-



nescent method for NO  monitoring as applied to nitric acid plants.
                     -J\.


3.3.3  Mobile Sources



     Standards and techniques of measurement for nitrogen oxides have



been promulgated for most mobile sources.  These methods and technique



result from research and development efforts of the Chemistry and Physics



Laboratory.  The analytical system specified throughout was the chemi-



luminescent nitric oxide plus ozone reaction with prior conversion of



nitrogen dioxide to nitric oxide.  Standardization and efficiency



determinations are also made with CPL-developed procedures.



3.4  CARBON MONOXIDE MEASUREMENT



3.4.1  Ambient Air



     Carbon monoxide (CO) is by far the largest single pollutant found



in urban atmospheres.  Although the background level is about 0.01 ppm,



concentrations of 300 ppm have been reported in congested industrialized



urban areas during prolonged periods of air stagnation.



     CO is a product of incomplete combustion of carbonaceous fuels.



The largest man-made source comes from the combustion of motor vehicle



fuels.  Estimates vary, but CO introduced into the atmosphere in the



United States is from one-half to three-fifths of the global input, cal-



culated to be about 2.25 x 10   kg (250 million tons) annually.  Without





                                    60

-------
removal processes this input would be sufficient to raise the background



0.03 ppm per year.  The mean residence time has been estimated to be



between 0.2 and  three years.



3.4.1.1  Calibration--Calibration of methods to measure carbon monoxide



has probably been the hardest problem faced by the analyst.  Probably it



also accounts for measurements discrepancies and arguments that have



arisen from comparing data.  When there are problems in calibration,



usually they can be traced to errors in concentration values of calibra-



tion gas sources or differences in the diluent gas.  In many instances,



these gases have a CO content higher than the ambient concentration the



analyst has attempted to measure.



     It appears that lacking a primary standard, manufacturers have



assayed the concentration of a carefully blended mixture in a reference



cylinder.  This cylinder subsequently has been used to calibrate instru-



mentation to determine the content of subsequent mixtures blended to



approximate the concentration requested.  The reference cylinder might



be used for many months, and during that period of time, the CO concen-



tration is changing.  Depending on the concentration of CO in the



cylinder, the diluent gas and metallurgical aspects of the cylinder,



the decay rate ranges from dramatic to tolerable.  Some vendors peri-



odically reassay the reference cylinder or prepare new mixtures to



minimize the problem.  Meanwhile, the cylinder concentration in the



"certified" mixture is shipped to the consumer and change in the



mixture occurs.  If the CO concentration is very low, the cylinder wall



oxidized, or reactive impurities present, the CO level will decrease



significantly within the first month before tapering off.  The purchaser





                                 61

-------
may use this "standard" cylinder for several years.  It is not surpris-



ing, therefore, if standard cylinders are brought together from various



sources and introduced into a single analyzer, that a difference of 7 ppra



between cylinders certified at 25 ppm might be seen.



     Aluminum cylinders for pressurized specialty gases introduced within



the last year promise to substantially reduce the calibration problems



of CO methods.  The original assay of the mixture must be accurate, and



this can only be accomplished now by rigorous attention to detail and



use of expensive and delicate equipment by a very competent analyst.  The



purchase of such blends would be very expensive.



     EPA is supporting investigation of generating precisely known con-



centrations of CD according to the scheme:



          A -> B + CO,



where A is a compound capable of unimolecular decomposition (e.g., by



pyrolysis) to produce a stoichiometric quantity of CO, and further being



stable and volatile enough to be precisely dispensed from a permeation



device.  Metal carbonyls are excluded from consideration because of



toxicity.  Support is also being given to improvements in permeation/



diffusion devices expected to facilitate the technique for dispensing



precise small quantities of CO.



3.4.1.2  Manual Measurements--No new manual methods have become popular



in the last five years.  There may have been laboratory work on new



manual techniques for ambient air analysis, but it has not been docu-



mented in air pollution literature.



3.4.1.2.1  American Public Health Association (APHA) Method--About two



years ago the Intersociety Committee adopted the method for colorimetric





                                     62

-------
determination of CO that uses a solution of the silver salt of p-



sulfaminobenzoic acid.  The solution is made by adding to 20 ml of



p-sulfaminobenzoic acid, 20 ml of 0.1 M AgNo3 and 10 ml of 1.0 M HaOH



with shaking.  Ten ml of the solution is transferred to a 125 ml



Erlenmeyer flask with a standard taper joint at the mouth.  A stopcock



adapter is placed into this joint and the assembly is evacuated until



the solution begins to bubble, after which the stopcock is closed and



the assembly is removed.  The sample is introduced simply by opening



the stopcock.  Total volume of flask plus stopcock adapter is deter-



mined by measuring the water required to fill the apparatus.



     After introduction of the sample, the stopcock is again closed and



the flask allowed to shake on a wrist shaker for two hours.  A portion



of the solution is transferred to a 1 cm spectrophotometer cell and the



absorbance is determined at 425 nm for 0-400 ppm samples.  The absorp-



tion at this wavelength results from the formation of a colloidal sus-



pension of silver produced when the silver salt is reduced by CO.



     Acetylene, olefins, H.?S and aldehydes in high concentration will



interfere with this method either by reducing the silver or by forma-



tion of insoluble silver sulfide.  These interferences can be removed



by passing the sample through a silica gel filter containing HgSO..



When standard samples are analyzed with each series of unknowns, repli-



cate analyses agree to within ± 5%.  Because this method is empirical,



it is important that all conditions be maintained for the analysis of



samples and standards.  These include shaking time, the interval of



time between completion of shaking and measurement and the temperature.
                                 63

-------
A long (two hours) shaking period is required because the reaction rate



is slow and shaking increases the contact between reagent and gas sample.



3.4.1.2.2  Draegor Type Tubes--There has been marked improvement in the



last year or two in lower detection limits for devices manufactured by



several firms based on the adsorption of CD on solid surfaces with a



simultaneous color reaction.  The method employs a hand pump which sucks



air through a specially designed glass test tube containing the reagent.



Depending on the kind of tube, the length of stain is either a measure



of CO concentration in the tested air or a colorimetric comparison



between standards and sample.  Formerly these Draeger-type tubes were



considered a semi-quantitative means for rapidly detecting dangerous CO



concentration in an industrial environment.  Now, with care, concentra-



tions as low as 2 ppm can be estimated with the length of stain tubes.



The tubes are sealed and just prior to use, the glass tips are broken



off the tubing ends, with the designated end coupled to the pump.  The



tubes are not reuseable.  While it is not appropriate to use this



technique to obtain a mean concentration (e.g., hourly average), it is



useful for determining the approximate CO in an indoor/outdoor surround-



ing, a vehicle or other type enclosure.



3.4.1.3  Automated Analysis--A number of instrumental methods for auto-



mated analysis of ambient CO concentration are very satisfactory.



Several instrumental methods that have been marketed have not been



suitable, including amperometric, mercury vapor and certain species of



electrochemical analyzers.



3.4.1.3.1  NDIR--The most popular technique used in commercial instru-



mentation for CO monitoring is the nondispersive infrared (NDIR)




                                     64

-------
technique.  This is also the basis for the reference method specified by



EPA in Federal Register 36 (228) 22384, 1971.



     NDIR analysis is based on broad-band spectral absorption sensitized



for CO by means of a selective detector and optical filters.  Commercial



instruments for ambient CO concentrations are available from about four



or five manufacturers in the U.S. and about the same number abroad.



     Typical nondispersive infrared analyzers use a double-beam arrange-



ment of the type shown in Figure 3.  Infrared radiation from the fila-



ments is directed onto two cells:  (1) a reference cell filled with a



non-infrared absorbing gas, such as nitrogen or argon, and  (2) a sample



cell through which the sample air containing the gas of interest is con-



tinuously drawn.  The detector consists of a gas-impermeable double



chamber with a flexible metal diaphragm as a partition.  Both chambers



are filled with the gas of interest.  The infrared radiation passing



through the reference cell enters one chamber of the detector, and



radiation passing through the sample cell enters the other chamber.  The



gas in each chamber is heated by incoming energy, causing a pressure



increase in the two chambers.  The pressure rise is greater in the



chamber receiving radiation from the reference cell, since a portion of



the radiation transmitted through the sample cell has been absorbed by



the gas of interest before entering the chamber on the sample cell side.



This difference causes a diaphragm displacement which is electronically



measured as a capacitance ctemge.  The infrared radiation is chopped by



an optical chopper to cause a periodic capacitance change, which modu-



lates a radiofrequency signal from an oscillator.  The signal is subse-



quently demodulated, amplified, and the output fed to a meter or a recorder.





                                 65

-------
     NDIR  instruments are usually subject to  interference because other


gases  (e.g., H~0 and CCL) absorb at the wavelengths of CO.  To eliminate


or minimize interference, auxiliary absorption cells or optical filters


are incorporated to remove most radiation at  wavelengths at which the


interfering substances absorb.  This could be achieved, for example, by


placing cells  containing CCL in both light beams pictured in Figure 3.


     For monitoring CO in ambient air, water  vapor is the main interfer-


ing substance.   Even using corrective filters,  the discrimination ratio


may be as much as 4000-7000:1 (i.e., 4000-7000 ppm of water vapor causes


the meter  to respond as if there were 1 ppm of CO).   This could result


in an error of as much as +5 ppm under humid  conditions, although +3 ppm


is more typical.   Use of refrigerated dehumidification or drying traps


reduces error  to <1 ppm.   Other sources of error include gas leaks in


detector and reference cells, nonlinear response and drift in the elec-


tronic circuits.   However, if conditions are  optimum most analyzers set


to span at 50  ppm full scale will reproduce to ±0.5.
                              Infrared
                              source
uu
 I
uu
 I
                             Reference
                                     Chopper
                                       Sample
                                       cel

                                               Sample in*-
                                            o_om

                                               Somple out

                                            o^o-A^- ^
                                      Diophagm  .
                                      distended?
                                         . • ••••I

                                            -^Component

                                           * of Interest


                                            /Other
                                            molecules
                                  Control unit
                             Figure  3.3.   NDIR analyzer


                                       66

-------
3.4.1.3.2  Catalytic Oxidation--Detection of CO by catalytic oxidation



has been reported in the literature over the years and analyzers incor-



porating the principle have been marketed.  In the past, full-scale



sensitivity has been about 0-500 ppm.



     Within the last two years Mine Safety Appliances, Inc. (MSA) has



converted CO to C02 by a catalyst called Hopcalite, and temperature



increases as a result of the oxidation proportional to the CO concentra-



tion.  Present MSA analyzers are measuring 0-10 ppm full scale reliably



with drift tolerances for zero and span about ±1% per day.  Shortcomings



of this type instrument such as sensitivity to interferences have been



practically eliminated in MSA's most recent design.  The cost of the



analyzer is competitive with NDIR analyzers.  The same sensitivity can



be achieved using gas chromatography techniques, but this analyzer is



continuous and provides a real time analog signal.  Unknown is how well



the instrument will perform over a period of years.



3.4.1.3.3  Gas Chromatography—Gas chromatographic (GC) analyzers



encompassing the automated measurement of CO have passed from the



prototype stage to commercial production.  Several hundred GC analyzers



have been sold in the U.S. by a half-dozen manufacturers.  Twenty-five



St. Louis RAMS stations are equipped with the Beckman model 6800 which



is designed to measure total hydrocarbons, methane and carbon monoxide.



     The first automated GC analyzer for analysis of methane and carbon



monoxide was developed by EPA.  Commercial systems essentially are



copies of the original design except for augmented analytical capability



to include total hydrocarbons and in some cases other hydrocarbon species



such as ethylene and acetylene.  The basic system has an electronic






                                67

-------
 program to cause the introduction of two sample aliquots.   One is ana-



 lyzed for its total hydrocarbon content by direct introduction into a



 flame ionization detector.   The second aliquot is first transferred



 through a stripper column via a carrier gas.   C02, water and all



\inwanted species of hydrocarbons are removed by the stripper column



 before it is backflushed for the next analysis.  The eluting hydrocar-



 bons and CO pass through a  molecular sieve column, where the substances



 are separated, and through  a catalytic reactor to a flame ionization



 detector (FID).   The hydrocarbons pass through the catalytic reactor



 quantitatively and the CO is quantitatively converted to methane which



 is then measured by the FID.



      The system is designed for semi-continuous operation and can per-



 form an analysis about every five minutes.  It has a linear output for



 measured substances and a wide operating range that suggests its use



 both in heavily polluted areas and relatively clean locations.  Concen-



 tration of CO from about 0.03  pm to several  hundred ppm can be



 measured with this instrument.  The major disadvantage of this analyzer



 is that its complexity requires a highly trained, skilled operator.



 Data is not available for from several hours  to several days following



 installation while the system stabilizes.



 3.4.1.3.4  Dual Isotope Fluorescence--Modification of the NDIR method



 has been made using the principle of dual isotope fluorescence (DIP).



 The technique consists of absorption spectroscopy in which the source



 of energy is fluorescence of CO.   This gives  excellent wavelength cor-



 relation, high signal-to-noise ratio and discrimination.   The system



 is illustrated in Figure 3.4.  Infrared radiation from the Broadband IR





                                     68

-------
source stimulates the CO molecules in the sealed fluorescent cell that in


turn provide fluorescent radiation as the source of energy for absorption

                                            1 f\       T ft
measurement.  The chopper cells containing C  0 and C  0 are part of the


analytical scheme whereby the measurement is uniquely sensitive to the

                                            1 f\       1 ft
presence of CO in the sample tube.  If the C  0 and C  0 signals are


defined as the "A" and "B" signals, respectively, only the "A" signal


will be attenuated by the presence of CO gas in the sample tube since


the natural isotopic abundance of C  0 is only 0.2% of C  0.  The pro-


cessing electronics generate an output proportional to the quantity *


          B-A
This expression shows sensitivity to differential absorption of the two


signals.  In addition, maintenance of the "B" signal at fixed amplitude


by automatic gain control allows the measurement to be independent of


variations in source power of detector response.


     Relatively high cost and a reported high incidence of malfunction


and temperature sensitivity have held down widespread acceptance of the


analyzer, but the latter two problems are being overcome.  The license


to manufacture the analyzer was purchased about a year ago by Beckman


Instruments, Inc. for Andros, Inc.
                                 69

-------
                                               Sample Gas
                                               Inlet
                      Signal
                      Processing
                      Electronics
                                                   A. Synchronous
                                                     Spin Motor
G. Isotope Outlet
  Chopper Wheel
                                   CO Concentration
                                   Meter
                                                   B. Broadband IR     H. Filter, Cell
                                                      Stimulation Source   (CO)

                                                   C. Broadband IR Inlet I. IR Outlet
                                                      Chopper Wheel       Window

                                                   D. Inlet Windows
J. Magnet Pickup
  For Sync Pulses
                                                    E. Dual-Isotope-
                                                      Fluorescent Cell

                                                    F. Filter Cell
                                                      (CI60)
              Figure 3.4.  Dual isotope  fluorescence analyzer


3.4.1.3.5  Electrochemical Analyzer--At the time of this writing, Ener-

getics  Science,  Inc.  (ESI) had sold about 2500 "Ecolyzers," with the

number  sold now  over 100 per month.  In the future  it could be the most

prevalent instrument in the  U.S.  for ambient CO analysis.  Because of

the Ecolyzer's importance, we are quoting the entire conclusion of an

EPA, ERG, Environmental Monitoring and  Support Laboratory manuscript

presented at the Instrument  Society of  America Symposium, May 13-15, 1974:

               "ESI  has made  available to the air pollution
           analyst a low cost useful instrument.  The ana-
           lyst must be alert to the analyzer's limitations.
           He should keep them in mind in using the  analyzer
                                        70

-------
         and exercise caution in assessing the values
         obtained in terms of absolute accuracy.

              We view the Ecolyzer as a portable ana-
         lyzer that gives us a capability for rapidly
         sighting potential or real dangers be it in
         a garage, tunnel, intersection, industrial
         plant or inside a conveyance.  It is an ana-
         lyzer that is suited for that type of
         emergency episodes where one need not be as
         concerned about accuracy as about the con-
         centration in terms of a hazardous situation.
         Portability of the analyzer makes it useful
         for locating a "hot spot," a place where
         higher concentrations occur and if interest
         lies in that direction, locate a permanent
         sampling site.  The Ecolyzer should be kept
         in a condition of readiness for the activi-
         ties mentioned above.  A weekly check of
         its operational condition and calibration
         would be in order.  A spare sensor on hand
         would likely be desirable.

              The Ecolyzer is not looked upon as
         desirable for continuous operation at a
         fixed monitoring site.  Problems of lin-
         earity, drift, temperature sensitivity,
         rise vs. fall time are potential sources
         of error that could prove misleading.

              A person with little training can take
         an operating instrument into the field and
         obtain satisfactory results."

     The calibrated pumps a constant flow of sample air through a filter

and sensor.  Carbon monoxide in the sample air is electro-oxidized to

carbon dioxide (CO-) at a catalytically active electrode in an electro-

lyte as shown in the reaction:  CO + H20 + C02 + 2H+ + 2e.

     The electro-oxidation of CO occurs at a sensing electrode in a

sulfuric acid electrolyte.  The counter electrode is the cathode where

oxygen reduction occurs.  Additionally, a reference electrode is neces-

sary for operation of a potentiostat to balance the system.  In the

electro-oxidizing reaction, current flow between sensing and counter
                               71

-------
electrodes is approximately proportional to the CO concentration of the



sample and is registered on a meter or an optional recorder.



3.4.2  Stationary Sources



     A large number of commercial CO analyzers are available including



manual methods (colorimetric) and instrumental methods (catalytic oxi-



dation, electro-chemical cell, gas chromotograph--flame ionization, NDIR



and DIR).  Gas-filter correlation (GFC) is an advanced form of NDIR



which has all but eliminated the interference from water vapor, C02 and



particulates.  By combining GFC with an in-situ, or non-extractive cross-



stack measurement, a continuous, accurate CO measurement can be made



without problems of sample extraction and handling.  One instrument using



this method is commercially available, and a second is expected to be on



the market in early 1975.  The GFC technique is also applicable to remote,



single-ended measurement of CO emissions.



3.5  HYDROCARBONS



3.5.1  Ambient Air



     Biological processes, petroleum, coal and natural gas account for



almost the total hydrocarbon loading of the atmosphere.



     Complex problems are involved in study of the reactants and products



of atmospheric photochemical reactions, one being the determination of



atmospheric hydrocarbon levels and their relation to hydrocarbon emission



from vehicles and other sources.  The greatest interest is in those hydro-



carbons participating in photochemical reactions.



     While methane is innocuous and does not participate in photoinitiated



reactions, it does constitute a major portion of hydrocarbons present in



the air, and in certain areas and atmospheric conditions has accounted




                                     72

-------
for more than 95% of hydrocarbons present.  Typically CH. makes up
nearly all the nonreactive fraction.
     Thus a rough correlation exists between "reactive hydrocarbons"
and "total hydrocarbons less methane."  Pending development of a type-
specific method for determining reactive hydrocarbons, a compound
specific method has been found to be useful and is now used in setting
national primary and secondary ambient air quality standards for
hydrocarbons.
     The standard as written does not allow for natural sources of
hydrocarbons such as the terpenes, which emit into the global atmos-
phere an estimated 1.8 x 10   kg/yr.  The terpenes are associated with
forest areas and the blue haze of the Appalachian Mountain region.
Concentrations of total hydrocarbons less methane have been found in
remote rural surroundings at levels close to the standard.  The par-
ticipation of naturally occurring hydrocarbons in photochemical reac-
tions producing oxidants is under investigation.
     There are limitations to the categorization of all hydrocarbons
of other-than-methane species into a single grouping.  Given the same
conditions for photoreaction, half-life for some hydrocarbons will be
minutes while for others it will be hours to days.  It is known that
the reactivity (make-up) of the grouping may differ markedly from one
urban area to another.  For example, gas chromatographic analysis has
shown that within the same urban area  (the Los Angeles basin), make-up
of the grouping is such that relative reactivity  (near the Pacific
coast in the morning) is notably greater than the same carbon concen-
tration of the same air parcel reaching another portion of the city
later in the day (inland Azusa area).
                                  73

-------
3.5.1.1  Calibration--Blends of CH. in air, pressurized in gas cylinders,



have been used over the years for field calibration of HC analyzers.  The



mixture even at low concentration is stable for long time periods.



Capability was developed as early as 1965 for preparing concentrations



in the ppm region with a tolerance of ±0.1 ppm.  Although demanding and



time-consuming, the technique gave EPA an ability to evaluate the product



of commercial suppliers.  Until several years ago, cylinders delivered by



manufacturers had a certified analysis either moderately or grossly



inaccurate, although there was one reliable gas supplier.  Recognizing



a need, competitors have now upgraded their products so that accurate



standards of low molecular weight hydrocarbons are available from a



number of them.  In the laboratory and for special studies, mixtures of



hydrocarbons, including the reactive species, can be made by skilled



personnel in inert plastic bags or chambers for specialized studies or



calibration of special analytical methods.  Included are gas chromato-



graphs and sophisticated 1R, W and fluorescent analyzers.  This in-



house capability has helped EPA study atmospheric kinetics and photo-



chemical reactions.



     Presently the agency has the problem of an acceptable hydrocarbon



to calibrate analyzers measuring the fraction of other-than-methane



hydrocarbons in the atmosphere.



     Very accurate concentrations of one or more hydrocarbons can be



delivered using the EPA permeation technology.  At least a score of



permeation tubes containing different species of hydrocarbons have been



successfully fabricated and used for this purpose.  Many are commer-



cially available.






                                    74

-------
3.5.1.2  Manual Methods--Improved collection media for hydrocarbons has
been the object of several investigations in recent years.  Subsequent
stripping of the hydrocarbons for indentification by mass spectrometry
or quantification by gas chromatography has helped the laboratory
researcher in profiling more than two hundred hydrocarbons found in
polluted atmospheres.
     No new wet chemical methods of significance have surfaced in the
last seven  or eight years.  In Air Pollution, Vol. II, ed. Stern,
A. C. P.  15 Academic Press, 1968, Altshuller described manual methods
for measuring certain hydrocarbon species or groups.
3.5.1.3  Automated Analysis--As stated earlier, EPA's interest in
hydrocarbon measurement is primarily related to reactive hydrocarbons
grouped into a category referred to as hydrocarbons corrected for
methane, which is in turn called hydrocarbons as methane  (i.e., total
count of carbon atoms, C, in the measured sample) minus the methane,
CH., concentration.  Conventional instrumental systems measure total
hydrocarbon concentration and methane separately.
     The Federal Register, 36^ (158) 15491, August 14, 1971 states "it
may be assumed that the degree of total hydrocarbon emission reduc-
tion necessary for the attainment and maintenance of national standard
for photochemical oxidants will also be adequate for the  attainment of
the national standards for hydrocarbons."  EPA therefore does not
require states to monitor hydrocarbons for compliance with national
ambient air standards.
     In 1974 an EPA investigation found a lack of comparability between
different commercial analyzers for non-methane hydrocarbon.  Reasons
for the discrepancies are still being investigated.
                                  75

-------
 3.5.1.3.1  Gas Chromatography--A procedure for collection and concentra-



 tion of trace hydrocarbons and rigidly controlled introduction into a GC



 where separation of compounds takes place and compounds elute into a



 flame ionization detector.  Compounds generally elute in relation to



 their mass, with heaviest species last on the chromatogram.  The peaks



 have qualitative and quantitative meaning gained by systematic empirical



 fingerprinting through analysis of measured concentrations of known



 hydrocarbons.  Advances in chromatography have allowed speed-up of the



 analysis by temperature programming automatic peak identification and



 quantification using state-of-the-art magnetic tape recorders with



 sophisticated peak identification and integration (concentration) print-



 out systems.



 3.5.1.3.2  Programmed Gas Chromatograph--The reference method for deter-



mination of hydrocarbons corrected for methane is contained in Federal



 Register, 36^ (84), April 30, 1971, as described earlier.  This reference



method is being reevaluated.  Present commercially available instruments



using the technique are expensive, complex and demand considerable



 operator skill.  They are marginal in ability to measure hydrocarbons



 corrected for methane on a routine unattended basis at or below levels



required by the national ambient air standard.



3.5.1.3.3  Reactive Hydrocarbon Analyzer—Bendix Process Instruments



Division has made available its model 8201 Ambient Hydrocarbon Analyzer



designed to measure what Bendix calls "reactive" hydrocarbons (total



hydrocarbons less CH.).  In operation, a programmer causes an aliquot



of sample air to be transported through a column via a carrier gas.



Hydrocarbons other than CH. are stripped from the gas stream in the





                                 76

-------
column.  Following the elution of CH., the column is back-flushed, and



the CH. is carried to a FID for measurement, amplification and signal



storage.  Then a discrete volume of ambient air is passed directly to



the detector for measuring total hydrocarbons; the signal is also



amplified and stored.  The concentration of CH. is then electronically



subtracted from total hydrocarbon concentration for the measurement of



"reactive" hydrocarbons.  During each programmed cycle, approximately



three minutes long, automatic zeroing of the detector output ensures a



stable base line.



     When first evaluated this analyzer had several weaknesses that



were almost eliminated by substitution of more rugged components and



plumbing changes.  Currently there are about 300 such units in the



field.



3.5.1.3.4  Dual Channel Hydrocarbon Analyzer--The Mine Safety Appliances



Company (MSA) instrument is nearly a complete system in itself, and is



a recent commercial development in hydrocarbon instrumentation.  The



device is independent of programming, mechanical and electromechanical



functions and has a built-in supply of zero gas and purified combustion



air.  All that must be supplied is hydrogen and electrical power.  (See



Figure 3.5.)  Operation entails continuous measurement of two gas



streams:  one stream containing only CH., the other THC.  The two



streams are simultaneously introduced into a dual flame detector mounted



in a constant-temperature-controlled oven.  The CH. stream is ambient



air passed through a catalyst column containing Hopcalite (TM) at 260°C.



Essentially all hydrocarbons except CH. are converted to carbon dioxide



(CO) and water vapor, and all CH. is passed to the detector.  The





                               77

-------
instrument, designated 11-2 by MSA,  has a built-in pump and catalytic

oxidizer supplying purified combustion air and is used as a source  of

zero air for calibration of the analyzer.  The electronic design pro-

vides for continuous voltage generation proportional to the total

hydrocarbon, QFL and nonmethane concentrations.  (See Figure 3.6.)

Both sides of the system are calibrated using a known concentration

of CH, in air; range selectors plus  manually adjusted potentiometers

permit exact alignment  so that hydrocarbon other than CFL will be

accurately reflected as nonmethane.
                  AMIIENT
                   AIR ••
                              DUAL HFID














r





}

1
1





i














-\
j


                               GAS INLETS FROM
                               DISTRIBUTION BUCK
          Figure 3.5.  Block  diagram of dual hydrogen flame detector
                                     78

-------
  Figure  3.6.  Electronic diagram of dual  flame  detector







3.5.1.3.5  Ghemiluminescence---A new technique has been developed by EPA



which reacts hydrocarbons in air with atomic nitrogen to produce a



chemiluminescence approximately proportional to the photochemical



reactivity of hydrocarbons present in the air sample.  The method has



applicability for measuring reactive hydrocarbons species in auto



exhaust as well as for measuring the photochemical potential of air



samples containing hydrocarbons.



     Another detector developed by EPA is based on the reaction of ole-



finic organics with an excess of ozone.  The method is analogous to the



ozone, ethylene reaction currently used to monitor ambient ozone except



that the roles of ozone and ethylene  (olefinic organic) are reversed.



The method gives either a single measure of reactivity or, with a gas



chromatographic column, can monitor  individual hydrocarbons.
                                79

-------
3.5.2  Stationary Sources



     Ambient air quality standards for hydrocarbons relate the photochemi-



cal reactivity of these species to oxidant formation so that any future



requirement on measurement of emissions from stationary sources must con-



sider:  (1) emissions which react mutually or in the presence of other



atmospheric contaminants to produce oxidant, and (2) emissions which



react photochemically and serve as precursors of oxidant formation.



     The use of present analytical hydrocarbon measurement techniques



applied to source emissions is limited.  Both total hydrocarbon and non-



methane hydrocarbon instrumentation used for ambient air measurement



have been used, and there is a need for development of adequate sample



interface systems.  Monitoring systems based on process gas chromato-



graphy have been shown to be impractical, since separation schemes would



have to be developed on a source-by-source basis.  Manual or "compliance-



type" methodology requires a sample collection scheme using bag collec-



tion, freeze-out traps, or charcoal adsorption devices for collecting



samples in the field with laboratory analysis using gas chromatography.



     At present, our research and development efforts involve a grab-



sampling system which can collect emissions in class fractions, i.e.,



paraffins, olefins, aroraatics, oxygenates and halogenated compounds.



The class fractions can then be analyzed collectively in the laboratory



by a total class hydrocarbon measurement or by on-column injection into



a chromatograph for identification of each species within a class.  The



objective is to provide basic emission data from a variety of source



emissions.
                                    80

-------
3.5.3  Mobile Sources



     Procedures for measuring total pollutant hydrocarbons and condi-



tions under which they are measured are defined in the Federal Register



based on their ability to participate in oxidant forming reactions.



Mobile sources thus regulated include light- and heavy-duty over the



raced vehicles and aircraft.  Qxidants per se are not emitted directly



from motor vehicles, but formed later after photochemical reactions.



Most hydrocarbons are capable of forming oxidants photochemically in



the presence of NO ; exceptions are methane, propane, acetylene and
                  Ji.


benzene.  Other organic emissions such as oxygenates and nitrogen com-



pounds may also participate while higher hydrocarbons including such



classes as the polynuclear aromatics, i.e., benzo-a-pyrene, may not be



reactive.  These compounds may be either gases or particulates depend-



ing upon conditions, molecular weight, concentrations, etc.



     Mobile sources are diverse, each requiring special measurement



techniques.  In all cases, mobile sources are considered diffuse



sources, i.e., sources in which no individual is a significant con-



tributor but the sum of all sources is of great importance.  Mobile



source emissions are directly related to conditions of operation as



well as to other factors, such as environment and fuel.



     Sample collection is critical to all sources and is of overriding



importance with mobile sources.  The constant volume sampler (CVS) has



been specified in the regulations as the method used to integrate



samples collected over a total operating cycle, allowing the total



mass of pollutant emitted to be measured and mass weighed in relation



to its impact.  The procedure causes an average dilution of about 10
                                 81

-------
to 1.  As applied to well-controlled vehicles, this extra diffusion



increases the sensitivity requirements of the analytical system to



levels approaching those of ambient air.



     Dilution of the CVS stream provides cooling and time for particu-



late formation to occur.  The cooling is especially important as



temperature fluctuations of many hundred degrees occur.  The CVS system



as specified allows the cycle to be broken into three segments with



each segment analyzed and weighed separately.  Routine measurements for



hydrocarbons are made on samples collected in bags, while more reactive



materials such as oxygenates are collected directly from the gas stream.



     The specified analytical system uses the Flame lonization Detector



(FID).   This measures total carbon concentration in the flame and there-



fore allows an estimate of mass emissions to be made although mole con-



centrations are not defined.  It is used in detailed gas chromatographic



(GC) systems as well as in total hydrocarbon analyzers.  The operation



in the two systems is somewhat different, with the total FID operating



as a premixed flame while the GC system operates as diffusion flames.



This difference has important consequences when catalytically controlled



vehicles are tested, since individual response factors for hydrocarbons



are dependent on operating conditions.  Methane is more refractory to



catalytic composition than other materials and may be markedly enhanced



in vehicles so equipped.  Recent work, both in-house and by others, con-



tinues to show the importance of response factors and effects of operat-



ing conditions and oxygen content on them.



     GC systems have been designed to routinely measure non-reactive



components.  Methane alone may be measured by simplified GC systems or
                                    82

-------
directly by infrared gas correlation spectrometry.  Standard infrared
techniques are inhibited by water vapor interferences.  A rejection
ratio of 10  or greater is required.
     Detailed hydrocarbons are determined by sophisticated GC methods.
In this laboratory, 52 individual compounds are measured by an auto-
mated system programmed from -100°C to 75°C.  The specificity necessary
determines the type of separations made and other systems have been
used.
     Higher molecular weight hydrocarbons are determined by several
methods.  Usually other material is first trapped, isolated, on a short
column containing appropriate packing material such as chromosorb 101
or firebrick and "tris."  This precolumn or collection column becomes
the first part of the analytical column.  For diesel emissions the most
common columns provide boiling point separations only, since there are
too many isomers present to separate in a reasonable time.  These
techniques are also applicable to higher molecular weight substituted
compounds such as oxygenates.
     Use of liquid chromatography is becoming widespread for the sepa-
ration of higher organics, and a system combining these techniques is
used to evaluate diesel and jet odor.
     Higher molecular weight materials are very susceptible to wall
losses and reactions.  All f;urfaces must be heated to prevent such
losses and much earlier work must be doubted due to poor practice.
     Oxygenates is a commonly found class of organics in emissions of
all mobile sources.  They are usually analyzed after derivative forma-
tion either by spectrophotometic or chromatographic procedures.  Cur-
rent methodology is not fully satisfactory because of interferences
                                 83

-------
and difficulty in performing analysis.  Spectrophotometric methods may



be applicable to specific compounds such as formaldehyde.



     Polynuclear aromatics analysis is not completely satisfactory at



this time.  Procedures are complicated and reproducibility and sensi-



tivity are problems.  Screening methods have been developed for specific



members of this series, but even these are non-routine, the large number



of compounds in the class further complicating analysis.



     Other non-regulated organics are just now being sought.  These



involve compounds of nitrogen and sulfur.



3.6  PHOTOCHEMICAL OXIDANTS



3.6.1  Ambient Air



     Photochemical oxidants (0 ) are a class of atmospheric pollutants
                              -A.


arising from reactions between hydrocarbons and oxides of nitrogen in



the presence of sunlight.  The class is known primarily for ozone



peroxyacyl nitrates--mostly peroxacetl nitrate (PAN)--and hydrogen



peroxide.  The latter two compounds in a highly oxidant atmosphere like



Los Angeles may each represent 10% of the total (0 ) concentration,
                                                  .A.


while in a reducing atmosphere like New York City, they each may account



for 2% of the total.  Their chemical formulas are:



          ozone                        0.,



          peroxacetyl nitrate (PAN)    CH3COON02



          hydrogen peroxide            H^O^




     Photochemical oxidants traditionally have been defined by air pol-



lution agencies as atmospheric substances which will oxidize certain



reagents, the most frequently used being a solution of neutral-phosphate-



buffered potassium iodide (KI).  This reagent responds to ozone, nitrogen






                                     84

-------
dioxide and the peroxyacyl nitrates, and, to a lesser extent, to



hydrogen peroxide.  Reducing agents such as sulfur dioxide (S09) have
                                                              Li


the opposite effect of oxidants on the reagent solution.  The KI



method may be used, therefore, to provide a measure of net oxidizing



properties of atmospheric pollutants without complete discrimination



as to species of oxidants or reducing agents.



     Various terms describe photochemical oxidant concentrations.  Two



of the terms, "oxidant" and "total oxidant," are used to describe the



"net" oxidizing ability of the sampled air.  Use of these non-specific



terms is required because measurement (usually by the KI method) does



not always differentiate between oxidizing or reducing agents.  The



terms "corrected oxidant" or "adjusted oxidant" show that the measure-



ments have been corrected for certain known responses (usually SCL and



N02) other than ozone or peroxyacetyl nitrate.  The term "ozone" and



"peroxyacetyl nitrate" show that the measurement method is specific



for these gases.



     We emphasize that the terms, "photochemical oxidant," "total



oxidant," "oxidant," "corrected oxidant," and "adjusted oxidant," have



no exact meaning since response obtained in the KI method depends on



the presence of various substances responding in a different manner.



3 6.1.1  Calibration--Ozone generator calibration systems are available



from nearly a dozen commercial suppliers.  Generally they are quality



products stable, reliable and able to be taken into the field.  EPA was



responsible for the basic design of the generators (Figure 3.7).  The



ozone source is an ultraviolet mercury lamp which irradiating a quartz



tube through which clean air flows at 5-10 liters/minute.  Ozone





                                 85

-------
concentrations from 0 to 1 ppm can be  generated by varying UV intensity

with a variable shield around  the lamp envelope and the flow rate is

controlled by a needle valve and measured by a rotameter.   The ozonized

air passes to a manifold from  which the monitor under test draws its

sample.
                            PEN RAY' PHOTOLYSIS
                                LAMP
                                                 VAHIABI e SHIEID
                Figure  3.7.   Typical ozone source, dilution
                                   and manifold system
     In using ozone generators, care must be  taken  to  eliminate  all

impurities including NO in the diluent air stream.

     Thus far only a source of ozone has been described.   This source,

which has a numerically indexed variable shield  for precisely reproduc-

ing settings, must be calibrated using a primary calibration method.

The presently accepted primary standard calibration method is the manual
                                     86

-------
wet-chemical KI method described in Federal Register, _36_  (84) 8196,



April 30, 1971.



3.6.1.2  Manual Measurement--Methods used for the measurement of photo-



chemical oxidants (0 ) range from those responsive to all oxidants and



reductants (and therefore indicate to a degree a "net" oxidizing effect)



to those which respond most to a specific oxidant such as 0,.



     It is possible to apply corrections to a value obtained using a



given manual method to improve accuracy.  For example, using the (to-be-



discussed) KI method one can correct for the positive interference of



NCL and negative interference of SCL if concentrations of each are known.



An ideal method for 0  does not exist and is not. likely to be found.
                     .A.


Such a method would have an equivalent response for all photochemical



oxidants including 0,, PAN and other peroxyacyl nitrates, the aldehydes



(formaldehyde and acrolein), peroxbenzoyl nitrate, H?0?, alkyl hydro-
                                                    Lt I*


peroxides, organic peroxide and as yet unidentified other compounds



believed to account for certain measurement anomalies.  The method would



not respond to any atmospheric reductants such as SCL, or oxidants not



photochemically generated, such as most NCL.



     Compounds measured can differ dramatically in reactivity, and



therefore the true measure of potential damage to man, other animals,



vegetation and materials would be unknown.  Further, some NCL present in



polluted atmospheres is photolytically generated.



     Fortunately the problem is not as formidable or perplexing as it



seems.  0, is at least the most abundant of the 0  compounds and ranks



in the top group of reactive species, so that an accurate fix on 0,



concentration would provide a meaningful measure of harmful 0  in the
                                                             .X


polluted atmosphere.


                                87

-------
3.6.1.2.1  Rubber Cracking--A quantitative method for determination of



CL was developed by Haagen-Smit and Bradley in 1951, the essence of the



procedure being to put a flat rubber strip under stress, bending it to



form a tight "u" clipped together at the ends, placing it in a glass



tube and drawing the raw atmosphere directly over it until cracking



appeared at the outer edge as seen using a 3X eyepiece.  The exposure



period preceding the appearance of cracks served as an index of the 0,.



We mention this procedure since high 0., concentrations from the 1950's



through '60's were reported by the Los Angeles County Air Pollution Con-



trol District (LAAPCD) using rubber cracking.



     Variations have been investigated including microscopic measure-



ment of crack depth, elongation of a weighted rubber strip and continu-



ous unattended open exposure of a strip for a prolonged time with



subsequent optical examinations to estimate total material effect.  The



original method required a skilled operator, was time-consuming and



necessitated close scrutinty during analysis.  The other procedures had



shortcomings limiting their use to where error tolerances were not



stringent.



3.6.1.2.2  Colorimetric Procedures--As with colorimetric procedures dis-



cussed earlier, optical absorbance of a solution is measured spectro-



photometrically:  the absorbance is linearly proportional to concentration



of the colored species which ideally is directly proportional to the con-



centration of pollutant.



     There are about eight procedural!zed manual methods.  Manual methods



have various advantages and disadvantages, depending on the information



desired, personnel available and other considerations.
                                   88

-------
     Ambient manual oxidant sampling using wet chemistry depends on a

collection device as illustrated in Figure 3.8.  Sampling precautions  are

strict owing to reactivity of the pollutant.  Sample systems should be

fabricated preferably from glass or teflon.  Location of the intake

probe can be critical, and consultation with an expert is advised.








3



E mm
— -
(
\

(






E
E
CO


j

INSIDE
CLEARANCE















D















*-
\_, \
10mm OD





30
25
20

15


10
'
UU-
. t
) 24/40,
OUTER
^ 	 WITH ^


IN IER\
s* WAY A
NOZZL
1mm, P
cfm AT
PIECES
CHANG





'
                           25 mm
                            OD
                                      CHANGEABLE, MAINTAINING
                Figure 3.8.  All-glass midget impinger


3.6.1.2.2.1  Neutral Buffered Potassium  Iodide Method—This  has  been

adopted as the tentative  standard manual reference method by the

Intersociety Committee and the ASTM Committee D-22 on Sampling and

Analysis of Atmospheres and is also the  EPA reference method for

calibration of ozone generators.

                                 89

-------
     In this method oxidants are absorbed in a one percent potassium



iodide (KI) solution buffered at pH 6.8 ± 0.2.  For ozone the reaction



can be written:



          07 + 3KI + H00 -*K+I~ + 2KOH + 0
           3          23           2


The liberated tri-iodide ion (I.,) is measured colorimetrically at 352 ran



and is directly related to the concentration of ozone in the air sample.



A 1:1 stoichiometry between moles of 0, absorbed and moles of tri-iodid



ion released is accepted.  Sampling efficiency is very high when two



impingers are used in series.



     Qxidant measurement in a range from about 0.01 to 10 ppm is possi-



ble.  SCL produces negative interference equivalent to 100% of an



equilmolar concentration of CL, but the interference can be removed with



a U-tube containing an absorber located in the sampling train upstream



from the impinger.  The absorber usually is of glass fiber paper impreg-



nated with chromium trioxide.  Since the SCL absorber oxidizes any nitric



oxide in the air sample to nitrogen dioxide, a correction for nitric



oxide will be required.  The chromium trioxide scrubber can, if wet,



cause loss of 0, and NCL-  NO- is known to give a response in one percent



KI equivalent to 10% of that for an equimolar concentration of CL.  The



contribution of NCL to the oxidant reading is eliminated by concurrently



analyzing for NCL and subtracting one-tenth of the NCL concentration from



total oxidant value.



     PAN gives a response approximately equivalent to 50% of that of an



equimolar concentration of 0,.   Other oxidizing agents will cause posi-



tive interferences with this method.  Other reducing agents, in addition



to S0?, can cause negative interference.





                                     90

-------
     Color measurement is recommended within 30 to 60 minutes after



sample collection.  Time is required for color development (10-20



minutes), but color will fade; with more than 60 minutes.  Evidence is



that the amount of tri-iodine ions liberated by CL depends on design



of the gas bubbler and phosphate concentration of neutral pH.  Error



due to these variables is probably about plus or minus 10% of true



value.



     The neutral buffered KI procedure was the EPA reference method



for determining oxidants until its replacement in 1971 by the continu-



ous chemilurainescent method.  The KI method remained in the primary



dynamic calibration method for instrumental analysis methods.



3.6.1.2.2.2  Alkaline Potassium Iodide Method--This method is for



manual determination of oxidants in the range of about 0.01 ppm-20 ppm.



An absorbing reagent of potassium iodide in sodium hydroxide solution



is used.  After sampling the solution is treated with H-CL to remove



SCL interference and is finally acidified with phosphoric acid contain-



ing a small amount of sulfamic acid to release iodine for spectrophoto-



metric measurement.



     The advantage over the neutral-buffered potassium iodide method is



that delay between sampling and completion of analysis does not involve



color fading.  This procedure requires a stoichiometric correction fac-



tor- -0.65 mole of iodine is liberated for each mole of ozone absorbed.



Rapid acidification is necessary because of certain irreversible losses



of microquantities of iodine.  The neutral-buffered KI method is prefer-



red for its simplicity over the alkaline KI method.
                                 91

-------
 3.6.1.2.2.3  Phenolphthalin Method--This method is based on oxidation



 of phenolphthalin to phenolphthalein.  Phenolphthalein is pink in alka-



 line  solution.



      Because the technique is very sensitive to pH and temperature



 changes, it has dropped out of usage.  Concentration measurements



 obtained by it are about twice those obtained by the neutral-buffered



 KI method so that it is necessary to correct data for the difference.



 3.6.1.2.2.4  Other Manual Methods--Miscellaneous acceptable methods were



 developed in the late fifties and throughout the sixties, with EPA



 researchers responsible for the l,2-di-(4-Pyridyl) ethylene method -



 (DPE) method, Ferrous Ammonium Sulfate method and Saltzman and Gilbert



 method based on the reaction of 0, with NO to form NO- with wet chemi-



 cal analysis for NO™.  Outside of EPA were the 4-allyl-2-methoxyphenol



 method - (Eugenol method, sodium diphenylamine sulfonate method and Acid



 Potassium Iodide method) - (Deutsch) method.



      It is clear why some methods have not survived.  The Ferrous



Ammonium Sulfate method was used in EPA's National Air Sampling Network



 (NASN) for 24-hour sampling of total oxidant.  Correlation between



measurements by this method and those of the continuous colorimetric



 analyzer were poor and NASN discontinued its use.  All methods used in



 the field lacked some desirable characteristic.  Part of the problem



may be lack of a clear-cut description of the substance to be measured;



 publication of the "equivalency document" to be discussed later should



provide needed criteria.



 3.6.1.3  Automated Analysis
                                     92

-------
3.6.1.3.1  Colorimetric Analyzers--Colorimetric continuous analysis of



total oxidants almost always involves a 10 or 20% solution of neutral-



buffered potassium iodide as the absorbing medium.  The first instru-



mental approach in general use was the Colorimetric oxidant recorder



developed in 1953 by Littman and Benoliel.  Instruments of this design



using a 201 neutral-buffered KI solution were incorporated into the



Los Angeles County Air Pollution Control District (LACAPCD) air moni-



toring station network in the early 1950's.  About 1957 the KI was



reduced to 10% because of objectionable crystal build-up.  The instru-



ments continue in use.



     Sample air is passed at a known rate through a liquid absorbing



reagent with a vacuum-pump arrangement.  Oxidants in contact with the



KI react to liberate the tri--iodine ion (I.,) which is determined



spectrophotometrically at 352 nm and recorded on a strip chart recorder



as ppm oxidant.  Figure 3.9 illustrates a typical Colorimetric



analyzer.  The reaction with ozone at pH 6.8 ± 0.2 is approximately:



          03 + 3KI + H30 + K+I3 + 2KOH +02



     Colorimetric oxidant analyzers operate best at atmospheric oxi-



dant levels ranging from 0.01-1.0 ppm of ozone or other equivalent



oxidant.



     SO- produces a negative interference equivalent to 1001 of an



equimolar concentration of oxidant.  Response to NO- varies with the



reagent formulation and scrubber design.  For 10% KI, N02 produces



positive interference of approximately 20%; for 20% KI, an interfer-



ence of approximately 30%.
                                 93

-------
     Filters and scrubbers for removing SCL have been used, but  informa-



tion as to performance is not available.  One device often used  consists



of glass fiber strips impregnated with chromium trioxide  (CrO,)  and
                                                              O


sulfuric acid (PLSO.).  As discussed in 3.6.2.2.1  (Neutral Buffered



Potassium Iodide Method), these scrubbers convert  a portion of the



ambient NO to NO-, necessitating an additional correction factor.



Despite these drawbacks, CrO, scrubbers are the most generally used for



removing S02 interference, and they are particularly useful during



periods of high SO- concentration.  (When S02 levels are  less that  20%



of the NO concentration, use of this filter is not recommended.)



     The contribution of nitrogen dioxide to the oxidant  reading is



determined by measuring the instrument response to a known stream of



N0? and concurrently analyzing for NO,, in the atmosphere.  The appro-



priate subtraction can then be made to correct for N0~ interference.
                     r
                 MAGENT 5TOR.AG-E
                  A&tNT ST

                  TWT. KIJ
          Figure 3.9.  Schematic of colorimetric oxidant analyzer


                                      94

-------
     Disadvantages of colorimetric oxidant analyzers are need for rigid



maintenance including changing of reagent, carbon column, pH adjustment,



lubrication of moving parts (pumps) and leak checks.  Other disadvan-



tages are sensitivity of flow systems, non-specificity and fragility of



components.



3.6.1.3.2  Amperometric Analyzers--Amperometric analyzers measure the



current necessary to maintain halogen concentration at a fixed level,



the current being proportional to the amount of absorbed reactant.



Analyzers operating on this principle are often referred to as "coulo-



metric" analyzers.  In coulometry, the quantity of electons necessary



to oxidize or reduce a substance is measured.  Because it is the cur-



rent and not the charge which is measured, "coulometric" analyzers are



more properly called amperometric analyzers.



     Oxidant amperometric analyzers operate on the principal that 0^ and



other atmospheric oxidants in an air sample react with iodide ions in



the sensing reagent to produce iodine which forms the tri-iodide ion



(I,).  The tri-iodide ion in turn is electrically converted back into



iodide ions through cathodic reduction using either an electrolytic



(Brewer or Schulze) cell or a galvanic  (Hersch) cell.



3.6.1.3.3  Electrolytic Analyzers--For about fifteen years Mast Devel-



opment Company has sold an 0, analyzer with Brewer-type cell.  It is



portable, can be operated off batteries or line voltage and costs about



$1,000.  Hundreds have been sold.



     In the Mast 0, analyzer an iodine-containing electrolyte is used.



A potential (approximately 0.25 V) is applied between electrodes.  The



initial current polarizes the cathode with a layer of hydrogen  (l-
                                95

-------
which prevents further current flow.  Tri-iodide ion produced by the



reaction between oxidant or ozone and KI immediately reacts with the H~



to depolarize the cathode.  Consumption of hydrogen causes flow of



polarization current to replace the reacted hydrogen and reestablish



polarization.



     The polarization current is proportional to the tri-iodide ion con-



centration according to the configuration of the electrodes.  The reac-



tion at the electrodes gives an electron yield less than 1001 of



theoretical and must therefore be calibrated with a known ozone source.



This technique is now used in the Intertech, Mast and Welsbach ampero-



metric analyzers.



3.6.1.3.4  Chemiluminescent Analyzers--In the early 1960rs a detector



based on measurement of Chemiluminescent emissions from the reaction



between 0, and Rhodamine-B was constructed by Regener.  The concept of



chemiluminescence for 0, detection went through a number of stages as



variants were explored.  Nederbragt did initial work on a gas-phase



analyzer which is the choice approach based  on number of analyzers in



use (over five hundred) and manufacturer numbering about 10.  It is also



the reference method designated in Federal Register, 36^ (89), April 30,



1971.



     The reaction between ozone and ethylene yields Chemiluminescent



emission in the 300 to 600 nm region with maximum intensity at 435 nm,



intensity being proportional to the ozone concentration.  Figure 3.10 is



a diagram of a typical gas-phase (ozone-ethylene) Chemiluminescent ozone



analyzer.   The detector resonds linearly to ozone concentrations from



0.002 to above 5 ppm; there are no apparent interferences.  Small






                                    96

-------
  improvements in sensitivity result from cooling  the phototubes used to

  detect emitted light or by increasing the ethylene flow rate.

       Using pressurized cylinders of ethylene  is  prohibited in many

  locations by OSHA regulations and local fire  codes.   Using the cylin-

  der may require construction of an external housing that is well-

  ventilated, adequately secured and protected  from flame or excessive

  heat, with flow-limiting orifices at the cylinder outlet.   Leak-free

  corrections are essential.  An alternative is a  blend of ethylene and

  inert gas that is flammable but not explosive.   Requirements for stor-

  age and use of this gas are less stringent, and satisfactory analyzers

  are available.
       C2H4
                                      QUARTZ.
                                      WINDOW
SAMPLE
INLET
^°
 ;v'*

 •ft
CONTROLLER
\rU,
CTION '
MBER J
/
', PM



— runcn
i— SUPPLY
N

                                                           AMP
                        METER
                                                                       RECORDER
                                                  THERMO-ELEC.
                                                    COOLER
       Figure  3.10.  Automated gas phase chemiluminescent ozone monitor



       Chemiluminescent methods for monitoring ozone other than the 0.,:CJ-L

  reaction are now available commercially.   Philip Eindhoven of the Nether-

  lands has developed an ozone monitor  based on the classical Rhodamine-B

  ozone reaction.  His system is automatically calibrated one an hour due
                                    97

-------
to the change in response characteristic of the Rhodamine disc used.



This monitor is being sold in Europe but not yet in the U.S.



3.6.1.3.5  Ultraviolet Absorption Ozone Analyzer--Dasibi, Inc. sells an



0, analyzer that continuously monitors CL in the air with parts per mil-



lion readable directly from the front panel.  An analog output is avail-



able for continuous strip-chart recording, as well as a binary-coded-



decimal (BCD) output for direct interfacing with a computer or a printer.



It is sensitive to 0.01 ppm 0, and reads to 9.99 ppm.  A schematic of the




instrument is shown in Figure 3.11.  This unit employs modern electronic



circuitry, including a stabilized mercury W light source, dual detec-



tors, digital electronics, and signal integration.  The sampled air is



pumped into the instrument at a flow rate of approximately 1 liter/



minute.  The sample stream alternately bypasses and then passes through



the catalytic converter, which removes (X selectively.  This air sample,



stripped of CL, enters the absorption cell in which the photodetector
             O


measures the amount of UV light transmitted through the cell, measured



at 253.7 nm.  The result is stored as the reference measurement and



includes effects due to other pollutants present in the sample stream.



The next cycle brings the air sample directly into the absorption cell.



The detector now measures attenuated ultraviolet light due to 0, in the



sample stream and a subtraction is made from the stored reference mea-



surement.   The difference is ozone concentration.



     The ultraviolet absorption technique has the advantage over chemi-



luminescence that it requires no reagent; it has the disadvantage that



very high concentrations of certain hydrocarbons or mercury vapor may



be interferences.
                                     98

-------
3.6.2  Stationary Sources



     Since publication of the "Air Quality Criteria for Particulate



Matter" in January, 1969, EPA has published (December 23, 1971,



Federal Register) methods for finding the rate of particulate emission



from certain stationary sources.    Methods one through four are for



obtaining the number and location of sampling points, stack velocity,



stack gas molecular weight and stack gas moisture.  Method five is for



obtaining the mass concentration of particulate emissions.  Using these



five methods, the emission rate of the source being tested can be



determined.



     These methods were prescribed for compliance testing of sources



covered under the Standards of Performance for New Stationary Sources



as described in the Clean Air Act.  The first sources covered were



steam generators, Portland Cement plants and incinerators.  Standards



for particulate emissions from a second group of six industries were



promulgated in the FR March 3, 1974.



     In addition to use in measuring particulate emissions from new



sources, Method five has been widely used on existing sources and is



the method used by many state and local agencies.  When the sampling



conditions are met as described in the Federal Register, it is appli-



cable to most types of stationary sources, although special problems



will require adaptation or use of an alternate procedure.



     Evidence shows excellent analyzer repeatability.  Some EPA



scientists suggest that an accurately calibrated analyzer can be taken



into the field with an ozone; generator and used as a secondary standard



to obtain a multipoint (typically seven) calibration curves for field
                                  99

-------
analyzers.  Returned to the laboratory, the Dasibi analyzer calibration



could be reestablished.  It is contended this would be an excellent way



to maintain the accuracy of field CL analyzers.
                 CAl SAMPU INlfT
     Figure 3.11.  Ultraviolet absorption ozone analyzer





     EPA is working on UV spectrophotometric methods for absolute



determination of ozone generator output and preliminary results sug-



gest it may be possible to make such determinations in the 50 ppb ± 10%



range with relatively inexpensive instruments.



     Several other methods are being or have been studied as alternate



methods for stationary source particulate emission measurement.  In-



stack filter methods are promising.  The current ASTM method uses an


                                                           12
in-stack Alundum thimble to collect the particulate matter.    As with



most methods, in-stack methods are not suited for all sources.



     Several instrumental methods are available also, with instruments



based on beta radiation attenuation (beta gauges) now being produced



commercially.  While the beta gauge can yield accurate measurements,
                                    100

-------
its use, like other extractive methods, depends on obtaining a repre-



sentative sample in the measuring zone.  This is a difficult problem.



     To overcome errors inherent in the use of current sampling equip-



ment, improved in-stack devices and non-extractive optical devices are



being developed.  Reviewing the state of the art of instrumental methods



for particulate emissions for combustion sources has been done on an EPA



contract.



     Besides determining total mass, measure of particle size distribu-



tion is of major importance for future regulations on fine particle



emission.  Most size measurements are now made by inertial sizing



devices.  An EPA study of most of the commercially available devices



was made by contract.    Other approaches to size distribution measure-



ment including optical methods are being studied.  Volume III of



reference four describes many of these methods, as does the NERC/RTP



briefing report on fine suspended particulate matter.



     Method eight published In the December 23, 1971, FR measures SO^



and H-SO* from a sulfuric acid plant.  Except for this method and



methods published for hazardous air pollutants mercury and beryllium,



no methods to determine composition of particulates emitted from sta-



tionary sources have been prescribed.  For data on chemical composition,



particulate matter collected by either Method five or other methods  is



generally analyzed by standard methods, as for sulfates and nitrates.



No new approaches for these two not included in the NERC/RTP task force


              ., ,,  16,17
report are available.



     Presently, x-ray fluorescence  (XRF) spectroscopy is the most



attractive method for routine multielemental analysis of particulate
                                 101

-------
matter, as shown in a study carried out by EPA interagency agreement


                                                         18
with the Naval Research Laboratory.  A first phase report   described



the laboratory evaluation of XRF for elemental analysis of filter-


                                               19
deposited particulate material.  A later report   demonstrated the



usefulness of simultaneous multispectrometer instruments available from



x-ray equipment manufacturers, for large-scale routine analysis.  More



recently a small, low-powered portable XRF analyzer was designed and a



prototype instrument built to show applicability of the x-ray technique



to on-site use.



3.7  SUSPENDED PARTICULATE



     Current research is advancing our understanding of the sources,



properties, chemical composition and dynamics of the atmospheric aero-



sol or total suspended particulate matter.  Progress has been made in



establishing multimodal distribution of the atmospheric aerosol, the



typical observation of a biomodal mass-size distribution and differences



in chemical composition, identification of organic material as a major



primary and secondary component of fine particulate matter, and devel-



opment of improved instruments and techniques for measuring aerosol



parameters.



3.7.1  Calibration



     For suspended particulate, the concept of calibration needs special



attention.  Methods in air pollution are generally designed to be spe-



cific for an element, compounds or class of compounds.   All substances



in the air above a certain diameter may be considered,  for some purposes,



as suspended particulate.  There are many devices for collecting air-



borne particulate.  The mass, density, surface area, electrical charge
                                    102

-------
and shape of a particulate are properties that may determine sample
design characteristics and collection efficiency.  Operating princi-
ples of remote sensing devices may depend on color, refractive index,
opacity, light scattering, or even attenuation of ultrasonic fre-
quencies.  Calibration techniques may vary with the type of instru-
mentation, but will usually involve the generation of aerosols or
participates of known physical and chemical properties.  For example,
polystyrene latex spheres of known diameters are available and useful
for calibration of particle size analyzers.
3.7.2  Ambient Air
3.7.2.1  Impactor Measurements of Size Distribution--EPA has completed
tests on impactors showing that apparent size distribution can be
seriously affected by the type collection surface used.  A Cascade
impactor with silicone grease-coated-aluminum collection surface was
compared with an identical Cascade impactor with either glass fiber or
clean aluminum collection surfaces.  For the greased collection sur-
face, it was seen that apparent mass median diameter is decreased by
factors two to three, when clean aluminum and glass fiber collections
are used respectively.  Serious particle-bounce errors can occur in
conventional impactors when a greased collection surface is not used.
3.7.2.2  Virtual Impactor Optimization--To eliminate particle bounce
errors associated with conventional impactors, in a virtual impactor
size fractionation is accomplished aerodynamically without the aid of
an impaction surface.  In this device, particles are collected by
filtration downstream of the fractionator.  The Lawrence Berkeley
Laboratory has studied loss mechanisms for the virtual impactor and
and developed methods to lower losses for particles smaller than 20 ym.

                                  103

-------
3.7.2.3  Automated Dichotomous Samplers--Twelve automated samplers to



separately collect particles in the 0-2 and 2-20 ym size range have been



fabricated and will be operated in St. Louis beginning November 15,



1974.  The devices use a virtual impactor for size fractionation.  Auto-



mated sample changing allows collection of up to 35 aerosol samples for



sampling intervals adjustable from two to 48 hours.



3.7.2.4  Manual Dichotomous Samplers--A sampler for collecting parti-



cles for 24-hour intervals in the 0-3.5 and 3.5-20 inn range is being



developed for health effect measurements and routine monitoring.  A



virtual impactor is used for size fractionation.  A prototype is being



tested.  An improved device with flow rate regulators is under develop-



ment and will be tested in 1975.



3.7.2.5  Beta Gauges--A number of beta gauge devices for measuring par-



ticulate mass collected on a filter are presently being tested.  These


                                           14
devices consist primarily of a radioactive   C source and a solid state



detector.  Although the beta gauge method is not necessarily more accu-



rate than a gravimetric method, it is much better adapted for low-cost



automated and semicontinuous measurements.  Documentation of field



accuracy will become available in 1975.



3.7.2.6  X-Ray Fluorescence Analysis--X-ray fluorescence spectrometers



are used routinely to determine concentrations of elements with atomic



numbers above 19.  Procedures for obtaining quantitative analysis for



elements with atomic numbers between 13 and 19 are being developed.



Good sensitivity for sulfur is obtained using both energy dispersive



and wavelength dispersive techniques.   More than ten laboratories were



actively using this technique during 1974.
                                     104

-------
3.7.2.7  Measurement of Visibility Reduction due to Aerosols- -Recent



studies show good agreement between human observer and time averaged



integrating nephelometer measurements of visibility.  However, gravi-



metric measurement of total suspended and fine particulates we find



to be only a fair measure of visibility.



3.8  SULFUR OXIDES



3.8.1  Ambient Air



3.8.1.1  Sulfur Dioxide--A new technique to measure SCL has been devel-



oped by the National Bureau of Standards based on measuring the



fluorescence of SCL induced by exposing SCL to ultraviolet monochromatic



radiation.  The fluorescence emission is a linear function of S0? con-
                                                                LJ


centration.  Systems to measure both ambient and source concentrations



of SCL using this principle are now commercially available.  This system



is virtually flow insensitive, a major advantage over other S0? monitor-
                                                              LJ


ing principles.



     Under EPA sponsorship an ultra-sensitive flame photometric detector



has been developed to measure 0.1 ppb of SCL.  The system uses a pair of



rare earth optical filters which measures the ratio of emission of the



SCL luminescence to background flame signal.  This ratio measurement



improves sensitivity and specificity of the flame photometric detector



for SCL.  The detector has applications in areas where background con-




centrations of SCL are needed.



3.8.1.2  Sulfates- -Various classical colorimetric and turbidimetric



methods of measuring sulfates are being compared to measurements of



total sulfur by x-ray fluorescence  (XRF).  Each study is intended to



establish the limitations of classical methods for sulfates and to
                                 105

-------
yield data on the applicability of XRF methods for sulfate analysis of



particles collected from the atmosphere.



3.8.1.3  Sulfuric Acid--An automated instrument has recently been devel-



oped which collects sulfuric acid from ambient air on an inert teflon



surface.  Sulfuric acid is separated from other particulates by volati-



lizing it with warm, dry air.  The sulfuric acid volatilized is deter-



mined with a flame photometric detector sensitive to sulfur-containing



compounds.  The system is capable of measuring 0.1 ugm/m  of H~SO,.  EPA



is working to characterize and improve the instrument's performance for



use as a routine field monitor.



3.8.2  Stationary Sources



     The SO- compliance test method (Method six, Federal Register,



December 23, 1971) involves gas sample extraction from a source and



measurement by the barium thorin titration procedure.



     In addition to compliance testing for SCL the December 23, 1971,



FR requires continuous monitoring for the pollutant gas.  Proposed



emission monitoring and performance testing requirements for SO- (NO ,
                                                               i*    jC


CO and H-S) continuous monitoring systems were published in the Septem-



ber 11, 1974, Federal Register.  The approach taken by EPA requires



each source owner or operator to demonstrate the capability of continu-



ous monitoring systems to meet the proposed performance specifications



for his particular source.



     Research since 1972 into new analytical techniques for S0? source



measurement has been active.  The UV fluorescence technique for source



and ambient SO-? levels has been demonstrated and is now available in a




commercial instrument system.





                                   106

-------
     The feasibility of using a PbSnTe-diode laser system for SO- source


measurements has also been shown.  A present liability of the technique


for field use is the necessity for liquid helium temperature operation.

                                            o
     Under an EPA contract Burch and Gryvnak  have applied gas filter


correlation techniques for in-stack measurement of S0_, NO, HF and


HC1.  Field evaluation is being done by EPA personnel.


     The Barringer correlation spectrometer system for the remote detec-


tion of S0~ was evaluated and appears to have serious drawbacks and


seems unusable for enforcement or research.


     The general technique of gas filter correlation appears quite


promising for the remote sensing of gaseous pollutants.  An EPA con-


tract has developed a remote sensor for S0~.  The sensor is relatively


small (25 Ibs., 1 cu. ft.), simple to operate and field usable with


battery operation.  It has undergone field testing at a California oil-


fired power plant and a North Carolina coal-fired power plant.  Com-


parative SO- measurements for Method six, a continuous in-stack monitor

and the gfc remote sensor gave relatively good (±15%) agreement among


the three techniques.

3.8.3  Mobile Sources

     Sulfur in fuel is normally determined by one of several methods


including x-ray (ASTM P-2622), lamp (ASTM P-1266) , and bomb (ASTM P-129).


MLcro coulimetric and x-ray fluorescence methods have also been employed.


The latter technique yields quick qualitative and quantitative informa-


tion, but is difficult to use with leaded fuels because of peak overlaps


of lead and sulfur.  High resolution x-ray fluorescence instrument appears


to have overcome this difficulty.
                               107

-------
     As yet, there is no standard procedure for sampling and analyzing



sulfur oxide emissions from mobile sources.  Most earlier data on sul-



fur oxide emissions were obtained using modifications of the Federal



testing procedure for sulfuric acid mist and sulfur dioxide emissions



from stationary sources.  In most cases raw exhaust is sampled by



inserting a sample probe anywhere between the exhaust manifold and the



tail pipe.  The exhaust sample is drawn from the probe through a heated



sample line at a constant flow rate into a series of impingers contain-



ing 801 isopropanol solution and 31 solution of hydrogen peroxide to



selectively collect SO, and SCL respectively.  The S02 is oxidized to



sulfate and is retained as such in the hydrogen peroxide solution.  The



sulfate content of the impingers is determined for SO., and S02 by barium



perchlorate or barium chloride titration using thorin as indiator;



variation involves insertion before the impingers of a controlled con-



densation coil with a fritted filter at the end.  By controlling the



condenser temperature between 60 to 90°C, sulfuric acid can. be removed



by condensation and filtration.



     Another sampling technique which has gained popularity lately is



the dilution tunnel method.  Raw exhaust from the tail pipe is fed into



a dilution tunnel where it is mixed with a stream of clean air and drawn



through the tunnel by a pump at the opposite end.  A nominal ten-to-one



dilution is normally attained.  The temperature of the exhaust drops



during expansion and dilution with clean air in the tunnel, resulting



in formation of sulfuric acid mist.  Sample probes protrude into the



air stream at the far end of the tunnel and sample the air-exhaust



mixture in the tube proportionally and isokinetically.  Particulates,





                                  108

-------
including H-SO. aerosols, are trapped on the filter in the sample probe.
           h  T-


SO- is collected by absorption in dilute aqueous sodium tetrachloro-



mercurate and determined by the standard West-Gaeke pararosanilive



method.




     In recent months, instrumentation for in-Line monitoring of SCL has



become commercially available.  The principle is based on fluorescence



of SO.-, when pulsed irradiated with light of a certain wavelength.



Original application is in-stack monitoring of S0? where the concentra-



tion is in the hundreds ppm range, but adaptation to SO,,-monitoring in



mobile exhaust is a promising possibility.



     The analysis of SO- by oxidation to sulfate and titration with



barium ion in the presence of a suitable color indicator or by the West-



Gaeke pararosanilive technique is straightforward.  Sampling and collec-



tion techniques appear to be a major source of problems in the overall



analytical scheme.  Concentration of S02 in auto exhaust is high enough



that titratable quantities can be collected within a reasonable time



frame.



     Analysis of SO, on soluble sulfates in automobile exhaust presents



a much harder problem, especially for cars not equipped with catalyst.



The amount of soluble sulfate varies from almost nothing to a maximum



of about 2% of the total sulfur burned.  In a simulated urban driving



cycle, the amount of sulfate particulate sample collected on a 47 mm



filter by sampling tunnel diluted exhaust at flow rate of 1 cfm may



total no more than 10 micrograms as SO..  This amount is much lower than



the sulfate background of some filter collection media, especially glass



fiber filter.  Compounding the problem is the fact that this amount is
                                109

-------
usually beyond the detection limit of most existing analytical methods



of sulfate.



     The choice of filter media for particulate sulfate is quite criti-



cal at low concentrations.  At high concentrations, the media background



may be reduced to negligible levels by proper dilution.  Even supposedly



low sulfate background glass fiber filters were found to contain greater



than 30 micrograms per 47 mm diameter filter.



     Fluoropore, a Teflon filter with polyethylene backing, had almost



zero sulfate background.  It is available in large enough nominal pore



size to permit sampling at a reasonable flow rate without excessive



pressure drop and is inert to most solvents.  One disadvantage, however,



is that only solvents with low surface tension, such as isopropanol or



methyl alcohol, or mixtures of these with water, can be used to extract



the samples from the filter.  The filter also curls up after removal



from the holder, thus presenting problems for mounting the filters on



cassettes to do x-ray fluorescence analysis.



     Nucleopore, a polycarbonate filter, is another good candidate for



filter medium.  It has low sulfate background and remains relatively



smooth after removal from the filter holder.  The only drawback for



mobile source sampling is an excessively high pressure drop during



sampling.



     Most analytical methods for soluble sulfates involve so much sam-



ple handling--extraction, rinsing, evaporation and concentration, pH



adjustment--that the possibility of sample losses during a handling



process is increased.  X-ray fluorescence would obviate most of the



handling steps, but has a rather stringent requirement for filter
                                  110

-------
samples.  In most cases only a certain area of the filter is examined



and the deposits are assumed to be uniform.  Filters must be reasonably



flat and free from wrinkles.  Preliminary analysis of K?SO. aerosols



generated in a bag and collected both on fluoropore and Nucleopore fil-



ters show better correlation between x-ray and gravimetric measurements



with Nucleopore filters than with Fluoroposre filters.  At high sulfate



loadings, x-ray fluorescence gave lower values than gravimetric



measurements.



     The collection of S0_ in exhaust via absorption in 80% isopropanol



is reported to result in high sulfate values.  Apparently, some S0^> is



retained, partly oxidized to SO., or the resulting sulfite responds



quantitatively to barium ion tritration.  This problem becomes acute



when baseline data are being generated with low sulfur fuel and non-



catalyst cars.



     The Mobile Source Measurements Research Section has developed an



automated version of the barium chloranilate method for sulfates appli-



cable to soluble particulate sulfate from cars run on non-leaded fuels.



It is based on the reaction of sulfate ions with the solid barium salt



of chloranilic acid.  The reaction precipitates out BaSO. and releases



highly UV nm and related to sulfate concentration.  The sensitivity of



the method is greatly enheinced by conducting the reaction in a medium



less polar than water, such as ethanol-water or isopropanol-water mix-



tures, where the solubilities of both BaSO. and barium chloranilate are



reduced.  Sensitivity of the method is better than 0.5 yg SO^/ml of the



extracting solution.



     Exhaust samples diluted in a tunnel are collected on Fluoropore



filters, extracted with 60/40 isopropanol/water mixture and injected





                                111

-------
into a liquid chromatographic system.  The sulfate sample is fed through



a strong cation exchange resin in hydrogen form to remove cationic



interference and then through a column of barium chloranilate where



color reaction takes place.  BaSO, is retained in the column and the



colored species is measured with a UV-monitor at 310 nm.  Through-put



time from initial sample injection is less than four minutes and sensi-



tivity is better than 0.5 yg SO, per ml of extracting solution.  Preci-



sion obtained in early work was about ±.05 yg SCK~/ml.  There are ionic



interferences from such anions as cl , Br, F  and PO.H.  For exhause



samples from cars run on non-leaded fuels, ionic interference is minimal.



3.9  ASBESTOS



3.9.1  Stationary Sources



     The present NESHAP regulation for asbestos, based on prescribed



control practices rather than maximum permissible emission levels, is



partly the result of inadequate methods for measuring airborne asbestos



concentrations.  It is generally agreed that more satifactory asbestos



measurement methods than now exist are need both for  (a) rapid routine



screening purposes (to detect sources, measure ambient levels or imple-



ment an emissions standard), and for (b) research applications (e.g.



in support of health effects studies) where maximal information on



fiber count and size distribution are required.  A new x-ray diffrac-



tion technique is being developed as a rap d screening procedure though



an interagency agreement with the Naval Research Laboratory.  For



research applications, however, and possibly also as a reference pro-



cedure, it is likely that one or more of the current electron micro-



scope (EM) techniques will be used for an indefinite future period.
                                   112

-------
     Problems associated with EM methods are well known.  The proced-



ures are tedious, expensive (about $250 per sample) and time-consuming



(about one man-day or more per sample).  Each of the steps in an EM



assay, e.g. sample acquisition and treatment, specimen preparation,



morphological and confirmatory identification, fiber counting and siz-



ing, etc., can be the source of error.  A chaotic situation exists



because there are probably a dozen EM procedures in use that differ



with respect to one or more: of the steps cited above and there has been



no attempt to establish the accuracy or precision of the various methods.



There is an urgent need to establish a single EM procedure as acceptable



standard analytical technique so that valid comparisons can be made of



data obtained by different laboratories.



     The feasibility of a new x-ray diffraction (XKD) technique as a



rapid screening method has been shown.  The approach consists of



measurements in a specially-designed broad-beam diffractometer after



samples have been pretreated to align asbestos fibers.  Measurements



with standard chrysotile samples indicate a detection limit of about



0.3 yg for a 500-second measurement time.  During FY 1975 a prototype



XRD asbestos analyzer based on this principle will be built for



delivery to  ERC/RTP and testing with field samples by the Chemistry



and Physics Laboratory.



3.10  BERYLLIUM



     Methods 103 and 104 for measuring beryllium emissions from sta-


                                                      20
tionary sources are described in the Federal Register.    These methods



are applicable to all tests for beryllium required under Part 61,



National Emission Standards for Hazardous Air Pollutants.  Presently,
                                113

-------
Part 61, Subparts C and D, requires control of beryllium emissions from



the following beryllium-handling activities:  extract and ceramic plants,



foundries, incinerators, propellant plants, machine shops and rocket


                                                    21
motor test sites.  A background information document   issued with the



regulations describes the development of standards.  Test methods require



a representative portion of stack gases to be removed from the stack and



filtered, with filtered material analyzed for beryllium content.



     Developing instrumentation to continuously monitor particulate mat-



ter, including beryllium, was conducted under contract.  The principal



objectives applied to beryllium emissions were two:  (1) to prepare a



document on the status of the problem of continuous monitoring and (2)



to produce a prototype monitoring system.



     The study identified various methods available, but concluded that



no one method is applicable to the concentrations and types of beryllium


                                                                    22
particulates existing in stack gases today.  The work of Webb, et al.,



suggests a continuous monitor based on emission spectroscopic measure-



ments of a continu us flowing (40 1/min.) sample stream of stack gases.



Such an emission spectroscopic measurement can provide a means of moni-



toring beryllium or most other metallic elements and some non-metals



simultaneously.  The technique has the necessary (a) selectivity, (b)



speed (30 sec.) for rapid repeated analyses, and (c) sensitivity


        3                          9          12
( 1 yg/m ).   A method based on the  Be(a,n,y)   C reaction can be used



for measuring beryllium continuously in atmospheres or stack gas emis-



sions containing principally beryllium or its compounds down to 1 yg/m ,



but cannot be used where other particulate matter is present in large



amounts.  A prototype proved not feasible at this time due interfering



particulate matter.


                                    114

-------
3.11  MERCURY



     The National Emission Standard for mercury promulgated in April,



1973, is applicable to stationary sources processing mercury ore and



those using mercury chlor-alkali cells to produce chlorine and alkali



metal hydroxide.  Reasons for selecting these soures for regulation



and excluding other mercury sources are stated in the background docu-


                                                      21
ment issued with the first group of NESHAPS standards.    The standards,



stack sampling procedures and reference measurement methods are pre-


                                20
scribed in the Federal Register.    The reference methods are manual



procedures based on isokinetic collection of particulate and gaseous



emissions in acidic iodine monochloride solutions.  Method 101 is for



sampling air streams and Method 102, for hydrogen streams encountered in



chlor-alkali plants.



     Caution must be exercised in applying this method to other than



regulated sources.  For example, if the sampling stream contains high



sulfur dioxide concentr tions, such as are present in fossil fuel power



plants and non-ferrous smelters, the efficiency of collection is ques-



tionable du  to reaction of the SO- with IC1 Impinger solution.  Sulfur



dioxide scrubbers such as sodium carbonate solutions have been placed



in the front of the sampling train and are reported to overcome this


   ,,   23,24
problem.  '
                                115

-------
     Optical instrumentation has been the most universal approach in



mercury analysis and monitoring.  Optical techniques utilize the strong



ultraviolet absorbance of mercury vapor at 253.7 nra.  Since mercury is



an atomic species, it absorbs and emits energy at the same frequency.



The extinction coefficient for mercury is approximately 4x10 .0.  While



the technique is not specific for mercury, its strong absorpiton allows



mercury to be determined in the presence of 100-1000 times the concen-



tration of weakly-absorbing species.  (This is not enough for non-ferrous



smelters and power plants which emit mercury in low concentrations in the



presence of high levels of sulfur dioxide.)



     UV analyzers are available commercially in single beam, dual wave-



length and dual beam configurations.  To increase the rejection ratio



for interfer nces and make the instruments more specific for mercury,



one approach uses Zeeman splitting of the mercury resonance line while



another makes uses pressure broadening of the 253.7 rnn mercury line.  A



third approach to improve specificity involves isolation of mercury by



absorption on a noble metal (silver or gold) collector and subsequent



therman desorption and analysis.



     The laboratory phase of the EPA-funded study included development



of a mercury generation system, measurement of interferences and evalua-



tion of pyrolyzers to decompose hydrocarbons and convert mercuric com-



pounds to elemental mercury and evaluation of scrubbers to remove sulfur



dioxide.  These data were obtained for each instrument:  accuracy, pre-



cision, sensitivity, stability, interferences, reliability and sample



treatment required.  The laboratory test program was followed by field



tests at three mercury sources:  (1) secondary processing of mercury;



(2) chlor-alkali production; and (3) non-ferrous (zinc) smelting.




                                  116

-------
     Precision and accuracy of monitoring instruments is greatly



affected by the sampling interface system and its ability to trans-



port a representative sample.  Mercury concentrations sampled in the



field ranged as high as 40 mg per cubic meter, requiring a dilution



system capable of controlling mercury concentration in the range of



the instruments (normally )-1.0 mg per cubic meter).  The system used



in the field performed less than adequately to satisfy these require-



ments, but sample treatment for interfering species and conversion of



participate and organomercury compounds to elemental mercury was



accomplished successfully.  Laboratory results indicated that a sodium



carbonate scrubber absorbed sulfur dioxide without removing mercury,



     All species of mercury tested were converted to elemental mercury



by pyrolysis in a catalytic converter.  Hydrogen stream test results



showed that mercury species, other than elemental mercury were present



so that total mercury monitoring of chlor-alkali hydrogen lines would



require some means of gas stream pyrolysis to convert particulate



mercury or organomercury species to elemental form.



     It was found that available mercury-measuring instrumentation can



be adapted to measure total, mercury emissions from certain stationary



sources, particularly chlor-alkali plants.  The transporting and con-



ditioning of the sample poses difficulties requiring more research.



The need for a dynamic dilution system to condition high-level mercury



emissions sets the requirement for a fairly sophisticated automatic



interfacing subsystem.



3.12  METHODS STANDARDIZATION AND PERFORMANCE EVALUATION
                                117

-------
3.12.1  General Discussion



     EPA is working to standardize reference methods for industrial air



pollutants in ambient air and stationary and mobile sources.  The pro-



gram involves in-house methods evaluation and ruggedness testing, method



inter-relativity studies and collaborative testing.  All criteria pol-



lutants are under study, and some results have been published for all



six criteria pollutants.



3.12.2  Particulates



     After reference method was tested by 12 laboratories, statistical


                                      25
analysis of the resulting data showed:



     1)  Relative standard deviation for single analyst variation is



3.0%.



     2)  Relative standard deviation for multilaboratory variation is



3.71.



     3)  Minimum detectable amount of particulate matter is 3 mg,



equivalent to 1-2 yg/m  for a 24-hour sample.



3.12.3  Sulfur Dioxide



     The 30-minute sampling option prescribed in the reference method



was collaboratively tested by 14 laboratories and a statistical analysis

                   o/r

of that data showed:



     1)  Standard deviation for within-laboratory variation varies


                                        3                   3
linearly with concentration from 15 yg/m  at zero to 36 yg/m  at



1000 yg/m3.



     2)  Standard deviation for between-laboratory variation varies



linearly with concentration from 29 yg/m"  at zero to 70 yg/m  at



1000 yg/m3.
                                    118

-------
     3)  No systematic error,  bias or inaccuracy was detected and the



lower limit of detection is 25 yg/m  (951 confidence level).



     The 24-hour sampling option prescribed in the reference method was



collaboratively tested by four laboratories and a statistical analysis



of the data shows:



     1)  Standard deviation for within-laboratory variation varies



linearly with concentration from 18 yg/m  at 100 yg/m  to 51 yg/m  at



400 yg/m3.



     2)  Standard deviation for between-laboratory variation varies


                                        333
linearly with concentration from 37 yg/m  at 100 yg/m  to 104 yg/m  at



400 yg/m3.



     3)  The 24-hour sampling method apparently has a concentration-



dependent bias which becomes significant at the 95% confidence level



at about 400 yg/m .   Observed values tend to be lower than expected



SCL concentration levels.



     4)  Comparison of results from 30-minute and 24-hour sampling



options shows the 24-hour procedure to be more precise than the 30-



minute procedure.  However,, these differences are based on tests of



differing experimental design.  Although accepted statistical tech-



niques were used to process the data, the exact degree of improved



precision is uncertain.



3.12.4  Carbon Monoxide



     The reference method was collaboratively tested by 16 labora-


                                                   28
tories and statistical analysis of the data showed:



     1)  Standard deviation for within-laboratory variation is



0.57 mg/m3 (1 ppm CO equals 1.15 mg/m  CO).
                                119

-------
     2)  Standard deviation for between laboratory variation varies non-



linearly with concentration with a minimum of 0.85 mg/m  at 20 mg/m



and ranges as high as 1.54 mg/m  in the concentration range of zero to



60 mg/m .



     3)  The minimum detectable limit is 0.3 mg/m .



3.12.5  Nitrogen Dioxide



     Evaluation shows the sodium arsenite manual procedure for measure-



ment of ambient NCL has a high, constant collection efficiency of 82%


                                3     29
over its range of 20 to 750 yg/m  NO,,.    The method is insensitive to



normal variations in orifice bubbler diameter, temperature of absorber



solution during sampling and concentration of sodium arsenite.  No and



CCL were confirmed as positive and negative interferents, respectively.



     Evaluation shows the TGS-ANSA manual procedure for ambient NCL has



a high, constant collection efficiency of 931 over its range of 20 to



700 Mg/m  NCL.    The method is insensitive to normal variations in time



between sample collection and analysis, storage conditions after sample



collection, flow rate, CCL concentration, sampling time and orifice



size.  The time interval between addition of the diazonium salt forming



reagent and the diazonium salt coupling reagent is critical and must be



carefully controlled.



     Evaluation shows the Triethanolamine (TEA) manual procedure for



ambient NCL has a constant collection efficiency over its range of 20



to 700 yg/m , both with and without added n-butanol using either frits



or restricted-orifice bubblers.    The collection efficiency using frits



is about 80%, while the efficiency drops to about 50% using restricted-



bubblers.  More work is not contemplated because other methods show more



promise for measurement of ambient NCL.




                                    120

-------
3.12.6  Stationary Sources



     EPA test methods promulgated for use in the determination of emis-



sion levels specified in the New Source Performance Standards were



collaboratively tested by four teams simultaneously sampling emissions



from a fossil fuel-fired steam generator.    Tested were Method seven



(Oxides of Nitrogen), Method six (Sulfur Dioxide) and Method five



(Particulates).   Conclusions derived from the data are:



     1)  Method seven (NO ).  Estimated within-laboratory standard
                         J\.


deviation is 6.6% of the mean of values measured and estimated between-



laboratory standard deviation is 9.51 of the mean of values measured.



Estimated minimum detectable limit is 5.33 x 10   Ib/scf.


                                                                 _y

     2)  Method six (S07).  The method is accurate below 300 x 10



Ib/scf, but shows significant negative bias in the range 300-500 x



10   Ib/scf.  Estimated within-laboratory standard deviation is 4.0%



of the mean of the values measured and estimated between-laboratory



standard deviation is 5.8% of the mean of values measured.  Estimated



minimum detectable limit is 3.16 x 10   Ib/scf.



     3)  Method five (Particulates).  Estimated within-laboratory stan-



dard deviation is 31.1% of the mean of values measured and estimated



between-laboratory standard deviation is 36.7% of the mean of values



measured.



     EPA test Method five (Particulates) was collaboratively tested at



a municipal incinerator by having four teams simultaneously sample



particulate emissions.    Estimated within-laboratory standard devia-



tion is 25.3% of the mean of the values measured and estimated between



laboratory standard deviation is 38.7% of the mean of measured values.
                                 121

-------
                                    34
     In tests at a nitric acid plant   estimated within-laboratory



standard deviation is 14.91 of the mean of measured values and esti-



mated between-laboratory standard deviation is 18.5% of the mean of



measured values.
                                    122

-------
                                REFERENCES
 1.   Standards of Performance for New Sources,  Environmental Protection
     Agency,  Federal Register,  3(5 (247)  24876-24895,  December 23,  1975;
     38 (111)  15406-15415,  June 11,  1974.

 2.   Requirements for Preparation, Adoption,  and Submittal of Implemen-
     tation Plans, Environmental Protection Agency,  Federal Register,  36_
     (158)  15486-15506,  August  14, 1971.

 3.   Emission Monitoring Requirements and Performance Testing Methods  for
     Stationary Sources, Environmental Protection Agency,  Federal
     Register, 39_ (177)  32852-32874, September  11, 1974.

 4.   Nader, J. S., F. Jaye, W.  Conner.  Performance Specifications for
     Stationary-Source Monitoring Systems for Gases and Visible Emissions.
     Environmental Protection Agency, EPA-650/2-72-013, January, 1974.

 5.   Snyder,  A. D., et al.   Instrumentation for the Determination  of
     Nitrogen Oxides Content of Stationary Source Emissions.  Vol. I and
     Vol.  II.   Monsanto  Contract No. EHSD 71-30.  NTIS PB  204-877  and
     NTIS  PB  209-190. January, 1972.

 6.   Dee,  L.  A., et al.   An Improved Manual Method for NO   Emission
     Measurement.  Environmental Protection Agency,  EPA-Rz-72-067,
     October,  1972.

 7.   McNulty,  J. J., J.  R.  Ehrenfeld, R.  L. Goldsmith, J.  F. McCoy.
     Investigation of Extractive Sampling Interface Parameters. Waiden
     Research Assoc., Interim Report Contract No. 68-02-0742, Environ-
     mental Protection Agency,  EPA-650/2-74-089, October,  1974.

 8.   Burch, D. E. and D. A. Gryvnak.  Infrared  Gas Filter  Correlation
     Instrument for In-Situ Measurement of Gaseous Pollutants.  Philco-
     Ford  Contract No. 68-02-0575.  Environmental Protection Agency,
     EPA-650/2-74-094, December, 1974.

 9.   PhiIco-Ford Corp.  Contract No. 68-02-0766.  Evaluation of a  Remote
     Passive  Technique Based on Gas  Filter Correlation Spectroscopy.

10.   Federal  Register, Vol. 36, No.  247,  Thursday, December 23, 1971.

11.   Federal  Register, Vol. 39, No.  47, Friday, March 8,  1974.

12.   ASTM Method D 2928, Annual Book of Standards, Part 23.

13.   Instrumentation for Measurement of Particulate Emissions from Com-
     bustion Sources. Vols. I, II,  III.   Reports under EPA Contract
     CPA 70-23 by Thermo-Systerns, Inc.  Vol.  IV EPA Report 650/2-73-022,
     1971.
                                 123

-------
REFERENCES (continued)
14.  Field Measurement of Particle Size Distribution with Inertial Siz-
     ing Devices, EPA Report 650/2-73-035 by Southern Research Institute.

15.  Problems Relating to Fine Suspended Particulates.   Briefing Report,
     Office of Research and Development, Environmental Protection Agency,
     September, 1972.

16.  Suspended Sulfates and Sulfuric Acid Aerosols.  Task Force Report,
     Environmental Protection Agency, Research Triangle Park, N.C.,
     October, 1972.

17.  Nitrates, Task Force Report, Environmental Protection Agency,
     Research Triangle Park, N.C., February, 1974.

18.  Development of X-Ray Fluorescence Spectroscopy for Elemental Analy-
     sis of Particulate Matter in the Atmosphere and in Source Emissions,
     EPA Report R2-72-063, submitted by Naval Research Laboratory,
     October, 1972.

19.  Development of X-Ray Fluorescence Spectroscopy in Elemental Analysis
     of Particulate Matter Phase II:  Evaluation of Commercial Multiple
     Crystal Spectrometer Instruments, EPA Report 650/2-73-006, submitted
     by Naval Research Laboratory, June, 1973.

20.  Environmental Protection Agency Regulations on National Emission
     Standards for Hazardous Air Pollutants.  Federal Register, Friday,
     April 6, 1973, Washington, D.C., Vol. 38, No. 66,  Part II, pages
     8845-8850.

21.  Background Information on Development of National Emission Standards
     for Hazardous Air Pollutants:  Asbestos, Beryllium, and Mercury,
     U.S. Environmental Protection Agency, Research Triangle Park, N.C.
     27711, Publication No. APTD-1503.

22.  Instrumentation for Monitoring Specific Particulate Substances in
     Stationary Source Emissions, U.S. Environmental Protection Agency,
     Office of Research and Development, Research Triangle Park, N.C.
     27711, Publication No. EPA-R-2-73-252.

23.  Statnick, R. M., D. K. Oestreich, and R. Steiber.   Sampling and
     Analysis of Mercury Vapor in Industrial Streams Containing Sulfur
     Dioxide.  Research Branch, Control Systems Laboratory, Environmental
     Protection Agency, Research Triangle Park, N.C.  (Presented at
     August, 1973 ACS Meeting in Chicago, Illinois.)

24.  Katzman, L, R. Lisk, and J. Ehrenfeld.  Evaluation of Instrumen-
     tation for Monitoring Total Mercury Emissions from Stationary
     Sources, Walden Research, Contract 68-02-0590, Environmental Pro-
     tection Agency Report EPA 650 12-74-039, June, 1974.

                                     124

-------
REFERENCES (continued)
25.  McKee, H. C., R. E. Childers,  and 0.  Saenz.    Southwest Research
     Institute.  Collaborative Study of Reference Method for the Deter-
     mination of Suspended Participates in the Atmosphere (High-Volume
     Method), PB 205-891.  June, 1971.

26.  McKee, H. C., R. E. Childers,  and 0.  Saenz.   Southwest Research
     Institute. Collaborative Study of Reference  Method for Deter-
     mination of Sulfur Dioxide in  the Atmosphere (Pararosaniline
     Method), PB 205-893.  September, 1971.

27.  Camann, D. E. and H.  C.  McKee.  Southwest Research Institute.
     Collaborative Study of Reference Method for  Determination of
     Sulfur Dioxide in the Atmosphere (Parorosaniline Method) .  EPA-
     650/4/74/027. December,  1973.

28.  McKee, H. C. and R. E,. Childers.  Southwest  Research Institute.
     Collaborative Study of Reference Method for  the Continuous Mea-
     surement of Carbon Monoxide in the Atmosphere (Non-Dispersive
     Infrared Spectrometry),  PB 211-265. May, 1972.

29.  Beard, M. E. and J. H. Margeson.  An Evaluation of the Arsenite
     Procedure for the Determination of Nitrogen  Dioxide in Ambient
     Air.  March, 1974.

30.  Fuerst, R. G. and J.  H.  Margeson.  An Evaluation of the TGS-ANSA
     Procedure for the Determination of Nitrogen  Dioxide in Ambient
     Air.  March, 1974.

31.  Ellis, E. C. and J. H. Margeson.  Evaluation of Triethanolamine
     Procedure for Determination of Nitrogen Dioxide in Ambient Air.
     EPA-650/4-74-031.  July, 1974.

32.  Hamil, H. F., D. E. Camann, and R. E. Thomas.  Southwest Research
     Institute.  The Collaborative  Study of EPA Methods Five,  Six, and
     Seven in Fossil Fuel-Fired Steam Generators  - Final Report.  EPA-
     650/4-74-013.  May, 1974.

33.  Hamil, H. F. and R. E. Thomas.  Southwest Research Institute.
     Collaborative Study of Method for the Determination of Particulate
     Matter Emissions from Stationary Sources (Municipal Incinerators).
     EPA-650/4-74-022.  July, 1974.

34.  Hamil, H. F. and R. E. Thomas.  Southwest Research Institute.
     Collaborative Study of Method for the Determination of Nitrogen
     Oxide Emissions from Stationary Sources (Nitric Acid Plants).
     EPA-650/4-74-028.  May, 1974.
                                125

-------
                       4.  ENVIRONMENTAL APPRAISAL





4.1  SOURCES



4.1.1  National Emissions Report



     National Emissions Reports estimate source emissions of those air



pollutants for which national standards have been promulgated.  The cri-



teria pollutants are particulates, sulfur oxides (SO ), nitrogen oxides
                                                    A.


(NO ), hydrocarbons (HC) and carbon monoxide (CO).  The reports are
   .A.


compiled from source information of the National Emissions Data System



(NEDS).  Compilations are presented for the nation, for individual states,



for Air Quality Control Regions (AQCRs) and for interstate AQCR portions.



This first annual report represents the best available indicators of



national emissions for the calendar year 1972.  The estimates reported



are based on source records in NEDS prior to receipt of the December 31,



1973, Semiannual Report.  Thus, the data are generally comparable to data



collected for the development of State Implementation Plans (SIPs), but



include revisions and updates whenever available.



     The NEDS point source file contains data on stationary facilities



that are individual emitters of relatively large quantities of one or



more air contaminants.  A point source is often arbitrarily considered



to be a facility in which the total annual emiss on of any one criteria



pollutant equals or exceeds 100 tons per year.  In general, individual



     emission points are defined as those annually emitting one or more



pollutants equal to or greater than 25 tons per year.  In certain instan-



ces, possible significant contributors, although emitters of lesser



annual amounts, are accorded point source designation.
                                     126

-------
     At the present time, NEDS contains data for approximately 75,000



emitting points in all states, the District of Columbia and three



territories.  Considerable information is stored for each point source;



for example, data on annual operating rates or activity levels (i.e.,



amount of fuel consumed by a boiler, or quantity of product produced by



an industrial process, etc.).  Information on existing air pollution



control devices and their efficiencies is also recorded.  These and



similar data are subsequently used in determinations of source emission



according to procedures outlined in the following discussion of the



NEDS emission factor file.



     Area sources are all other emissions sources not identified as



point sources.  For example, the NEDS area source file contains data



on all mobile sources (motor vehicles, aircraft, railroads, etc.),



small stationary sources, gind miscellaneous sources such as forest



fires, agricultural burning and retail gasoline marketing operations.



Unlike point sources, however, individual source data are not stored



in NEDS for each small source.  Rather, estimates of total emission



levels for specific categories of area sources are stored for



individual geographic area;;.



     A summary of emissions by category is given in Tables 4.1 and



4.2.  The data shown in Table 4.2 are not reflected in Table 4.1, so



amounts shown in Table 4.2 should be added to the grand total shown



in Table 4.1.
                                127

-------
CO

I
LO
WJ
i—i
Di
C "O
0 S
£ o
<3 §
c c
~- \
! * 'j
a. e
I If

3
=3
^ K
W5 O
S
•o
CU

Emission categories
c -o
•£ o
"I
in
. II
— X
z °

"5 x

VI
3
•0
0-
Emission categones
sss

y, ^ s


S8?i
—

2SS

oo t~- r^
VI -V t


Other
Commercial- Institutional
Diesel Fuel
Other
3 23
* r- »
I 35"
sll
s SB
* 06 ae
S 2»"
24,051,2
10,3*0.8
[ 13,670.3
9 ;s
e — oe
S 'R
? £S
£ SE£
- -
Gk\ND TOTAL
-AREA
-POINT
S— OOrJww^* rn f^ ? o — o~ — aciC^^c^S^S^ JQ ae o r^ — 5 — O'^'^Sf^acSSvPj.??'''^^ & S*»
t-^,, m "" PS?S°"'

^5"'- &r'f: ^oao.o^-'* g;5*_ "> * §1^^^^ P; « ? * S SS-^S^^^SS M "s^^.^
*n r* — £2^^*^"" ~


r^ri xsc^^— 	
5» p.|iSs5S§issllsl5Is5IISslilS<'~<='ls = iSse= RlIIi5il|aqli?fti5g!s=>0°s
S * 5 ~ " S ~ * ' " "
ss siisSlsSss^SsallslsSiKsSslsl?8'!^;!?!^! S53lSI5s?'S5ils5sls=5i°°
s.sss.ss.s;^ - ^2-"" ss-- - - ?*=- = - p?|s-- = '--f!- -" - =:

£ I| ' si ' ' ' i i
1. "•» -IN!' ' it I' 2 • i< g
|r I || j j | i'||_ I'm s^ ,_5 _, _ |i -|
O U tii £ cxi S oi ? W S M (— ^ O Q O QS O — S ^ ™ < > C — ^ y «
S M5 f- £ 7
3§3322!p8P3§3i«*S=S5S SS=l§=5a3Ei*loaS==2lsia£S*SS*§gsSi-E= =5ssigg5=5

S'S°5"SS*S;>"SSRgPSS'cS S|~XK"'S|C5SS2!;-3S'cgSg:~R^a75§ICSS7SS|-*'c SKS'SfSSS??



^O^Sx^^5* S^^S^^"""" SS o* r^S"'*1 ^ -M "^ ~-H r^30 g^S ~ =
r*1rjr^r4 ^^~* — •*•• r4

r.SSsa-^^^-^s-S25^"^ IE "Sl^sssssa SM _ ,^5? -SK'S-S ^- ---

• : " T &
: *''.': c ' u c
,ic ^5 15 ' ^ — . "5 "^'y*_L'"3 tJ~w»p?or E 3_1.'"^ t>~°-o^ ^~c-
I ^ Iili|lil|lliiliiill I I || I | i li'iyi | I |l \ I i ' il^illilf i||
j w ™
u.
§
 0)

-------
            Table 4.2.   EMISSION FROM MISCELLANEOUS SOURCES
Category
New York point
sources
Forest wild
fires
Agricultural
burning
Structural
fires
Coal refuse
fires
Total
L 1 . 2 Nitrogen
Particulates ,
tons/yr
343,000

413,00
300,000
57,000
110,000
1,223,000
Oxides Emissions
SO ,
tons/yr
1,028,000

0
16,000
0
141,000
1,185,000
(NOJ
NO ,
tons/yr
421,000

97,000
32,000
7,000
34,000
591,000
HC,
tons/yr
140,000

583,000
300,000
67,000
68,000
1,188,000

LI. 2.1 Stationary Sources --Stationary sources contribute at
CO,
tons/yr
49,000

3,399,000
1,600,000
220,000
340,000
5,608,000
least half
the total man-made nitrogen oxides (NO ) in the United States.  Recent
                                      X


estimates are that over eleven million tons of NO  were emitted from
                                                 _A.


stationary sources in 1972.  Of total stationary source emissions, about



98% result from combustion of fossil fuels.  The remainder comes from



industrial processes such as the manufacture of nitric acid, sulfuric



acid and explosives.  Figure 4.1, showing major stationary sources of N0



emissions, indicates that utility boilers are the major contributors



(48%).  Utility boilers and stationary internal combustion engines and



gas turbines together account for approximately 70% of the total.



Industrial steam-raising boilers account for more than 18% of emissions.
                                  129

-------
     As shown in Figure 4.1, the major combustion source categories are



utility boilers, industrial boilers, stationary internal combustion



engines, gas turbines, commercial and residential heating systems,



industrial process furnaces and incinerators.  For each of these cate-



gories there are sub-categories based on equipment design and these may



be further subdivided depending on type of fuel.  Stationary combustion



processes are fired with a variety of fossil fuels (i.e., coal, heavy



oil, light oil and natural gas) dependent on user and equipment design.



     The emission inventory being developed for the Control Systems



Laboratory (ERC/RTP) has subdivided stationary sources into 138 dif-



ferent categories of equipment design and fuel burned.  Rank of sources



in general categories appears in Figure 4.1; rank of sources in more



detail is shown in Table 4.3, where those accounting for about 70% of



total emissions are listed.  These leading combustion sources show the



very large number of different equipment and fuel combinations and



emphasize the complexity of developing NO  control technology for such
                                         A.


varied sources.  The two leading sources in Table 4.3 are gas-fired spark



ignition stationary I. C. engines (accounting for over 16% of emissions)



and bituminous coal-burning tangentially fired utility boilers (account-



ing for about 12%).



4.1.2.2  Mobile Sources--Oxides of nitrogen form in mobile sources pri-



marily by the fixation of atmospheric nitrogen in the combination process.



Peak temperatures found are those most significant in dissociating N7
                                                                    LJ


atoms.  Exhaust gas recirculation (EGR) and water injection schemes are



methods to reduce the peak temperature and thus the amount of oxide of



nitrogen produced.  EGR methodology was employed in 1973 vehicles.  It
                                      130

-------
CO   bO
W   G
S

>H




O
I—I
H
co
Pi
PH

CO

o
I—1
CO
CO
 o
 o
 u
T) tO
 0 G

 G-H
 3 LO
pq to
 0 pq

SrH
   03

 G O
 TO E-H

 0 MH
 o< o

[-H o\o
   o
P r-


 8*
    MH  o
     o  5n
        PH
rH   P  5H

H   en  O
CO   -H '-4H

PJ   nJ
     03
Csl


CD
 0
rH

•8
H
     p
     rH
     03
rH
P 03
G -P
0 H
5n
0 <-w
PH 0
to o
£ rH
O
•rH ^"^
t/)
t/1 >H
._] O
(-3 F"^
•
§ pq


















£>^
O 0
bo 3
0 PH
P \
03 p
U G
0
0 S
O O.
5-1 -H
3 3,
0 cH
CO pq








oo
rH
0
rH





to
t"^
oo
rH




to
3
O
G
•H
-a 3
0 P
rH -H
•H PQ

•*
[/) (}£
03 C
CD *H
^H
-•H
ff rr .
0
•H rH
-P 03
•H -H
as
KH 0
W
,-Sr^ C«
^ TO
03 H
CO -
•s ^H
to 0
0 rH
G -H
bQpq
&fr
' -H
U rH
•H
• P
CD
CD
rH
rH





OO
OO
to
rH


































rH
03
O
U

rH
to
vO






0

t^-
o


rH
03
O
u

(/)
o

•H


P
•H
PQ

*t
G/3
r-j
'rH
•H
PH
0
O
rH
U

&
to
5n
0
rH
•H
£
X
p
•H
rH
•H
P
rH
CD
,H-






OO
^O
LO
o

-
G
•H
JH
•H
f T !

rH
rH
03


!-£J
0
to
0

QH
£^

rH
rH
P
0

•H
5-i
O

to"
5-c
0
i— 1
•H
P?
£
•H tO
rH 03
•H CD
P
CD
to
to






to
CD
to
O










(fl
o3


•*
bo
p^
• tH
^H
•H
PH
rH
rH
03

P
G
O
rH

t/)
rH
0
rH
•H
O
PQ
fr
•H
rH
•H
P














*
p*
•H
5n
•H
PH

rH
rH
03
12

r-£j
0
to

p*
Ol
c^

i— 1
rH
03
4J

N
•rH
rH
O
a:
C/)
5-i
0
rH
•H
O
PQ
X
P
rH
•H
P
OO
rH
to






oo
^o
to
o




















'rt
o
u
'}
C)

•rj

;3
4-J

•v
§
+->
P
O
P;
1*


*3"tO ^HT rH *3-*3- OO OtOCD
rH r — \o \o to to c — vo LO ^-
tOCNI CN! tNl r-JCM I — 1 < — IrHrH






tOvO vO CN1 rHrH VO CN1 t^ f>J
^O rH c ~ i c i £•*-, f^^ [""i CD C — • t""~-
tOtO tO IO CNltNl CO rHrHrH
C3O O O OO O OOO

bO bo 'id
G G rH 0 rH
•> -H - 'H -H bO 0 -H
6 rHgrHOOSbOO
O -H O -H ^ ft
+-> LL,4JpHrHU^rH
P P 03 03 CJ o3
0 rHOrH30H033
PQ I/) rH pq i— IT) PnTJ
I — 1 Cti TO -H T3 .H
X 03: -P ^ to0 nd to
5-i 3 ^ 05-100

CO 0 P-, 'H
•\ rH tO — t/) *> PH "
bO o3 O bO O bOrH bO
Pl3P3 

H S -H PQ -H Di -H T) |g T5 CO -H t/) P *-P P P PC G Po3 T) rH 0 •H PH •\ T3 0 5H •H PH rH rH 03 r^ P S PH «s to 5-H 0 rH •H O PQ rH 03 •H rH P ^ T) G to ^f rH LO rH 0 rH •H O rH -3 T3 •H t/} Q^ pi •\ O rO 3 rH 0 -P 03 T-, 0 •P O 0 PJ to •^f rH LO ^O rH O rH rH -H rH O 03 S rH 03 T) 3 0 TJ tO -H O to PH.^ ^^" *\ X 0 rH ,0 rH 3 03 P P 5n CH 0 0 P N 03 •H IS O T3 P - U t/) 0 5n 5n 0 UH rH •H T) O rH pq 0 •H rH PL, 03 •H tut rH C P -H trt rH 3 -H CH ^DOr-f to t-- OO to LO 131


-------
          3.6 grains per mile
          4.3 grams per mile
          5.5 grams per mile
          5.1 grams per mile
          4.8 grams per mile
          2.3 grams per mile
          1.6 grams per mile
          0.4 grams per mile
reduces oxides of nitrogen emissions from 40 to 60% depending on the
base year chosen.
     Oxides of nitrogen emission factors for vehicles are:
               Light-duty vehicles
                 pre 1968
                     1968
                     1969
                     1970
                    1971-72
                    1973-75
               Diesels pre 1975
                 Statutory
               Heavy-duty vehicles
                 gasoline pre 1970        9.4 grams per mile
                             1970-73      9.2 grams per mile
               Diesels                     34 grams per mile
               Aircraft (for example, a
               JT-9D jumbo jet)
                 taxi-idle                2.75 kg/hour
                 take-off                  327 kg/hour
                 climb-out                 208 kg/hour
                 approach                 24.5 kg/hour
                 per landing-take-off cycle  14.2 killograms
     The variations seen for aircraft demonstrate the complexity of
deriving meaningful factors.  Fluctuations of two or three orders of
magnitude are common to all mobile source emissions depending upon
operating cycles.  In light-duty vehicles these fluctuations may
occur in seconds or less; for this reason, physical integration of the
sample through the constant volume sample is used.  This is much more
efficacious than mathematical integration.  The latter approach must
132

-------
be used to determine nodal emissions as in design research for control



devices.




     In addition to EGR for light-duty vehicles, reduction catalysts



are proposed to attain the statutory limits.  These catalysts would



be placed prior to the oxidation catalysts immediately after the exhaust



manifold.  The vehicle would be operated in a reducing mode, somewhat



rich.  After the reducing catalyst air would be added to the exhaust



stream which would then be passed through an oxidizing catalyst.  Single



bed catalysts have also been proposed.  These require precise control of



air/fuel ratio in each cylinder and would probably be practical only if



automotive fuel injection were used.



     Single bed catalysts may have unique properties depending on operat-



ing conditions.  Usually catalyst temperature is controlled, but one



experimental catalyst which showed minimal NO  emissions on the Federal



test cycle could be operated under other conditions which (a) showed



almost no NO  reduction or (b) almost quantitatively reduced the emis-
            .A.


sions to ammonia.



     Review of the statutory limit now under way is the key to future



control efforts.  The rise of NO  in light-duty vehicles seen in 1968-
                                J\.


69 was one result of cleaner vehicle operation due to hydrocarbon and



carbon monoxide controls.  A fuel penalty varies with each engine class.



4.1.2.3  Ambient Air Concentration Summary--In 1972, of 24.1 million



tons of N02 emitted to the atmosphere of the United States, 36% was from



transportation and 57% from stationary point sources.



     Figures 4.2 and 4.3 present the seasonal diurnal patterns of NO and



N02, respectively.  These curves reveal that NO and NO- have markedly
                                     133

-------
different diurnal patterns; NO concentrations follow traffic patterns



while NCL does not.  The quantity of NCL builds up throughout the day-



light hours, reaching a maximum in the early afternoon around 4:00 p.m.



(see Figure 4.3) and then leveling off to a minimum just before sunrise.



     Seasonal curves (see Figures 4.3 and 4.4) demonstrate the lower



autumn but higher spring and summer NCL values.  Figure 4.4, which is a



composite NCL pattern from all six CAMP sites, shows the more consistent



summer peaks, especially since 1969.



     A long-term trend line for NCL is shown in Figure 4.5, which is



again a composite graph of the six CAMP sites.  It shows a general



increase in NCL concentration levels at these six sites.



     Historically, NCL measurements were made in most of the AQCR's by



now discredited FRM.  According to these data, there were 41 AQCR's



which should be classified priority 1.  An intense monitoring study was



conducted in these 41 AQCR's using the arsenite and chemiluminescent



methods.  After two years of monitoring in these AQCR's, three cities



had yearly averages over 100 yg/m --Chicago, Springfield, Massachusetts



and New York City.  In addition, Denver, Cincinnati, Philadelphia and



Salt Lake City should be carefully watched for a future problem.



     As part of the NASN gas network, samples were collected once every



12 days since 1972 at approximately 200 urban and nonurban sites across



the U.S.  Annual averages from this network show that in 1972 40 sites



had concentrations over 100 yg/m , and in 1973 three sites had over



100 yg/m , all located in one AQCR--Metropolitan Los Angeles Intrastate.



(Note:  Continuous data were also collected in L.A. as part of the



CHESS Program.  These data also indicate that L.A. is priority 1.)
                                134

-------
<
DC
O
u
                                                                       SUMMER:	

                                                                          FALL:

                                                                       WINTER:
   0.00
                                                   12          15


                                             TIME OF DAY


                  Figure 4.2. Seasonal diurnal patterns of nitric oxide concentrations.
   0.07
   0.06
_ 0.05
2  0.04
<
cc
   0.03
o
u
   0.02
   0.01
    0.00
                             6
9          12          15


      TIME OF DAY
18
21
24
                 Figure 4.3  Seasonal diurnal patterns of nitrogen dioxide concentrations.



                                                 135

-------
   250
   200
~  150
E
   100
A
    50
         62     63      64     65     66      67      68

                                                 YEAR
  70      71       72      73
       Figure 4.4. Seasonal pattern of nitrogen dioxide concentration levels, composite graph of the
       six CAMP sites.
         62     63      64      65      66     67      68     69      70      71      72      73
        Figure 4.5.  Long-term trend line for nitrogen dioxide concentration levels composite graph of
        the six CAMP sites.
                                               136

-------
Year
1972
1973
Sites
129
169
<50
79
78
50-74
41
69
                Table 4.4.   KECLASSIFICATION STUDY - 24-HOUR DATA


                        Total            No. of Sites within Interval-,
                     No. of Urbai        Concentration Interval, yg/m
                                                           75-99     >99

                                                               5       4

                                                              19       3


                        Total            No. of Sites within Interval?
                     No. of Urbaa        Concentration Interval, yg/m
           Year         Sites                  <20           >20

           1972           22                    20             2

           1973           29                    21             8


     We find that NCL is essentially an urban problem influenced by

local sources (primarily mobile in areas of high levels) and meteorologi-

cal factors, as indicated by seasonal patterns.  In areas with more than

one monitoring device, data show that local maximum concentrations do

exist where one site is over the standard and others are not in excess

of the standard of 100 yg/m .

     Overall, the N0? problem is less severe than we first thought.  How-
                    L*
ever, with four areas above the standard and another four near the stan-

dard, it remains a problem.

4.1.3  Carbon Monoxide

4.1.3.1  Natural Sources--The primary source of CO in urban atmospheres

is incomplete combustion.  In the global atmosphere, most carbon monoxide

is produced by natural sources from the oxidation of methane by hydroxyl

radicals.  The same OH radicals account for a large amount of global CO

loss.  These two competing formation and destruction processes can account
                                     137

-------
for the 0.1 year residence time of CO estimated by radiocarbon measure-



ment.  While important in explaining the global balance, oxidation of CO



by OH is insignificant in polluted atmospheres, being unable to compete



with the much faster reactions of hydrocarbons with OH.



     Evidence suggests that large amounts of CO are produced through



reaction of methane in the troposphere.  The oxidation of CH, by



hydroxyl radicals liberates CH, radicals that can later undergo reaction



to form CO.  McConnell, et al.  estimated a substantial rate of CO pro-



duction from the reaction of CH. and OH.  They concluded that while



combustion sources determine local levels of CO, the natural sources



determine the global level, with the oxidation of methane playing a



leading role.  From an analysis of radioactive CO data in the tropo-


                          2
sphere, Weinstock and Niki  concluded that CO is produced at a rate



25 times greater than that of CO formation from combustion.  Based on



their measurements, they calculated the rate of CO formation from the



reaction of CH. and OH.  The value they derived is of the same order



of magnitude as that extimated by McConnell et al., lending support



to this view.



     Levy  recently developed a model showing that sufficient global



concentrations of water vapor, CH., 0_ and NO  exist to cause chain
                                 HO       JC


reactions that can destroy CO as well as produce it.  He calculated



that the hydroxyl radicals produced in chain processes can oxidize CO



at a rate in excess of the rate of CO production from the reaction of



CH, with OH.  His model predicts that competing formation and destruc-



tion processes result in a residence time of 0.1 year for CO, agreeing

                  4

with the Weinstock  estimate deduced from radiocarbon measurements.
                               138

-------
4.1.3.2  Mobile Sources--With the start of the 1975 model year, many new



cars  were  equipped  with oxidation catalyst-converters for reducing



emission levels of both CO and hydrocarbons.  Preliminary results on



prototype 1975 cars available at this laboratory indicate three to seven



times lower CO emission levels for catalyst-equipped cars over equivalent



1973 and 1975 cars and better than 10-fold improvement over 1972 cars.



The 1975 prototype vehicles evaluated are in some cases considerably



different from production vehicles actually being sold.  One manufacturer



uses the catalyst with only one bank of cylinders.



     Another method to reduce CO1 and other harmful exhaust gas components



is the new engine design using the stratified charge concept for combus-



tion in a two-chamber engine.  Reported values for the only stratified-



charge equipped car commercially available, Nonda CVCC, show it meeting



the 1977 emission standards for CO and hydrocarbons without extra treat-



ment of exhaust gas.  CO emission levels are about 2 gm/mi for all com-



mercially available engine sizes of the Honda.



     One complication in achieving the ambient air quality standard for



CO by controlling auto exhaust emission is the effect that temperature



has on emission rates for both CO and hydrocarbons.  This was first



reported by R. W. Hum of the U.S. Bureau of Mines , who found it to



exist in six 1973-73-74 catalyst-equipped cars.  Comparing relative emis-



sions for the three regulated species at ambient temperatures from 20°F



to 110°F, it was found that CO and hydrocarbon emission increased up to



six times at the lowest temperature compared to the normal Federal Test



Procedure temperature range of 70-75°F.  There was no significant change



in NO  emissions, however.
     .A.
                                     139

-------
     Other work has also shown higher emission levels at higher tempera-
tures, so that tests under defined ambient conditions represent a mini-
mum case.  The importance of these findings is that while new model cars
may meet the emission standard as measured by the Federal Test Procedure,
actual operation of these catalyst-equipped cars at sites of different
temperature or in early morning could produce unexpected higher emission
rates for CO and hydrocarbons.  We need to know more about causes and
extent of departures from standard conditions; the Federal Test Pro-
cedure should be capable of detecting emissions in all possible operating
conditions and environments.
4.1.4  Hydrocarbons
4.1.4.1  Mobile Sources--The Clean Air Act specifies a 901 rollback on
hydrocarbon emissions from 1970 levels for light-duty vehicles.
     Standards are:
               Pre-1968          8.6 estimated grams/mile
               1973-74           3.0           grams/mile
               1975 US           1.5           grams/mile
               1975 Calif.       0.9           grams/mile
               1976              0.41          grams/mile
     Due to the complexity of hydrocarbon mixture emitted from light-
duty vehicles, control of total emissions was adequate.  Minor varia-
tions in composition did not seriously effect the total.  Catalytic
controls strongly enhance some materials like methane which is much
more stable and has a profound effect on relative reactivity of total
emissions.  Non-catalytically-controlled vehicles produce less than
101 methane.  Acetylene is also significant.  In catalytic vehicles
higher molecular weight species are preferentially oxidized and methane
                               140

-------
may account for 30 to 40% of total emissions.  In specific operating
modes, as much as 801 of hydrocarbons may be methane.
     The N.A.S. report has supports current standards, but only if
other mobile sources conform to similar controls.
     As is discussed in Section 3, hydrocarbon emissions vary with
cycle and operating conditions.  Emission factors and regulations try
to integrate these emissions into numbers which can be related (through
number of vehicles) to impact of specific source on the environment.
     A compilation of these factors by an average use cycle is given in
AP-42 compilation of Emission Feictors, Supplement 2.
     Current in-house tests show prototype vehicles* emit:
                    Ford          0.20 + .02 gm/mi
                    Plymouth      0.23 ± .03 gm/mi
                    GM            0.44 ± .03 gm/mi
4.1.5  Sulfur Oxides
4.1.5.1  Mobile Sources--Trace quantities of sulfur mostly in the form
of organic compounds are present in gasoline (0.038%).  Combustion of
gasoline in an automotive engine yields principally carbon dioxide
(CO-) and water along with hydrocarbons (HC), carbon monoxide (CO),
nitrogen oxides (NO ), sulfur dioxide (S0?) and sulfur trioxide (SO,).
During normal combustion, sulfur in gasoline is almost all converted to
S02 and SO- with the latter accounting for less than 2% of all sulfur.
The SO, reacts very rapidly with water in the exhaust and is emitted as
sulfuric acid or sulfate particulate.
 *These data cover emissions from one vehicle  from each manufacturer.
                                    141

-------
     The amount of SCL and SO, emissions from mobile sources nationwide

is negligible  (less than II) compared with that from stationary sources.

For this reason they are not a significant portion of overall sulfur

oxides air pollution except in a few places like Los Angeles, where

stationary source emissions of sulfur oxides are relatively low.

     It was recently reported and has since been confirmed that cars

with catalytic converters emit substantial amounts of sulfuric acid.


Conversion of 401 of the fuel sulfur has been reported.  In the absence

of the catalytic converter, conversion is less than 2% of the fuel

sulfur.

     Although the contribution of mobile sources to total regional


airborne sulfate is not significant, use of catalytic converters as

presently designed may result in localized buildup of sulfuric acid

and sulfate salts concentrations to dangerous levels, especially near

places like Southern California where the sulfur content of gasoline

is higher than the national average.  Because health problems may

result from direct emissions of substantial amounts of sulfuric acid

mist by catalyst-equipped cars, EPA is reassessing the automotive

sulfur oxide emission question.

4.2  TRANSFORMATION AND TRANSPORT

4.2.1  Oxides of Nitrogen

     In the laboratory, investigators have been able to account for over

90% of carbon atoms; however, only 50% of the nitrogen could be accounted

for in many cases.  Apparently most of the unaccounted nitrogen atoms end

up as nitric acid either on the walls of the reactor or in the gas

phase. '   Recent investigations suggest that nitric acid is also pro-
                                          o
duced in atmospheric photolytic processes.

                                142

-------
     Nitric acid in the gaseous state is colorless and photochemically



stable.  It is volatile acid in solution.  The equilibrium vapor pres-



sure decreases with increasing dilution and at the parts-per-hundred-



million level—as might be expected in the atmosphere--the solution



would be extremely dilute.  In the atmosphere, nitric acid can be pro-



duced by two reactions:


                        M
          (1)  OH + N02 y HN03



          (2)  N205 + H20 -> 2HN03


       9

Nicolet  has postulated reaction (1) for the presence of nitric acid in



the stratosphere.  Gay and Bufalini  have postulated reaction (2) for



the formation of nitric acid in smog chambers.  It is not known which



reaction is  ost important in polluted atmospheres.  Good nitrogen bal-



ances have been obtained in smog chamber studies when nitric acid is



included as a product. '



     Nitrous acid is not formed in as great quantities as nitric acid.



It can be produced in the atmosphere by the reaction,



          NO + N00 + H-0 -*• 2HNO,,
                 L    L        i.


This acid is important because of its photochemical reactivity.  Nitrous



acid absorbs sunlight and dissociates into OH and NO.  Its photolysis



rate is lower than the photolysis of N02, but in photochemical smog pro-



duction it produces very reactive hydroxyl radicals when photodissociated.



     Although strategy to alleviate NO -related pollution is in existence,
                                      J\.


the transformation of NO  in ambient air is still at issue.  The "NO
                        .X                                           3C


issue" consists of the following partly answered or unanswered questions:



          •What are the products; of atmospheric reactions of NO
                                                               .A.


           and what determines accumulation levels?
                                      143

-------
           •What is the quantitative dependence of NO- on NO  and



            on other possible precursors?



           •What is the role of NO  in the atmospheric oxidant
                                  A.


            formation process?  Should NO  control be included in



            oxidant control strategy?



     EPA is currently conducting laboratory and field studies to develop



analytical methods for measurement of the atmospheric reaction products



of NO .
     x


     Present NO- control strategy assumed NO  to be the sole precursor
               Lt                            .A.


of NO- and to yield NO- on a 1:1 basis.  This, however, is only a simpli-



fying approximation.  Although NO- is a product of the thermal reaction



of NO  with atmospheric oxygen, this reaction alone cannot cause the



observed accumulations of NO- in ambient air.  Such accumulation is



caused by a photochemical process that involves both NO  and HC as
                                                       X


reactants.



     Smog chamber testing of simulated atmospheric mixtures has shown



that maxiumum NO- concentration during the test is proportional--in fact,



almost equal--to the initial concentration of NO  and nearly independent
                                                .A.


of the initial HC concentration (Figure 4.6).  However, unlike the maxi-



mum NO-, average NO- concentration during the test was found to depend on



both NO  and HC.  The average NO- increased with increasing initial NO



but decreased with increasing initial HC (Figure 4.7).



     The aerometric data analysis done thus far verified the 1:1 rela-



tionship between the early-in-the-morning (6-9 a.m.) NO  and the later-
                                                       J\.


in-the-day NO- maximum (Figure 4.8), but failed to establish the depen-



dence of the average NO- on both (the NO  and HC) precursors.
                       Li                J\.
                                 144

-------
uidd  'ON -inoq-y

-------
                                                                                                   CO
                                                                                                   to
                                                                                                   OO

                                                                                                   o
                                                                                                   f--

                                                                                                   06

                                                                                                     O-
                                                                                                      X
                                                                                                     o
                                                                                                      03
                                                                                                     •H
                                                                                                     •H
                                                                                                      c
                                                                                                   LO


                                                                                                   o
                                                                                                   IO


                                                                                                   O
                                                                                                   o
o
o
to
o
LO
CM
o
o
o
LO
o
o
o
in
                            UTUI x  mdd
                                                   -  146  -

-------
     It appears that the daily maximum NCL concentration relates to the
NCL precursors simply; namely, it is proportional to the daily 6-9 a.m.
NO  and is independent of HC.  Unlike the daily maximum, the daily
  X
average NCL is neither simply nor predictably related to the NCL pre
cursors; this makes it difficult to determine control requirements for
NCL, because the NCL-NAQS is defined in terras of an  (annual) average
NCL concentration.
     To determine control requirements for achievement of NCL standards,
one must consider that the yearly average concentration of NCL in a
region results from combined effects of the following processes:
          •Photochemical conversion of the morning-traffic-peak NO
                                                                  A.
           into N07, occurring only during daytime.
          •Thermal conversion of the morning- and afternoon-traffic-
           peak NO  into N0_.
           F      x        2
          •Reaction of the afteinoon-traffic-peak NO  with oxidant.
                                                    X
     The "photochemical" MIL--the largest contributor to the annual
N07--depends on the 6-9 a.m. NO. and possibly on the 6-9 a.m. HC also.
  £t                            Jk.
More aerometric and smog chamber data are needed here for accurately
determining dependence of the average MIL on initial (or early-in-the-
morning) levels of NO  and HC.
                     J\.
     The "thermal" N07 depends strongly and predictably on NO  so that
                     Z                                       -X
it could be controlled effectively by NO  control.  However, thermal
                                        JTV.
N0? does not contribute to annual MIL in a major way.
     The "evening" N07, resulting from the 09-NO  reaction, appears to
                     />                      L,   X.
depend mainly on the oxidant level.  Therefore, the most effective
means for controlling such MIL to the 24-hour N07 average has not been
                                      147

-------
•4       4
                                                                                  CTl
                                                                                  00
                                                                                      OH

                                                                                      On
                                                                                  VO   X
                                                                                    • O
                                                                                      03

                                                                                     cr>

                                                                                  LO  I

                                                                                     vO
                                                                                                         rt

                                                                                                         CTl
                                                                                                          I
                                                                                                          X6
                                                                                                         O  P-i
                                                                                                         Z
                                                                                                            LO
                                                                                                         c
                                                                                                         O   I
                                                                                  03      ?^ (X
                                                                                   <
                                                                                  O  3 U
                                                                                  M  O
                                                                                                             I
                                                                                 14-1
                                                                                  O
                                                                                     I
       s
       o
 C  6  fn
 O  3 "4-1
•H  e
4-> -H  Cfl
 03  X -M
i—i  03  03
 
-------
established.  However, it has been significant, especially during the
smog season.  Analysis of aerometric data is needed here to establish
the importance of such NCL, within and outside the smog season, and to
determine its dependence on the oxidant and NO  levels.  Since present
                                              X
photochemical pollution control strategies aim at reducing oxidant to
0.08 ppm, one could reasonably assume that evening NCL is decreasing
and will eventually become negligible.
     Smog chamber studies have shown that both HC and NO  have a role
in the atmospheric oxidant formation process.  They have shown the
oxidant to increase with increasing HC reactant, and to show a maximum
dependence on NO .  Aerometric data'similarly showed the oxidant to
                J\*
increase with increasing concentrations of HC reactant but were not suf-
ficiently abundant to permit delineation of both HC and NO  effects.
                                                          X
Based on this data, an oxidant control strategy calling for unilateral
control of HC emissions but overlooking the role of NO  may not be the
                                                      X
most effective.
     Present oxidant control strategy is based on empirical correlation
of ambient oxidant and HC concentration data that shows the daily oxi-
dant to decrease with decreasing 6-9 a.m. HC concentration  (Figure 4.9).
unfortunately, there is insufficient data to establish the correlative
dependence of oxidant on NO  .  rfhere is evidence to suggest, however,
                           -A.
that the NO  effect is an inhibitive one, and that as ambient HC levels
           x                            '
decrease with control, the NO -to-HC ratio increases and the inhibitive
                             .A.
effect of NO  is intensified.  According to this evidence,  ignoring the
            X
NO  effect unavoidably leads to an  overestimation of HC control require
  A.
ments.
                                     149

-------
   0.30
   0.25
   0.20 —
X
o
    ,
   0.10
   0.05
     APPROXIMATE UPPER-LIMIT
     OBSERVED OXIDANT
                       ^ j
                                      "WASHINGTON A
                                                        LOS ANGELES
                        LOS ANGELES    A
                               k     DENVtR
                                                       LOS ANGELES
                                         A A PHILADELPHIA
                                         LOS ANGELES
  PHILADELPHI/
     PHILADELPHIA
     WASHINGTON

WASHINGTON  A A A
     A   .
WASHINGTON *
     A> A A   A A A
     A A A   A
            A
A  At A      AA      A      AA
A  A   A AA     A
       4*A*   A         A   A  A
       A * A / A i A  A A   AA
                                                            A  A
                 0.5          1.0          1.5
                           NONMETHANE HC, ppm C
                                              2.0
                                                          2.5
    Figure 4-2. Maximum daily 1-hour-average oxidants as a function of 6-to 9-
               a.m.  averages of nonmethane hydrocarbons at CAMP stations,
               June through September, 1966 through 1968, Los Angeles, May
               through October 1967,
                                 150

-------
     Hypothetical oxidant control strategy considering the NO  role
                                                             .A.
should be expected to call for less HC control.  Such a hypothetical
strategy is not possible simply because, as yet, no one has been able
to quantitate the role of NO .   Aerometric data are not complete
                            X
enough to permit such quantification.  Smog chamber data are more
complete; however, such data do not necessarily represent ambient
atmospheric conditions.  This hypothetical strategy may have merit in
an urban region, but its effectiveness in controlling "transported
oxidant" buildup in rural areas downwind from cities is questionable.
4.2.2  Carbon Monoxide
     The oxidation of CO by hydroxyl radicals
          CO + OH ^ C02 + H
is rapid enough to suggest that this reaction might be a significant
removal process for CO in polluted atmospheres.  It was recently
determined, however that the reaction cannot compete effectively with
the much faster reactions of hydroxyl radicals with hydrocarbons.  '
In the absence of reactive hydrocarbons, modeling studies predict that
                               12
OH is an effective sink for CO."   Subsequent chain reactions are effec-
tive in converting NO to N02 and small amounts of 0,  an be formed,
although under non-urban conditions, not enough to exceed the air
quality standards.  No significant oxidation reaction of CO has yet to
be found for urban atmospheres.  The reaction of CO with H02
          CO + H02 -»• C02 + OH
was though to be an atmospheric reaction of possible importance, but
this reaction is extremely slow.
                                    151

-------
4.2.3  Hydrocarbons



     New findings on pollutant transport and hydrocarbon reactivity



suggested that organics formerly classified unreactive actually may be



reactive.  Based on these findings, a new classification of organics



was derived and the use of reactivity criteria was reexamined.  devel-



opments prompting this reexamination include:



          •Reactivity criteria used inconsistently in existing



           control regulations.



          •Recent smog chamber studies have improved our under-



           standing of the photochemical reactivities of organic



           compounds and raised questions as to the validity of



           the reactivity classification in the widely used Los



           Angeles County Rule 66.



          •It has become increasingly evident that pollutant



           transport does occur, and that such transport enhances



           formation of oxidant from low reactivity organics.



          •The present emphasis on control of mobile source



           emissions may eventually make solvents and other



           stationary source emissions the predominant emission



           problem.



     The Los Angeles County "Rule 66" is lacking in two respects.  First,



its reactivity classification of organics is inaccurate, the error being



in the direction of less stringent control.  Second, it assumes that



organics of unknown reactivity are non-reactive--an assumption that is



probably wrong and that again leads to less stringent control.  EPA



Appendix B is lacking in that it assumes that all except very few
                                152

-------
organics are equally reactive--an assumption that is known to be wrong



and that causes inflexibility.



     Recent findings concerning pollutant transport provide additional



support for the "all-organics" control concept.  Thus, under prolonged



irrad ation conditions occurring in transported air masses, it is very



probably that the "less reactive" organics are induced to form as much



oxidant as the "more reactive" ones.  Therefore, to alleviate the down-



wind area, nearly universal control of organics probably would be more



effective than the more selective control prescribed by Rule 66.



     Control requirements for each source should include consideration



of:  (a) the degree of total hydrocarbon control required for the region



or area; (b) the relative strength of the source; (c) the reactivity of



the emissions, and (d) the availability of control technology.



     A new reactivity classification of organics based on existing smog



chamber reactivity data has been derived.  The new classification cate-



gorizes hydrocarbon and non-hydrocarbon organics into five reactivity



class s and gives a numerical reactivity rating to each class.



4.2.4  Oxidant



     Dependence of the atmospheric: oxidant on ambient levels of hydro-



carbon and NO  has been explored in laboratory  (smog chamber) as well
             JC


as field studies.  Early laboratory studies had little success--mainly



because atmospheric conditions could not be closely simulated in the



smog chamber.  The oxidant - HC - NO  relationships from those studies
                                    A.


have only qualitative validity.  Aerometric data gave a somewhat more



valid, but considerably less complete, relationship--namely, a corre-



lative dependence of oxidant on HC alone.  The dependence on both HC



and NO  could not be obtained.
      .A.



                                    153

-------
     Recent smog chamber studies have used improved methodology and



experimental conditions much closer to those occurring in the real



atmosphere.  Their results, therefore, are more valid than those of



earlier studies.  The most significant deductions from these recent



studies are that:  (1) oxidant concentrations exceeding the standard



(0.08 ppra-0,) can form from only a few parts-per-hundred--million of



hydrocarbon, and (2) the oxidant level within an urban area can be kept



below the standard by maintaining the early-in-the-morning HC-to-NO
                                                                   J\.


ratio at 2.5:1 or less.



     Nevertheless, the question of comparability of smog chamber atmo-



sphere remains open, and the validity of these or any other smog chamber



data cannot be fully defended at this time.



     Some recent studies suggest that ozone and ozone precursors can be



transported over long distances.  Concentrations of ozone are found in



remote areas that frequently exceed the air quality standard.  The



probable cause for these high ozone levels has been hypothesized to be



long-range transport.  Present evidence is insufficient to implicate



natural sources as major contributors, although the possibility cannot



be ruled out.



4.2.5  Particulate



     Since the original criteria document was issued, major advances



have been made in understanding the sources, properties, chemical com-



position and dynamics of the atmospheric aerosol or total suspended



particulate matter.



     Current problems are examined in  ERC-RTP Task Force documents:



Summary Report on Suspended Sulfates and Sulfuric Acid Aerosol and






                               154

-------
Briefing Report on Problems Relating to Fine Suspended Participates.



The National Academy of Sciences has prepared a review, now in draft,



as background for preparation of a new criteria document.  Therefore,



in this document only a few key references are discussed.  While no



decisions have been made, it is clear that both particle size and par-



ticle composition must be considered and that in addition to primary



aerosols, gaseous precursors of secondary aerosol (aerosol formed by



chemical processes in the atmosphere) must be controlled.  These include



S0? (forms of sulfate aerosol), NO  (forms nitrate aerosol) and certain
  Li                               .A.


organic vapors (from organic aerosol).



     Key areas of progress include:



     (1.)  Understanding the multimodal distribution of the atmospheric



aerosol, the typical observation cf a bimodal mass-size distribution,



and the differences in chemical composition and effects of fine and



coarse aerosols.



     (2.)  Use of microscopy and the chemical element balance technique



to determine aerosol source coefficients from measurements of ambient



aerosols.  This has led to the realization that secondary sulfate,



nitrate and organic aerosol comprise most fine particulate matter and



that in urban areas, road dust, tire debris and other material generated



by vehicular traffic make a major contribution to coarse particles.



     (3.)  Identification of organic material as a major primary and



secondary component of fine particulate matter, and determination of the



chemical composition of many individual organic compounds in the atmo-



spheric aerosol.
                                     155

-------
     (4.)  Realization of the regional nature of sulfate pollution,



identification of several compounds including acid sulfates in the



atmosphere, improved understanding of the coversion of SCL to sulfate



and measurements of transformation rates in power plant plumes and



urban atmospheres.



     (5.)  Development of improved instruments and techniques for mea-



suring aerosol parameters important in visibility reduction, radiation



balance and weather and climate modification.



4.2.5.1  Distribution of Aerosol and Chemical Composition as a Function



of Size-Distribution--Early studies of ambient particulate matter



used five-stage impactors and found that the size distribution could be



adequately accounted for by a log-normal distribution.    However, in



recent years counting techniques and eight-stage impactor studies have



demonstrated a bimodal size distribution in some locations.  In the fall



of 1973, three separate studies confirmed a bimodal mass distribution



and review of counting studies indicated a bimodal volume distribution



for almost all measurements.



     Most aerosol scientists agree that atmospheric particulate matter



is multimodal with a variety of particles from different sources having



different properties.  It is a convenient hypothesis to consider particu-



late matter as being composed of two distinct size classes, fine and



coarse, and such a hypothesis has both an experimental and a theoretical



basis.



     There are two mechanisms for creating new particles in the atmo-



sphere.  Nucleation and gas-particle conversion produce very small



particles which grow by coagulation and condensation.  As these small
                                156

-------
particles become larger, the growth processes slow down and virtually



cease as the diameter approaches one micron.  Comminution or mechanical



processes such as breaking condensed matter into smaller particles by



grinding, rubbing, etc., produce particles with a mass mean diameter



much greater than one micron.  The resulting atmospheric distribution



in terms of number, surface and volume is shown in Figure 4.10.  The lower



mode may be called the optical mode since it covers the size range most



effective in scattering light, or the accumulation mode since smaller



particles grow into this size range.  Particles in the lower mode are



also within the respirable size rajige.



4.2.5.2  Composition and Concentration--Although the concentration



distribution of fine and coarse particles in the ambient air has not



been adequately measured, considerable information about the fine par-



ticulate mode can be obtained by observing composition as a function of



impactor stage.  Most comes from the National Air Surveillance Cascade

                 "IT                                                   "I fL

Impactor Network.    Other data have been obtained by research groups.



These data indicate that among metals, Pb and V are found primarily in



the fine particle mode; Fe, Mg, Mi, Ba, Cd and Cr are found primarily



in the coarse particle mode.  SO^, NO^, Carbon, Cl, NHj and organic



particulate are found in the fine particle mode and P0| in the large



particle mode.  Zn, Cu, Ni and Sn do not fall clearly in either mode.



The data are sparse and limited to a few locations.



     Where complete analyses of atmospheric particles have been made



(in a limited number of locations), fine particles comprise 25-6-1 of



the total suspended particulate matter, and from 60 to 80% of the fine


                        14 17
particles are secondary.   '
                                    157

-------
                     rrmrj—.-? iiini|—rnmri—I  JTUIIIJ  rn
  Hgure  4.10.  Number,  surface area,  and volume distributions of a
  hypothetical  smog.   The linear ordinate normalized by total  number,
  area,  or  volume is  used so that the  apparent area under the  curves
  is  proportional  to  the quantity in that size range.
4.2.5.3  Determination of Aerosol Source Coefficients from Ambient Air

Sampling and Analysis—Combined chemical, physical and microscopic

analysis of collected aerosol is a powerful tool for the identification

and quantification of aerosol sources.   Aerosol emission inventories

are source-oriented, giving primary,  anthropogenic emissions only.

Inventory information is in mass of particulate material with no size

or chemical composition.  Aerosol source coefficients are receptor-

oriented and express various source contributions to the total ambient

aerosol at the point of measurement.   Instead of primary anthropogenic
                               158

-------
emissions only, natural sources, secondary aerosol and unanticipated



sources (such as roadway dust) are included.



     Source coefficients are useful for providing quantitative informa-



tion on potential improvement in local aerosol concentrations that would



result from either partial or total elimination of emissions from par-



ticular sources.  Also, they emphasize the substantial contributions to



urban aerosols from natural and secondary sources.



     The technique of calculating source coefficients from measurements



of tamospheric aerosol concentrations and chemical composition was devel-


                    18
oped by Friedlander.    It has been applied to Pasadena, California, by


            19            20                                   21
Miler et al.,  Friedlander   to Chicago, and St. Louis by Gatz.



     This technique can be combined with a simple meteorological model


                                                               21
to give areawide emission rates of various individual elements.    When



size-differentiated measurements are available, additional information



is obtained for a better estimate of health effects and visibility


          22
reduction.


                  18
     Friedlander's   results for Pasadena are shown in Table 4.5.



     Data from several other cities show that secondary sulfate, nitrate



and organic aerosol contribute 60-80% of fine (< 2 micron diameter) par-



ticles and that the fine particulate component varies from 25-60% of the



total suspended particulate.  The contribution of some secondary compon-



ents to total suspended particulate matter is shown in Table 4.6.
                                   159

-------
   Table 4.5.
               ESTIMATED CONCENTRATIONS OF LOS ANGELES
                     AEROSOL PARTICLES BY SOURCE18
                        (Annual Average, 1966)
              Source
Natural background
PRIMARY
Dust rise by wind
Sea salt
Spores, pollen, etc.
SECONDARY
Vegetation (organic vapors)
Biological (soil bacterial action,
  decay of organics)
Man-made
PRIMARY
Motor vehicles
Organic solvent usage
Petroleum
Aircraft
Combustion of fuels
Other
SECONDARY
Organic*
                     NH,, NO, , S. .
SO
  ,12.
  Total accounted for
  Measured total
                                        Mass Concentration
                                        	(iig/m5)
 8-20
  3
Unknown

 3-6

 0-7
15
 6
 1.3
 4
 5
 5

11
13.5
14.4
                                              90-105
                                               119
*Benzene soluble organic material.  This is probably low
 because some oxidized organic material may be insoluble
 in benzene.
                         160

-------
       Table 4.6.  PARTICULATE POLLUTION INCLUDING CONSTITUENTS
                           LARGELY OF SECONDARY ORIGIN
                                  Annual Geometric Mean
                                          vg/m
City
Boston
Chicago Site 01
Detroit
Los Angeles
New York
Philadelphia
Pittsburgh
San Francisco
Total
93
112
134
129
118
112
161
84
SQ2-
6.0
10.7
12.5
10.8
18.6
18.4
14.2
7.6
N03.
1.0
--
3.5
7.7
--
2.1
2.5
2.9
Org*
--
7.4
7.4
15.0
9.3
8.5
9.3
7.7
NH4
1.3
0.8
0.5
0.8
--
1.8
0.8
0.2
        Source:  EPA
        *Benzene soluble organic material.  This includes some
         primary aerosol but is probably low because some
         iodized organic material may be insoluble in benzene.
     A substantial fraction of coarse particulates in urban areas can

be attributed to vehicular traffic-tailpipe emissions, rubber tire dust

and mineral fragments.  In areas with unpaved roads or parking lots,

                                              23
very large amounts of road dust are generated.    Road surfacing and

street cleaning are effective control techniques.

4.2.5.4  Organic Aerosol--It has been discovered that organic particu-

late matter contributes more to total particulate matter than previously

indicated by benzene-soluble measurements.  Especially during photochemi-

cal smog are highly oxidized, polar organic compounds formed which are
                                   161

-------
insoluble in benzene.  Studies using more polar solvents have shown that



the percentage of organic matter in total suspended particulate in


                                                               24
Pasadena, California, averaged 30-40% and varied from 5 to 60%.


               25
O'Brien, et al.   studied the organic fraction in suspended particle



matter collected at several California sites.  Benzene soluble varied



from 1-121 and averaged 4%; additional organic material extracted by an



alcohol mixture varied from 10-42% and averaged 23%.  Less extensive



studies in Columbus, Ohio, New York City and Pomona, California, gave an



average of 36% and a range of 16-56%.



     Field and laboratory studies have been conducted to determine the



chemical composition of the org nic fraction.  Model aerosols have been



generated from individual hydrocarbon precursors-toluene, alpha-pinene,



cyclohexene, and 1-heptene and nitrogen oxides under simulated atmo-



spheric conditions in a 17.3 m  environmental chamber.  Aerosols were



collected on glass-fiber filters and organic matter was obtained by



solvent extraction.  Organic reaction products were fractionated into



acid, neutral, and basic components, and were analyzed by techniques



including gas chromatography and gas chromatography combined with mass



spectrometry.  Different polyfunctional reaction products were identi-



fied, including alcohols, aldehydes, ketones, mono- and dicarboxylic



acids, and phenols.  Tentative identification was made of nitrogen-



containing products including nitrate esters and aromatic nitro


          17
compounds.



     Computer-controlled high resolution mass spectroscopy was used to



identify organic compounds in ambient air samples collected in Pasadena



and St. Louis.  Several hundred different compounds can be identified
                                 162

-------
based on their mass spectrum and time of volatilization from the heated
       27
sample.    The diurnal variation in aerosol composition has been studied
for two size ranges (less and greater than 2 wn) and used to postulate
primary and secondary origins of the aerosol.  The primary organic aero-
sols included alkyl benzenes, alkaaes, polycyclic aromatics and phenols.
Secondary organic aerosols included acids, aldehydes, alcohols, chlo-
                   28
rides and nitrates.
     Laboratory studies of aerosol generation have shown that aromatic
compounds and cyclic olefins are very effective in producing organic
        29
aerosol.    The aerosol-forming reactivity of various hydrocarbon com-
pounds is shown in Table 4.7.
     It has been suggested that some or all of the reported organic
aerosol may be organic vapors adsorbed on the fiberglass filter.  Hanst,
et al.30 measured HCHO, HCOOH and PAN on one of the days that Friedlander
measured organic aerosol.  There was as much carbon in these gaseous pol-
lutants as in the organic aerosol.  Hanst has suggested that some of the
material reported as organic aerosol may have been absorbed HCHO and
HGOOH and absorbed decomposition products of PAN.
4.2.6  Sulfur Oxides and Aerosols
4.2.6.1  Laboratory Investigations;
4.2.6.1.1  Photochemical and Chemical Oxidation--Chemical mechanisms
transforming SO- in the atmosphere: are still not well known.  Oxidation
                                    163

-------
                                                                29
      Table 4.7.  AEROSOL AND OXIDANT REACTIVITY OF HYDROCARBONS
Hydrocarbon
Hexanal
Isooctane
Butane
2-Methylbutane
1-Butene
Ethylene
Cyclohexane
2 -Methyl - 2 - butene
1-Pentene
1-Heptene
Toluene
Mesitylene
Benzene
3-Heptene
n-Butylbenzene
o - Die thy Iben zene
t-Butylbenzene
m-Xylene
Cyclohexene
Max
. 0
0.16
0.37
0.79
0.39
0.68
1.4
1,1
1.1
7.7
11.1
5.7
17.0
4.2
15.8
18.2
20.8
13.7
36.4
Avg
0
0.08
0.18
0.21
0.32
0.34
0.45
0.84
0.89
2.1
2.8
3.0
3.5
3.8
7.2
7.6
7.9
9.5
32.4
Category'*"-'
1
1
1
1
1
1
1
1
1
2
2
2
2
2
3
3
3
3
3
Max
0.15
0.08
--
0.05
0.45
0.46
0.10
0.12
0.37
0.17
0.37
0.65
0.06
0.41
0.10
0.22
0.04
0.36
0.41
Category1 J
2
1
1
1
3
3
2
2
2
2
2
3
1
3
2
2
1
2
3
(a) Category   Aerosol^ ^   Oxidant
       1         <1.3         <0.1
       2        1.3-4.0     0.1-0.4
       3         >4.0         >0.4

(b) Category based on average aerosol.
by photochemically generated intermediates and catalytic oxidation are

now thought the most likely mechanisms.

     Laboratory investigations of the photochemical oxidation of sulfur

dioxide in air--alone and in the presence of nitrogen oxides and
                               164

-------
hydrocarbons --indicate that the homogeneous reaction of electronically
excited sulfur dioxide ( SO-) cannot account for the observed oxidation
rate of SCL in the atmosphere.  Current belief is that reactive imter-
mediates formed in the hydro carbon -NO  photochemical system are react-
                                     X
ing with ground state molecules of S02 to form products.  These products
are thought to account for the homogeneous formation of SO, and sulfuric
acid mist.  Swedish and U.S. workers have identified acid aerosol (H^SO.
and/or NH4HS04) , (NH4)2S04, (NH^^fSO^ and CaS04 in atmospheric sam-
     31,32
pies.
     The three-body oxidation of S0? + 0 atoms has been postulated to
explain the conversion of S0~.    However, the recent evaluation of the
                      34
rate constant by Davis   with N? as the third body has shown the reac-
tion to be almost four times slower than previously thought.  Thus,
this reaction is of only minor importance under most conditions.

          H0x + S02
     Wood, et al.   recently conducted a series of photochemical experi-
ments to measure the kinetics of the S0~ reaction with OH.  Their data
were interpreted according to the following mechanism:
           OH + S02 ->- HS03*
          HS03  + M •* HS03
          HS03 + OH -> products
                           2    -1    -1
A rate constant of 5.6 x 10  ppm   min   for the OH + S02 reaction was
obtained.  Depending on the altitude and presence of pollution sources,
OH concentrations between 10  and 10  molecules/cm  have been predicted.
Assuming S0? = 1 ppm and OH = 4 x 10   ppm, the rate of S02 oxidation is

                                    165

-------
81 per hour.  Thus particle formation from the reaction of S0? with



hydroxyl radicals will be significant under some atmospheric  conditions.



     The transient species H0? has long been postulated to play  an


                                                       37
important role in atmospheric chemistry.  Davis, et al.   have demon-



strated that H0? can readily react with S0?, with the rate constant  for


                                  2    -1    -1
this reaction found to be 4.4 x 10  ppm   min  .  This implies that  the



H02~SO? reactions may be important in both tropospheric and strato-



spheric chemistry.



     Recent modeling of reactions of S02 in the presence of hydrocarbons



and NO  mixtures at reactant concentration levels less than 1 ppm indi-
      A.


cate that reactions of SO- with OH and HO- can account for up to 10% of

                  •70

total S02 reacted.




          R0x + S02


     Indications are that oxidation of SO,, by oxygenated organic radi-



cals (RO, R0?) may be important.  Recent studies have been made  of



the propylene-S07-0, dark reaction to identify the specific radical


                                                  39
responsible for the formation of SO,.  Cox, et al."  attributed  the



oxidation of S02 to a reactive species formed in the 0,-olefin reaction.


       40
McNelis   studies indicate that the reactive biradical species,  RCHOO  ,



is responsible for the oxidative consumption of SO,.,.  The steps  of the



proposed mechanism are



          03 + CH3-CH=CH2 -> HCHO + Q^CHOO-



          03 + CH3-CH=CH2 + CH3CHO + HCHOO-



             RCHOO- + 02  -> -OH + RCOO-



             RCHOO- + 07  -> 09 + RCHO
                       Li     Li


                CH CHOO   -* CH?=C=C + H?0
                  •3           L*        t*
                                166

-------
          •OH + CH3-CH=CH2 + CH3CH-CH OH



              RCHOO- + S02 + SO  + RCHO



     Other Reactions



     Other reactions have been postulated as possible contributors to



SO,, oxidation processes.  S0~ has been observed to react in the presence



of N0~ and 0_; it has been speculated that this could be due to reaction



of S0~ with N0_ or NJDr which are generated by the reaction of 0, with



N02.



     Although the reaction of S02 with 0, has been shown to be slow in



the gas phase, there is some evidence that this reaction occurs rapidly



in the presence of water droplets, and might thus be expected to occur



rapidly on the surfaces of moist particles.



     Oxidation Rates



     Recent results from smog chamber studies at Battelle, Calspan



and the University of Minnesota show that the SO,., photooxidation rate



differs from chamber to chamber by as much as two to three orders of



magnitude.  The highest reported rate for S0? in the "clean" air cham-



ber system (61 per hour, Battelle) is comparable to that in the real,



urban atmosphere and does not seem to be much affected by the presence



of propylene/NO .  Experimental study is now under way to find whether
               J\.


observed discrepancies in the oxidation rate reflect contaminant effects



or chamber surface effects.



4.2.6.1.2  Aerosol Formation--The marked influence of S02 on aerosol



formation in photochemical smog simulation studies is well documented.



Although the exact mechanism by which S02 is converted into aerosol



remains uncertain, these general conclusions can be drawn:   (1) In the
                                   167

-------
absence of SCL, saturated hydrocarbons produce little, if any, aerosol.



In the absence of SCL, aromatic hydrocarbons and olefinic hydrocarbons



with five or more carbon atoms form aerosols; those with four carbons or



less do not.  Dienes, terpenes and cyclo-olefins also form aerosols in



the absence of SCL.  (2) SCL increases light scattering in studies of



individual hydrocarbons and is particularly noticeable with olefins,



where the increase is enormous.  Increase with paraffins is moderate,



and with aromatics, small.  (3) SCL increases the condensation nuclei



count in studies of hydrocarbon-NO  mixtures.  In the case of 1-



dodecene and 1,3-hexadiene, only a few ppb of S0? are required to pro-



duce an order of magnitude effect.  With aromatics only small increases



are seen.  (4)  In general the formation of aerosol in hydrocarbon-NO -
                                                                     J\.


SCL systems does not occur to any appreciable extent until most of the



NO is converted to N0~ and 0_ begins to form.  (5) Experimental evidence



shows that S0~ influences the reaction rate parameters in simulated smog,



the degree of influence depending on such factors as realtive humidity,



initial N09/N0  ratio, hydrocarbon/NO  ratio and hydrocarbon type.  (6)
          L,   -X                      !X


There is controversy about the chemical composition of aerosol formed



from the hydrocarbon-NO -S07 photochemical system.  However, there is
                       -A-   L*


compelling evidence that the aerosol formed from C<5 olefins-NO^-SO^ is



predominantly inorganic--mainly H~SO.--whereas the higher olefinic hydro-



carbons produce carbonaceous aerosol as well.  Studies on the propylene-



P_-SO,, system indicate that the dominant conversion for SO- results in



formation of H-SO..  In the presence of NH_, NH.SO. aerosol is observed.



Infrared spectra of dried, Cf-LCl- extracts, of atmospheric and smog cham-



ber aerosols, show C-H absorptions around 3 y, C = 0 absorptions around
                                168

-------
6.5 y, C = C and/or N = 0 absorptions around 6.7 u and a number of peaks



at longer wavelengths.  Gas chromatographic-mass-spectrometric studies



indicated organic acids and nitrate esters were also present.  Infrared



spectra of aerosols formed from 1-heptene-NO  with and without SCL indi-
                                            Jv                    b


cated that with SCL the aerosol contained a sulfonic acid.



4.2.6.1.3  Catalytic Oxidation--Reaction rates for the system SCL-H-O-



solid surfaces have been made.  It was found that fractional collisions



of SCL leading to reaction with AKO, and MnCL is 3x10  , and with fly



ash and charcoal, 5x10  .  These values suggest lifetimes of about one



hour in urban plumes and 10 hours in coal-fired power plant plumes for



relative humidities of 50%.  Lifetimes increased as realtive humidity



decreased.  However, other studies of SCL-H-O-Fe^O, indicate that reac-



tion does not depend on relative humidity.  For high SCL concentrations


                                                           41
(>700 ppm) and large liquid droplets, Matteson and Giardina   measured



a 601 increase in the mass transfer of SCL to the droplet if a surface

                            2
charge density of 6stat C/cm  was applied.  The magnitude of the effect



is not known for ambient SCL concentrations charged raindrops.



4.2.6.1.4  Physical--The solubility in water of SCL at low concentrations


                                              42
has been measured at 25.1 C as function of pH.    The scheme assumed was:



          SCL     + H00, .    t  SCL    + H00
            2 gas    2 liq        2 aq    2


          SCL    + H~0       ?  H70 + HSO%
            2 aq    2            3        3


The second ionization



          HSO~ + H20         +  H30+ + S032"



was assumed to be negligible.  The experimental results agree well with



values extrapolated from measurements at higher SCL concentrations by


                     43
Johnstone and Leppla.
                                     169

-------
4.2.6.2  Field Studies--Atmospheric data on SCL and particulate sulfates


are available from:  1)  24-hour integrated network measurements of SCL


and suspended water-soluble sulfates at urban and nonurban continental


and maritime sampling sites in the United States, and 2) from field


studies of atmospheric aerosols and gaseous smog components.  Interpre-


tation of data has emphasized:  (1) the distribution of SCL and sulfate,


(2) the relationship between SCL and sulfate, and (3) chemical forms of


sulfur in particulate matter.


4.2.6.2.1  Distribution of SO,-,--Recent analysis of national and regional


trends in sulfur dioxide show a pronounced decline in sulfur dioxide

                             44
levels throughout the nation.    Figure 4.11  shows that  this downward trend


for 1970-1973 occurs throughout the nation with perhaps a degree of


leveling off at stations where concentrations are well below the annual


standard.  Based on the number of observation sites (Table 4.8), these


downward trends represent general patterns in urbanized population cen-


ters, but may not adequately represent SCL levels near nonurban point


sources.  Data from background sites show that background SCL levels


remained relatively stable in the 1970-1973 period.



     Table 4.8.  SURVEILLANCE CATEGORIES FOR SULFUR DIOXIDE SITES44
                                 (Number of Sites)




                     	     Geographical Area	
                                        North
                     Northeast  ^outh  Central  Midwest  West  Nation
Population-oriented
Source-oriented
Background
65
1
4
id
1
2
62
2
2
33
0
2
21
0
0
199
4
10
     Total              70       21      66       35      21    213
                                170

-------
   T~I   i   ni    r
  o
  a.
  t
  3:
  o
I    I    I    I    I   I    I    I
                                            UJ
                                            £

                                            O
                                                                                        T3
                                                                                         X
                                                                                         O
                                                                                         3
                                                                                         co
                                                                                         C
                                                                                         (LI
                                                                                         S_
(T3
C
O

en
O)
                                                                                        •o
                                                                                        c:
                                                                                        ro
                                                                                           CO

                                                                                        ra CT>
                                                                                        c: i—
                                                                                        o  i
                                                                                        •i- O

                                                                                        ro cr»
                                                                                         B,
                                                                                        •H
                                                                                        ft.
                                             171

-------
                                                              45
4.2.6.2.2  Relationship between S0? and Sulfates--Altshuller's   analysis



of 1964-68 National Air Surveillance Networks data for S02 and sulfate



showed that the relationship between atmospheric SO- and sulfate is not



simple.  His results showed that a reduction of SCL may not cause a pro-



portional reduction in sulfate, suggesting in turn that control of other



factors--hydrocarbon, NO , primary aerosol and NH,--in addition to SCL
                        X                        O                   L*


also may be necessary to achieve acceptable low sulfate levels.  A labora-



tory program designed to determine the effect of these factors on oxida-



tion of SCL has been initiated.  These effects are being studied under



(1) conditions similar to those prevailing in air above an urban area,



(2) conditions simulating transport where the transported pollutants



receive prolonged irradiation, and (3) conditions within air masses in



the vicinity of roadways.



4.2.6.2.3  Chemical Forms of Sulfur in Particulate Matter--In the past



most studies have determined only the sulfate content of ambient



aerosols.  Craig et al.   have undertaken a study to establish a com-



plete inventory of sulfur compounds present in ambient particulate



matter.  Seven separate chemical species of sulfur have been identified


                                                 -2         -2   0
in atmospheric samples taken in California: SCL, SCL , SCL, SO, , S , and



two kinds of sulfides.  Sulfates were found to be the dominant species,



although reduced forms of sulfur were at times comparable to the sulfate



concentrations.



     Novakov et al.   determined the chemical states of sulfur in smog



particles collected in two particle size classes as a function of time



of day in Pasadena, California.  The sulfur content was found to be



highest at night and consisted of S   species and S   species.  The S
                                 172

-------
species predominated at night on the smaller particles, and was presumed



to be adsorbed S02 which was later oxidized to S    (SO.  ), and predomi-



nated in larger particles during the day.


                                         48
     In laboratory studies, Taarit et al.   have shown that S0~ and MgO



powder react in sunlight to form SO,.  It is likely that this reaction



occurs in a liquid phase on the surface of the MgO, and may occur on all



basic metal oxides in the atmosphere.  The ion SO,.,  is formed by exposing



V20r on silica gel and MgO to SO,-,.  Although SO,, and H2S in the gas phase


                              49
react alowly, Rao and Lunsford   have found the reaction of the S02



surface ion is rapid and yields free sulfur.  They  also observed the SO.



surface ion.



4.2.6.3  Transport and Removal--SO,, in the atmosphere may  undergo reac-



tion with the earth's surface (grass, trees, concrete, etc.).  The flux



of SO,, to ground can be expressed as



          Flux = K  9c

                  Z 3i"


     where K  = the vertical eddy diffusitivy of mass, cm  /sec
            Li


           3c = the vertical concentration gradient of S07 near

           3l                                            Z

                the ground, gm/cc/cm



The flux is directly proportional to the local SO,,  concentration, and



          Flux = vc



     where v = proportionality constant, commonly called the "deposition



               velocity,"  cm/sec



           c = SO,, concentration



Therefore, v = 1 K  3c  .

               c  Z 3z
                                    173

-------
The three terms on the right side of the above equation can be measured.
The magnitude of the deposition velocity, v, is a measure of the
reactivity of the surface.  The values reported recently for the depo-
sition velocity, v, of SCL on a variety of surfaces are given in Table 4.9,
                  Table 4.9.  S02 DEPOSITION VELOCITIES
         Type of Surface
         wet leaves
         grass

         grass
         grass
         vegetation
           (St. Louis)
         iron (90% rela-
           tive humidity)

         zinc (90% rela-
           tive humidity)
Deposition Velocity
1 cm/sec
0.8 cm/sec (summer)
0.3 cm/sec (autumn)
0.55 cm/sec
0.8 cm/sec
.5 to 5 cm/sec

0.015 cm/sec

0.01 cm/sec
0.049 cm/sec

0.063 cm/sec
Reference
   50
   51
   52
   53
   53

   54

   55
   54

   55
If the deposition velocity is as large as more recent studies indicate,
surface removal of S0? in air layers which are well mixed to the ground
may dominate S07 removal and conversion processes.
4.2.7  Mathematical Modeling
     The EPA Meteorology Laboratory concentrates most of its efforts on
studies of transport and dispersion.  It develops and tests mathemati-
cal models to help to relate rates of source emissions to concentrations
                               174

-------
at receptors, depending on meteorological conditions.  A general discus-



sion of modeling is given in Appendix A, Air Quality Criteria for Sulfur



Oxides.     Models have been developed to estimate pollution concentra-



tions over an entire city from a single large source like a power plant



stack, or from a source such as a highway or an airport.



     The UNAMAP (Users' Network for Applied Modeling of Air Pollution)



was put into operation in May, 1973.  The purpose of UNAMAP is to make



available current air quality simulation models to both EPA and non-EPA



users via a teletype-processing network.  The models are all in the form



of computer programs accessible from remote terminals connected to a



central computer by telephone lines.



     The six models now on UNAMAP are:



          APRAC - urban carbon dioxide model.



          HIWAY - hourly concentrations from roadway segments.



          CDM - Climatological Dispersion Model.



          PTMAX - maximum hourly concentrations from a point source.



          PTDIS - hourly concentrations at various downwind distances



                  from a point source.



          PTMTP - hourly concentrations at various receptor locations



                  from multiple point sources.



     The practical application of dispersion models is shown by the fol-



lowing example.  Studies concerned with the impact of state implementa-



tion plans on low-sulfur coal requirements predicted a probably deficit



in 1975.  Therefore, hourly emissions and meteorological data were used



to model peak 1-hour, 24-hour and annual concentrations of SCL in the



vicinity of  180 power plants.  It was determined that 62 plants might
                                   175

-------
be able to operate with full variances, 39 with limited variances and 80


with no variances.  The shift in full requirements should result in an


annual saving of 137 million tons of low (less than 1.0%) sulfur coal.

                                           S7 *-iR
     A different type of mathematical model  '   has also been developed


based on actual air pollution measurements in cities at intervals of


time from one hour to one year.  It shows statistical relationships and


is needed for interrelating air pollutant effects, air quality stan-


dards, air quality monitoring results, diffusion calculations, source-


reduction calculations and emission standards.


4.2.7.1  Fluid Modeling Facility--A fluid modeling facility is being


established to study the flow and diffusion of pollutants around build-


ings, highway configurations and complex terrain.  It includes large


and small wind tunnels, a model shop, electronics shop, minicomputer,


photographic darkroom, classroom and offices.  A contract has been


awarded for the construction of a recirculated water channel/stratified


towing tank.  Layered mixtures of salt water will be used in the test


section to produce density stratification.  Dyes and shadowgraphs will


be used for flow visualization.


     Examples of results that can be obtained with a tow tank are

                                                   59
found in similar work performed under EPA contract.    One study was


of plume dispersion from an elevated source upwind of an idealized


mountain under two different stability conditions.  Highlights of


the study were:  (1) within stably stratified flow is upstream blocking


that causes increased plume rise and spreading; (2) the plume tends to


flow around rather than over the ridge, thus greatly enhancing the


plume's lateral spread; (3) concentrations would be larger at stations


on the mountain ridge than at other surface stations.



                                176

-------
4.2.7.2  Regional Air Pollution Study (RAPS)--There is a need to develop



and validate improved air quality simulation models for applying to



least-cost pollution control strategies, and to other models such as



those for land use, ecological and total cost effectiveness.  This need



was recognized in setting the objective for the Regional Air Pollution



Study (RAPS), a five-year study in the St. Louis metropolitan area using



an extensive base of emission, meteorological and air quality data with



research on the processes of pollutant transformations, dispersion and



removal.  A 25-station telemetering network will provide measurements of



CD, NO, NCL, 0.,, total hydrocarbons, non-methane hydrocarbons, total



gaseous sulfur, SCU H S, fine particulates, total particulate and meteo-



rological observations.  Two large helicopters from EPA's Environmental



Research Center at Las Vegas are outfitted to measure most of the para-



meters measured at the fixed stations.  Considerable effort has been



spent setting up data formats and developing software from the RAPS data



bank, which will include emission data and models, all data from the



aerometric network, meteorological upper air sounding data, and most



data from special studies to be performed in conjunction with RAPS.



     Studies have already been performed to describe the urban boundary



layer structure with emphasis on morning and evening transition periods



and investigators have made extensive measurements of aerosols in and



around St. Louis.  Most special studies are being done cooperatively



with the METRQMEX project, which is concerned with the increased pre-



cipitation amounts observed downwind from large urban or industrialized



areas.
                                     177

-------
4.2.7.3  Large Power Plant Effluent Study  (LAPPES)--The Large Power


Plant Effluent Study (LAPPES) was to determine the pattern of ground-


level concentrations of pollutants released to the atmosphere from


large coal-burning mine-mouth power plants.  Four volumes of basic

                                                          60-63
data obtained from the LAPPES project have been published.       Early


analyses indicate that tall stacks help to reduce or sometimes eliminate


significant ground level concentrations under some meteorological condi-


tions, particularly in the stack's vicinity.  However, the study also


showed that there are some things tall stacks cannot do.  For example,


reasonably increasing stack height will not significantly reduce epi-


sodic ground-level concentrations of a plume trapped within a limited


mixing layer; if emissions increase, so will ground-level concentrations.


Washout of SCL from the plume was also studied in the LAPPES.  The effect


of precipitation falling through the plume seems to bring SCL closer to


the ground.


4.2.7.2  Rough Terrain Effects--According to theoretical estimates, high


concentrations of air pollution can occur when a plume from a stack


encounters high ground, and we need to know if such concentrations can


actually occur.  Field studies using tracers have been conducted in rough


or mountainous area, one such having been done cooperatively with the AEC

                           64
at Huntington Canyon, Utah.    There it was found that depending on


atmospheric stability conditions, dispersion rates were 4-15 times


greater than might have been estimated using customary procedures.  Nfore


rough terrain field studies are planned.


4.2.7.5  Highway Studies--In the past few years more and more governmental


and private groups have used highway (line source) air quality models for
                                 178

-------
environmental impact statement (EIS) preparation and review.  Although


several mathematical models have been developed for highway evaluations,


little is known about the initial spread of pollution due to the turbu-


lent wake of vehicles and subsequent dilution within the first hundred


meters of travel from the highway.  The Meteorology Laboratory has


sponsored a tracer study of dispersion within the immediate vicinity of

          65
a highway.    An inert tracer gas (sulfur hexafluoride) was dispersed


from a vehicle moving in the traffic stream of a six-lane highway for


sampling at 12 locations at distances of about 100 meters downwind and


20 meter upwind.  Carbon monoxide was measured simultaneously.  Early


results indicate that vertical dispersion in the immediate vicinity of


the highway is larger than assumed in the EPA HIWAY model and that the


turbulent wake significantly affects concentrations.


4.2.7.6  Airport Studies--Two field studies have been conducted at air-


ports.  The first,   at Washington National Airport, was to validate

                                                              f\ 7
and further develop an existing mathematical dispersion model.    For


six months continuous records of air quality, meteorological and


operational records were compiled.  Carbon monoxide, particulates, non-


methane hydrocarbons and nitrogen dioxide were sampled at eight loca-


tions.  The final result showed the modified model to consistently


predict mean and median values for CO and particulates  (ranging from 16%


under prediction to 36% over prediction).  These validation results were


without calibration of any kind.  Better results are expected in the


future when the model will be calibrated.  The second study,   at


Atlanta International Airport, was to determine the effect cf experi-


mental aircraft emissions control operations on air quality.  The
                                    179

-------
emissions control procedure consisted primarily of shutting down one


engine by approved aircraft during taxiing from landing runway to


terminal building.  A network of eight monitoring stations was used.


While a maximum hourly reduction of about 15% occurred in aircraft


emissions, the instrument network did not detect a statistically sig-


nificant reduction in air quality levels which could be attributed to


emission control procedures.


4.2.7.7  Precipitation Washout of Sulfur Compounds--A model for the

                                                                     69,70
washout of sulfur dioxide from power plant plumes has been developed


based on reversible gas absorption phenomena.  It can be used for pre-


dicting washout of pollutant gases other than sulfur dioxide, with


substitution of appropriate physical properties.  The model is based on


concepts of reversible behavior and negligible plume distortion by the


washout.  Field experiments showed that sulfur dioxide concentrations in


rain can be calculated within a factor of two of observed values, although


predictability is reduced in the immediate vicinity of the source and


complicated by the occurrence of chemical reactions.


     Conclusions from the model, verified by observation, are:


     1.  Washout of sulfur dioxide from a concentrated, high-elevation


plume can be obscured by the presence of low-elevation, low-concentration


background levels;


     2.  The acidity of rain strongly influences its sulfur dioxide


scavenging potential and


     3.  Negative washout occurs as the result of desorption of sulfur


dioxide from the rain below the sulfur dioxide plume.
                                180

-------
     Sulfate washout measurements vrere also made.  Results indicate that
the rate of sulfur removal via sulfate washout is up to five times more
rapid than that via sulfur dioxide washout.
5.2.7.8  Precipitation Scavenging of Inorganic Pollutants from Metropoli-
tan Source--In the summers of 1972 and 1973 field experiments were con-
ducted in the St. Louis area to measure the precipitation scavenging of
                     71
inorganic pollutants.    Concentration measurements of collected rain-
water have shown that precipitation, scavenging by convective storms can
be an effective mechanism for removal of urban pollutants from the
atmosphere.  Results of the study indicate that scavenging removal rates
can be comparable to urban emission rate estimates.
4.2.7.9  Simulation of the Photochemical Reaction Processes Within a
Power Plant Plume--Based on studies of chemical mechanisms observed in
smog chambers a preliminary plume dispersion model has been developed
to investigate SCL + S0| transformation in power plant plumes.  Pre-
liminary results indicate transformation rates of 2-3% per hour.  Higher
                                                               72
rates of about 20% per hour were reported by TVA investigators.
                          73
Results from another study   agree with the model.  Large concentrations
of particulate in the TVA plume may have caused more rapid SCL conversion
because of catalytic reactions.  In the other study the plumes had low
particulate concentrations and therefore only homogeneous gas phase con-
version processes were important.
4.2.7.10  High Surface Ozone Concentrations--Recently, high surface
ozone concentrations have been observed in rural areas remote from urban
centers, with values at times exceeding the National Ambient Air Quality
Standard.  Consequently, mechanisms for bringing ozone down from the
                                    181

-------
stratosphere, formation during lightning discharges, and near surface


chemical processes were reviewed.  High surface values can be caused by


direct transport downward from the stratosphere through the jet stream


region behind strong cold fronts and by convective activity transport-


ing downward ozone previously injected into the upper troposphere.


Lightning contributes only brief small rises in ozone concentration, a


conclusion agreeing with observations of thunderstorm effects made in

                                                               74
a study of ozone conditions near 33 cities during summer, 1971.


Chemical reactions make significant contributions over a period of


time, but chemical and physical processes that cause high surface ozone


concentrations are not well understood.  Laboratory and field studies


are in progress.  In one instance computerized meteorological data from


regularly reporting stations, compiled on a global scale, is being used


to prepare trajectories automatically for tracing the origin of air in


which high ozone concentrations have been observed.


4.2.7.11  Los Angeles Reactive Pollution Project (LARPP)--During the


Los Angeles Reactive Pollution Project (LARPP), a photochemical field


experiment, parcels of air were followed by especially instrumented


helicopters and mobile van in order to determine changes in reactive


pollutants.  The helicopters were tracked by radar and guided by bal-


loons that floated at near constant levels.  Tracer materials were


also released and sampled.  Results of this project are to be reported


in the Santa Barbara, California, workshop-symposium to be conducted


November 12-14.


     In connection with LARPP a team from the Meteorology Laboratory


made special solar radiation observations from August 30 through
                              182

-------
November, 1973.  Six stations were instrumented, one of which was on a



mountain at 6000 feet elevation,  /is expected, atmospheric pollution



substantially reduced incident ultraviolet energy.  For example, when



visibility at El Monte was approximately three to five miles (a common



occurrence during the pollution season), the incident ultraviolet energy



was typically about 30 to 40% less than that received on top of the



mountain, depending on solar elevation.  In the absence of pollution



the difference would have been expected only to be about 5% less.



Obviously, the top of a pollution layer receives considerably more



ultraviolet irradiance than the bottom layer.  Most photochemical models



today treat ultraviolet energy in a simplistic way and do not account for



its vertical variation through the pollution layer.  It has been suggested



that these models improved by allowing for such vertical variation of the



ultraviolet radiation.
                                      183

-------
                              4.3  REFERENCES
 1.  McConnell, J. C., M. B. McElroy, S. C. Wolfsy.  Natural Sources of
     Atmospheric Carbon Monoxide.  Nature.  233 (5316):187-8.  1971.

 2.  Weinstock, B., H. Niki.  Carbon Monoxide Balance in Nature.  Science.
     176:290.  1972.

 3.  Levy, H. II.  The Tropospheric Budgets for Methane, Carbon Monoxide
     and Related Species.  Presented at the Meeting on Sources, Sinks,
     and Concentrations of Carbon Monoxide and Methane in the Earth's
     Environment.  St. Petersburg Beach, Florida.   August 15-17, 1972.

 4.  Weinstock, B.  Carbon Monoxide:  Residence Time in the Atmosphere.
     Science.  166:224-225.  1969.

 5.  Hum, R. W. and T. W. Chamberlain.  Fuels and Emissions--Update and
     Outlook, 1974.  Society of Automotive Engineers.  Bureau of Mines,
     Paper No. 740694.  June, 1974.

 6.  Gay, B. W. Jr. and J. J. Bufalini.  Nitric Acid and the Nitrogen
     Balance of Irradiated Hydrocarbons in the Presence of Oxides of
     Nitrogen.  Environ. Sci. Technol. _5:422.   1971.

 7,  Spicer, C. W. and D. F. Miller.  Nitrogen Balance in Smog Chamber
     Studies.  Paper No. 74-247.  Presented at the 67th Annual Air
     Pollution Control Association Meeting.  Denver, Colorado.  June 9-
     13, 1974.

 8.  Miller, D. F. and C. W. Spicer.  A continuous Analyzer for Detect-
     ing Nitric Acid.  Paper No. 74-17.  Presented at the 67th Annual
     Air Pollution Control Association Meeting.  Denver, Colorado.
     June 9-13, 1974.

 9.  Nicolet, M.  Nitrogen Oxides in the Chemosphere.  J. Geophys., 70:
     679.  1965.

10.  Dodge, M. C. and J. J. Bufalini.  Advances in Chemistry.  Series
     113:232.   1972.

11.  Dimitriades, B. and M. Whismen.  Carbon Monoxide in Lower Atmosphere
     Reactions.  Environ. Sci. Technol. _5:219-222,   1971.

12.  Demergian, K. L., J. A. Kerr, and J. G. Calvert.  The Predicted
     Effect of Carbon Monoxide on the Ozone Levels in Photochemical
     Smog Systems.  Environ. Letters.  3_:73-80.  1972.

13.  Lee, R. E. Jr., S. S. Goranson, R. E. Envione and G. P. Morgan.
     National Air Surveillance Cascade Impactor Network, II.  Size
     Distribution Measurements of Trace Metal Components.  Science
     178_:567-575.    November 10, 1972.

                               184

-------
REFERENCES (continued


14.  Durham, J. L., W. E. Wilson, K. Willeke and K. T. Whitby.   Comparison
     of Volume and Mass Distribution for Denver Aerosols.  Presented
     before the Division of Environmental Chemistry, American Chemical
     Society, Los Angeles, California.  April, 1974.

15.  Lundgren, D. A. and H. J. Paulus.   Direct Determination of Total
     Atmospheric Aerosol Mass Distributing.  Presented before the Divi-
     sion of Environmental Chemistry.  American Chemical Society, Los
     Angeles, California.  March 30-April 4, 1974.

16.  Patterson, R. K. and J. Wagman.  Mass and Composition of an Urban
     Aerosol as a Function of Size for Several Visibility Levels.  Seminar
     10.

17,  Schwartz, W. E., P. W. Jones, C. J. Riggle and D. F. Miller.  Chemi-
     cal Characterization of Model Aerosols.  Final Report Grant
     No. R-801174.  EPA. 1974.

18.  Friedlander, S. K.  Characterization of Aerosol Distribution with
     Respect to Size and Chemical Composition.  J. Aerosol Sci.  1_:295-
     307-  1971.

19.  Miller, M. S., S. K. Friedlander and G. M. Hidy.  A Chemical Element
     Balance for the Pasadena Aerosol.   J. Coll. Interface Sci.  59, No. 1.
     April, 1972.

20.  Friedlander, S. K.  Chemical Element Balances and Identification of
     Air Pollution Sources.  Environ. Sci. Tech. 7^:235-240.    1973.

21.  Gatz, C. R.  Carbon Monoxide in the Atmosphere.  Presented at:
     Atmospheric Chemistry Mr Pollution Seminar.  Oregon State University,
     Corvallis, Oregon.  1972.

22.  Heisler, S. R., S. K. Friedlander, R. B. Husar.  Relation of Smog
     Aerosol Size and Chemical Element Distributions to Source Character-
     istics.  Atmos. Environ. 7_: 633-649.  1973.

23.  Roberts, J. J., E, S. Gobe, A. S. Kennedy.  Urban Atmospheric Disper-
     sion Model.  Chem. Abst. 139828, Vol. 79.  1973.

24.  Grosjean, D. and S. K. Friedlander.  Gas--Particle Distribution Factors
     for Organic Pollutants in the Los Angeles Atmosphere.  Presented at
     the 67th Annual Meeting of the Air Pollution Control Association.
     Denver, Colorado.  June 9-13, 1974.

25.  O'Brien, E. F., V. P. Gutschick, V. McKoy, J. P. McTague.  Polariz-
     ability of Interacting Atmospheric Relation to Collison-Induced
     Light Scattering and Dielectric Models.  Phys. Rev. A.  8:690-696.
     1973.

                                    185

-------
REFERENCES (continued)
26.  Miller, D.  F., W. E. Schwartz, P.  W.  Jones, D.  W.  Joseph, C.  W.
     Spicer, C.  J. Riggle, and A. Levy. Haze Formation:   Its Nature
     and Origin  1973,  EPA Contract No. 68-02-0276 with Battelle-
     Columbus Laboratories.  Columbus,  Ohio.   June,  1973.

27.  Schuetale,  D., A. L. Crittenden, and  R.  J.  Charlson.   Application
     of Computer Controlled High Resolution Mass Spectrometry to the
     Analysis of Air Pollution.  J. A.  Poll.  Con. Assoc.   23:704.
     1973.

28.  Schuetale,  D., D. R. Cronn, A. L.  Crittenden, and R.  J.  Charlson.
     Molecular Composition of Secondary Aerosol  and  Its Origin.  Pre-
     sented at 172nd National American Chemical  Society Meeting,
     Symposium on Surface and Colloid Chemistry  in Air Pollution Con-
     trol.  To be published in J. Colloid  and Interface Science.  1974.

29.  Wilson, W.  E., D. F. Miller, and A. Levy.  The  Effect of Fuel
     Composition on Atmospheric Aerosol Due to Auto  Exhuast.   J. Air
     Poll. Con.  Assoc.  23(11):949.  1973.

30.  Hanst, P. L., J. Lehman, H. Reichle,  M.  Tepper.  Remote  Detection
     of Air and  Water Pollution from Satellites  and/or Airplanes.
     Man's Impact on Climate.  W. F. Matthews, ed.  MIT Press.  Cam-
     bridge, Massachusetts.  1974.

31.  Brosset, C., K. Andreasson and M.  Perm.   The Nature and  Possible
     Origin of Acid Particles Observed at  the Swedish Coast.   Reported
     by the Swedish Water and Air Pollution Research Laboratory.  July,
     1974.

32.  Charlson, R. J. and N. C. Ahlquist.  Apparatus  and Method for Mak-
     ing an Iii Situ Determination of the Chemical Properties  of
     Atmospheric Aerosols.  U.S. 3,700,333.  Battelle.  Corp.   October,
     1972.

33.  Cadle, R. D. and J. W. Powers.  Some  Aspects of Atmospheric Chemi-
     cal Reactions of Atmoic Oxygen.  Tellus  18^:176.   1966.

34.  Davis, D. D.  New Rate Measurements on the  Reaction of 0( P), 0,
     and OH.  AIAA Paper No. 73-501.

35.  Wood, W. P., A. W. Cartleman,  Jr., and I. N. Tang. Mechanisms of
     Aerosol Formation from SO™.  Paper No. 74-153.   Presented at  the
     67th Annual Meeting of the Air Pollution Control Association,
     Denver, Colorado.  June 9-13,  1974.
                               186

-------
REFERENCES (continued)


36.  Want, C. C. and L. I.  Davis, Jr.   Measurement of Hydroxyl Concen-
     trations in Air Using a Tunable UV Laser Beam.  Phys. Rev.  Lett.
     32;349.   1974.

37.  Davis, D.  D.,  W. A.  Payne, and L.  J.  Stief.   The Hydroperoxyl
     Radical  in Atmospheric Chemical Dynamics:  Reaction with Carbon
     Monoxide.   Sci.   17^:280-282.   1973.

38.  Dodge, Marcia.  Personal Communication.  EPA Chemistry and Physics
     Laboratory, Research Triangle Park, North Carolina 27711.  Septem-
     ber, 1974.

39.  Cox, R.  A. and S.  A. Penkett.   Aerosol Formation from Sulfur
     Dioxide  in the Presence of Ozone  and  Olefinic Hydrocarbons.  J.
     Chem. Soc.  Faraday Transaction I, Part 9, 68_:1735.  1972.

40.  McNelis, D. N.  Aerosol Formation from Gas Phase Reactions  of
     Ozone and Olefin in Presence of Sulfur Dioxide.  Ph.D. Disserta-
     tion. University of North Carolina,  Chapel Hill, North Carolina.
     1974.

41.  Matteson,  J. M.  and P. J. Giardina.  Mass Transfer of Sulfur Dioxide
     to Growing Droplets.  Environ. Sci. Tech.  8^:50-55.  1974.

42.  Hales, J.  M. and S.  L. Sutter. Solubility of Sulfur Dioxide in
     Water at Low Concentrations.  Atmos.  Environ.  7_: 99 7-1001.   1973.

43.  Johnstone, H.  F. and P. W. Leppla. Solubility of Sulfur Dioxide  at
     Low Partial Pressures, lonization Constant and Heat of lonization of
     Sulfurous Acid.   J.  Atmos. Chem.  Soc.  56_:2233.  1934.

44.  Monitoring and Air Quality Trends Report, 1973.  U.S. Environmental
     Protection Agency, Research Triangle  Park, North Carolina 27711,
     EPA-450/1-74-007.   October, 1974.

45.  Altshuller, A. P.   Atmospheric Sulfur Dioxide and Sulfate.   Environ.
     Sci. Tech.  7;709-712.  1973.

46.  Craig, N.  L., A. B.  Harker, and T. Navakov.  Determination of
     Chemical States of Sulfur in Ambient  Pollution Aerosols by X-Ray
     Photoelectron Spectroscopy.  Atm.  Environ.  8^:15-21.  1974.

47.  Navokov, T., P.  K. Mueller, A. E.  Alcocer, and J. W. Otros.  Chemical
     Composition of Pasadena Aerosol.   J.  Colloid Interface Sci.  39:225-
     235.  1972.

48.  Taarit,  Y. B. and J. H. Lunsford.   Electron Paramagnetic Resonance
     Evidence for the Formation of S0~ by the Oxidation of SO" on MgO.
     J. Phys. Chem.  77:1365-67.  1973.                      ^

                                  187

-------
REFERENCES (continued)
49.  Rao, K. V. S. and J. H. Lunsford.  EPA Grant 801136.

50.  Spedding, D. J.  Uptake of Sulfur Dioxide by Barley Leaves at Low
     Sulfur Dioxide Concentrations.  Nature.  224:1229.  1969.

51.  Shepard, J. G.  Measurements of the Direct Deposition of Sulfur
     Dioxide onto Grass and Water by the Profile Method.  Atmos.
     Environ.  8_:69-74.  1974.

52.  Garland, J., D. Atkins, C. Readings, and S. Caughey.  Deposition
     of Gaseous Sulfur Dioxide to the Ground.  Atmos. Environ.  8_:
     75-79.  1974.

53.  Owers, M. and A. Powell.  Deposition-Velocity of Sulfur Dioxide
     on Land and Water Surfaces Using a   S Tracer Method.  Atmos.
     Environ.  8_:63-67.  1974.

54.  Sydberger, T. and N, Vannerberg.  The Influence of the Relative
     Humidity and Corrosion Products on the Adsorption of Sulfur
     Dioxide on Metal Surfaces.  Corros. Sci.  12^:775-780.  1972.

55.  Duncan, J. R. and D. J. Spedding.  The Effect of Relative Humidity
     on Adsorption of Sulfur Dioxide on to Metal Surfaces.  Corros.
     Sci.  13:993.  1973.

56.  U.S. Environmental Protection Agency.  Air Quality Criteria for
     Sulfur Oxides, Appendix A.  (First Working Draft).  National
     Environmental Research Center, Research Triangle Park, North
     Carolina 27711.  July, 1972.

57.  Larsen, Ralph I.  An Air Quality Data Analysis System for Inter-
     relating Effects, Standards and Needed Source Reduction.  J.  Air
     Poll. Con. Assoc.  213:933-940.   1973.

58.  Larsen, Ralph I.  An Air Quality Data Analysis System for Inter-
     relating Effects, Standards and Needed Source Reductions, Part 2,
     J. Air Poll. Con. Assoc.  24_:551-558.  1974.

59.  Lin, J. T., H. T. Liu, and Y. H. Pao.  Laboratory Simulation of
     Plume Dispersion in Stably Stratified Flows over a Complex Ter-
     rain.  Final Report under Contract 68-02-0800 with EPA.  Flow
     Research Report No. 29.  Kent, Washington.  February, 1974.

60.  Schiermeier, F. A. and L. E. Niemeyer.  Large Power Plant Effluent
     Study (LAPPES).  Vol. 1 - Instrumentation, Procedures and Data
     Tabulations APTD 70-2, National Air Pollution Control Administra-
     tion, Raleigh, North Carolina.  410 p.  June, 1970.
                               188

-------
REFERENCES (continued)
61.  Schiermeier, F.  A.   Large Power Plant Effluent Study (LAPPES).
     Vol. 2, Instrumentation, Procedures and Data Tabulations (1967
     and 1969), Environmental Protection Agency, APTD 0589.   Research
     Triangle Park, North Carolina 27711.  337 p.  1970.

62. Schiermeier, F. A.   Large Power Plant Effluent Study (LAPPES).
     Vol. 3, Instrumentation, Procedures and Data Tabulations (1970),
     Environmental Protection Agency, APTD 0735.  Research Triangle
     Park, North Carolina 27711.   296 p.  1972.

63.  Schiermeier, F.  A.   Large Power Plant Effluent Study (LAPPES),
     Vol. 4, Instrumentation, Procedures and Data Tabulations (1971)
     and Project Summary.  Environmental Protection Agency,  Research
     Triangle Park, North Carolina.  286 p.  November, 1972.

64.  Start, G. E., C. R. Dickson,  and L. L. Wendell.  Diffusion in a
     Canyon within Rough Mountainous Terrain, NOAA Tech.  Memo.   ERLTM-
     ARL28, Air Resources Laboratories,  Idaho Falls, Idaho.   1973.

65.  Clarke, J. F. and K. F.  Zeller.  Tracer Study of Dispersion from a
     Highway, Meterology Laboratory, Research Triangle Park, North
     Carolina 27711.   AMS Symposium on Atmospheric Diffusion and Air
     Pollution, Santa Barbara, California.  September 9-13,  1974.

66.  Thayer, S. D., D.  J. Pelton,  G. H.  Stradsklev, and B.  D. Weaver.
     Model Verification - Aircraft Emissions Impact on Air Quality,
     Final Report, EPA Contract 68-02-0665.  May, 1974.

67.  Platt, M., R. C. Baker,  E. K.. Bostress, K. M. Chug,  and R. D.
     Siegel.  The Potential Impact of Aircraft Emissions on Air Quality.
     Final Report Numbers 1167-1 and 2 (Vols. 1 and 2), Northern
     Research and Engineering Corporation, Cambridge, Massachusetts,
     NTIS No. PB-208-950.  1971.

68.  MacWaters, J. T.,  R. C.  Koch, and S. D. Thayer.  Air Quality
     Measured at Atlanta International Airport Before and During Experi-
     mental Aircraft Taxiing Gperatings, Final Report, EPA Contract  68-
     03-0358.  June,  1974.

69.  Hales, J. M.  Fundamentals of the Theory of Gas Scavenging by Rain.
     Atmos. Environ.   6_: 635-359.   1972.

70.  Dana, M. T., J.  M. Hales, W.  G. N.  Slinn, and M. A.  Wolf.   Natural
     Precipitation Washout of Sulfur Compounds from Plumes.   Ecological
     Research Series, EPA-R3-73-047, Environmental Protection Agency,
     Research Triangle Park,  North Carolina 27711, 204 p.  1973.
                                   189

-------
REFERENCES (continued)
71.  Dana, M. T., T. M. Hales, C.  E. Hane, and J.  M. Thorpe.  Precipi-
     tation Scavenging of Inorganic Pollutants from Metropolitan
     Sources.  1974.

72.  Gartrell, F. E., F. W. Thomas, and S. P. Carpenter.   Atmospheric
     Oxidation of S09 in Coal-Burning Power Plant  Plumes.   Amer. Indus.
     Hyg.  Assoc. J.  ZZ4:113.  1963.

73.  Manowitz, B., L. Newman, and W. D.  Tucker.  The Atmospheric Diag-
     nostics Program at Brookhaven National Laboratory:   Fourth Status
     Report.  BNL 50361 (Meteorology - TID-4500).   1972.

74.  Fankhauser, R.   1971 Summer Study of Ozone at 33 Cities,  Quality
     Assurance and Environmental Monitoring Laboratory, Environmental
     Protection Agency, Research Triangle Park,  North Carolina 27711.
     1974.
                             190

-------
                               5.   EFFECTS





5.1  HEALTH



5.1.1  General Discussion



     The Clean Air Act amendments  of 1970 mandated that the Administrator



of the U.S. Environmental Protection Agency promulgate ambient air



quality standards for substances that may be emitted into the atmosphere



and thereby represent potential health hazards.



     To fulfill the mandate, standards were established which in com-



pliance with the law were designed on the basis of the best information



available to include a margin of safety sufficient to assure protection



of the most sensitive segments of our population.  Because the informa-



tion base on which standards were  established was incomplete, the agency



committed itself to a continuing research program designed to determine



their adequacy.



     As results from this and other research efforts around the world



become available, it is necessary to reappraise and update the health



basis for the standards, as is done in this document.



5.1.2  Nitrogen Oxides



5.1.2.1  Human Studies--The National primary standard for nitrogen



dioxide is 100 yg/m  (0.05 ppm) annual arithmetic mean.



5.1.2.1.1  Evidence upon which standard was based--The existing primary



N09 standard of 100 yg/m  was based primarily on the Chattanooga School



Children studies ' '  conducted from November, 1968 through April,



1969.  Long-term exposure to ambient N0~ concentrations between 117 and



205 yg/m   (0.062 and 0.109 ppm) accompanied by suspended nitrate
                                 191

-------
concentrations between 4 and 6 yg/m  for six months and longer was



associated with the following effects:  (1) an 18.8% excess in acute



respiratory illness in families;  (2) significantly decreased lung func-



tion  (FEVn _,.) in elementary school females; and  (3) significantly



increased bronchitis morbidity in elementary school children exposed for



two and three years.



5.1.2.1.2  Interim evidence (1969 through January 1, 1973)--Estimates of



community exposure to NO- in the initial Chattanooga study were derived



from air monitoring data obtained with gas bubblers employing the 24-hour



Jacobs Hochheiser method.  Since the time of the study, the Jacobs Hoch-



heiser method has been found unreliable, creating the need to reevaluate



the relationship between quantitative exposure level and observed adverse



health effects in Chattanooga using data obtained with other methods of



monitoring.



     Alternate exposure estimates were derived from the network air



monitoring stations established by the Division of Abatement, National



Air Pollution Control Administration (U.S. Public Health Service) in the



Chattanooga, Tennessee - Rossville, Georgia interstate area.  Continuous



recordings of NCL were taken, utilizing the colorimetric Saltzman tech-



nique at ten stations from December, 1967, through November, 1968.  A



complete report of data obtained from this network is given in the pub-



lication Chattanooga, Tennessee - Rossville, Georgia Interstate Air



Quality Study 1967-1968 (U.S. Department of Health, Education and Wel-



fare, National Air Pollution Control Administration Publication No. APTD-



0583, 1970).4



     Observed NCL concentrations, wind speed and direction and topo-



graphical characteristics were used to obtain NCu exposure.  Although





                                   192

-------
health data were collected from November, 1968, through April, 1969, in



the initial Chattanooga study (the six months immediately after the



period of monitoring by the Division of Abatement), NCL exposures of



the affected communities probably did not change substantially from



those measured from December, 1967, through November, 1968, because TNT



production by the Volunteer Army Ammunition Plant remained at peak



capacity throughout these months of 1968 and 1969.



     In the original Chattanooga health studies, the frequency of sam-



pling for NCL exposures using the now discredited Federal Reference



Method allowed dissociations of adverse health effects only with daily



or annual average NCL concentrations.  Air monitoring data from the



national abatement air monitoring network using the continuous Saltzman



NCL method provided additional information on hourly and daily frequency



distributions of NCL concentrations.  Experimental animal studies sug-



gested that short-term peak exposures lasting for two to three hours



were sufficient to account for excesses in acute respiratory diseases.



Therefore, the 90th percentile of the frequency distribution observed



for hourly concentrations measured by the Saltzman method was selected



as a more appropriate estimate of NCL exposure for relating to the



observed adverse health effect in the original Chattanooga study.



Ideally one would like to look at maximum hourly distributions as well.



An excess of acute respiratory illness among families was observed con-



sistently when the 90th percentile of hourly NCL concentrations was



376 yg/m  (.20 ppm) or above.  When similar hour exposures were 188 to



282 yg/m  (0.10 to 0.15 ppm), the evidence was not consistent.  In the



study on bronchitis rates in children, a measure of more severe
                                193

-------
respiratory disease, children exposed for two or three years to peak



hourly N02 concentrations of 188 to 282 yg/m3 (0.10 to 0.15 ppm) had



significantly higher bronchitis rates than children in the lowest



exposure neighborhood.



5.1.2.1.3  New Evidence (Since January, 1973) Recent Nitrogen Dioxide



Exposure in Chattanooga, Tennessee--Since the initial CHESS study in



Chattanooga, Tennessee, a vigorous pollution control program by the



Department of Defense and a decrease in TNT production has been accom-



panied by a decrease in NCL emissions, evidenced by a decrease in the



mean of the annual average levels of NCL in the most exposed study



neighborhoods from 282 yg/m3 in 1968 to 56 yg/m3 in 1973.  (Table 5.1)



Despite these lower annual NCL levels, the population living in the



community in 1972 with the highest annual average exposure to NCL con-



tinued to experience repeated short-term exposure to NCL as measured by



the 90th percentile of average daily concentrations (75 to 220 vg/m ).



(Table 5.2)  The 90th percentile of the maximum hourly NCL values ranged



from 228 to 815 yg/m3 in 1972 (Table 5.3).  In 1968 and in 1971, the



neighborhoods closest to the plant also were exposed to relatively high



levels of suspended nitrates (5.0-6.0 yg/m ).  In the intermediate



exposure community, the mean of the annual average NCL levels also fell



(113 yg/m3 in 1968 to 49 yg/m3 in 1973 - Table 5.1).  Short-term exposures



in this community were decreased from former high levels, but still the



90th percentile of the maximum hourly values of about 116 to 164 yg/m



were noted on 36 days each year (Table 5.3).  In the low exposure area, the



mean of the annual average NCL exposures were also reduced from 56 down
                                    194

-------







w
[J3
(T!
pTJ
*3"
2 CM
rH t-~-
0>
CO rH
J 1
W CO
,> \o
as
S w
3 W
CO CO
O CO
OH ty
S ip
1^
— ' O
i-3 O
2^
^£
^j^ ^£
1"*") ^H
E^ C3
§r
^ 2
i — i
83
W £4
^> <^
<
>-l
Q e
£P
SS co
r>-l
i — i
H
CO
w

rH
*
LO
CD
rH
•8
H







13
cO 0
n3 bO
g co
X 3 5-i
P P 0
•H CO >
rH rH <
SlPrH
O C3X eg cti
*rH ^ jj
•P rH -H S
^•^£l




o ^)
• H fi
+-> a

•H
^-4
<^
v — '


to
b?
3.
rH «
3 O
§ P
5n
CD P
tiO C-J
CO 0
5n O
0 a
> ^0

t^
CT>
rH


rH

CT)
rH

O
t~^
CJl
rH



CO
vO
a>
rH



•K
bp
pi
X
f^
TO
""d Od
ro 0
^«|
JH ^3
o a
O ?s
CO W





i
3
rH
rH
0
OH





rf_
6
bo
3.

O
o
rH




* * *
* * *
* * *
tO CTl vO


•JC
* *
LO LO CM
^ ^ LO

•K *
* *
LO LO tO
•*•«*•*

*
CM
co
CM
•X -X I
vO to CO
LO rH LO
rH rH



0

•H
*"O
0
1 J,
0 bo
•P -H
> rt x
O rH 1
i-J 1 KH
1 rH rH
h- 1 rH I-H





0 0
bOT3
O -H
5n X
P 0
•H -H
2 Q









0

O





<<<
2,§S




c^-j to vO



M csi ro







C4 tO vO





Q^
I t
cd
•H
rO
(p
g 42
0 bfl
+-> -H
B5K
,-J 1 rH
1 1— 1 rH
r~l rH rH





Is
li

to -p
3 -H
00 2









0
a
0





< < <
§§§




O 0 0
rH rH rH


to to to
rH rH rH






CM O O
rH rH rH




0
P
CO

rO
0
S rC
0 M
P -H
O i — i i
1 rH t— 1
rH 1 — 1 1— 1





1 S
C P
0 cO
P.MH

CO CO






to

bo
p.

LO





CO CM rH
vO \O LO




•^- CM CM
vO vO LO


•=*• tO rH
\iO vO LO






CM CM rH
\o r~> co




0

•H
rO
CD
P rC
0 bO
P -H
O rH 1
_J 1 rH
1 rH rH
1 — II — 1 rH


*
* t/)
* 0
* P
T^ CO
0 rH
T) 3
rH 0 -H
CO P.P
P t/3 M
0 3 cO
H CO PH


























cO
0
cO
§
IS)
o

f^
0

f-j
bO
•H
O C
£_<
P TJ
000

5n 0 0
O  O
rH JD t/)
O O 0
""d 'H
S f^ S
S 5H rH
NI P -H
p e

co o rd c3
CO 5n O 0
1 1 i c
i i
tJ 0
0 0 CO -H
P P P 5-4
cO cO cO P
Q S O 0
CM -P CM O
O (/) O 0
2 W 2 U
* * * *
* * *
•K *
*
195

-------

CO

CXI



LO



 CD

c/)
rH
rt
r
0
X
rH
•H
cd
Q




•H
CD
rH
99th
Percent]
CD
rH
•H
O CD
CTi U
CD
OH
CD
rH bO
Oj rt
g CD
rt
CD
rl
CD
z;
o
rt
p
CO
rH
CD
P rQ
3 E Z
&j CD
Z CTJ 0
03
p
CO
P CD
•H J-i
g 0
Is-
u w
O CTl OO
OO LO O
OO tO CX]
rH

vo to LO
\D to OO
<* tO rH
rH

rH O OO
CX] CX] rH
CTi CX] i — 1

LO rH O
CTi CTl vO
OO CXI IO
vO t^-- ["*"•••
O"} O^ O"i
rH rH rH

rH
to


rH

CX] CXI LO tO \O
OO rH rH rH rH

vO CO t — *^- \O
CX] CX] *3- O CO
LO rH i— 1 rH ,— I

CX] OO rH LO •xt
CO \*O CTi t^^ vO
CX]

CD rH t~~- VO ^j"
LO *x1" LO ^- ^d"
rH
«
*
OO O rH (Nl tO
rH rH rH i— 1 rH

cxi
to


LO
rH

tO vO tO "^ ^D
o to \o i — i r~~-
CX] Cxi rH rH rH
rH

CTl O O 1\ CXI
LO O LO O CX]
CTl CX] rH rH rH

CTl LO -vt ^O tO

OO LO ^Sr CTi CTi
OO LO LO «* tO
rH
•K
•K
OO CD rH CX) tO
\& c^ c^^ r^ r^~
CTi CTl CTi CTl CTl
rH rH rH rH rH

to
to


rH

rH OO O
rH f~- CTl
I-- rH
rH

o to t>-
i~; rH
rH

C~^ O LO
f^- C^*' LO

CX] t-- rH
OO tO tO
CXI
*
*
OO CXI tO
CTi CTi CTi
rH i— 1 i— 1

•xf
to


O
CX]


00
•H
CX] rH rH
LO CTi CTi

*3" Cxi vO
rH OO OO

O •xt CX]
cx] vO O
to

O rH i— I
LO •<*• *3"
rH
*
*
OO CXI tO
CTi CTi CTl
rH rH rH

i— 1
CX]


rH
rH

CX] CX]
1 -=t CX]
rH rH

rH CX]
1 rH rH
rH rH

00 CTl
I t~- 00

^O to
l uo vO
•K
*
OO cx] tO
CTl CTl CTl
rH rH rH

cxi
CX]




1
V CO
p p
c cd
rH -H
                                                196

-------
           vO O
           LO O

           t~- rH
         1  vO OO
           t-O r--
           **• LO
           *
           •K
         00 CXJ l-O
         CT»
               cr>
.s
p
 §
 U
(Nl


LO
•s
H
                      
                       OS      0
                       CD      f-i
                       S      o
                               P
                       tfl     -H

                       g      g
                       •H      M

                       o3     rxi
                       >H  .  r-
                       P t)  CT>
                       P! Q  I-H
                       o ^
                       u p  m

                       ss   °
 o
    0
rH  O
r-~  P!
01  S
rH  O
    t/)
T3  0)
 S  £
o  3
r-- rH
cr> •H
rH  S

  "^
oo  U
o
01  X
rH &
•K
                               Crt
I

P
 to
 o3
 X
rH

s
•K
•K
                                                 197

-------
to 43 yg/m  (Table 5.1).  Peak hourly exposures on all but a few days were


much like those of the intermediate exposure community.


     This set of circumstances provided the opportunity to assess whether


or not individuals experiencing a decrease in annual average exposure to


NO- levels, but still exposed to intermittent high levels of N0~, would
  Li                                                            L*

continue to experience significant adverse health effects.


Prevalence of Chronic Respiratory Symptoms in Chattanooga 1971


     The frequency of chronic respiratory disease symptoms was increased


during or right after the previously mentioned high exposure period


(1968-1970) only in the most heavily impacted area where increases in


symptom frequency, which are not statistically significant, were observed


three years after the high annual N0~ exposures were reduced 43 to 56


yg/m .  However, peak short-term NCL exposures continued.  This increase


in symptoms might represent a residual effect from previous excessive


long-term exposures or it might indicate that prior high exposures


coupled with peak current exposures are sufficient to trigger the onset


of chronic respiratory disease symptoms.  The presence of elevated


levels of suspended nitrates may also be a contributing factor.


Lower Respiratory Disease and Nitrogen Dioxide Retrospective Survey in

                            7
Chattanooga, Tennessee, 1971


     Acute lower respiratory disease morbidity in the period 1969-71 was


surveyed retrospectively among children one to 12 years of age from the


three original CHESS communities representing an exposure gradient for


NCL (Table 5.4).  Lower respiratory disease morbidity rates among children


of residential families residing in areas exposed to high and inter-


mediate levels of nitrogen dioxide continued to be significantly higher
                                 198

-------







g
I-H
H
<
H
CO

<>
^
t— 1 *
£2! t"O
^3 r*-- /•— \
2 1 r<
2 O 0
Br~~ P
CTi ,0
rH r>\
>H
pq « O
W -H
CO W ,£>
S83
i — i H
H § rH
§3 H PH
b ^
pq - S
2: S f-i
O Q W>
u o o
c^S
O EH 'H
^J. r 	 ! ^T1
gb
0
rC

*Sj^
3
1— 1
§
•
to
•
LO

0
rH
•3
H













i — \
to
e
v^_>
CD

• H
^
o
•H
O
0
z
P
•H
^"




^
3
r^
'd
S

0
rH
•rH
X P
P CH
CTi 0)
a> o
^
0
PH

0
rH
•H
^-t I 1
4-J CJ
O 0)
CT) O
0
OH




O
•H 0
rH P bQ
rt 0 cs
§ J 0
S P >
'rl
"^

JH
Oj
0

a
CO O r4
CO -H 0)
rr"! ^j o
S CO g
CO 2
P
P! Pi
0 0 JH
g -H 0)
0 P -Q


rd CO 2



P 0)
•H rH
C 3

S O
S r^4
O ><


\o f^*
CO t —
CTl CTi



LO <*
O vO
a> oo







LO CXI
rH CXI
00 LO









\o o
^ ^





cxi to
r~- t~^-
o o



rH





O}
rH





^* o o\ cxi
O ^ vO LO
LO OS vO C^^



oo o o oo
OO CXI tO CTl
^ LO LO tO







LO o oo r^
CXI t-- CXI LO
CX] CXI (XI t-H









vO CXI O tO
O LO rH O
rH rH rH rH





O rH CXI tO
f^^ f~^. r^. f^*.
< <] 0 O



CXI
to




LO
rH




1
CT^ OO O^ CXI
o cxi cr> LO
rH rH LO t~^
rH rH



O O CT> LO
CT) CT> TJ- LO
fp vO LO V«O
rH






o o •rf LO
LO LO O tO
•53- tO tO CX!









CXI LO •* t-^
CXI \o vO cxi
(XI rH rH rH





O rH CXI tO
< 
c^-^ \o
CXI rH









to t~-
CXI OO
i—t





cxi to
t"^- r^ —
0 0



T^-
to




0
(XI










r~*
GO
•H


^- o
LO O
r-H f->



O OO
LO OO
rH rH







\o *^
rH CXI
rH rH









t~*-~ C~"-~
r^ oo





cxi to
0 0



rH
(XI




rH
^O
rH




O OO
r-^ to
CXI N-)



LO OO

CXI CXI







to «*•
^~ vO
rH rH









LO tO
O rH
rH rH





CXI tO
r*~~ r~^
o o



CXI
CXI












1
0

£^
0
.{_>
pj
i— i

t-^ v£)
OO rH
rH CX)



CTl tO
LO OO
rH rH







to o
rH LO
rH rH









LO LO
OO O
rH





CXI K)
0 0



rH
"*

















^
O
^












































P
c
0
o
t/)
0
y~j
•H
S rt
•H i
•H N
S P
M ^
O CO

CO CO
CO CO
LO LlJ
hn rTJ
QJ ^^
0 <
199

-------
     Table 5.4.  THREE-YEAR FREQUENCY OF "ANY LOWER RESPIRATORY DISEASE1
                  AND BRONCHITIS:  MODEL PREDICTED RATES FOR CHILDREN
                   AGED ONE TO 12 YEARS FROM HOUSEHOLDS WITH A HIGH
                               SCHOOL EDUCATION OR GREATER7
                                       (1969-1971)
Morbidity
Condition
"Any Lower
Respiratory
Disease"


Bronchitis






Number of
Episodes
One
or
More

Two
or
More
One
or
More

Two
or
More

Male
Female





Male
Female


Male
Female

Model
I -Low II
28.
28.


14.


12.
9.


4.
4.
3
0


0


2
8


4
2
Predicted* Rates, \
- intermediate+
28.
30.


17.


13.
16.


8.
9.
9
9


0


9
1


8
8
III -High
38.
36.


20.


19.
20.


10.
9.
5
5


2


8
0


5
6
High/ Low
Community
(p< 0.01)
1.
1.


1.


1.
2.


2.
2.
36
30


44


62
04


39
29













*Age, education head of household adjusted rates for nonasthmatic chil-
 dren with three or more years residence duration.

+Intermediate exposure community significantly higher than low exposure
 community in 5/8 sex by number of episode categories but significantly
 lower than high exposure community in only 2/8 categories.
than those of comparable children living in a low exposure area.  Fur-

thermore, lower respiratory illness rates in intermediate exposure

neighborhoods were significantly lower than rates in the high exposure

community.

     Because this study was not designed to determine yearly rates, it

was not possible to assess whether the significantly higher rates in the
                                 200

-------
intermediate- and high-exposure communities were consistent over the


three study years or were heavily weighted by the single year, 1969,


when annual mean NO- levels were above the primary standard.


Incidence of Acute Respiratory Disease, Chattanooga, Tennessee, 1972-


19738


     A study of acute respiratory disease was conducted in 1972 and 1973
                                                           f

in the three Chattanooga CHESS communities.  In the 1972 study the excess


risk of acute respiratory disease remained consistently higher for those


living in the high-pollution community compared to those in the low-


pollution community.  (Table 5.5)  As was noted in an earlier study, the


highest excess risk (50%) was observed in pre-school children.  The


intermediate exposure community also showed excess risk of lower


respiratory disease compared to the low-pollution community.  Moreover,


excess risk for total respiratory disease was not as great in the inter-


mediate community as in the high-pollution community.  Pre-school chil-


dren living in the intermediate exposure area had a lower excess risk


than other age groups in that community.  In the second year of study,


the pattern persisted across the three communities, but the excess risks


themselves were lower than the preceding year.


     The excess risks of acute respiratory disease in the 1972 study


were similar to those found in the earlier 1968-69 Chattanooga study.


Although the annual average NO- levels in the initial study were sub-


stantially higher than those in the 1972 study, short-term 90th per-


centile hourly NO- exposures associated with an effect were similar in


the two studies (^300 yg/m  in the high-exposure area in the 1972 study).
                               201

-------
LO


LO
•§
H





















•°3
CL)
c
rH
rH
1 — 1
X
O
rH
•H
O-

(D
PH

CD
P
•-*
3
<^



















U)
0)
c/)
0)
rH
1 j
rH
1—1
O
"rrt
rH
•rH
t/)
r?
P-I
rH
^^

-P
O
CT3
H
*_,
r-*
(P
o
w>
a
•H
rH
O
>
r— 1



P
u
aj
rH
f-H


(D
p<
a

00
•H
rH
0

r— 1





X
I— 1

§
Co
OH

1 — i
I~H
X
-o
3
p


— 1

•d
3
p
'A

rH
	 1

X
3
P

— i

X
P
CO



rH
—\

X

r^
P





1 — 1
^
P
CO
o
p
u
0>
CO

p
Pi
§
i.
00

CO
rH
•ct


O O 
                                                              to
                                                              I
                                                                 rH

                                                                 
-------
(Table 5.6)  At this time it is not know to what extent those families


living in the neighborhood experiencing the highest short-term exposures


of NC>2 as well as elevated levels of suspended nitrates contributed to


excess risk in the total high-exposure community.


     That persistence of excess risk for acute respiratory disease four


years after long-term exposure has decreased may reflect residual


effects from previous prolonged exposure, the effects of intermittent


high peak exposures or both these factors.  Findings for pre-school


children in the 1972-73 study suggest the latter may be the case.  The


pre-school children in the high-pollution community had limited pro-


longed exposure to high annual average levels of NO- but did have short-


term high exposure, yet these children showed the highest excess risks


in their community.  Their counterparts in the intermediate community


had the lowest risk.  However, excess risk persisted in the other age


groups living in the intermediate exposure community, suggesting a


residual effect from previous annual average exposure to NO- of 150


yg/m , (Table 5.6) or 90th percentile hourly exposure of ^300 yg/m .


Ventilatory Function in School Children in Chattanooga, Tennessee 1971


     Studies showed ventilatory function of children in Chattanooga


was no longer impaired two years after annual exposures were reduced


from vL50-282 yg/m  to 43 yg/m  even though short-term peak hourly


exposures continued to range from 228 to 815 yg/m  for 10% of the days


each year.

                    q
Asthma Panel Studies


     In recent unpublished studies the EPA CHESS program in the New


York-New Jersey metropolitan area, increased asthmatic attacks were
                               203

-------

OO
•K
CO
2;
o
b
H
CO

C^3
2i
I-H
O
H
tH
2:


i— i

£3
rH
rrj
£>

rH
rH
3
o
re



















i
•9
jn
^?


0
rH
•H
nfj ^_J
+-* ci
CTi ^)
CTi O
QJ
OH



0
i
•H
-G 4-^
+-» c
O CD
CTi O
0)
OH
0)
rt nJ

C 0^
1^

s_(
rt
d)
^>H


1
CO §
co 2;

O o
•H
P
rt

CO

0)
e S
< 5 3
u e 2:

 tO
t LO VO


^
•X
OO (X] tO
vo t^^ r~^
CTl CTl CTi
rH rH rH




CM
CM











1




l
i
0) 0)
P -p
c! rt
r— 1 -H
204

-------
               OO  VO
               OO  rH
               rH  CXI
 §
 (/)
 CO
               t-O (X)
 (ft
 c
 o
•H
P
 rt
                  01
                           §
                           g
                           (J
                           CTi
                          CX]
                          t^~
              K)
                  IS)
              *
              *
           OO CXI
           o t-~.
           Oi O1
§
                                   O
                                   P
                                  CX]
                                  t^
                                  Oi
 §
 O
LO
 0)
rH
•a
        ^
       ^
        P
        VI
        CO
                                   X
                                                                   205

-------
significantly associated with elevated levels of suspended nitrates when



temperatures were 50°F or above.    No such effect was observed with



NCL.  Chemiluminescence instruments showed NCL levels met the annual



average standard at a central city station but only the old  (now dis-



carded) Federal Reference Method was used for measurement of NCL in



study neighborhoods themselves.



     In another study conducted by the same group in to Southeast com-



munities, there was evidence of excess risk of asthmatic attacks asso-



ciated with elevated levels of suspended nitrates, but the findings were



less consistent than those observed in the New York study.    Because of



problems in present methods to measure and analyze suspended nitrates,



findings in these studies should be viewed qualitatively rather than



quantitatively.  These two studies raise a question as to levels of NCL



which might be necessary to prevent levels of transformation products,



such as nitrates, which in themselves may contribute to adverse health



effects.



     Preliminary analyses of California asthma panel studies show no



easily demonstrable increase in attack rates occurs with NCL exposures



ranging up to 400 yg/m  for one hour and 200 yg/m  for 24 hours.  How-



ever, effects of other stronger illness determinants, like aerosols



containing sulfates and nitrates, had not been disentangled at the time



of the present summary.



Indoor No,-, Studies
     Preliminary measurements by EPA of NCL indoor air concentrations



show peak hourly levels in the range of 470-940 ug/m  (0.25 - 0.50 ppi



in the heating zone of persons cooking with gas stoves.  The highest
                                   206

-------
peak indoor NCL concentrations measured was about 1 ppra.  EPA's CHESS
studies suggest a greater relative risk of acute lower respiratory
illness among occupants of homes with gas stoves.  Mothers were the only
family segment significantly affected.  Presumably this excess could be
related to periodic hourly NO,, exposures in the 0.25-1.0 ppm range.
                             Li
Followup studies in CHESS, however, have not confirmed a relationship
between air pollution due to gas stoves or gas space heaters and lower
respiratory disease in mothers.  A study in Ohio also did not find any
respiratory disease health effect related to gas cooking.  In all three
health studies, measurements of indoor N07 air pollution were not
                                         LJ
related directly to health.  Like EPA, those investigators also found
increased peak indoor NO-., levels, generally about 470 yg/m  (0.5 ppm)
but at times as high as 940 Mg/m  (1.0 ppm), to be associated with gas
cooking.  Thus, there are still questions as to whether or not indoor
hourly NO- air pollution in the range of 0.25-1.0 ppm is related to
increased risk of respiratory disease.  Such a relationship would be
qualitatively consistent with data in experimental animals showing an
effect of short-term N02 exposure on resistance to infection.
                                                         12
5.1.2.1.4  Other new evidence--Von Nieding and associates  studied the
acute effects of experimental NO- exposures on healthy and diseased
subjects using pulmonary ventilation, diffusion and perfusion as end-
points.  Exposure of 16 healthy subjects to 9400 Mg/m   (5 ppm) No~ for
15 minutes caused a significant decrease in diffusing capacity.  Four-
teen subjects with chronic respiratory disease showed a significant
decrease in arterial partial pressure of oxygen and a significant
increase in the alveolar-arterial oxygen pressure gradient upon exposure
                                207

-------
to 7520 or 9400 yg/m  for 60 minutes while no effect was observed at NCL



concentrations of 3760 yg/m  (2 ppm).  Healthy subjects (n=39) and those



with chronic respiratory disease  (n=70) were exposed to 30 breaths of



NCL at concentrations over a range of 1880 to 9400 yg/m  (1 to 5 ppm).



These subjects demonstrated increased airway resistance at NCL concen-



trations of 3000 to 3800 yg/m  (1.6 to 2.0 ppm).  At lower concentra-



tions, NCL exerted no effect, but airway resistance markedly increased



as concentrations exceeded 3800 yg/m  (1.6 to 2.0 ppm).



     Kennedy  studied a group of 100 coal miners with a history of



exposure to nitrous fumes from shotfiring in the mine.  Eighty-four of



the mean had emphysema based on a residual volume of more than 150%.



The 16 miners with a residual volume less than 150% of normal had less



exposure to fumes than the remaining 84 men.  Kennedy compared the pul-



monary function of the miners exposed to nitrous fumes with non-exposed



miners and those with simple pneumooconesis and found the indirect maxi-



mum breathing capacity, vital capacity, total lung capacity and residual



volumes showed a markedly higher percentage of abnormal values in the



nitrous-exposed group.  The primary and secondary charges of the hydrox



shells used in the mines were largely nitrates and fume analysis revealed



(NO and NCL) up to 88 ppm after normal firing and up to 167 ppm after



misfires.



     A full report of the study of chronic bronchitis among housewives



aged 30 or more living in six localities throughout Japan conducted dur-



ing the winter of 1970-71 is not yet available in the U.S., but a summary


                                      14
of this study has been made available.   This is the study on which the
                                   208

-------
Japanese standard of 0.02 ppm 24-hour annual average is based.  The


prevalence rate of chronic bronchitis was found to exceed 5% only in



those areas where the annual NCL concentration was 0.042 ppm (79 yg/m )



or above.  However, total suspended particulate concentrations were also


very high, ranging from twice to six times the U.S. primary standard


indicating that the pollutant-disease association in the study cannot be


ascribed to NCL alone.


     In a study by Speizer et al.,  *  '  the prevalence of chronic non-


specific respiratory disease was assessed using a modified version of



the Medical Research Council's respiratory disease questionnaire in a


population of 268 policemen exposed to a spectrum of levels of automo-


bile exhaust as traffic officers, patrol car officers and indoor cleri-


cal officers.  The over-all prevalence of disease in the policeman


population was 36.9%, and two--thirds of chronic conditions were chronic



bronchitis.  There was a clear relationship between smokers and the


prevalence of disease.  In nonsmokers and current smokers, men with


greater duration of exposure In traffic tended to have higher disease


prevalence rates, but the difference was not statistically significant.


Measurement for exposure to automobile exhaust was limited, since only


16 work stations out of a total of 58 were chosen for study, and sam-


pling at each station was conducted for only two days during each season



of the year.  The NCL values ranged from a minimum of 0. 005 ppm to


0.090 ppm while carbon monoxide ranged from 1 ppm to 44 ppm and hydro-



carbons from 4.4 to 15.8 ppm.

                                          1 8
     In a recent preliminary report, Sprey   correlated death rates


from hypertensive and arteriosclerotic heart disease and lung cancer
                                209

-------
with annual NCL concentrations.  The author's data source was the



National Air Surveillance Network which operated a single station in



each of 42 metropolitan areas.  NCL was measured once each two weeks



by the Jacobs Hochheiser method.  The twenty-six values for the year



1962 were averaged and were correlated with cause-specific death rates



for the years 1959-1961.



     The results showed a linear relationship with annual NCL concen-



trations for 1962.  Higher death rates were found even in areas with



NCL concentrations below the primary national standard, when compared



with the lowest NCL areas (56 yg/m , .03 ppm).  Adjustments for area



differences in family income and education, population density, tempera-



ture and sulfate and nitrate concentrations did not affect the basic



association between NO- and death rates.  A similar linear relationship



was shown for lung cancer deaths among males and females over 65 years



and NCL concentrations in the 42 areas.  The relationship was not



weakened by adjustments for area differences in SCL, sulfates, nitrates,



climate, socioeconomic factors and population density.



     The quantitative basis of NCL exposures in Sprey's work is open to



question because of the limited number of air monitoring stations used



as well as the unreliability of the measurement technique.  However, the



qualitative nature of the work should draw attention to possible extra



pulmonary systemic effects of ambient NCL.



5.1.2.1.5  General discussion of NO,, Human Studies--Studies of NCL and



human health effects are limited, and many conducted thus far are con-



founded by the presence of high levels of other pollutants.  In addition,



measurement data used in these studies were limited either by use of too
                                     210

-------
few sampling stations or the use of an unreliable method for measurement


of N02 or both of these factors.


     Five categories of human health effects have been identified in


association with NCL:  acute toxic, often fatal, reactions, diminished


lung function, structural and bronchial changes of lung most likely to


promote development of chronic respiratory disease, susceptibility to


infection and systemic effects.


     There is sufficient information from both human and animal studies


to determine the levels of N02 which may contribute to toxic, often


fatal, reactions.  There is some evidence to show that prolonged


exposure to NCL levels of 117 yg/m -205 yg/m  can contribute to increased


prevalence of chronic bronchitis, increased incidence of acute lower


respiratory disease and diminished pulmonary function in school chil-


dren.  Unanswered questions still remain with respect to short-term


exposure of NCL and the effect on acute and chronic disease, those


levels of NCL which may contribute to systemic effects and levels of


NCL which may be necessary to control possible adverse health effects


from suspended nitrates.


5.1.2.2  Animal Studies


5.1.2.2.1  Biological effects of N0?--The toxicological aspects of NCL


have been reviewed recently in these documents to which EPA has had


direct input and liaison:  (1) NATO Committee on the Challenges of


Modern Society, "Air Pollution:  Air Quality Criteria for Nitrogen

                            19
Oxides," (N. 15) June, 1973;   and (2) The National Academy of Sciences,


"Air Quality and Automobile Emission Control," No. 93-24, September,

     20
1974.    Material contained here treats only a few reports in the
                              211

-------
literature which are considered significant and which have been pub-


lished since these reviews were compiled, and material which is now



being prepared by various known sources.  NO- biological work being



carried out currently in EPA is discussed in some detail.  The pos-


sible relevance of such information is discussed in the light of



previous data and predicted future possiblities.


5.1.2.2.1.1  Pathological effects of N0? on the respiratory track--



Action of NO- on the respiratory tract has been reviewed previously.


Its proclivity to elicit necrobiosis and desquamation of Type I alve-



olar epithelial cells with subsequent replacement by Type II cells and


eventual regression to normal is well-known.  Such changes are not

                                                          21 22
specific for NCL, but occur with CL and hyperbaric oxygen,  '   and


are probably indicative of lung reaction to an oxidant or possibly any


irritant at this level.  Changes are induced by approximately 2 ppm


NCL and above.  Exposure to higher concentrations, 10-25 ppm on a con-


tinuous basis for 3-12 months has induced pulmonary emphysema-like

                                        23_35
disease in rats, mice, dogs and rabbits. *      Lesions have been studied


in detail, principally in the rat for a number of years.  In the rat the


disease does appear to be emphysema, since the lungs are enlarged and


contain fewer air spaces, presumably from rupture of alveolar septae.


Four recent studies have examined the lesion phenomenon to determine


(a) if it is a problem associated with pulmonary growth, (b) whether it



mimics natural disease, (c) what is the physical mechanism of its pro-


duction and (d) whether interaction with ozone enhances its induction



or severity.
                                   212

-------
     Two studies have examined developmental features of the disease in

rats by means of morphometry and post mortem pressure-volume studies.

One, primarily on oxidant (ozone), showed that while exposure to 0.2 ppm

oxidant resulted in significant increase in lung volume and loss of lung

elasticity (lung recoil), no such effects were noted at 0.2 ppm in

N02.36  (Table 5.7)

     The other study designed presumably to answer the question of lung

maturation showed that while exposure to 15 ppm NCL from before birth to

65 days of age resulted in slowing of lung growth (interpreted as being

due to slowed general growth for the first 10 days), the animals subse-

quently caught up and had essentially normal alveolar maturation at 65

days.35  (Table 5.8)
                         •7/r
     One of these studies   examined the physical mechanism of lung

enlargement associated with both NCL and ozone exposure.  The data

indicate that exposure to 0.2 ppm ozone produced a stretching of the

stroma and loss of lung recoil.    The implications of this change may

be rather important in exposure to oxidant, NCL and possibly other

factors such as exposure to tobacco smoke, since in earlier studies

structural alteration of colleigen was noted by electron microscopy

examination, and chemical denaturation of collagen and elastin has been

reported in independent studies.

     The two studies cited above indicated, to summarize, that exposure

to either NCL or CL does not impair formation of pulmonary alveoli in

the growing animal.

     Another study examined the morphologic features of experimentally-

induced emphysema by NCL and papain exposure and compared them with
                               213

-------
                                              38
natural emphysema in horses and human beings.    This study showed that

the NCL-induced lesion had a "stretched" appearance, rather similar to

the natural disease and that thepapain lesion had a flaccid, "motheaten"

appearance.  A notable finding of this study was that the physical

appearance of emphysema varied with the species studied and was possibly

influenced by differences in the size and frequency of the inter-alveolar

pores (pores of Kahn) graded as follows:

          Horse   27.13
          Monkey   8.50
          Man      6.14
          Hamster  3.64
          Mouse    3.08
          Rat      1.28

In this study emphysema was shown to be induced in mice after continuous

and intermittent exposure to 100 pg/m  (0.5 ppm) NCL.

     A study was conducted to look at the possible interaction of NCL

and 0., by the parameter of induced pulmonary lesions.  Since these two

gases occur at approximately equal concentrations on a ppm basis in

ambient air, various exposures were carried out with equal parts of the

two gases.  The lesions described were qualitatively similar.  Desquama-

tive Type I lesions and replacement by Type II occurred at 0.25 ppm 0.,,

but required 10-20 times this amount for NCL to elicit similar lesions.

Thus, the NCL effect was obscured when equal parts of the gases were

employed.  Equivalent concentrations needed to produce equal lesions

were on the order of 0.5 ppm to 0.9 ppm 0, and 15-20 ppm NCL.  Effect
                                                 39
was noted at 0. 5 ppm CL after 24 hours exposure.

5.1.2.2.1.2  Biochemical effects of N0?--The biochemical mechanisms by

which NCL reacts with tissue resemble 0, to some degree by virtue of

their common oxidizing properties.  Thus, lipid peroxidation has been
                                   214

-------
       Table 5.7.  SUMMARY OF DATA FOR RATS IN MORPHOMETRIC STUDY36
                             Ozone  (20)           Control  (17)
Initial Body Wt.  (gm)      87.6   ±   1.2        87.0   ±   1.4       N.S.
Final Body Wt.  (gm)       284.8   ±   4.8       291.4   ±   4.5       N.S.
Wet Lung Wt.  (gm)           1.80  ±   0.03        1.80  ±   0.03      N.S.
Dry Lung Wt.  (gm)           0.438 ±   0.008       0.444 ±   0.011     N.S.
Lung Volume (ml)            9.28  ±   0.37        7.97  ±   0.41      <0.02
Mean Chord Length  (y)      62.5   ±   0.7        59.5   ±   0.8       <0.01
Alveolar Surface Area
  (on2)                  6,786     ± 242        6102     ± 247         <0.05
Alveolar Number
  (millions)               39.7   ±   1.4        37.8   ±   2.3       N.S.
Mean values ±1 S.E. for 10 Ozone and 17 Control animals.
N.S. = no significant  (P>0.05)

reported both from in vivo and in vitro exposure to NO-.  Exposure  of
rats to 1 ppm NO- produced evidence of peroxidation as apparent  from
the appearance of diene conjugates of polyunsaturated fatty acids in
                                                      40
extracts of lung lipids, as described by Thomas et al.    Peroxidation
was maximal 24 hours after exposure and persisted for at least 48 hours
after exposure.  When exposure consisted of  six daily four-hour
exposures, the diene conjugates increased cumulatively.
     As with ozone, animals receiving a tocopherol-deficient diet have
been found to be more susceptible to lipid peroxidation.  According to
these authors, reactions differ from ozone,  at least in  their thin
films, in that phenolic antioxidants retarded N02 but had little or no
effect on ozone.  The authors speculate that the N0?-catalyzed reaction
proceeds indirectly by the formulation of a  nitroso  free radical, citing
                                215

-------
LO
to
CO
^D
pT . *~^
0 5
CO
[H J O
<; C<
r j ^J
U W
Q CM
O
Q Z
^ Q
<>^
o o
LU Cd
i

2 'U

CO U
H Z
g eg
^3 i 1
f— i
f T~] H

i "] ty^)
& H
2 S
7T^ ^ "I
§

S ,_j
^ s
Q

0 >
n
w S
g rH
§ §
]
-Q 52
Ss





T-
o ;

g T
rH T
X> f










4J
•H
f~]
^3

0
crS
o ,
CO
1
•^




O
S
rH
03
P-i
MH
o
SH
0)

g
Z











tn
-p
•rH ^~>
i ^^ i
3 c^
3 dl rH
> & X
} CO^rH
3 ' 6
H r-l v — '





X
O
cuto"^
PL, 0
rH
'S ><
e vJS
^
o




txO
s
-^
r-t O
Q__J
"i
!*£ ^
•^.^
rH
OH



OJ
§
rH
O /— N
J>^
O
4-* rH
•H
.§ ^S
rH
 t~- LO CM CD OO tO
OO to OO OO tO \O to
rH CM t-~ O~i CTi CM
rH CM










tO tO O rH LO VO CM
OO LO i-H ^J- VO OO rH
CM CM tO tO CM CM tO






rH tO O O LO LO LO
rH CO tO LO r~-
216

-------
the work of Estefan et al.    The nitroso free radical, in turn, initi-



ates auto-oxidation by the abstraction of methyl hydrogen.  The alkyl



free radical then reacts with molecular oxygen-forming fatty acid, hydro-



peroxide, leading to peroxidation reaction in a normal manner.  Antioxi-



dants thus prevent NCL catalyzed by reaction with the peroxy free



radicals.



     The ozone-catalyzed reaction proceeds by the direct addition of CL



across the fatty acid double-bond.  These differences may explain the



lower toxicity of NCL as compared to ozone.  The autocatalytic reaction



induced by NCL might be expected to produce a low development of the



products of initiation followed by a rapid reaction once critical con-



centration was achieved.  Thus, normal cellular protective mechanisms,



such as the antioxidants, may extend this period more or less indefi-



nitely, unless an overwhelming concentration of NCL is employed, whereas



for ozone, direct attack on the fatty acid double-bond would not be



autocatalytic and repair forces would be ineffective.  Thus, the



phenolic antioxidants would be ineffective in blocking the reaction.



     Studies by Buel, et al.   suggest that exposure to NCL may alter



the molecular structure of lung collagen.  When animals were subjected



to one exposure, the reaction appeared reversible, but animals exposed



to 0.25 ppm repeatedly showed persistent structural alterations when



viewed by electron microscopy.  These changes persisted for at least



seven days after the final exposure.  Considerable attention has been



paid to the ability of NCL to cause alterations in blood or tissue



enzymes.  Buckley and Balchum  "   have described the influence of



acute and chronic exposure to NCL on the total activity of lactic
                                217

-------
dehydrogenases (LDH) and on the proportion of its various isoenzymes.
Briefly, exposure for 10 weeks or longer at 10 ppm or two hours at 40 ppm
caused changes both in tissue oxygen consumption and LDH and aldolase
activity.  They noted also that a shift to the anaerobic isoenzyme
                              46
occurred in the lung.  Ehrlich   also noted this anaerobic shift in the
heart muscle of exposed hamsters, and Sherwin et al.   noted that hyper-
plastic epithelial cells formed in response to N0~ exposure stained
heavily for LDH and suggested the demonstration of these cells by his-
tochemical technique might be a useful index of exposure.  This increase
                                                                    48
in number of LDH positive cells was also noted by Buckley and Loosli
after exposure of germ-free mice to NCL.
     The significance of the above findings is unclear, since the high
levels of exposure may have produced artifactual response.  However,
recent unpublished and unconfirmed data suggest that a number of blood
and tissue enzymes may be altered in guinea pigs by intermittent expo-
sure for four months at levels as low as 0.5 ppm.  These data urgently
need confirmation since their implications for biological effects of
N02 are evident.
     The striking difference in methemoglobin generation between in vitro
and in vivo exposure of blood possibly may be accounted for by the
activity of methemoglobin dysmutase, which causes a rapid reversal to
oxyhemoglobin in the intact animal, and that during actual exposure by
inhalation, the conversion to methemoglobin does not exceed the power of
this enzyme to effect the reversal to oxyhemoglobin.
     Two biochemical studies currently are being conducted.  The first
examines the prospect that the toxicity of NCL and 0, may be an "ultimate"
                                     218

-------
toxicant produced by a reaction between theoxidant and unsaturated fatty


acid.  Ozone is known to react with unsaturated fatty acids to produce


fatty acid ozonides.  Fatty acid ozonides produce Heinz bodies in human


and mouse erythrocytes.  Heinz body formation is inhibited in human red


cells by supplementation with Vitamin E.  This property is responsive to


Vitamin E as is the inhalation toxicity of CL in animals.  The same


pathways are likely to occur in animal models as in man if fatty acid


ozonides are the true toxicant.  Fatty acid ozonides also produce lung


edema.  If fatty acid ozonides produce the same anatomical lesions in


the lung as 0  inhalation, one? could suppose that ozonides manufactured
             O

on inhalation are the responsible agents.  NCL similarly can react with


unsaturated fatty acids to produce nitroxide fatty acids which have an


unpaired electron and are likely to be very reactive.  No data are


available on their properties, but nitroxide fatty acids could likewise

                                             49-52
be the "ultimate" toxicant on NCL inhalation.


     These studies are important because:


      (1)  Identification of the chemical mediators of intoxicant ion


allows a rational approach to estimation of health hazards and preven-


tative measures;


      (2)  Li vitro systems can be used to accelerate studies of long-


term exposure;


      (3)  Indicators of human exposure may be possible by measuring


blood levels of the "ultimate" toxicant, a by-product or an alteration


of a blood cell population (Heinz bodies in red cells, numbers of poly-


phonuclear cells or modifications of platelets);
                                219

-------
     (4)  The occurrence of systemic effects from NCL or 0_ inhalation



(such as carcinogenesis, mutagenesis, impaired liver function or



splenomegaly) may be predicted; and



     (5)  Animal exposure effects may be related better to human effects,



refining data for criteria and standards.



     Progress to Date:  Methyl oleate ozonide has been synthesized and



purified.  Methods of rat lung fixation for electron microscopy have



been established by either perfusion of the vascular system or by



intratracheal instillation.  The former appears most useful for obser-



vations of the alveolar surface while the latter appears best for



general anatomical surveys.  A method of imbedding which orients macro-



slices at the light microscopic level has been applied to the lung.



Studies are focused on the terminal bronchiole-alveolus region which



has been shown by Freeman's group to be the most sensitive area of the



lung to NCL or CL inhalation.



     Synthesis of the ozonides of all of the remaining common unsatu-



rated fatty acids (linoleic, linolenic and arachidonic acids) is



planned.  Studies of methyl oleate ozonide effects on the lung (using



intraperitoneal and intravenous injection) are under way.  Lungs will



be examined by the two methods to assess morphological changes at the



alveolar surface and the pneumocyte-capillary interchanges caused by 0,



inhalation.  The dose-response relationship for ozonides will be com-



pared with 0, inhalation to estimate the in vivo conversion of fatty



acids to ozonides.



     Nitroxide fatty acids will be synthesized and used as above to



determine the similarities and differences between NCL inhalation and
                                    220

-------
nitroxide fatty acid toxicity.  The conversion to nitroxide fatty acids



on NCL inhalation will be estimated as for CL by comparative toxicities



using parallel-line bioassay.  These observations and those for 0., will
                                                                 O


be compared to determine if a similar mechanism of action exists.



     Because these studies relate to mechanistic observations, future



studies are likely to involve the systemic effects of long-term expo-



sure on cells other than penumocytes.  Potential mutagenic and carcino-



genic properties are now known, but likely, since these compounds appear



to act on the cell surface by free radical generating mechanisms.  The



co-carcinogenic potential is marked since they are likely to interact



with microsomal oxygenases which are known to produce the ultimate



carcinogens of chemical carcinogenesis.  The properties of these ulti-



mate carcinogens, arene oxides;, are similar to fatty acid ozonides.



Co-carcinogenesis studies using the Saffiotti hamster tracheobronchial



tumor induction model and ozone exposure are under way in-house at



this time.



     The second biochemical study examines the mechanism of action of



of nitrates and sulfates--The purpose of these studies is to determine



if vasoactive compounds are released from the lung by SO,, or sulfate,



or NCL or nitrate.  Since SCL inhalation results in bronchiocon-tric-



tion below the begal reflex, it is likely that direct action on the



bronchial smooth muscle is involved.  Histamine aerosols produce



effects very similar to SCL inhalation.  Sulfate particulates have been



suggested by the CHESS studies to be better correlated with human



effects than SCL per se.  The effects of sulfate as a modulator or



releasing agent of vasoactive compounds from an in vitro model system



were therefore studied.


                                 221

-------
     Using guinea pig lung slices because of their supposed similarity



to human lung, histamine was found to be released by sulfate ions in



the presence of ammonium ion.  Nitrate ion produced some release also



but ammonium ion is a requisite for release of histamine.  Histamine



release was not due to ionic artifacts.  By the use of   SO. ion uptake



of sulfate was found to occur simultaneously with histamine release.



Sulfate uptake was found to be intracellular.  Ammonium ion decreased



sulfate uptake simultaneously with histamine release, suggesting that



histamine release occurred either by cell lysis or by degranulation of



lung mast cells.  Sulfate effects were not blocked by pharmacological



agents such as adrenergic or cholinergic drugs nor by cyclic-AMP or



GMP.



     These studies suggest that sulfate can act directly upon the lung



mast cell to cause histamine release.  Sulfate requires ammonium ion



for effect.  (Table 5.9)  Sulfate particulates are principally asso-



ciated with ammonia, but ammonium ion could be supplied from the blood.



The potentiation of sulfate effects by ammonia may explain the toxicity



of these aerosols over SO-.  Ammonium ion probably exerts this effect



by acting as a proton sink within the cell.  Sulfate is probably trans-



ported by the chloride ion carrier.  Inhibitors of chloride transport



such as phloritin are being investigated.



     An important result of these in vitro studies is that the ammonia



concentration of the inhaled mixture may cause substantial changes in



toxicity studies in animals.  Ammonia arises from the action of gut bac-



terial urease on urea in the gut.  The second generation catalytic con-



verters deliver ammonia by the incomplete reduction of NO .  Ammonium
                                                         J\.
                                  222

-------















s
t-OJ
LO
py I
I— lO*l
^-
CO CO
E~* P^i
Z O
Ej i— t
O 5
"^ i—3
PC O
tin CO

CJ H
5 •<
J CO
g tjs
OH
Ei, 0
0
LLj rH
^7
I— 1 PH
S O



i— i z
nn FTI
CO
a,
w

 a! 03
C P 0
0 !/) rH
O -H 0
r< PC Pi
0
PM



(r— ^
0 bfl

.^ (/J ^
S 03 rH
o3 0
•P rH c
t/i 0 oh
•H C£ ^^
pr| QO
3.
^ — '




to
p
Pi
m 53
o s
•rl
• 5-1
O 0
r^ Oj
fl
C-M











*"O
g
o
&1
o
o











t"— o^
o o
LO OO
t-O LO













oo «*
o o
bO LO







OO K)
• •


0 0 +| +1

** LO
• •
CTl LO
I— 1










O ^O CTi ^f











a>
T.\ 0
(D -H P
T3 0 5-i o3
•H P O P
5-i Oj rH 0)
O "-H JE; o
rH t— I O 

03

T3
0
a
•rH
to
10
o3

X
rH
•H
5-i •
03 to
5-( 0
P 5-i
•H O
<*"i [ ^
5-i 10
03
0
t/) p!
OS -H

o3
0 P
p w
03 -H
t_l _J (-H
rH
3 0
tn ^
G
•rl O
Pi

s °
5 o

*
223

-------
sulfate may therefore result and be more toxic than sulfate or sulfuric


   .,  ,    53
acid alone.



     Sulfate and possibly nitrate is likely to cause the release of



histamine by competing for histaraine binding sites on heparin in the



histamine granule of the mast cell.  Rat peritoneal mast cells will be



used to isolate mast cell granules in studies planned to investigate



this possiblity.  Sulfate release of histamine and binding to granule



heparin will be measured using acridine orange metachromasia.  The



release of other vacoactive compounds by sulfate from lung slices will



be examined.  Prostaglandin synthesis and release will be measured by



radioimraunoassay and smooth muscle bioassay.  Slow reacting substance



of anaphylaxis  (SRS-A) release will also be measured by guinea pig ileum



assay.



     SRS-A has been suggested to be a sulfate ester.  In later studies,



the incorporation of   SO. into SRS-A and other substances will be



measure  to determine if sulfate inhalation stimulates vasoactive hor-



mone synthesis.  Sensitized guinea pigs will be used to repeat the sul-



fate studies above to determine the effect of sulfate on atopic-lik



release of vasoactive hormones.  Sensitized animals are models of



asthmatic individuals.  An important mechanism for sulfate effects



which could influence all hormone action is the sulfation of the  enzyme



adenyl cyclase.  Adenyl cyclase controls almost all hormone action in



the cell.  Phosphorylation of the enzyme has been proposed as a control



mechanism.  Sulfate could compete for this reaction leading to a sulfo



enzyme which could be more stable than its phosphorylated counterpart.
                                    224

-------
A reduction in adenyl cyclase levels could have broad effects.  The


effect of sulfate on membrane adenyl cyclase will therefore be


determined.


5.1.2.2.1.3  Pulmonary physio1ogy--Few studies on the pulmonary physio-


logic effect of NO- have been reported.  The subject was thoroughly

                              19
reviewed in the NATO document.    A small amount of activity on the


pulmonary physiologic effect with nitrate will take place under the EPA


sulfate research program, rationale being the possible similar irritant


action of nitrate and sulfate ions and their respective acids, and the


fact that the chemicals occur generally in the same polluted atmospheres.


Work will proceed on this project commensurate with allocated resources


on the basis of pulmonary physiologic response of nitrates and nitric


acid mist together with sulfate and sulfuric acid, evaluation of the


influence of the ammonium ion.  With the present allotment of effort,


work should be completed on the relative irritant action of one nitrate


by July, 1975.


     Studies which employ the interaction of pathogenic organisms and


air pollutants to demonstrate increased susceptibility to infectious


pneumonia are unique  to the EPA program.  This sytem has been effi-

                                                                 54  55
ciently utilized in environmental toxicological studies of ozone,

                 56                     57
nitrogen dioxide,   irradiated auto smog   and exposures to trace


metals such as NiO, MnO-.   '"   It has been shown that the role of

. P   . .       ,     ,      , .   -   55,56,58,59      60 ,        56
infectivity can be enhanced in mice,            rats,   hamsters


and squirrel monkeys.    Among the infectious agents eliciting this


reaction in the above animals are Streptococcus pyogenes, Klebsiella
                                225

-------
pneumoniae, Diplococcus pneumoniae, and influenza PR-8 virus.  Thus,



this model is an exquisitely sensitive indicator of biological effects



in vivo.  In addition, the model is useful in studying the mechanism of


                         f\*y f\~{
action of the pollutants.  *



     An important problem in the toxicity of NCL (and ozone) concerns



the rela tive toxicity of the mode of dose since both of these gases are



subject to intermittent diurnal peaks whose frequency and magnitude



reflect the input into the atmosphere of NO and other precursor sub-



stances, and conditions favoring the formation of the secondary pollu-



tants (photochemical smog).  Thus, the population in any given area is



not subject to a continuous dose of pollutant, but a series of peaks



and valleys of variable duration and irregular occurrence.  Previous



biological studies have never concertedly attacked this problem and



since the import is obvious to heatlh standard-setting and control



measures, EPA is making a serious study of the problem.  A portion of



this program is incorporated into the US-USSR Agreement on Cooperation



in the Field of Medical Science and Public Health.  Manuscripts are in


                                                                   64
preparation for presentation in Riga in the USSR in December, 1974,



for the above program and in New Zealand at the Australia/New Zealand



Clean Air Conference in February, 1975.    The principal parameter



employed at this state to evaluate the important of mode of dose is



the infectivity system described above.  A brief review of this infor-



mation follows.



     Figure 5.1 shows greater mortality from pulmonary infection result-



ing from the same concentration X time for exposure to NCL over dif-



ferent time periods.  Note that the actual concentration has more
                                  226

-------
influence than duration of exposure.  If no interaction existed between

concentration and time (i.e., if they had equal importance) , all the

test groups should show the same mortality in the above experiment --15%.

But the trend of the combined data indicates a gradient response from a

high of approximately 50% to a low mortality equal to controls.

     The interaction of a constant concentration with time over a longer

period was examined.  Two concentrations of NCL have now been studied.

A level of 3.5 ppm was used for comparison with the study mentioned

above.  A lower value of 0.5 ppm was selected since this concentration

represented the lowest figure in the published literature showing posi-

tive results for chronic exposure in the infective system.    The data

shown in Figure 5.2 represent 60 individual observations for the 3.5 ppm

level and eight observations for the 0.5 ppm.  The simple linear

regression shows that mortality increased with time and concentration

and was statistically significant at the 0.01 probability level.  Pre-

dictions that can be generated from these regressions show that sta-

tistically significant difference from controls occurred after one-hour

exposure to 3.5 ppm and after three weeks at the 0.5 ppm concentration.

While the first series of experiments (Figure 5.1) showed that there was

a strong interaction in favor of concentration over time, the latter

study still shows the importance of toxicological information from long-

term exposures for NCL.

     The data from the same series of experiments was analyzed for

influences of exposure time to 3.5 ppm on mean survival period calcu-

lated according to the equation:
          MST  - CA+B) = (d=L)
             d         n
                              227

-------
-   h
        s
        T
-*-
 s
"T
                                                          S
                                                                  s
              Figure  5.1.   % difference in mortality
                                 (NCL  -  control)64
                                                     y s 10.42 -f 27.5S LOGio (TIME)
                   HOURi
                                      TIME
                                               CAYS
                                                MONTHS
           Figure 5.2.  Difference  in % mortality versus
                        length of exposure to  .5  or 3.5
                                     ppm N0

-------
"A" is the last day that any individual mouse was alive; "B" is the num-


ber of mice surviving "A" days; "D" is the last day of the experiment


(in this case 15); "L" is the number of mice that were alive on day "D"


and "n" is the initial number of mice in the experimental group.


     A statistically significant (P<.05) regression with a negative


slope was shown for mean survival of mice challenged with Streptococci


versus length of exposure to 3.5 ppm for various periods prior to the


challenge. Figure  5.3  shows  that there  is  an inverse  relationship between


survival and length of exposure at constant concentration.  With this


parameter, effects were also statistically significant after one hour


of exposure to 3.5 ppm.


     Using the same model system (fixed concentration versus time),


other concentrations are now being tested for the purpose of developing


information that can be used to develop regression curves at other con-


centrations.   That can then be used for predicting purposes.


     Other experiments are also designed to test interaction of concen-


tration and time as above, but they use an intermittent exposure model


in place of continuous exposure.  As this report is being prepared,


data from this experiment is still being collected.


5.1.3  Carbon Monoxide


5.1.3.1  Human Studies--The present ambient air quality standard for

                        3
carbon monoxide  [10 yg/m  (9 ppm) averaged over eight hours and of


40 yg/m   (35 ppm) one hour average] produces carboxyhemoglobin levels


of approximately 1.51.  Since the time of establishment of the stan-


dard, new evidence has appeared giving additional support to the cur-


rent standard in three areas.  These are:  (1) Effects on individuals
                               229

-------
  •10

  7.0

5 M
a
3E
^ 5.0
o
X

i 4'°
o 3.0
cc
1 2-0
3C
y LO
l«J
£ o.o
u_

  -1.0

  -2.0
               •»• 2.519
               (tine)  X
        .,
                                        10
                                    TIME IN HOURS
                                                        100
                                                                   1001
           Figure  5.3.
                    The difference in mean  survival time between
                        control of NCL mice versus  length of
                               exposure  to  3.5  ppm  NCL
with atherosclerotic vascular disease,  (2)  efffects on exercise capacity

in healthy individuals and (3)  additional evidence on alertness effects.

5.1.3.1.1  Effects on individuals with  Cardiovascular disease--Three

separate studies       have shown that  individuals with atherosclerotic

heart disease manifested by angina pectoris experienced chest pain

earlier during exercise  when carboxyhemoglobin concentrations are in  the
                                                              69
2.5-3.01 range than when they are about 1.01.  Another study   has shown

that men with peripheral atherosclerotic disease develop leg pain after

less walking at carboxyhemoglobin levels of 3.0%.  These studies were

well controlled and demonstrate increased morbidity in a segment of the

population with a common disease process.

5.1.3.1.2  Effects on exercise--Young,  healthy men at carboxyhemoglobin

concentrations of 5.0% have increased heart rates and decreased maximal
                                    230

-------
                                                      70
oxygen consumption when undergoing strenuous exercise.    Preliminary



analysis of an EPA study indicated lessened exercise performance at



COHb levels of approximately 5-6%.



     Decrements in exercise capability in the healthiest segment of the



population suggest more serious impairments in older persons who



frequently have subclinical cardiovascular disease.



5.1.3.1.3  Effects on alertness--Several recent studies have shown



impairments on vigilance tasks at carboxyhemoglobin concentrations


                      72-74
ranging from 3.0-6.51.       These data tend to support the original


                                              75
neurobehavioral work used to set the standard.



     Other evidence has appeared in recent years implicating levels of



carboxyhemoglobin below 10% with increased risk of atherosclerosis,



impaired fetal development   and in altered drug metabolism.    While



this evidence is certainly inconclusive at present, it still indicates



the range of pathophysiologic functions possibly affected by carbon



monoxide and the need for additional research.



     The strongest evidence now supporting the present standard rests



on the harmful effects of CD on individuals with cardiovascular disease.



Cardiovascular disease is widespread among adults and present studies



indicate aggravation of symptoms in a large sub-set of these adults.



     The ambient standard is given in Table 5.10.  Table 5.11 gives the



judgment threshold estimates for health effects of CO.  Values are



given for CO concentrations at light activity and during exercise as



well as rest since equilibration with a given CO concentration occurs



more rapidly with increased ventilation.  Table 5.12 gives the estimated



size of the population at risk from adverse effects of carbon monoxide.
                               231

-------
    Table 5.10.  AMBIENT AIR QUALITY STANDARD FOR CARBON MONOXIDE
                                 National Primary Standard
                                            3^
       Pollutant         Concentration (mg/mj)Averaging Time




    Carbon Monoxide           10  (9 ppm)           Maximum 8-hour



                              40  (35 ppm)          Maximum 1-hour





5.1.3.2  Animal Studies - -Apparently no animal experiments have been con-



ducted since publication of Air Quality Criteria for Carbon Monoxide



(1970) that employed <50 ppm CO exposures.  This concentration was the



lowest exposure level reported in that document.  The emphasis since



1970, however, has shifted from reporting ambient concentrations to



reporting carboxyhemoglobin (COHb) levels and the relationship of the



parameter with the effects.



     New data from animal experiments reported since publication of the



1970 criteria document have shown that COHb levels as low as 2% in



animals decrease pO~ of brain and liver.  Dogs were previously reported



to show blood changes at 7.3% COHb, but newer data shows that 5% COHb



increases coronary blood flow.  COHb levels of 9-10% maintained in rab-



bits during half of the gestation period resulted in decreased birth-



weight and increased neonatal and infant mortality.


         78
     Zorn   studied the effects of CO inhalation on the brain and liver p0



of animals using Lubber's platinum electrode and surface electrodes.  In



both tissues the p02 decreased, even at carboxyhemoglobin of 2% saturation



and the decrease varied approximately linearly with the increase in COHb.
                                    232

-------
               0)
           bO
          •H
          ,-J
                0
                in
               •H
                o   i-o
                fn   t-^
                0
P
•H
 >
•H
P
 U
                          .3
                               O
                               CTl
                                             Ol
                                             LSI
                                             LO
                                                       LO
                                                       INI
                                                       LO
                                             CTi
                                             •*t
                                             (Nl
           8
           3  B
           co •
           £3"
           rH  10
           03  O

           %%
           3  0
           c"
           w
           0  0
 o  0
•H  t/1
           P  10
           03  n3
               •H
                U
                M
                0
                P
               •H

               •H
                P
                (J
P
 10
 Q
                                             CTi
                                             O
                                             LO
                                             o\°
                                             O
                                             LO
                                             O
                                             LO
                                                        o
                                                         •
                                                        LO
0
o
p]
0

• rH
0
P
P^
0
•H
O
•H
m

fi
•H
0
U
c
0

';>
0
p
Pi
0
•H
U
•H
m
^
P!
•H
0
O
PH
0
•X)
•rH
0
•p
P!
0
•H
O
•H
<4H
m
P!
•H
LO

 0
I—I

•s
H
    10
    P
    O
    0
               w
               JS
               p
               i— i
               o3
               0
               0
               10
               fH


              I
                                             03
                                             P


                                             I
                                             0
                                             O  X
                                             JH  >
                                             0 -i-l
                                             m P
                                             ^  u
                                             0  rt
                                             P
                                                   0
                                                  I— I
                                                   u
                                                   10
                                                   8
                                                   0
                                                   03

                                                  <-H
                                                   O
                                                  TJ
                                                   0
                                                   10
                                                   n3
                                                   0
                                                   (H
                                                   U
                                                   G
I
O
                                                                         •8
                                                          03
                                                          P
                                                          0
                                                                                    0
                                                                                    !H
                                                                                   •H
                                                                                    03
                                                          233

-------
e
n,
w
Q
|

2:
nJ

O
DH

PH
O

^
CO
I—I
rt


^
w

s
PH


^

§
OH
 H,
 O

 w
 tsi
 rH
 CO
LO

 o>
rH

•8
H
*
tfl
p
oj
Pi
5
•H
P
OS
rH
PH
O

o
 0
*"O p,
0
MH P
O OS
!H
S^v. 	 /
(_)
Pi P!
0 o
3 -H
O* P
0 OS
£ 3
_ P-
TJ O
0 a,
p
u
0
w

p
u
0
m
m
w

^
rH
as
0
a:
to
0
1









Pi
o
•H
rH
'£
CXI
<*











*
«
;>
t/) O
rH OS
^J
TT? "^
OS p!
as
MH
O t/)
^
o\° as
LO 0
X
oo
rH
v — '





•5 0
0 as
O 0
C^ l/l
Co *H
!H T3
0
. t J ^
O >H
0
C/1
'u ^
§'g
0 10
TJ O
0 10
rH rH
•H 0
aS p*

rH





Pi
O
•H
rH
•H
e

O
iH
















cN3
0
o
rH













0
U
TO
tf
^li
O
m
rH
0

^
as
O
•H
10
t

1
as
0
0
a





rj
O
•H
,_)
•H
6

o
rH
















d*P
0
0
rH












K^
?***
•H
•H
O
as

rH
as
P
p|
^
^
•5
•H
8
c
§
MH
rH
0
P
Pi
HH
                                                o
                                               •H
                                               P
                                                O
                                                p.
                                                0)
                                                e/)
                                                aj
                                                (U
                                                !H
                                                O
                                                10
                                                OS

                                                S
                                               •S
                                                t/)
                                                    CO
                                               CXI   CO
                                                          234

-------
                             79
     A second study by Rondia   found that there was a decreased ability



of rat liver to metabolize 3-OH benzon alpha pyrene in rats exposed to



60 ppm CO.


                    80
     Cobum and Kane   studied COHb concentration of 10-12% in anaesthe-



tized dogs and found that this concentration resulted in an inhibition



of loss of hemoglobin-haptoglobin from the plasma.  Researchers studying



the relationship of varying concentrations of COHb and increased



coronary blood flow exposed conscious dogs to CO at increasing concen-



trations and observed a 13% increase in coronary blood flow with a 4%



increase in COHb.    At 20% COHb coronary blood flow increased by 541.



Coronary flow measurements at 4 COHb concentrations suggested a linear



relation between COHb concentration and flow.  A threshold value was not



observed, although measurements were not made below 5% COHb.



     COHb levels chronically increased to an average of 12.4% in



cynomolgus monkeys produced polycythemia with an increase in hematocrit


                                   82
from 35-50% volume of packed cells.    All animals developed increased



amplitude of P-wave in the EKA, and some developed T-wave inversions



suggestive of myocardial ischemia.  Monkeys with experimental myocardial



infarction had higher COHb and more severely abnormal EKG than normal



monkeys or monkeys with myocardial infarction breathing room air.

          OT

     Wells   studied pregnant rats exposed to 15,000 ppm (1.5%) for 5-8



minutes 10 times every other day during 21-day pregnancy and found



maternal unconsciousness and abortion or resorption absorption in most



of the fetuses.  The surviving newborns did not grow normally.  No



pathologic changes in nervous system were noted.  Similar exposure to



5900 ppm affected only a small portion of the animals.
                                235

-------
                       84
     Williams and Smith   exposed rats to GO at 3400 ppm for one hr/d for



three months.  Peak COHb = 60 = 70%; of seven exposed females, half the



control number pregnancies occurred.  The number of young delivered



decreased and only 2/13 newborns survived to weaning.  In five females



exposed for five months, no pregnancies occurred.


                  77
     Astrup et al.   studied pregnant rabbits exposed to CD of 90 ppm for



30 days.  Exposure during first pregnancy resulted in COHb 9-10%.  Birth-



weights decreased 12%.  Neonatal mortality increased from 4.5% in controls



to 10% in exposed.  Mortality during the following 21 days increased from



13-25%.



     In a second experiment, pregnant rabbits were exposed to CO of 180 ppm



for 30 days.  Exposure during first pregnancy resulted in COHb 16-18%.



Birthweights decreased 17%, neonatal mortality 35% vs. 1% and mortality in



following 21 days was 27% vs. same in controls.


                        85
     Baker and Tumasonis   exposed chicken eggs to various concentrations



of CO 0-650 ppm continuously from laying through 18 days of incubation and



found that hatchability was inversely related to [CO].  425 ppm reduced



hatching to 75%, embryo weight was normal, no congenital abnormalities,



650 ppm reduced to 46% and developmental anomalies of tibia and metatarsal



bones.

                o/r

     Baker et al   also exposed eggs 12 and 17 days old to CO of 425 ppm



for 24 hours.  COHb in 18-day-old chicks averaged 36%.  Livers of 18-day-



old chicks had about 50% increase in the activities of two hepatic mixed-



function oxidases, hydroxylase and 0-demethylase.  No effects were seen on



13-day-old chicks.
                                    236

-------
                       87
     McGrath and Jaeger   found that 50% o£ newly hatched chicks with-



stood exposure to 10,000 ppm for 32 minutes.  Survival time to this [CO]



decreased with postnatal age from 10 minutes in one-day-old chicks to



four minutes at ages 8-21 days.


          88
     Jones   exposed rats, guinea pigs, monkeys and dogs to 51, 96 and



200 ppm for 90 days and found no toxic effects of the 00.  The only



reported physiological change was increased hemoglobin and hematocrit



values for all species.


         89
     Ator   exposed rats to 100-1000 ppm of CO for 90 minutes and found



no effect on response rate for differential reinforcement of low-rate



schedules at exposures up to 250 ppm.


                90
     Gage et al.   found significantly higher activity in female mice



exposed to 100 ppm CO for four-seven days than in males similarly



exposed or in female controls.  No statistically significant effect on



the activity of male mice occurred under these exposure conditions.



5.1.4  Hydrocarbons



     The National Ambient Air Quality Standard for hydrocarbons was



based almost entirely on their role as precursors of other compounds



formed in th- atmospheric photochemical system and not upon direct



effects of the hydrocarbons.  Particulate hydrocarbons and more specifi-



cally polynuclear hydrocarbons were not considered on the criteria



document.  Ambient air data are limited primarily to non-methane gase-



ous hydrocarbons and benzo-a-pyrene.



     The National Academy of Sciences published a review on particulate


                                  91
polycyclic organic matter in 1972.    A scientific and technical assess-



ment report by EPA on the same subject is in the final stage of
                                 237

-------
publication.  EPA reports on polychlorinated biphenyls and vinyl chloride



are also in the final stage of publication.


                 92
     Aksoy et al.   has reported on six cases of Hodgkin's disease in



workers with a history of chronic benzene exposure.  The subjects were



exposed to benzene for a period ranging from 1 to 28 years with a mean



of 11 years before the onset of Hodgkin's disease.  The concentration of



benzene in the working environment ranged between 150 and 210 ppm.  Ven-



tilation in the work places was reported as poor.  A summary of these



cases is shown in Table 5.13.  There was no indication in this report of



the number of workers at risk or any discussion of other possible agents



that might have been present in a poorly ventilated work place.


                      93
     Ahmad and Whitson   reported on one incidence of rapid loss of con-



sciousness of 10 new female employees reporting for work in an industrial



garment company.  Immediately after the incidence, measured concentrations



of formaldehyde ranged from 2 to 10 ppm.  Other workers in the area had no



apparent difficulties.  The authors suggest that the response was due to



exposure to formaldehyde although little additonal evidence was given.


           94
     Thorpe   conducted a study of eight affiliates engaged in the manu-



facture, transportation and marketing of petroleum or chemical products



containing benzene for at least 10 years.  The incidence of leukemia in



the general population with an age distribution similar to that in the



Thorpe study is about three to eight cases per 100,000 population.  Eigh-



teen cases of leukemia were reported for the period 1962 to 1971.  These



cases were distributed among four of the affiliates--the other four



reported none.  A summary of the 18 cases is shown in Table 5.14.
                                    238

-------
     Thorpe also found that the occurrence of leukemia in a population



of 38,000 working in a variety of petroleum and petrochemical operations,



some of whom were exposed to low levels of benzene over a 10-year period,



was not abnormal compared to the general population in the countries



concerned (see Table 5.15).  As pointed out by Thorpe, there were prob-



lems with the data base and a number of important assumptions were



necessary.
                               239

-------
 X
 t—I
 CO
 to
 U
 z
 I—I
 Q

 l-H HJ
 U, CO
    <
 u ia
 i—I W
 U M
 O Q
 OH  ^


 Q  Q




 u  a:
 t—I  f-H
 CJ  I—I
 O  2
S  w
uj  i—i
X  H



U
i—i
2
o
CO
LO
.0
rt
E-
u
W
rt


u
^ 3)
0 C
•£•5
/? c


2 a
I' C






V)
C
M
E
0

Cu
E


Cl
V)
d
W

>


>,
§1

rt*
WBC 4200,
lymphopeni
ESR:
149 mm./hr





S^rt
•« •? 60
Cervical, inguin
lymphadenopatl
hepatosplenome
R
?!
^
-c>
Ul t«
""» >
&.£




00



*
OO

in a
* £
O,.vj

32



T-l

>


;»,
"0 ^
_
rt"
WBC 5400,
lymphopeni
ESR:
(A
~'£
'rt *-*
o rt
> °*
u F
Both inguinal, c
axillar lymphadl
moderate
.R

•->

Uj ^
"^ >
£,£




o




"
VI
U
Shoemak

$s



CM








E
CM
OO





"rt
nn
hepatosplenome


























»— *
o
*^"i
>>
u c
J.I
E-5
|fr
J -a
0
X ..
o E to .c
OO >.ttj —7.
^"s «• E
1 s §.3
«f
•IS
rt *^
C ™
• - Q. >s
3 o -^;
60 C 3;
Both cervical, ii
axillar lymphadl
moderate
hepatosplenome
.R
Sj
^ m

Ln uT •"•
-J. > 5
£££




vO




^
V
_M
rt
'I
JC
LO

sa



rO

>

Q
O.
u
X


WBC 5800,
lymphopeni
ESR:





w
r-
Cervical, axillar
lymphadenopatl
findings of liver






^




* '




00
14
u
c
1
0

8S



^1








-C
E
E
00






cirrhosis

























^
«
o 8
'w C
>^ rt
U C
-§£
D. o
n
J D.
C

It





• r*
Both cervical,
axillar, inguinal
lymphadenopatl


4_,

5P

5*J2




o





U,




**




r-"
c
Televisio

r~-
CM



\o






.
rt*
lymphopeni
ESR:
97 mm./hr.





vt
o
(-"
lymphadenopatl

















(-"
repairmai

^






































c
'g
T3
rt
•6
"*C
*

                                                          240

-------
               Table  5.14.    LEUKEMIA  EPIDEMIOLOGICAL  STUDY
Leukemia
Age
Epidemiological Study — Summary of 18 Cases ol Leukemia by Set,
at Death (or 1971), Last Job Assignment and Type of Leukemia.
Sei Age it Death Last Jcb Assignment
F 19
M 26
Mt 33'

M1 36
Mt 40
Mt 41
M 42
M 46
Mt 60
M 61
M 62'
Mt 66
M 68
M 68-
M 69
Mt 70
M 71
Ml 73'
Clerk. Head Office
Engineer, Refinery
Passenijer Car Driver
(Tank Truck Driver 196066)
Mechanic in Refinery
Plant Operator, Refinery
Filler, Refinery
Kerosene Truck Driver, Airpoit
Mathematician, Head Office
Marketing Superintendent
Industrial Assistant Dealer
Carpenter, Refinery
Truck Driver, Marketing
Comme'Cial Clerk. Head Office
Clerk Chauffeur, Refinery
Clerk, Head Office
Process Operator, Refinery
Manage', Head Office
Mechanic. Marketing Repair Shop
Type of Leukemia
Leukemia, Type'
Leukemia, Type'

Chronic Myeloid Leukemia
Leukemia, Type'
Myeloid leukemia
Acute Leukemia
Leukemia, Type'
Leukemia, Type'
Leukemia, Type'
Leukemia, Type'
leukemia, Type'
Leukemia, Type'
Leukemia. Type'
Leukemia, Type'
Chronic Myeloid Leukemia
Leukemia, Type'
Acute Myeloblastic Leukemia
Chronic Lymphatic Leukemia
           Living
          ! In Exposed Group
Table  5.15.    EXPECTED  VS.  OBSERVED  DEATHS  FROM  LEUKEMIA  IN
                            EIGHT  EUROPEAN  AFFILIATES  1962-1971
                   Eipected n. Observed Deaths From  Leukemia in >  European Affiliates  1962 • 1971.
           Age it Tim*
            of Duth
 Estimated
Age Adjusted
   Totil
Person Yftir1
 Age Specific*
   Modality
Rites (WHO-1966)
                                                         No  of Deaths
              Obwrvtd
             No. of Deiths
           1519
           2024
           2529
           3034
           3539
           4044
           4549
           5054
           5559
           6064
           6569
           7074
           7579
           8084
           85 And Over

           Totil All Apt
   3.248
   15.592
   36.707
   49,051
   47.102
   51,000
   48.726
   37,681
   3S.049
   25.960
   11.519
   B.064
   5.610
   3,214
   1.753

  M3.276
     22
     1 7
     27
     21
     30
     34
     *6
     61
     80
     124
     168
     206
     285
     37 7
     300
 007
 026
 099
 103
 141
 1 73
 224
 230
 304
 322
 194
 166
 160
 1 21
 053

23.23
 1
 0
 1
 1 (1)"
 1
 3
 1
 0
 0
 3(1)"
 4(11"
 3(1)"
 0
 0
 0

II
        • The Age Specific Mortality Rites shown »ere taken from those ol the counlry (or average ol the countries) reporting the uses
        in the Esso population
        Cises shown (  )"are still living but for these calculations were assumed to have died it tfmr age in 1971 (see leil)
                                           241

-------
     Some polycyclic aromatic hydrocarbons are the most ubiquitous car-



cinogens known.  The noxious effects of tobacco smoke in humans and



animals has been attributed to presence of various hydrocarbons.  Short-



term exposures of guinea pigs to cigarette smoke decreased the number of



free lung-cells--macrophages and leukocytes--as determined from lung


                    95
lavage preparations.    The decrease in numbers of macrophages was



attributed to the presence of acetaldehyde, tar, nicotine, hydrogen



cyanide and acrolein.  And the decrease in the number of leukocytes was



related to acetaldehyde, tar and pH of the particulate phase.



     Confirming the previous observations that toxicity of smoke was



part of the vapour phase of the smoke, the above studies also indicate



that biologically significant activities exist in the particulate phase



of the smoke.  Necessary long-term biological experiments are warranted



to verify these short-term observations.



     The cigarette smoke condensate (CSC) contains aromatic hydrocarbons,



such as pyrene, benzo[e]pyrene and benzo-[g,h,i]perylene, that have been



considered non-carcinogenic up to now.    In addition, CSC also contains



phenols, the most important of which is catechol (1,2-dihydroxy-benzene).



Attempts to assess the carcinogenic or co-carcinogenic activity of these



compounds in CSC on female mouse (1 CR/Ha) skin demonstrated remarkable


                                                                      98
carcinogenic activity of catechol and the three aromatic hydrocarbons.



Each of these produced skin papillomas and squamous cell carcinomas in



mice.  Catechol also exhibited co-carcinogenicity in these tests.  The



animals received catechol (2,000 yg), benzo[e]pyrene (15 yg), Pyrene



(12 yg) and benzo[g,h,i]perylene (21 yg) per 0.1 ml acetone,  three times



a week for 52 weeks.
                                    242

-------
                                                99
     Catechol is found in many plants and trees,   including tobacco



leaves.    Compelling practical problems suggested by this study include



immediate need to develop a less harmful cigarette and to reduce or



eliminate emissions of hazardous material from tobacco.



     Certain chemicals such as chloromethyl methyl ether (CMME) and bis



chloromethyl ether (BGME) are widely used as intermediates in organic



synthesis and preparation of ion-exchange resins.  An increased incident



of oat-cell carcinomas were seen (13 or 14 men with lung neoplasms) in



men exposed to CMME.     Commercial CMME contains 1 to 7% BCME.  Both



CMME and BCME are highly carcinogenic for mice and rats.



     Mammalian tissue cultures have been used to study induction of



microsomal enzymes because of ease of control of time of exposure and



concentration of inducer.  Following this lead, human foreskin obtained



from infants (two to four days old) at time of circumcision was grown



in tissue culture.     Such foreskin tissue cultures were exposed to



10 yM of benz-(a)-anthracene (BA) for 16 hours to induce benzo(a)pyrene



hydroxylase.  This hydroxylase activity was greater (1.78 to 5.30 times)



in foreskins treated with BA when compared to the foreskins in the con-



trolled medium without BA.



     Considering the size of "the skin pool and evidence of inducibility



of benzo(a)pyrene hydroxylase in skin, the role of skin in detoxifica-



tion of various polycyclic hydrocarbons may be significant.  The levels



of benzo(a)pyrene hydroxylase (BP hydroxylase) in liver and extraphepatic



tissues differ markedly from strain to strain of mice.  This difference



may mean that genetic factors influence the constitutive level and



inducibility of BP hydroxylase.  As the extra-hepatic tissues in mice
                                  243

-------
are frequently the targets for polycyclic hydrocarbon carcinogenicity,



the inducibility of BP hydroxylase in extra-hepatic tissues from mouse



strains investigated exhibited 3-methylcholanthrene and 5-6-benzo-


-.      107
flavone.



     Results from the liver, lung and skin of mice of various strains



show that tissues vary in their ability to produce BP hydroxylase in a



given strain.  The three (3) hydrocarbons above were equally capable of



inducing hepatic BP hydroxylase.  However, 3-methylcholanthrene was a



far less effective inducer of BP hydroxylase in extra-hepatic tissues



(lung and skin) than either benz(a) anthracene or 5-6-benzoflavone.



5.1.5  Oxidants
     The present U.S. National Primary Standard for photochemical oxi-



                                 :imum one


                                 108,109
dants is 160 yg/m  (0.08 ppm)  maximum one-hour concentration not to be
exceeded more than once per year.



     The original evidence for this standard for people included a



broad range of morbidity such as aggravation of asthma, aggravation of



chronic lung disease, irritation of the respiratory tract in healthy



adults, decreased visual acuity, increased eye irritation and decreased



cardiopulmonary reserve in healthy subjects.  These data were completely



reviewed in the original photochemical oxidant criteria document.



     Three important papers on pulmonary function after short-term ozone



exposure were published during the 1969-1974 period.  All three studies



were of healthy adults.  Bates et al.    observed substernal soreness,



cough and some phoryngitis and dyspnea along with decreased pulmonary



function among healthy, lightly-exercising volunteers experimentally



exposed to 1500 yg/m  of ozone for two hours.  Hazucha et al.    observed
                                    244

-------
                                                         3            3
similar effects in volunteers exposed to either 1500 yg/m  or 740 yg/m



of ozone for two hours.


          112
     Bates    reported a marked decrease in pulmonary function among



healthy subjects doing light exercise and exposed simultaneously to


        3                       3
740 yg/m  of ozone and 1000 yg./m  of sulfur dioxide for two hours.  This



deleterious effect may be synergistic and a deleterious synergism of 0,



and SO- upon plants has been described in the original criteria docu-


   «. 108
ment.



     Hammer et al.  ' studied student nurses in Los Angeles prospectively



using daily symptom diaries during three years of their training (6).



Headache, eye discomfort, cough and chest discomfort were found to be



related to ambient daily photochemical-oxidant exposure.  Dose-response



thresholds could be calculated for each symptom in relation to the daily



maximum hourly photochemical-oxidant concentration.  They were as fol-


                          3                           3
lows:  Headache - 100 wg/m , eye discomfort - 300 yg/m  , cough - 510



yg/m , chest discomfort - 580 yg/m .



     The threshold for eye discomfort was comparable to that observed in



several earlier experimental and panel studies.  Thresholds for cough



and chest discomfort were in the same range found in two studies of


      ^-             j    i     114,115
occupationally exposed workers.



     On highest oxidant days (800-1000 yg/m ), students reported 481



more cough and 100% more chest, discomfort than on days when ambient



oxidant levels were at or below the present U.S. National Primary Stan-



dard (160 yg/m3).



     Two recent reports summarize new studies on experimental ozone



exposure.  Kerr et al.    studied 20 lightly-exercising subjects exposed
                                 245

-------
to 0.5 ppm ozone for six hours.  Symptoms most commonly noted were dry



cough and chest discomfort.  These symptoms were experienced more fre-



quently by nonsmokers.   Significant changes in specific airway conduc-



tance (S Gaw) , pulmonary resistance (Rj), FVC and FEV,,, but not diffusing



capacity (DLGO), were also found.  In addition, nonsmokers showed a sig-



nificant decrease in dynamic compliance during exposure.  In general,



there was a relationship between experiencing symptoms and alterations



in pulmonary function among the study subjects.


            117
     Hackney    exposed adult male volunteers doing intermittent light



exercise to 0.37 or 0.50 ppm of ozone for two hours.  These subjects



not only developed measurable physiological and biochemical changes, but



felt physically ill and were unable to do their normal jobs during expo-



sure and for several hours afterward.  All subjects experienced biochemi-



cal changes.  The least sensitive subjects experienced no respiratory



symptoms or physiological changes after five-hour exposures to 0.5 ppm



ozone on two successive days.  The most sensitive subjects experienced



respiratory symptoms after a single two-hour exposure to 0.37 ppm of



ozone.  The more reactive subjects were generally had a history of asthma,



allergy or previous adverse symptom reactions to smog exposure.



     No additional effects were observed when 0.30 ppm nitrogen dioxide



was added to ozone or after adding 30 ppm of carbon monoxide to 0,-NCL



mixture.  There were no significant changes among the most sensitive



subjects during ozone exposures of 0.25 ppm for two hours suggesting



that this concentration was a lower limit for these effects in healthy



adults.



     Three comments about the new evidence are pertinent.  First,



experimental, occupational and epidemiologic studies of healthy males




                                    246

-------
and females exposed to ozone per se or ambient photochemical oxidants

                                                                        3
indicates that as little as one to two hours of exposure to 500-600 yg/m


of ozone or photochemical oxidants causes cough, chest discomfort, sub-


sternal soreness and impaired pulmonary function in these people.


Hence, it would seem that these thresholds should generally hold true


for healthy adults and would probably represent an upper limit for


especially sensitive persons, e.g., those with asthma or pre-existing


cardiovascular disease.


     Second, the synergistic effect of ozone and sulfur dioxide on human


pulmonary function has been reported in the past two years.  This  syner-


gism has been described in plants for several years and was summarized


in the original criteria document.  Also, there is concern that inter-


action of these two pollutants on lung function may actually be additive


and not synergistic.  Since lung function is impaired in a non-linear


fashion to any stimulus, "extra" decrement attributed to the combina-


tion of SCL and ozone could be an additive effect in the non-linear


part of the lung-function curve.


     Third, the terms "radiomimetic" and "mutagenic" should be used


with considerable caution when applied to ozone.  Animals that showed


alterations in red blood-cell fragility had been exposed to 10,000 rads


(a large radiation dose) as well as ozone.  Chromosomal breaks in peri-


pheral lymphocytes of hamsters following ozone exposure have been


observed.  But this may just be a peripheral and not a stem cell effect.


If so, it is not properly described as a mutagenic effect.


     Photochemical oxidants, ozone in particular, are primary irritants


aggravating asthma, impairing athletic performance, causing severe
                                247

-------
respiratory tract irritation and altering pulmonary function in healthy



adults under experimental, occupational and ambient exposure conditions.



In animals, ozone alters host defenses against infection, causes various



structural changes to lung and hematopoietic tissue and produces chromo-



some breaks in peripheral lymphocytes even at ambient concentrations.



     Old and new evidence to date suggests that the present primary



National Air Quality Standard for photochemical oxidants of 160 yg/m



(9.08 ppm) maximum concentration for one hour is reasonable.  The evi-



dence does not warrant a different standard.



     Air quality standards should be based on complete and reliable



dose-response relationships.  Most quantitative health intelligence to



date was obtained from animal models.  Direct extrapolation of this



research to humans is questionable.  Until comprehensive data are accumu-



lated about acute and chronic human exposures, margins of safety will



remain obscure.



     Exposures of other vulnerable people such as infants, pregnant



women and persons with heart and lung disease, have not been investi-



gated.  These persons may require more stringent air pollution controls



than healthy young adults.



     Finally, photochemical oxidants occur with other atmospheric pollu-



tants.  Nearly all epidemiologic findings to date may reflect interac-



tions between oxidants and other environmental factors such as ionizing



radiation, sulfur oxides or nitrogen oxides.  These interactions remain



to be discovered in the laboratory and field.  Because interactions have



not been characterized in laboratory or epidemiologic studies, existing



evidence can be applied only with reservations to community exposures.






                                   248

-------
Considerable human dose-response data under controlled laboratory condi-



tions and in natural community settings are urgently needed to establish



protective air quality standards for photochemical oxidants with adequate



but no excessive margins of sa.fety.



5.1.5.1  Animal studies--There is much documentation about exposure to



ozone at concentrations 
-------
macrophage) was also deleteriously affected by low level 0_ exposures
 [981.5 yg/m3 C-5 ppm)].122'124
     Ozone-induced tolerance to pulmonary edema is a well-recognized
phenomenon.   "     However, new investigations indicate that short-
term exposures to 1963 yg/m  (1.0 ppm) 0, produced some tolerance to X-
irradiation    and allergic responses.     Several bronchemical changes
are also produced by ozone.  Many experiments confirmed the anti-oxidant
character of Vitamin E that protected animals from some of the harmful
alterations produced by ozone.   "     This oxidant causes alterations
                       131-133
in lecithin information        and in activities of several pulmonary
                  134-143
and serum enzymes.         Short-term low level 0, exposures also pro-
duced changes in pulmonary function.   '   '
     Some interesting systemic 0, effects are also known.  It is possi-
ble that this oxidant produced pulmonary artery hypertension in animals
that were genetically susceptible.     The parathyroid gland was also
affected by exposure to 1472.3 yg/m  (.75 ppm) 0,.   Additionally, mice
that received pentobarbital after exposures of 1963 yg/m  (1 ppm) for
three hours/day for three days showed an increased sleeping time.  All
of the foregoing information is summarized in detail in charts follow-
ing this section.
     While reviewing the 0, literature, several gaps are noticeable.
Most research used healthy, young-adult animals.  Attempts were then
made to extrapolate this data to people.  Since many people are very
young, elderly or impaired in some way by various debilitating ill-
nesses, more research should be done with specialized animal models
capable of representing these groups.
                                  250

-------
     Also, exposures to 0_ are usually of a long-term intermittent nature



suggesting the need for longer-term experiments.  Some more recent work



also examines the question:  Are some pollutant effects naturally



reversible?  Perhaps more research should attempt to answer this impor-



tant question.  Also, since 0, induces tolerance to pulmonary edema, it



would be worthwhile to examine this matter further.



     Some researchers have tried to delineate the actual mechanism of



action of CL, but much work still needs to be done.  Furthermore, since



most research concentrates on 0,-induced pulmonary damage, it would be



of great interest to examine extra-pulmonary effects.   The existing



data on ozone's systemic effects justify further delving.



5.1.5.1.1  Pathological effects--The pathological effects of 0^ on pul-



monary tissue are well documented   '    and additional study would


                                119                              3
only be of interest.  Pan et al.    exposed rabbits to 785.2 yg/m



(.4 ppm) 0, for six hours/day,, five days/week for 10 months.  The



authors observed emphysematous and vascular lesions in the lung.  The



small pulmonary arteries were thicker than controls because of the



increased size of the tunica media vasorum that in turn appeared to be



a result of tissue edema or muscular hyperplasia in some instances.



5.1.5.1.2  Infectivity--Experiments reported in the initial criteria



document    showed that three hours of 1570.4 yg/m  (.08 ppm) 0,



enhanced mouse mortality because of subsequent exposures to Group C


                           , 3          , 147,148        ,   .
Streptococcus pyogenes.  Goldstein et al.        exposed mice to an


            32
aerosol of P   labeled Staphylococcus aureus either after  17 hours



of CL or before four hours of 0.,.  The concentrations used were 1177.8,



1374.1, 1570.4, 1963 or higher yg/m3  (.6,  .7,  .8 or 1 ppm).
                                251

-------
     Mechanical clearance and bactericidal capabilities of the lung were



then measured.  Pollutant exposure for 17 hours before infection caused



a decrease in tidal volume and a subsequent decrease in pulmonary deposi-



tion of bacteria (67% at 1963 yg/m ).   There were also significant

                                                           2
decreases in bactericidal activities beginning at 1963 yg/m  (1 ppm).
     When
the mice were exposed to four hours of 0^ after being infected,
slightly different effects were noted.  Bactericidal activity was



decreased at a lower level--1177.8 yg/m  (.6 ppm)  and there was no



effect on pulmonary deposition or clearance of the Staphylococci.  The



proposition was advanced that since mucociliary clearance is unaffected



by subsequent 0, exposure, bactericidal defects must be due to dysfunc-



tion of another line of pulmonary defense, most probably the alveolar



macrophage.



     Others working in the same field found that 981.5 yg/m  (.5 ppm)



of 0,, 16 hours/day for seven months had no effect on the mechanical



clearance of polystyrene and iron particles in rabbits.  There was only



a small decrease in bacterial clearance in guinea pigs.


                      121                                      3
     In other studies,    mice were exposed to either 1963 yg/m  (.1 ppm)



03 and 3762 yg/m3 (2 ppm) N02 or 785.2 yg/m3 (.4 ppm) 03 and 13731 yg/m3



(7.27 ppm) NO £ for 17 hours before infection or four hours after infec-



tion.  The lung was capable of functioning until the higher pollutant



level was reached.  Physical clearance was not affected at either level.



The injuries demonstrated were those that would be expected from each



individual oxidant, so no synergism was noted.



     In most of the foregoing studies, the authors recognized the pos-



sibility that damage to the alveolar macrophage was primarily responsible
                                    252

-------
for enhanced infectivity and lowered bactericidal response.  This func-



tional damage to the macrophage could occur through various mechanisms.



First, when rabbits are exposed to 981.5 yg/m  (.5 ppm) for eight hours/



day for seven days, they exhibit increased membrane fragility, even


                                                         122
though lipid peroxidation was undetectable at this level.     Since



phagocytosis begins with particle attachment to the cell membrane, this



fragility could be involved.



     In normal animals, alveolar macrophages are a renewable population,



so studies were conducted to see if this process continues after a six-



hour exposure to 981.5 yg/m  (.5 ppm), 2159.3 yg/m  (1.2 ppm) and higher



levels of 0 .  Aging mice (18-20 month-old males) were given injections



of tritiated thymidine to mark alveolar cells undergoing DMA synthesis.



Inhibi-ion of DMA synthesis occurred at all CL levels about equally,



representing miximum inhibition.  This depression was visible up to 24



hours after ozone mice were transferred to clean air.  ENA synthesis

                                                         124
did not completely return to normal until 72 hours later.

                                 150
     In a recent study, Fairchild    reported on the respiratory depo-



sition of vesicular stomatitis virus in mice after exposure to 1766



yg/m  (.9 ppm) 0,.  This exposure produced a 70% increase in respiratory



viral deposition.  The increase was also due to increased deposition in



the nasal cavity.  No changes occurred in the lung or trachea.  This



effect was particularly important since the respiratory volume in 0.,-



exposed mice was approximately 201 less than in controls.  The author



suggested that 0, may increase the severity of infections caused by



organisms that primarily exert their effect on or through the nasal



mucosa.
                                253

-------
5.1.5.1.3  Ozone induced tolerance- -Ozone induced tolerance to pulmonary



edema has been reviewed in prior documents.   '     However, other types



of tolerance have been recently investigated.  It is interesting to note



that when mice were exposed to 1963 yg/m  (1 ppm) 0, for one hour and



then X- irradiated to 800R after 10 days, 60% of these pre-exposed ani-



mals survived even though all non-ozonized mice died.  This tolerance


                        125
lasted at least 30 days.


              126
     Matsumura "  investigated the effects of oxidants on induced



allergic respiratory disease in guinea pigs.  When the animals received



a one-hour pretreatment of 1963 yg/m  (1 ppm) 0,, no allergic responses



to inhaled acetylcholine were visible after a later exposure to 3926
      (2 ppm) 03.



     The mechanism of tolerance development to 0,- induced edema is not



well understood, but the thymus appears to be involved.  Male mice,



thymetomized at birth, were unable to develop tolerance to a two-hour



dose of 39260 yg/m  (20 ppm) 0., even though they had been pre-exposed



to 588.9 yg/m  (.3 ppm) of 0, for one hour.  Sham-operated animals


                                                      148
exhibited tolerance under the same oxidant conditions.



5.1.5.1.4  Pulmonary function effects- -Ozone- induced changes have been



the subject of many recent reports.

                   1 OO

     Moorman et al.    investigated ozone decomposition in the naso-



pharynx of beagles by exposing the animals to the gas and measuring



mean tracheal concentrations of ozone.  One group was chronically



exposed to 1963 yg/m  (1 ppm) for three hours/day for 18 months.



Another group received an acute one-hour exposure to the same gas con-



centration.  The chronically treated dogs had higher tracheal levels
                                   254

-------
of O^ due probably to a reduced ability of the upper respiratory system



to remove the pollutant.


                              144
     In another investigation,    the right lung of rabbits was exposed



to 1963 yg/m  (1 ppm) 0., for three hours.  The left pneumatotic lung



was used as a control after the air pressure was returned to normal.



The exposed lungs of rabbits sacrificed one and three days after exposure



showed reduced vital capacity.  Those studied seven days after exposure



had only a slight, non-significant, reduced capacity.


             145
     Yokiyama    also studied the ventilatory functions of guinea pigs



before, during and after a two-hour exposure to 981.5 yg/m  (.5 ppm) CL.



The following results were noted:  air current resistance increased,



frequency of respiration increased and tidal volumes decreased.  Com-



parison studies were made with SCL and NCL and differences were found.



S0? produced a decrease in respiratory rates, while N09 and CL had the
  i_l                                                   L*      O


opposite effect.



5.1.5.1.5  Extra-pulmonary effects--Most 0, studies have involved pul-



monary effects.  But some interesting investigations have shown that



0, can effect other organs and physiological functions as well.



Gardner et al.    exposed mice to 1963 pg/m  (1 ppm) 0, for three hours



up to seven days and injected pento-arbital sodium immediately after



exposure.  There was a significant increase in the sleeping time of the



exposed animals after two and three days of 0, exposure.  After one day



and after four or more successive exposures, there was no effect.  Pos-



sibly, this resulted from development of tolerance.



     The authors hypothesize that increases in sleeping time might



result from formation of ozone reaction-products that could damage
                                255

-------
hepatic microsomal enzymes that detoxify pentobarbital.  The "tolerance"



could result from an increase in induction of these enzymes.  The actual



mechanism of 0, action is now under investigation.



     Circulating blood is also affected by ozone exposure.  Female mice



inhaled 1688.2 yg/m  (.86 ppm) for eight hours/day, five days/week for



six months.  At this time, the animals were infected with Plasmodium



berghei and exposed mice exhibited increased parasite infestation and



increased mortality.  Additionally, up to the sixth week of exposure,



there was a significant increment in acid resistance of the erythro-


      153
cytes.     Other investigators showed an increased resistance to hemo-



lysis in erythrocytes in mice exposed to 1963 yg/m  (1 ppm) for 30


 -  «.   154
minutes.



     The effects of CL on pulmonary arterial pressure was investigated



in dogs.     Eight animals were exposed to 1963 yg/m  (1 ppm) for 17



months and for varying hours per day.  Three dogs developed pulmonary



artery hypertension and nine dogs developed excessive systolic pressure.



Since there was no proportional relationship between pulmonary artery



hypertension and oxidant exposure, it was suggested that the results



seen were caused by genetic susceptability.



     Matsumura    exposed albumin sensitized guinea pigs to 1963 yg/m



(1 ppm) 0., and found no increases in anaphylactic attacks after subse-



quent antigen inhalation.

         1 £*f-\                           X
     Roth    exposed rats to 490.8 yg/m  (.25 ppm) 0, for two hours and



found no differences in gastric secreto-motor activities, even though a



temporary effect was present at higher levels.



     Atwall,    using light and electron microscopy, found histological



and ultrastructural changes after a four-eight-hour dose of 1472.3 yg/m



                                   256

-------
(.75 ppm) 03 in the parathyroid glands of rabbits.  The major changes


found in exposed animals were:  large number of secretion granules,


hyperplasia of chief cells, proliferation and hypertrophy of the rough


endoplasmic reticulum, free ribosomes and mitochondria, lipid bodies


and an accumulation of secretion granules inside the vascular endo-


thelium of the blood stream.


     This increased activity does not abate until 66 hours after expo-


sure.  The damage could produce alteration of parathormone production


and storage.


     Certain radiomimetic properties have already been documented for


0, and further studies have been made.  A review article by Veninga  ~


presents evidence for the radiomimetic properties of CL and includes


some of his own research in the presentation.


     C. Black Mice were treated with 392.6 yg/m  (.2 ppm) 0, for seven


hours/day, five days/week during gestation and then for the first 13


weeks of life.  0.9% of the normal newborn mice had unlimited incisor


growth while 0, exposed animals had an incidence of 5.4%.  In the same


species, neo-natal death rose from 9% to 34% after treatment.  Addi-


tionally, blepharophimosis in the normal mice occurred in .6% of the


animals while it was 9.6% in ozone groups.


     Similar, but less dramatic, results were seen in another species


of mouse where the rate of blepharophimosis rose from 4.5% to 9.2%.

                                        142
In another study by the same researcher,    binucleated lymphocytes in


murine blood doubled in number after exposure to 392.6 yg/m  (.2 ppm)


for two hours.


5.1.5.1.6  Smog--In the environment, 0, co-exists with many other pol-


lutants that can modify the actual 0, effect.  Some well-defined studies


                                   257

-------
on pollutant combinations have been reported elsewhere in this manu-



script.  This section will deal with the effect of synthetic and actual



smog on animals.


         123
     Emik    exposed various laboratory animals to ambient California



air over 2.5 years.  The average ambient concentrations were .057 ppm



oxidant, 1.7 ppm CO, 2.4 ppm hydrocarbons (as carbon), .019 ppm NCL,



.015 ppm NO and 4.2 ppb PAN.  The following results were obtained:



reduced pulmonary alkaline phosphatase in rats, reduced serum glutamic



oxaloacetic transasminase in rabbits, increased pneumonitis in mice,



increased mortality in male mice, reduced body weights in mice and



decreased running activity of male mice.  When older guinea pigs that



lived in smog for two years were exposed to 981.5 yg/m  (.5 ppm) 0_



for 10 minutes, they had lowered deleterious responses to 0, compared
                                                           o


to animals that existed in clean air prior to the same 0, exposure.



The authors suggest that a possible adaption occurred.  Pulmonary



tumors were found in the lungs of some mice, but there was no signifi-



can induction of lung adenomas in the two strains of mice exposed to



ambient, smog-containing air.  And it was thought that this exposure



was probably near the threshold of effect.



     In further attempts to produce synthetic atmospheres, Nettesheim

      158
et al.    exposed mice to ozonized, un-leaded gasoline.  The maximum



concentrations delivered to the animals were 1963 yg/m  (1 ppm) 0., and



24-30 ppm gasoline for 5.5 hours/day, five days/week for 127 weeks.



Some groups of animals were also treated with X-radiation (100R) and



infected with influenza virus.  Several results were found:  irradiation



raised the occurrence of lung tumors in females, but not in males;
                                    258

-------
chronic ozonized gasoline exposure increased the lung tumor incidence in



both sexes (p<.05) and the viral infection appeared to retard lung tumor



growth.  The only lung tumors found were adenomas and adenocarcinomas.



Furthermore, the investigators state that these experimental conditions



had no significant additive or potentiating effects.


                        159
     Schlipkoeter et al.    also investigated the possibility of syner-



gism using a variety of pollutant exposures to mice and rats.  They



found that 1688.4 yg/m  (.86 ppm) 03 and (50 and 100 ppm) CO had antago-



nistic effects on erythrograms.



5.1.5.1.7  Biochemical Effects--The actual toxicity of ozone at the



subcellular level is still debatable.  However, several theses have been



advanced about the biochemical damage caused by 0,.  They include the



following:  (1) non-specific stress with the release of histamine,



(2) oxidation of sulfhydryl groups or their precursors,  (3) oxidation



of polyunsaturated lipids contained mainly in cell membranes, (4) for-



mation of toxic compounds (ozonides) through reaction with polyunsatu-



rated lipid, (5) formation of free radicals, (6) injury mediated by



a pharmacologic action, i.e., via a neurohormonal mechanism.  These



mechanisms have been discussed in the prior document.  ~  '     Only new



or substantiating material will be presented here.



     Many experiments have been conducted to find the effect of 0, on

                                 -i i?/-                            *7

lipid perioxidation.  Chow et al.    exposed rats to 1472.3 yg/m



(.75 ppm) Ox and found an initial decrease and subsequent increase in
           O


the activities of glutathione peroxidase, GSH reductase, G-6-PD, 6-P-GD



and pyruvate kinase.  They reasoned that this pattern was probably due



to increased needs for reductive detoxification of  lipid peroxide.
                                259

-------
     Cortes    prepared a methyl linoleate ozonide and gave it to rats
by IV injection or oral dosage.  This treatment was lethal because of
acute lung congestion from edema.  Significant changes also occurred in

the fatty-acid composition of serum and lung lipids.  Other experiments
where rabbits were exposed to 1963 yg/m  (1 ppm) 0,, for four hours

showed a decrease in the rabbits of incorporation of fatty-acids into
lecithin.  Pulmonary lavage from thse animals indicated increased

activity of lecithins.
     The authors observed that 0, may affect the lung by decreasing
lecithin formation while simultaneously stimulating the release of sur-
factant lecthins.  Since surfactant serves to protect the host, this
                                             132
lipid damage could have harmful consequences.     The formation of pul-

monary phospholipid was investigated in another series of experiments.
When rabbits inhaled 981.5 and 1963 yg/m  (.5 and 1 ppm) 0, for one-two
weeks, the amount of C   taken into sphingomyelin, lecithin, phospatidyl
pthanolamine was significantly reduced.  The same researchers further
studied these phenomena.     Under exposure to 981.5 yg/m  (.5 ppm) 0,,
                                                14
rabbit lungs showed decreased incorporation of C   into lecithin until
three hours after exposure when this parameter returned to normal.  The
reduction in phospholipid formation was more pronounced at two than one
week exposure.
     That lipid oxidation is a significant cause of toxicity is further
supported by many experiments into the role of Vitamin E, an antioxidant.
            129                          3
Roehm et al.    exposed rats to 1963 yg/m  (1 ppm) 0., and this resulted

in 100% mortality because of pulmonary edema.  Fifty percent of the
alpha-tocopherol depleted group died in 8.2 days while the vitamin-
                                    260

-------
supplemented rats did not reach a 50% lethal time for 18.5 days.  Con-



current studies were carried out with 18810 yg/m  (10 ppm) NCL for four



weeks and comparisons indicated that 0, was more toxic and less sensi-



tive to protection by antioxiclants.  Later investigations by the same



group    revealed that rats continuously exposed to 1963 yg/m  (1 ppm)



0., for nine days show a significantly shorter 50% lethal time and greater



symptoms of respiratory distress when they were Vitamin E depleted.



     When exposure was lowered to 981.5 yg/m  (.5 ppm), pulmonary edema



and higher mortalities were noted after six weeks in animals with diets



depleted in alpha-tocopherol.  The lung weights of the alpha-tocopherol



starved rats were also different from those of the diet-supplemented



groups.  After six weeks of 07 treatment, significant changes were seen



in the fatty-acid compositions of total lung lipid.  The most extensive



change was an increase in arachidonic acid in both diet groups.  But the



increase was higher in Vitamin E depleted rats.  This effect did not



occur until late in the exposure when it was associated with the onset



of pulmonary edema and death.



     Unlike lung-tissue lipids previously described, fatty acids from



endobrochial saline lavage were affected little by 0, or Vitamin E.  In



both exposures, the onset of edema was associated with elevated levels



of arachidonic acid and another fatty acid (22:6).  These two compounds



are important constituents of cell membranes, so that could be the site



of ozone damage.

                         1 f-\ "7
     A review by Shakman    seems to support the idea that ozonolysis



causes peroxidation of unsaturated fatty acids of the cell membrane.


               128
Additional data    from the ssme group indicated that increases in
                               261

-------
arachidonic acid and decreases in oleic and linoleic acid after 65 days



of 981.5 yg/m  (.5 ppm) 0, exposure may be responses of the lung to



oxidant stress because there was also a depression of serum-reduced



glutathione and tissue sulfhydryl compound contents.  However, the



changed lipid levels could also reflect other metabolic roles of



Vitamin E in the bio-synthesis of polyunsaturated fatty acids.



     These authors also found concomminent depletion of Vitamin E from



erythrocytes of CU exposed rats in 23 days vs. 36 days for clean air


                     127
animals.  When others    studied the continuous effects on rats of CL



from 1570.4 yg/m  (.8 ppm) to higher concentrations for seven days,



they too found that alpha-tocopheral protected the animals from severe



toxicity (mortality) and weight change.  At low levels, Vitamin E pro-



tection against lung peroxidation was a reciprocal function of the



logarithm of dietary alpha-tocopheral.



     In a review, Shakman    also considered the protective anti-oxidant



character of Vitamin E.  Since varying dietary conditions exist in the



population, perhaps some malnutrition states would represent an impaired



group in terms of ozone exposure.



     Ozone may affect not only the cell-membrance unsaturated fatty-



acids , but may damage acetycholinesterase (ACHE), an enzyme bound to


                                                  141
the cell membrane.  This was demonstrated in vitro    by obtaining ACHE



from bovine erythrocytes and exposing it to various concentrations of



CL.  The threshold level was 588.9 yg/m  (.3 ppm).  Above this level,



the enzymatic activity was inhibited.



     A whole variety of enzyme activities have been investigated after



0, exposure.  Rats exposed to 1570.4 yg/m  (.8 ppm) 0, for seven days
                                   262

-------
exhibited increased activities of the pentose shunt and glycolytic


         * *u  ,     136
enzymes of the lungs.



     Marine blood and organs were assayed after exposure to 392.6 yg/m


(.2 ppm) 03 for periods up to eight hours/day, five days/week for three



weeks.  The following changes were noted:  increase in serum glutamic


pyruvic transaminase (SGPT) after two hours of treatment indicating



more fat deposits in the liver and increase in hepatic ascorbic acid.

                                                               142
There was no change in blood catalase, a strong reducing agentc



     A slow, but steady rise in serum protein esterase was also found


after rabbits were exposed to 785.2 yg/m  (.4 ppm) for six hours/day,



five days/week for 10 months. "    For 10 months, rabbits inhaled


785.2 yg/m  (.4 ppm) 0, and concentration of serum trypsin protein



esterase trippled by the end of treatment.  This rise may reflect

                                                           140
thickening of small pulmonary arteries that were also seen.

                   139
     Mustafa et al.    studied mitochondrial oxygen consumption in rats


exposed to 1570.4 yg/m  (.8 ppm) for 10-20 days.  A 451 increase in


lung cellular oxygen utilization was found by the 20th day of the


experiment.  There was also a 20-30% increase in the oxidation of 2-


oxyglutarate and glycerol-1-phosphate.  And there was a simultaneous


increase (3 fold) in the number of Type II alveolar cells that are



rich in mitochondria, suggesting the possibility that increase in CL
                                                                   LJ


consumption was produced by proliferation of these cells.  At 392.6  yg/m


(.2 ppm) 0, for seven days, there was a 17% increase in oxygen consumption.

               143
     Veninga's    work, where rabbits were exposed for 60 minutes to 392.6


yg/m  (.2 ppm), showed a small but significant drop in total blood sero-


tonin immediately after termination of CL.  This reduction was probably
                                263

-------
due to a loss of platelet-bound amine since there was no measurable


free circulation plasma serotonin.


     In still another study, rats were continuously exposed to 1374.1

    3                                         3
yg/m  (.7 ppm) CL for five days or 1570.4 yg/m  (.8 ppm) for seven days.


The activities of various lysosomal hydrolases were measured in whole-


lung homogenates and found to increase significantly.  That was attri-


buted to an infiltration of phagocytic cells into the lung in response


to CL.  The higher enzymatic levels may also reflect greater cell-


membrane lability.  And the increase in protease and peptidase activi-

                                                               129
ties could be related to chronic obstructive pulmonary disease.


     Damage to lysosomal membranes was also suggested by others after


histo and cytochemical studies into effects of 1374.1-1570.4 yg/m

                                           134
(.7-.8 ppm) 0, continuously for seven days.     These researchers saw


increased acid phosphatase activity with no change in B-glucuronidase


reactivity in alveolar macrophages of rats.  The terminal-airway


epithlium and adjacent structures also showed increased acid phosphatase


activity.  This particular enzyme had a nonvacuolar and an intracellular


distribution, indicating lysosomal membrane damage.


     In another publication, the same authors    reported on an examina-


tion of similarily exposed rats for enzyme reactivities.  In areas of


bronchiolar epithelium infiltrated by mononuclear cells, there was a


lower MATH- and NADPH- diaphorase activity and increased ATPase activity.


However, intra-alveolar septa in the centriacinar region had increased


diaphorase, LIH, ATPase and cytochrome oxidase activities.  These


increases were also seen in septa that were not thickened or infiltrated


with increased numbers of cells.  It is suggested that these enzymatic
                                   264

-------
changes are parts of protective-adaptive mechanisms that operate mainly



in the centriacinar region of lungs.



     Trams et al.    found no lipid peroxidation in brain tissue of dogs



chronically exposed to 1963 yg/m  (1 ppm) 0,.



5.1.5.1.8  Behavior Effects--Several studies have shown the effect of



ozone on behavior patterns in animals.  When rats were intermittently



exposed to 0., between 588.9-981.5 yg/m  (.3-.5 ppm) and clean air over



a two-month period, they required a longer time to learn specific tasks



and their learning was quite unstable compared to controls.  And they



exhibited reduced ability to discriminate temporal events such as judg-



ing lengths of time.



     Xintaris et al.   studied the evoked response to flash in the



specific visual cortex and in the superior colliculus of rats in response



to exposures of 981.5-1963 yg/m  (.5-1 ppm) 0., for one hour and found



depression of responses.  He suggested that altered evoked responses



reflect possible morphological or functional change in the central



nervous system.  Other researchers    exposed rats to 98.11, 196.3,



392.6, 981.5 and 1963 yg/m3 (.05, .1, .2,  .5 and 1 ppm) 03 and found



that the greater the concentration of gas, the greater the depression



in gross motor activity.



     The pollutant-exposed animals also had prolonged periods of inac-



tivity and an increase in urination rates.  In another series of



experiments,    sub-human primates showed an elevation of both simple



and choice reaction time in atmospheres of 981.5 yg/m  (.5 ppm) 0_



after only a 30-minute pre-exposure to this concentration.  When


        127                                        3
Fletcher    continuously exposed rats to 1963 yg/m (1 ppm) for seven



days to Ov he found an 84% reduction in voluntary activity.
         •O

                                 265

-------
            to
            0)
           •H
            O
            o
            ft
                   •p
                   •H
                   n}
            o^1
           to
                   8
                   CD
                   10


                   §X
                   •H  P
                   co  co
CO
O


£

Q
W



1

CO

B
55
            to

            p
            o
            <1J
w
13

 g
 0)
 to
CO
rH

3

^8
                      T3
                      t/) -
                    O fi  -H

                    X rH  H
                       O  oJ
\D
i—I

LO


 0>
rH


•8
         m
          O  ]


         3  \
          DO

          §
            W
                         O
                    VO LO rH
            o"1
                    LO

                    oo
                                                          266

-------
b
iz:
o
tsi
O

UH
O
e
&
w
t~^
rH

LO

 0
rH

•8
ed Effect(s) Species Ref
1
in
O











-4H
O 0
rH
jq 3
4-> m
DO O

CD r
1
P
U
0
m
m
CD

o




^_j
0
p
Lj_l
ctf

•
(/)
£_J
^f^

"^
0)
V)
Co
CD
o
>s
•H
•H
P
£
rH
•H
O
•H
rH
0
P
O
cd
OQ

CD
(_J
f~*








cd
•H
^1
0
HU>
U
cd
x>
ical clearance of rabbits 146
i ron parti cl es ,
c3T3
•y i

i p
p 0
O rH
0 >,
MH P
m in
0 X
rH
O O






^^
crS
rc3
-"x.^
t/) •
?H C/)
J^ O
£
0
1 — 1 t-~
rH
CN1
rH
bO
•H 0
bO-H
cd g
•H
in
•H
I
MH
O •
in
in I-H
0 rH
•P 0
Cd U
rH

T3 Cd
0 rH
rH O
0 0
f >
O rH
J cd









•
t/1
rH
t~J

vO
Oi
rH
rH
P
•H
XI
1
rH
cd
rH
0
£
rH
cd
m
o
•H
rH
•H

tl i ^
CD
"^j bo
0 cd
a^i
CO OH
0 O
rH rH
O O

HH 1
in
X
c?


[*-^

X

.
in
rH
<~J

OO
ivity inhibited by 0,, mice 117
ilicotic condition
p in
u
cd T3
3 3
"TD "^3
•H PI
0 -H
•H
£c3
p
O P
cd 3
PQ X









.
t/)
JH
r^

^j-
d to 7.27 ppm NCL mice 118
Physical clearance
t bactericidal activity
sm noted.
^
0
rH
O
rH

O
Pi
0

cd
rH
OH















in
0
0

o
in
rH
cd
0
u
.p-J
*


rH
O

'£
OH

.
t/1
rH
XI

r~-^
rH
3 -H
X^ rH
rH •> 0
3 0 X
O P W
0 O
g 0 O
P ' I 1
rH Cd
3
S +->
                               oo
                                        oo
                                        01
oo
CTI
         LO


         rH

         OO
LO
oo
LO

00
                                            267

-------
oo
         fM
                    to
















w
u

a
£
Q
8
3
g
I-H
a
o

CO
rH
*
LO
CD
r—t
g



















t/)
0)
•H
0
CD
PH


CD <1)
0 O
•g -a
00



^-^
t/)
^ — /
P
o
CD

<4H
w
•8
CD
I/)
,£>
0


o 1 o'S e
w o o
O *T^J Qt
rCJ ^1) Qi {> -H rt i
rH ,£ • -H 0) «*P
TO ,5 O "o M O
•H CD !H iH

cB 'rt '"T ° .
CD CD -H O CD
N rH C W > •
•H O CD i— 1 o\<= -H T3
P Oi CD 'rl ^ "Tj
OOP g • 
fi CD JH CD rH
X >  
? 1 i * '•rt
•£3 VI CD 8 -H
•P o P P f-t
.J W
S rH fi'o
CX CD CD 'H
P P r<
O rt »-J DH
.
1

o x1
w
^S i d
^^ cu tn
OO r< O

^
0
s
to


. .
rC X

I— 1 1— 1



_J
r'n

en
•
CO (O
oo vo
rH O)
rt
CD
C tn
•H GO
Boex






o
•H
CD rH
rH CO
"rt q CD
P O i-H
P O
8 CD'O
cB c ?•?
r< O .C
CD D,P
rH t/> CD
O 
-------
            m
                      en
         to
         •et
                                           LO
                                                          o
                                                          LO
                                                                       LO
                                                                                   10
                                                                                   LO
                                                                                                                       LO
CTl
rH

LO

 0
rH

•a
             tn
             0
            •H
             O
             0
             PW
            CO
             in
             o
             0
            m

            w
    JH
    0
    in

   3
m
 o  g


 p  in
 bo o •

 g£
             I
             Pu

              to
             o
           to
              to
             o
             0
             o
            •H
             S
                      Cfl
             cfl
            -§
            p
             0
                      B
                      0
             ^
            •H

             &
             0
            rH
             tn
             0
 JH
 U
 d
Td




43

to
to

CTi
          bO

         3
                               d in
                               to
                               \o
                               CTi
                      0
                      O
                                  in
                                  •H
                                  in
                                  X

                                            0
                      0
                      O

                      cB
                      p
                      in
                      •H
                      tn

                      %
                                  0
                                  (J
  •  tn  X    tn
 tn  d jo     d
 O  O TJ    -H
 e -H \    e
    JH  tn
f^-  Cfl  JH    O
rH  > 43    tO
                                  to
                                  \o
                                  CTi
                   cO
                   0

                  •H  t>0
                   3 -H
                   DO PL,
                                                  tn
                                        £
                                                  in
                                                  0
                                                  0
                                                  JH
                                                  U
                      0


                      &

                      2     g
                     43    ,-£3
                      p     tn
                      ^
                            P
                            o  •
                            C in
                      o        0
                      P    'Td DO
                                                     aJ
                   cO  0
                      bO
                  'Td -H
                   0 -p


                  s*
                  •H  JH
                   10  0
                   f3 P
                   0 <4H
                            'fO
                            '-O
                            CTl
                                     0

                                     U
                                                              tn
                                                              0)
                                                          •H  O
                                                          P  ^
                                                           O x!
                                                           0)  P
                                                              0)
                            £ °


                            cO U

                            x§
                            P 4->
                            •H (/)
                            rH -H
                            cfl tn
                            p 0
                            JH JH
                                     Pi 0
                                     o in
                                     •H Cfl
                                     P 0
                                     Cfl JH
                                     P O

                                     0 rH

                                     Pi
                                     •H

                                     T3 0
                                     0 43.
                                     in po
                                     cO
                                     0 0

                                     b-~
                                                              in
                                                                 in
                                                           OO LO
                                                 vD
                                                 OO
                            OO
                            OO
1
o
in
0
Pi
rt)
DO
CO
rH

> <
rO
0
£
6
43
in

g
•H
P
cO
Pi

£5
X
0

nj
£^
Co
i— I
00

Td
•H
O
JH
J^|
CO
JH
CO
CM
Is, prolifera-
ticulum, free
rH 0
0 JH
(J
O
m -H
0 6
•H 10
U rH
Pin

o ro
f4
cO 0
•H
tn 43
CO bO
rH 3
&2
0
PL, "4-1
X 0
accumulation
T3
g

«t
(/)
0
13
O


Td
•H
Pin
•H
rH

•H

Td
Pi
43 0
X43
"43^

Q.) O
i-H M
£5 +•*
C^ ^H
c3 0
JH CLj
t>o X

cJ
o Td
p 3
2d
U 0
0 -H
in P
o

^J
•H
E3

Td

Co

t/)
i
o
in
o
•H
JH
0
in
0
•
•H
rH
0
i_J^
P
O

Pi
0
JH
CO
rH
rj
(_J
in
cO
j>
0

•H
tn
p|
•H

tn
0
rH
^3
rH
CO
JH
M

CJ
Q
•H
•P
JH
O
0
in
o
0
tn
7^
0
J_<
0
P
MH
cO

tn
JH
j3
Q
^ <~|

\o

rH
g
^4
O
d
0


*"^
0
IP

(D
^
0
JH
in
0
CO
-5
P
cfl
JH
&
•H
•H
P
U
CO

JH
O
•P
Q
pJ
I
Q
p
0
JH
O
0
tn
o
•H
JH
P
tn
cfl
DO

Pi
•H

tn
0
o

O
J-(
MH
MH
•H
O
z
0
o
rH
O
d
1

0

0\°
CTi

d
•H

d
0
0
10
l/J
Co
£
43
p
^J
2
DC

JH
O
in
•H
U
d
•H

Td
0
p

•H
3
ncreased from
•H
43
P
cfl
0

iH
cO
p
cO
Pi

O
0

.
0
O
•rH
^
ITS
0
p
cO
0
JH
P

0

'4_i
MH
0

^
ccurrence to
o
oNQ
\o
,

g
JH
MH

0
in


in
•H
tn
o
G
•H
43
&
JH
CO
43
PL,
0
tH
pT)


•
o\=>


O
p
0\°
CTi
XrX

tn
JH


OO
i
^
LO
r--
to
•
cxi
r^~
*^j-
TH


































































f
in
JH
43

CXI
LO
(XI
•

OO
•
o
CTl
^f
Co
*"O
**»>^
t/J
J_4
43

^

cxi
•

^•O
*
CXI
CTi
to
^
's-v^
in

M
•^3

LO










another
^
•H
o\°
CS1
•
CTi
O
P

cX0
LO
•
*^"
6
o
^

r^
f^
cd
tn
0
•H
U
0
PU
10

0
Pl
0
Pl tn
•H 0
•H
o\° U
0 0
• PH
CTi 10
Pi CO JH
O rX -H
•rH [2 ,Q
•H
1
JH
8
m
cO
JH
0
d

d
•H

Td
CD
rH
^3
Q
"nJ

*x3
o
o
rH
43

d
•H

in
0
p
t_)
o
43

pq
£»^
rH

T3
0
P
CO
0
rH
^
•H
m


































•
2
^3
0
$
0



DOP '
. Pi
•H
JH
^J
Td








CO tO JH
-P 0
10 Td P
0 d '•H
DO CO CO








in
JH
43

cxi

rxi

vO
•
cxi
CTl
to













                                                      269

-------
                  LO

                  LO
                               LT>
ipecies
0
o
•d
82
•H CO
S
tfl
co rt
co
0 bo
0 Pi .H
U -H p,
           CO
U
c/5


§
£
HH
W
o
CV]

LO

 0
i—i

•8
H
           co
          V - /
           •M
           U
          ,0
          M-i
          m
          13
           0
           0
           CD
                  ^CO +3
                  0 N O
                  a PI^CI
                  •H 0
                  rH 3 C
                  O rH -H
                  CO 4-1
                  cd p| 0
                  bO-H O

                  SX 0
                  Pu-P 13
                  PVH.H


                  ^O 13 -H
                   • 0
                  «* P fn
                  CM U Q

                  ^£ i
                  0 P! P
                       bO
                  •H
                  rH CO
                  O ^
                  bO+->

                  TJ°

                  ^
                  g^B

                  SP"H
                     co 0
                  id -H p;
                  0 'd -H
                  >  CO iH
                  •H  ^H O
                  0  I  10
                  o X nj
                  0    bo
                  f-i  0
                     ?-i 13
                  to  0 0
                  rH  |2 Nl  .
                  g    -H CO

                  •H  § g X
                  Pj  O Nl 0
                  <; co o to
                               CD
                               L>
                               8

                               I
                               O
                               o
                               13
O bO
LO O
s;
• HO

Si3
•H O
r£} 0)
S 'M
o m
o 0

Cj U
•H -H
   4->
to to
0 -H

S g
8 cf
                                         P! PI  to
                                         •H -H <-»

                                         PI to  bo as
                                         O -H -H 0
                                         •H 4->  0 Pi
                                      LO  O fi
                                          0 3  O
                                          !H 0 4D
                                      -s-^'e-g
                                      •H 13 0  3
                                       X  0 to 13 Pi
                                       O  4-> ro  0 -H
                                       0  ^      _
                                      •H tO P!  tO >H +J
                                      *Q P; -H  CO O PL,
                                       SO    0 0 cO
                                       co JD    ?H 13 i3
                                         !H CO  O   CO
                                       O cS 0  C ^
                                      +•> o S -H e 13
                                         ox   co 0
                                       0)  fn
                                       fi

                                       .   _  p| 0 0  5
                                       3  XS U U&
                                       to j3    -H .H  to

                                       O| «\ fi       ^jQ
                                       PT o  o c c -H
                                      WO  to -H -H  Ct,
                        tn
                                       I
•p to
bo o
Sx^
-3 W

S
a
PL,

K>
0
& trtr^
^! X £
LO Tj t~^
(NJ
LO LO rH




rH

PI
•H
•P
c
o
o

o t^
OO LO
• o

V — 1
.
to
!-.
X

CXI


/ — \
e
Pv
S
           bO
                  vO
                               oo
                               00
                                       g
                                      •H bO
                                                270

-------
            LO
                                      CXI

CD
•H
O
CD
CO




bo
-§













2
O
P
Cj
§
pTj
/— ^
^  rH
0 10

£^
^, rH
•tn §

0
• o

p *"O
•H 0
U rH
S
PH r«(
•H Oi
a



t
0
rH
'-H .
0
'"CJ £
fH ^
CO rH
O
0 >
0

p 'S
V) -H
•H -P
co
0 Pi
rH -H

P 0
C t/3
0 co
rH 0
rH rH
3 0

'O
!H
•H Cti
cd
r^
s s
•H CO

0 g
(/) O
CO -H
0 -P
rH CO
U rH
G-H
•H PH
W

rH
rO ^H
0 O

l3 ^-«
tS 0
o rt
CD cr
00 O
           f.
            2
           rG

           00
OO
        •     V)
       rH     rH

      XI    X
                                       I/I
   I
                        LO
  "bo
            to
      to
      \Q
      01
                           to
                           \Q
                           CTi
LO


rH

00
                                           271

-------
CNl
CN1
LO

0

4-1
0
CT> O 00
CM to LO
&t rH rH rH
0
•H
(J
0
P,
P
•H
t*,
•s
CO rH












to
u
0
4-1
4-1
W
'd
0
rH
0
tfl
rQ
O










•p
P
o
CO
4-1
rH
3
4-1
0
0
cS
0
rH
s
T3
i
PI
o
•H
p
cO
,0
4-1

licithin
.
**O tfl
0 C
ro f*^
0 -P
rH -H
u o
0 0
H rH
4-1
O 0
A 3
4-J V)
bO O
X$

G
a

to
o
to
E
bO
3.

to
O
3
B to
* P« r-^
tfl -H ^
X PJ fM
•3- U i— 1


LO
rH


LO
tO rH
vO 00
CT> C%
i— 1

oo r^
CM CM
A A
\O LO OO
CM rsl CM
rH rH rH


to
ro
rH

0
go
(fl -H
pg
tfl ^O
S  P
S-bVS
13 -H -H
'x^ o
O - rH
•H X 0
+-1 P PH
c3 rH 13
ro -H
Cj ^"** O-i
« JH -H
O rH
Co ^^-^ ' *^3
t/) (/) Co
•^ c
0 5 P
CO -H P|
PJ CO P
P: 0 o
•H P U
4___1 ,__i
•H tOU
> O rt
S
|
Pi tfl tfl
•H X X

U 01 r--


LO OO
rH


LO ^f
tO rH 0
\Q CO t-~
cji o~i LO
rH i— 1


O
vO
i— 1



bO
•Q











•
0
3
tfl
(0
•H
P
P!
•a
rH
P!
•H
P!
O
•H
peroxi dat

•H
PU
•H
i— 1
0
^

0
•H
Pj
g
6



t— i



to
^o
CTl
1— 1


to
to
I— 1


(fl
co
rH



o
•H
p
x
rH
0
o
x
rH
bO
1
P
1
to
0
(fl
3
PI
0
o

to
0
activiti
f lungs.
Tj O
0
to to
co 0
0 S
(J N
Pi P!
i— i 0


tfl
X
•3



00
*


^J-
o
t —
LO
I— 1


vO
to
rH


tfl
4~J
C\J
rH
13 1

1 -P
O O rH Pi
P 4J CO 0
•H CO rH O
S rH O Pi
CO 0 O
bO-P > U
Pi 3 rH
3 I— 1 CO tO
iH 00 O
0 X^rH rH
& O 0
P 1 0 S
. CNJ cL, o
Pi XrH
-H 4-1 i?
O 0
0 4-1 ^
tfl pj O -P
ro o
D .H rH 4-J
?H .p 0 ro •
e r§ •§ r;-) g
'H '* 1 §, T>
O Q,
Pi P! **"! • 5
O -H +3 cO tfl
•H -H p|
•P PIT5 rH 5
ro o c TJ u
rH -H f3 Pi
•P -P O (Nl
f0 ^ C^
•p (J
co q PI
PI tfl & -P -rH
O Pi Pi-r-l
0 0 tfl S 0
rH°^fir3
0 (Nlp^.H 0
bO i— 1 -£i O
•H rH l TJ Pi
,C CtJ rH -H -H
•H O rH
0 rH rH
,£2 TJ 0 tfl ••
1-3 P! O rH Pi
O XrH O

< U bOO +->
tfl
t

o
1
o
I— 1


oo CM
*


** *°.
o f^J
t — . o^
LO tO
rH

to
•S
I— 1
to
I—I


tfl
ro
rH


%
tfl 0
.as
P TJ
•H
T3 -P
rH p>
ro 0
p)
tfl
0 T3 •
•p g tfl
co ro 0
PI OO
CD CD p;
bO (fl co
S 0 O
O P
fi 0 0
rH -H
bo p< +-1
Sal
r- 1 -H X
0 0 P;
rH tfl 0
o ro
•H h— 1 O

tfl _ r^
0 • -P
hydrolas
increased
along wi
rH PJ
ro tfl 0
S Pi 0
o o to
tfl -H
0 -P CD
tfl L) rH
X 0 0
H-3 tfl |£


to tfl

'S ^
LO t~~


t^
*



«3-
!*-»
to
1— 1


CNI
to
rH


tfl
ro
rH

0
(/)
Co
rH
O
-a
Sir
•H
rrt

-C
R
g
1
^i
|£
•H
rH >
0 -H
S t)
rH CO

rrj g)
ro to
f— | CQ
B <
•H
rH rH
•H -H
CO §

"o x
•H 4->
,d -r-l

rH U
PQ rt
B
§
PH t/)
•rH ^%
C 'S
CJ t^--


f-- oo
* *


rH ^f
**• o
^» t^.
to \o
rH f^^-


to
to
I— 1


tfl
-p
ro
rH


4-1 T3
°S
to
0 /-N
•P 1

r* 1
•rH CJ
P
O *
ro p

•H vO
0 O
tfl
cO "
0 0
rH tfl
O Cd
Pi P
•H 0
P 13
Pi 0
0 rH
CT* IE
0 CO
tfl Cj
-8 .

i j j_j *•*
•H 3 S
C rH X
rH 00 P,







LO
r~-
*


to
CM
f^^
«£^»
rH

                                                   272

-------
LO
IO
rH

to
p
•H

1
t*--
K)
rH

I/)
P
•H
X>
•a
oo at
to to
.— i i— i
o
f-,
4_)
•H
>



CD
c~j
•H
f-i
O
i— 1

in
p
•H
rO
•8
S
              *
            TO
            LO
ase





»
CD
{/J
TO
(H
CD
P
to
CD

c
•H
CD
J_J
T^
8
PU

€
3
rH
0
w
Pi
•H
CD
W
s
tl.

CD
to
rt
JM
CD
P
to
CD

cj
•H
CD

O

p)t

g
CD
to

PI
•H

CD
(/)
TO
CD
0
r^
1 — i






.
rrj
CD

•H
X
•rH
^c^
"{~^
• H

~>
CD
O


trans aminase ,
in blood catal,
o
•H CD
> £30
*3 C
rH CO
^NrCj
p>^ O

u o

E
Co
P •
^3 rT3
iH -H
t30 U
s rt
1 0
M -H
CD ,0
t/) f-H
o
P! o
•H (/)
Co
CD
to O
Oj -H
cp P
0 PL,
PI CD

It
tonin.
o

CD
to

rr3
0
o
t-H
JO

i— 1
rt
p
o
P

•H
CD
(/I
TO
CD
f-i
U
4)

i— 1
1
p^
£j
CO
VI
                                 to
                                    to
                                    O
                                    'O
 CD
^-1


I
LO

OO
                     (XI
LO
OO
oo
oo
LO
                        CM
'•O

1X1
^
IO
                                              273

-------
M-t

&
 0)
•H
 O
 0)
 ex.
CO
        *d-
        CNJ
        to



        I
CM
LO
                                          to
                     to










CO
b
^
w
r "1
§
o
£
^^
w
«



^
to
CM
LO


s
rH
0
^

p*
•H
fi
O
•rH
^_j
o
•s
8

o\o
OO
3
s
.3
4-*
g
o



rH

to
E
"S8
3.

to
0

to
\D
CTi




•
C/l
t \^
c§
^j

o
•H

•H
O
il

e
cO
rH
O

i
•H
4_)

f-!
0)

0
rH

CO

<1>
!H
•H
3
Cf
£
s
•H
|
0)
4-)
c
rH


to



en
oo
OO
LO










•
JC
(/J
C^J
o
^

w
s
3
5
f~
o
to


LO



LO
rH
oo
Cf^


cO
fH
-1
CD
18
(Li
rH
O

rH

^
4-)
•H
•H
4_)
O
CO
rH
O
^_)
g

w
to
o
rH
bO
M-l
O

f^ *
O C!
•H 0
to -H
tO P
JH f^
gi'H
(H 3







LO
O


rH
i— 1
OO
CPJ



                                             274

-------
5.1.6  Total Suspended Particulates



5.1.6.1  Human Studies--The national primary air-quality standard for



total suspended particulates is 75 yg/m  (geometric mean)  when measured



as an annual average and 260 yg/m  when measured on a daily basis.



5.1.6.1.1  Evidence for the standard--The current national primary air-



quality standards forparticulate matter are shown in Table 5.24.  These



standards are based on evidence of adverse health effects  ranging from



symptoms of increased irritation to excess mortality associated with



various concentrations and durations of particulate exposure (Table 5.25)



Although it was not possible in these studies to entirely  separate



effects of particulate and sulfur dioxide, setting separate standards



for both was wholly consistent with the Administrator's legislated



obligation to provide adequate safety margins in setting ambient air-



quality standards.



     Although these epidemiologic studies were the best available at



the time, their limitations were recognized.  Chapter 11 of the Par-



ticulate Criteria Document fully and completely discusses  interpretative



cautions.



     In brief, measurement methods were not often directly comparable.



The physics of particle size and chemistry of particulate  matter had



almost always been ignored in field studies and pollution and health



indices were not always measured over the same time periods.  Few



studies identified or adjusted for all other known or possible morbidity



determinants such as cigarette smoking, occupational and other past



exposures, past medical history, socioeconomic status, residential



mobility and indoor pollution exposure.
                               275

-------
        Table 5.24.  U.S. NATIONAL PRIMARY STANDARD FOR TOTAL
                             SUSPENDED PARTICULATES
                          U.S. National Primary Standard

      Pollutant     Concentration (pg/m )       Averaging Time


    Total                    75*             Annual geometric mean
    Suspended
    Particulates
                             260                   24 hours
    *Geometric mean


   Also, almost no epidemiologic studies had been possible in areas

characterized solely by particulate matter.  And almost no studies of

highly susceptible individuals had been done.

5.1.6.1.2  Interim Evidence--Subsequent evidence on health effects of

particulate pollution is sunmarized in Table 5.26. These studies were

also complicated somewhat by presence of   considerable amounts of sul-

fur dioxide.  Despite that complication, best judgment estimates for

the various health effects that have been associated with particulate

exposures are given in Table 5.27.

     These data strengthened and extended the initial observations on

health effects.  The CHESS studies were designed to indentify or adjust

for effects of other possible disease determinants in addition to

ambient air pollutants.  The limitations of the CHESS studies differ

for the short-term and long-term health effects studies.

     For the studies of short-term health effects, estimates of expo-

sure are more reliable.  But the indicators used to measure health

effects require further quantitative refinement.  For the studies of


                                  276

-------
to
CD
O
0
rH
CD

»j
S
g

J < -H T3

Z Z |S >
rH H 4-> 0
H CO 03 to
p O
CO 2 4-J c3
* L* O3 ^
, — 3 CJ rH
h— ( 4-) 4-)
ril t— i rjj (J
H pi 00
f-H «^ (_) <4H
pi j r^ LJ^
oi 00
SQ U
w
p— •)
Is
M 3
s w
•H
H
DO
PJ
•H
r?

0

"^

-r
-^_
DO
3.
y -*

<~*
O
•H
4->
03
4^
§
§
o
w^
rH D
PH H
rH
g
TTT
1 	 1
O P
CO O
0

LO fU
LO 4->
rH
0 oj
rH 0
^Q H
03
to
0





vO
\o
r 1
r~ i
LO
vD
rH
co

O

oo
1
«^J-
CXI




0
CO
•H


03

rH O
O 0
CXI
o
LO <4-l
t-- O











^
4J
•H
rH
03
4J
rH
0
(/)
CQ
0
o
i — i
.
rH




t~~-
v£>
rH



CO

T3

CXJ












O
O
CX]





X

• H
rH
ctf
1 1
rH
^ to'
*~* •$
c3 crJ
m 0
Cj Tj
•H
•gS
o]§3
0 U
rH
& £
rH 03
.
CXI

O"l
\^^
r J
r~i
C30
rH


co
rH
|

^*
CXI












*
LO
r^~
K)





r7
Q
P
03

•rH
to
rH
^
0
13
I
JB
o
PJ
rH
«
to































.
£*
•H
!Q
s^
o
s

(J
•H
rH
03

g
•H
4->
O
0
MH
PI
•H






CD
t—t


to

j2

«^i"
rxi












O
o
CXI




B
>^
•rH
rH
ctS
4J
J-4
|
CO
•H
4->
•rH
•6
|
CO
co
g

.
*3-




rH
rH




>f
•H
03
Q












O
O




p!
•3
i
o
4->

E^
?*•»
to
o

CJ
orseni;
£
CD
P
%
m
LO








































to
P!
0
4_)
03
CO
•H
4->
•H
'S
g







(X)
rH



to
0
X

CXI












0
o
rH


O
'p)
5
•63
03
g
OT3

(_j_) CD
X 0

rH 0
4-> -H
S fr
TJ O
0 4->
to 03 •
03 rH CO
0 -H 0
rH D-, CO
U CO 3
rH !H O
t
vO

LO
^
r^
to
rH



rH
3












O
O
CXI
1
0
o
rH




t>> • •* "^ rjj
rH CO CO
4-» rH 4->
c\3 ^Zl ?"^ 0^ CJ
^•H rt3 CJ t/) C«
•H o3 !2 o3 3
P^ Q (J_) C(— j
t/) (3 p~l C/)
0 -H -H X
Sp; os
c3 P pj
'S 0 fH 03 §
O rH 0 rH rH
rH H ^ 0
T3 fttJ O 0 rH
tO 0 tO 03 10 rH
O3 tO O3 rH -H -H
^-1 0 rH PVH U
o to y to s

B
I>-





















•
/. — ^
rO
E

M
p-

LO
r-j
rH
II
r-
s
r— 1
.p
0
rH
V__^

c/>
4—*
. i— (
g
33
CJ

§
rH
rrj
4^
rH
0
CJ
*
277

-------
long-term health effects, previous exposures had to be estimated because



of incomplete exposure monitoring data.  Hence, estimates of exposure



were somewhat less accurate.  But the observed health effects were quite



consistent.



5.1.6.1.3  New Evidence--Few epidemiologic studies on long-term exposure



to total suspended participates have appeared recently.  Those that have



appeared come from the CHESS program of EPA.  Responses related to long-



term effects include chronic respiratory disease and lower acute respira-



tory disease.  Recent findings from CHESS relevant to long-term health



effects of particulate pollution have come from studies in New York and



Birmingham-Charlotte.



     Of the two sets of findings, those from Birmingham-Charlotte are



more directly relevant to particulate health effects since the SCL pol-



lution there is minimal.   For that reason, the Birmingham-Charlotte



findings will be presented first and in more depth than the New York



observations.



     *  Birmingham-Charlotte Chronic Respiratory Disease



     During November,  1971 in Birmingham, Alabama and Charlotte, North



Carolina, the rate of chronic respiratory disease symptoms for parents



of elementary school children was determined by self-administered



questionnaires.  Survey results noted small, but not statistically sig-



nificant differences,  in prevalence between the cities.  Observed dif-



ference included the direction of pollution exposure.  Birmingham was



higher.  The equivocal nature of prevalence difference in this study



made it difficult to form firm conclusions about the relationship of



air pollution to chronic respiratory disease.  It appeared that long-
                                   278

-------
CXI
uo
0
rH
rQ
H

CD
O
PI
P
CD
Q)
H

00
Pi
•rH
00
03
rC rH
O CD
•H rO J>
P CD
03 to
tj ~S S
rH "~ 00
•P P 3.
PI U ^
CD 0
O MH p|
£H MH O
o w -H
U -P
03
rH
CD
O
Pi
0
o




P
U
CD
m
M
4J
CD
CD
to
rH
1





\&
rH

in
$~i
r-5
0

*^-
CXI







CTi

CXI
1
O
o
rH







*"O
CD
P
P U
t/) *H
CD rH
rC P
U (/)
CD
r^
?!
8 a
. p
t3 rH •
CD O X

rH O -H
U to 4->
PI -H 0
rH "O OS
rH



t^
r_^

•ft
^4
3
O
r
«^f-
CXI







(0
o
tH
I
O
<3O









10
Pi • ^
I -H fi CD U •
O -H fi V) CtJ OS
•H t/j P oS >P E
'•d E T3 -H CD P S
rH O pi f 
rH
3
O
•^
^-^.
txi







o
vO

1

r^-.






i
O

t[f*
'4^
•H
O to > OO
• H C
T3 CD t/) 3
rn tn P rH
03 crj pi
U CD CD U
to -H -H
m -H P d
O T3 oS O
PI f*^ rH
O H X O
•H O rH
p p f_ VH .
03 03 CD O CD
> rH T3 (/)
03 -H rH P 03
rH P< 0 rH 0
OO t/) OS t/)
00 CD P{ 0 'H
<£ rH 'rH f~^ rrj
to



oo
F~~
rH


rH
^
3
^3
<











0
rH
rH





O
•H
P
(J

fj
M-l

OS pi
C 0

§ T3
rH -rH
d -H
p-s
creased
school
a .s
^



Ol
t^-
rH


rH
03
3
g
<











O
o
rH









TJ rH
pj CD
m ^ rH
5 -H
XtH
|0|
^3 £3 t/) •
a4 u -H p|
0 Cfl T) 0
rn rH
m m x^
O H rH
T3 0 -H
0 X+-1 ra
to P 03 U
O3 -H rH rH
0 rH -H O
rH 0 fO, O
(J > (/> J^
pi 0) 0 O
1— 1 tO rH t/)
uo



0
oo
rH


rH
aS
3
g
<











o
o
rH






1
a3
rH
•H
P<

0 S
rH 0
P
Pi ?^
O 10
rH
rC| 0
U t/1
o3
T3 0
0 to
CO -H
03 T3
0
rH X
0 rH
Pi 0
1— t P
\£>






































•
tfl
•P
rH
03
1=1
•H
0
evalenc
rH
a,

                                          279

-------

p
co rt
U -H
W P
K (/>
PH W
W
t-H O
3 CO W
is £
o p
p., o p
rH rt
CO H CD
S 
 tu
Q> J>
r0 

rt rt
0 -H
•H
•P W
rt P
rH &

t*o S»%
•< en


r^
§
o

^
CXI











o

CXI
A






O
• H
8

•§
O •
0)
grt1
•H CD
P to
rt -H
rt
rH bO

GO S
< rH

^
to
rH
§
r~*
^
CXI











0
o
rH








rt
i
43
%
o

rt
o
•H
P
1
rH

W
<

^
^-
 10
 rH
        O
        O
O
o
               rH -P
               rt -H
               > X
               Ci) U
               rH rt
               4)

               C^.^H

               rH  O

               H^
o
o
280

-------
term exposure to total suspended particulates at 150 yg/m  or less in


the presence of low sulfur dioxide was not strongly related to chronic


    •   *    j-          *    184
respiratory disease symptoms.


     •  Birmingham-Charlotte Lower Acute Respiratory Disease


     The acute lower respiratory disease experience of 10,000 children


aged 1-12 years was determined in a retrospective survey of the chil-


dren's parents.  During the 12 years prior to the survey, estimated total


suspended particulate exposure ranged from 103 to 168 yg/m  in Birmingham


and from 72 to 107 yg/m  in Charlotte while SO- was less than 25 yg/m .


Significant increases in pneumonia and croup among blacks and "any lower


respiratory disease," bronchitis and croup among whites, were noted in


Birmingham residents.  Since increases were noted in children aged one


to four, the authors' best judgment as to the level of total suspended


particulate capable of producing an effect is between 103 and 139 yg/m

                                      185
in the presence of low sulfur dioxide.


     *  Birmingham-Charlotte Acute Respiratory Disease


     Panels of families in both Birmingham and Charlotte sent bi-weekly


reports of their morbidity status for 16 week periods in 1970-71 and


1971-72.  Incidence of acute respiratory disease did not show a con-


sistent relationship with air pollution, although data on severity of


illness among residentially stable families did indicate that exposure


to high air pollution was associated with restricted activity and


physician visits.  Best judgment estimates of air pollution effect are

       333                              186
90 yg/m  TSP, 12 yg/m  SS, and 3 yg/m  SN for three years' exposure.


     •  New York Studies


     Chronic respiratory disease rates among parents of elementary


school children was not elevated in areas of higher particulate and


                                  281

-------
sulfur dioxide exposure.  Complicating the interpretation of a unique


particulate effect was the presence of a previous study that did


observe an effect coupled with a long-term decline in levels of both


TSP and SCL and a short-term dramatic decrease in S02 between the two

        187
studies.      Lower acute respiratory disease was, however, shown to be


higher in areas of higher particulate and SCL exposure.  The authors'


best judgment of the exposures associated with increased lower respira-


tory disease were 175-250 pg/m  S02, 85-110 pg/m3 TSP and 13-14 pg/m


      A A   ir *   188
suspended sulfates.


     Similar to the long-term health effect of particulates, few new


studies have investigated short-term effect.  Studies involving panels


of asthmatics, elderly and families have been used to obtain data


relating to any short-term effect.  Again, studies done in Birmingham


and Charlotte are more likely to be relevant to such effects than


studies done in New York.


     " Birmingham-Charlotte Episodes


     Acute irritation symptoms reported by 1500 families of elementary


school children were studied in Birmingham, Alabama and Charlotte,


North Carolina during 1971 and 1972.  Following three designated air


pollution episodes (two only for Charlotte) and one control period,


telephone interviews were conducted and responses compared across all


time periods for each participating family member.  Although Birmingham


residents did experience an elevated symptom rate in the designated air


pollution episodes, especially the first, Charlotte residents did not.


The rate of symptoms even in Birmingham did not vary with level of

                                                                  189
pollution experienced by Birmingham residents across all episodes.
                                    282

-------
     * Birmingham-Charlotte Asthma


     Panels of asthmatics; located in Birmingham and Charlotte were


observed from the fall to the spring of 1971-72.  Aggravation of asth-


matic attacks was not shown to be related to TSP or RSP.   Some rela-


tionship with suspended nitrates was noted.   No reliable  estimate of the


level of nitrates necessary to produce an attack could be made because

                                                  190
of analytic problems associated with air sampling.


     " New York Studies


     The New York studies add relatively little information to the short-


term TSP exposure data base.  Adult panels of well and cardiopulmonary


patients show a TSP effect of between 70 and 120 yg/m  24 hour average.


These effects, however, occur in the presence of significant quantities

                  191
of sulfur dioxide.      Studies of asthmatics showed no association with

                                                  192
TSP, but did with suspended sulfates and nitrates.      The observed

                            3           3
threshold levels were 8 yg/m  and 3 yg/m  24 hour values  respectively.


However, there is a question about the accuracy of the analytic tech-


nique used for suspended nitrates so that the 3 yg/m  level should be


considered with caution.


5.1.6.1.4  Discussion--Results from the previously discussed studies


have not significantly altered the state of the art knowledge of health


effects of total suspended particulates.  Results from long-term studies


(chronic respiratory disease, lower respiratory disease and acute


respiratory disease) were unable, because of their design, to distinguish


between total particulates and respirable particulates.  Similarly, these


studies were not able to explain the possible effect of chemical composi-


tion of particulates because of the nature of the study design.  The



                                 283

-------
studies, however, did further document health effects associated with



long-term exposure of about 100 yg/m  (lower respiratory disease and



acute respiratory disease).



     Short-term health studies were somewhat more effective in provid-



ing insight into the relative importance of respirable to total particu-



lates and possible importance of chemical composition.  Studies of



asthmatics did not show any relationship between asthmatic attacks and



either total suspended particulates or respirable particulates, but did



with suspended sulfates and suspended nitrates.  Aggravation of symptoms



in panels of adults was most often associated with suspended nitrates,



respirable particulates and total suspended particulates.  There was



little difference in the strength of the relationship between health



effects associated with respirable particulates as compared to total



particulates.



     Table 5.28 presents the best judgment estimates of effects from



particulate exposure based on the new evidence summarized above.  In



general, few modifications are noted from the estimates presented in



Table 5.27 and most modifications are relatively minor.  These results



seem to indicate that the annual average TSP standard of 75 yg/m  (geo-



metric mean) is still quite acceptable,  but some modification in the



24-hour standard may need to be considered because of the evidence from



the adult panels.  Since the question of respirable vs. total and chemi-



cal composition of particulate matter has existed for a number of years,



definitive studies designed to find the answers to these questions are



needed and should be conducted in the near future.
                                    284

-------
1

2 ^

rrt
^ ^
O -H
^_>
et/)
w
W O T3
PH H *o
M 10
§ ™ £3
2s
S 2 •*-*
oi z S
So g.
P-* DO
P T3
CO PQ |j
p ^
<; PQ -p

i-1 CO 0)
S3g «
KH
g
•H
f-H

(M
Pi
• H
bO
CO
f-<
§


^6
bo
3.
* '


•H
j_)
g
P
rt
CD
O
CJ
96
O I-H
to S
§ §
s
f-H f^ -fJ
pt"] ^_)
f— i C^ Q^
^^ t^ MH
FTJ y^ LJ_ (
s cu w

r^ i"^ ^p|
^ rH
CO
H CD
CO X
w
pq CD
to
00 >
LO
CD
!Q


10 (/)
fi fn

0 0
^1 rJ5

^t1 ^"
 E?
f), ^.^
& V)

CO • PI
(/) O
MH rH 'H
O CD P
Pi CO
Pi CO -P
0 PH -H
•H fn
•P P fn
CO rH «H
CO rO CD
fn CO +J
bO 3
bO P! 0
<-H <

rH (NJ
CO
H


t/)
^
<™j
Q
(~|

•<*
csj








O

CV)
















(A
Cu

m
0


•H •
•P y
cO -P
<£, in

KJ






rH
rt
3

pj
•5








o
o
rH










m
o

CD
O •
cd t/n
CD *H
rH -P
03 *H
pH
0
CO 0
CO (/>
0 ro
!H 0
O 10
P! -H
M T3

LO






rH
CO
=!

pj
•<








O
CTi









P
O
P
cfl

•H

t/1
O
^

 .^1
!8r^
r^8
a -8
Q to

t-C


285

-------
    I
              1I I  ^

               o  in
               O     r-~,

              •H  -P O

              P  cd o

               rH     rH


               8,0  rH

               O  -H  CD
               rH  -P  &

              PH  C3

                  rH  CD

              13  3 P
               0  CU Cd

              P  O &

               U  p i v—'
              W  -P
                              O     O
                              O     O
                              O     O
                              O
                              cxi
                              cxj
                O
                CXI

                CXI
                                               o
                                               o
                                               o

                                               o
                                               o
                                               o
                  s

                  o
                  o
                  o

                  o
                  o
                  o

                  oo
                  ex)
                                     o
                                     o
                                     o

                                     o
                                     o
                                     o
                                            o     o
                                            o     o
                                            o     o
o
o
o
 o     o
P     O
       o
o       *      «*
o     o     oo
O     ^     rxl
  -    t—t
o
o
cxi
o
o
o

o
o
o
                                                                                  oo
o
o
o

o
o
o
                K)
                cxi
                          *

                          o
                          CD
                          cxj
                            in


                            3

                            K)
o
CX]
                                   CD
                                   O
                                                                                      in
                                                                                      oj

                                                                                      s
                                                                                      rt
                                                                                                                  CXJ LO
%
W
cn
cxi


LO


 0
 O
 CD
m
<4H
w
                      ai
 CD


 IS



I
                                     0)
^

•H

rH

 CS

P
                  O
                 •H

                  g


                 -6

                 MH
                                                rt
                  rH  DO

                  bO g


                  ^rH
                                                                 CD
                                                                 LO
 g

•H

•P

 O

                                                                        "O
                                                                        CD
                                                                        0 -H
                        m
                         o

                         0
                         o

                         0
                        rH
                         Ctf
               in
              •H
                                                                                   in  O
                                                                                   cd  -H
                                                                                   O  rH



                                                                                  r^-6
                                                                                             «J

                                                                                             rH
                      to
                      CD
                                                                        0

                                                                        s
                                                                        rt
                      0  in
                      tn  0
                      ro  in
                      0  rt
                      rH  0
                      O  in
                                                                                          000
                                                                                          bo bO bo
                                                                                          oj  cd  cd
                                                 (/)  4-) 4-»  -M

                                                 0  rH !H  rH

                                                 g  O O  O
                                                                  286

-------
5.1.6.2  Toxicology--At this point in time, theoretical definition of



suspended fine particles as they relate to health must necessarily be



broad and somewhat arbitrary.  The deposition of particles anywhere in



the respiratory tract, from the nose to the alveoli, may produce sig-



nificantly harmful effects on health.  There is some reason to believe,



however, that non-viable particles deposited below the trachea may be



more harmful than those deposited in the nasal cavity.



     Whether particles must reach the alveoli to harm is a more con-



troversial issue.  It is reasonable to assume that particles deposited



in the bronchi or bronchioles are more important in producing bronchitis



than those deposited in the alveoli.  At present, there seems to be



little value in confining the category of suspended fine particles only



to those particles that reach the alveoli.



     The Task Group on Lung Dynamics has calculated that up to 10% of



inhaled particles of diameter 2.5 ym are deposited in the tracheo-



bronchial compartment and that up to 30% are deposited in the alveolar



compartment.  Most particles of diameters above 5 ym are deposited in



the nasal cavity.  That means a size range of fine particulate up to



205 ym diameter, measured aerodynamically, is of principal interest from



the standpoint of health effects.



     Toxicological properties of inhaled particles are related to a com-



plex of factors that include specific physical-chemical properties of



the particles themselves and host conditions that affect response to



exposure to these particles.  As for toxicity of certain specific par-



ticulates that may exist; in the atmosphere, moderate amounts of infor-



mation are known.  But such information is often unavailable in a form
                                  287

-------
suitable for accurate assessment of minimum time-concentration for
exposure that will adversely affect health.
     Even less information is known about how physical environmental
variables (weather conditions) may interact with suspended particulate
matter and alter its chemical composition and affect its toxicity.
Weather conditions, per se, may affect man in such a way as to alter
his exposure to inhaled particulates.   The information that is avail-
able, however, provides a basis for estimating relative toxicity of
certain substances and provides insights into problem areas where our
information is inadequate.
5.1.6.2.1  Dose-Response Relationships--The principal way air parti-
culates exert an effect on health is presumed to be through inhalation
and consequent effects on the respiratory system.   This presumption is
acceptable in determination of short-term effects of irritant aerosols.
Such an assumption may be less tenable in consideration of long-term
exposure effects where such responses  as carcinogenesis, mutagenesis
and subtle metabolic effects result from whole body burdens.  In these
cases, other routes of entry besides inhalation may be important in
establishing dose-response relationships.
     Inhalation, however, may be a significant route of entry for non-
respiratory toxicants that are first deposited in the respiratory
system, but then translocated to the gastro-intestinal system by muco-
ciliary transport and swallowing.  There they may exert a primary
toxic effect or be absorbed and translocated to other tissues where an
adverse health effect might occur.
5.1.6.2.2  Physical Factors--Most calculated and experimental data on
respiratory deposits of particles uses the term "aerodynamic diameter."
                                   288

-------
Effective aerodynamic diameter is a function of particle size, density



and shape.  The distribution and mean of aerodynamic diameters are



required to predict patterns of deposit in the respiratory tract.



     In terms of mass, many aerosols fit a log-normal distribution,



that is, the logarithms of particle size are normally distributed.



Thus, two indices are used to describe particle distribution:  (1) the



mass median aerodynamic diameter (MMAD) and the distribution parameter



(erg) that represents geometric standard deviation.



     The MMAD is the particle size in a log-normal distribution below



which 50% of total mass resides.  The og is the ratio of particle sizes



at 50.0% and 84.13% probability.  These parameters, then, are used to



determine the mass of material that may be deposited in a given lung



compartment.



     In some cases, especially with fine suspended-particle materials,



numbers of particles may be more relevant than mass.  To relate number



of particles to mass size distribution requires determination of fre-



quency distribution.  Particle number can be toxicologically important



since the large surface area may promote gas-particle interaction or



volatile substance-particle interaction.  Coupled with small size,



these interactions may result in deeper penetration in the respiratory



tract and more rapid dissolution.  Surface area is also important for



highly insoluble particles that show their toxic potential only at the



surface.



     Another important factor in regional deposition of inhaled par-



ticles is hygroscopic!ty.  Particles as usually measured externally



are not saturated with water.  The growth of sodium chloride particles
                               289

-------
 is a  function of relative humidity as demonstrated in an experimental


                                      194
 study by McJilton, Frank and Charlson.     Particle size increased when



 relative humidity exceeded 75%.  The respiratory tract, with its satu-



 rated atmosphere, may increase effective particle size considerably



 over  and above that measured in ambient air.  However, hygroscopicity



 is of less significance with particles of high density.



      A moderate amount of information is available on respiratory par-



 ticle deposition in people and lower animals.  These data have been


                             195            196 197
 critically reviewed by Morrow    and others.   '     These data are



 based on mathmetical calculations and to a limited extent, experimental



 data  obtained from man.  The calculated data agree in general with



 experimental observations of people.



      A figure depicting respiratory deposition of particles as a func-



 tion  of particle diameter is shown in Figure 5.4.  These data indicate



 that  most particles larger than five ym are deposited in the nasal



 cavity or nasopharynx.  As particle size becomes smaller, an increasing



number of particles are deposited in lungs.  This is a possible explana-



 tion  of experimental results by Amdur who reported that sulfate aerosols



 of 1  ym diameter are greater respiratory irritants for guinea pigs than



 2-3 1 ym-sized aerosols.



      Only a few comparisons to people have been made on regional respira-



 tory  particle deposition in laboratory animals.  (Figure 5.5)



Although there have been some differences in particle deposition in



rodents, especially in efficiency of nasal deposition, patterns are suf-



 ficiently similar to justify use of laboratory animal experimentation in



inhalation toxicology.
                                   290

-------
 Each of the shaded areas  (envelopes)  indicates
 variability of deposition for a given mass
 median (aerodynamic) diameter in each compart-
 ment when distribution parameter ag varies
 from 1.2 to 4.5 and tidal volume is 1450 ml.
          0.05  0.1       0.5 1.0        5   10

                 MASS MEDIAN DIAMETER, microns
50  100
Figure 5.4.  Effect of particle size on regional
           respiratory particle deposition in man
                    291

-------
    100
     80
 oo
   ^60
 n. .
 012
     40
 CCin
 uio
 0-0.
  30
     „
     20
                             U C
 - Won
Q- Monkey
o- Guinea Pig
                                 I- 100
                                 z
                                 UJ
                                 o
2"
2 60
           O
           fc40
           o
           tr
           < 20
           O
           UJ
         _ 3 o-
         8 <  0
                -Man
               0- Monkey
               o-Guineo Pig
                 SIZE OF UNIT DENSITY  SPHERES, MICRONS
                                                           AP
                                                           7   8
Figure  5.5.   Deposition vs. particle size of inhaled particles
              in the  upper respiratory tract  and lungs  of guinea
              pigs and monkeys  compared to people
                        292

-------
     A major question exists, however, about applicability of respira-


tory deposition data from normal individuals to predictions of how


exposure to suspended particulate matter may affect particle deposition


rates and regional deposition.  To the extent that suspended particu-


lates may act as respiratory irritants, consequent effects on mechanics


of breathing may affect both the rate and site of particle deposi-

     205,206
tion.


     Under these circumstances, total inhaled dose may be increased.


However, this hypothesis lacks experimental verification.  Also, many


diseases and symptoms associated with elevated levels of particulate


matter are airway related.  In these diseases, the contribution of


inhaled particulate matter to their pathogenesis may not require pene-


tration into the alveolar region to produce a toxic effect.  This point


cannot be fully evaluated, however, since pathogenesis of chronic


obstructive lung disease is not adequately understood.

                                           207
     Finally, as noted recently by Casarett    the varied pulmonary


responses to particles can readily be seen as interacting with effects


produced by gases.  In any case, it is clear that effects of complex


mixtures of gases and particles are not likely to be accounted for by


simple summation of individual components.


5.1.6.2.3  Host-related Factors--The state of health, especially of the


cardiorespiratory system and the amount of activity of an individual


affect the total amount and site of deposition of particulates that an


individual may inhale at any given time.  The pattern of breathing


affects the depth of particle deposition, i.e., deep breathing increases


alveolar deposition of particles.  During exercise, people commonly
                               293

-------
shift from nose to mouth breathing and probably increase particle pene-

                               201
tration into lungs as a result.


     At the same time, exercise increases respiratory volume that then


increases the inhaled dose of any toxicant.  This effect of exercise

                                                                208
has been demonstrated in people experimentally exposed to ozone,    and


would presumably occur with inhalation of particulates as well.


     Pre-existing disease of the airways or alveoli is though to pre-


dispose affected individuals to more severe response when subsequently


exposed to atmospheres that contain high amounts of suspended particu-


late matter.  Exacerbation of symptoms of disease that occur in such


individuals usually occur in conjunction with weather conditions, i.e.,


cold and high relative humidity, that in themselves may have adverse

               209 212
health effects.   '     Just how interaction between physical weather


factors, particulate matter and gaseous pollutants interact to affect


health is not well understood.


5.1.6.2.4  Retention Factors--The deposition rate and retention time of


inhaled particles are separate phenomena with overlapping biologic


effects.  Particle retention time depends on (1) site of initial deposi-


tion in the respiratory tract and (2) chemical composition and properties


of the particles.


     If particles are deposited in ciliated epithelium of airways, par-

                                    213
tide clearance is reasonably rapid.      In this event, the toxicity


depends on solubility of the particle in mucus while in transit up the


muco-ciliary escalator.  If the particle is highly soluble, toxic


inflammation in the airway epithelium may occur.
                                    294

-------
     Particles deposited in alveoli of lungs may only very slowly clear


from this location.   '   '     The extent of clearing reflects solu-


bility and subsequent translocation via lymphatic drainage or macrophage

                                                                 217
phagocytosis and clearance via muco-ciliary transport mechanisms.


     The preponderance of evidence, however, is that non-soluble par-


ticles remain in the deep lung for long periods of time (weeks, months


and even years).  As a result of this slow clearance, carcinogenic


hazard of long-lived radioactive metals, i.e., plutonium and uranium


and airborne chemicals,  especially hydrocarbons, is of special concern.

                                   218
     A recent hypothesis by Kilburn    of a two-zone distal lung merits


some consideration of deep lung clearance of particles of limited solu-


bility .  The first zone consists of cul-de-sac alveolar ducts with


"resident" macrophages that assist in enzymatic digestion of particles


for clearance only to lymphatics or blood vessels.   The second zone is


represented by respiratory and terminal bronchioles permeable to macro-


phages and polymorphonuclear leukocytes.  These cells are subject to


recruitment when dusts contact "sentinel" macrophages in the area.  This


hypothesis is consistent with a considerable body of circumstantial


evidence and deserves further investigation.

                                               207
     A second hypothesis expressed by Casarett,    not exclusive of the


one just presented, is that phagocytesis by macrophages or, to a lesser


extent, by alveolar epithelial cells, is preliminary to removal of par-

                                                          207
tides whatever their subsequent destination.  So Casarett    supports a


concept of a rate-limiting biological process in lung clearance composed


of phagocytosis and cellular movement.  This concept does not deny the

                                      219
importance of physicochemical indices,    but views them in terms of


their influence on interaction between particle and cell.



                                295

-------
     In support of this view, it can be said that the central role of



the alveolar macrophage in defense of the lung against insult by par-


                                            220 221
ticulate material is now firmly established.   '     Investigations to



examine influence of particulate materials and soluble analogues on



structural and functional integrity of alveolar macrophage have been


                                    222                     223
reported recently by Bingham et al.,    Burrell and Anderson    and


                          224
Waters, Gardner and Coffin.



     There is much evidence that particles that penetrate into fixed



tissues show clearance half-times ranging from a few days to thousands



of days.  The probability, then, of particle penetration is critical in



determining clearance of particles from non-ciliated regions of the



lungs.  Phagocytosis by alveolar macrophages decreases the probability



of particle penetration and aids clearance.



     The crucial issue in a discussion of clearance rates is whether



they are sufficiently great to balance deposition rates.  It is the



equilibrium level, or retention integrated over time and the physi-



cochemical nature of the particle itself, that presumably determine



probability of a pathological response.
     In a recent report, Brain^J applied the ICRP lung model



described in the Air Quality Criteria Document for Particulate Matter



to predict retention of particles in lung compartments at different



times.  Three exposure patterns were considered in the predictions:



acute pulse, continuous chronic and 40-hour work week exposures.



     The results of the study underscore the importance of both size



distribution and physicochemical composition in quantitation of par-



ticle retention.  They clearly demonstrate that changes in particle





                                  296

-------
size and solubility can alter the magnitude of retention and integrated


exposure in some compartments even when identical masses of particulate


are inspired.  Although simplifying assumptions were made in preparation


of the ICRP lung model, results of Brain's study reinforce the growing


conviction that air quality standards must take into account size distri-


bution and solubility of particulate material.


     As for certain metallic air contaminants, there is more awareness


of concentration gradients that exist in particulate samples as a func-

            . ,                 , 226,227   3   ^   228-230 ,
tion of particle size.  Lee et al.        and others        have


established that Pb, Cd, Zn, Cr, V, Ni, Mn and Cu are found at highest


concentrations in the smallest particles collected from ambient air.  To


this list have been added As, Sb, Se and Tl, found by Natusch and

       231
Wallace    to be most concentrated in the smallest particles emitted


from coal-fired power plants.


     Unfortunately, little is known about matrix composition of small


particles with which Fovic metals are preferentially associated.  It


is thought, however, that surface absorption or condensation of


volatilized elements and organic compounds on to small particles is


responsible for increased efficiency of respiratory deposition of these

           232
substances.     That this view has considerable significance in terms


of environmental health is suggested by the fact that 1 ym MMAD par-


ticles are deposited predominantly in alveolar regions of the lung

                                                               231
where absorption efficiency for most trace metals is 50 to 801.


Similar conditions may prevail in the case of potentially carcinogenic


organic vapors.


     Because certain metals may be soluble in respiratory secretions,


toxic properties of these substances may be manifested in lung



                               297

-------
parenchyma or airway epithelium or translocated so as to induce lesions



in other sensitive tissues.  Vanadium is an example of such a metal



whose effects may show up through this mechanism.  However, minimum



time-concentrations of vanadium and other metal exposure that produce



toxicity are not well understood.  Also, toxicological assessment of



metals that accumulate in the lung or other tissues present different



problems than many other respiratory irritants because the relationship



of tissue burdens to carcinogenesis, metabolic defects and mutagenesis



or tetrogenesis is more difficult and time-consuming to assess.



5.1.6.2.5  Biological Respirable Particles--There are species of pollens,



fungi, bacteria and viruses within respirable range in particle size.



These biological particles are included among particles collected for



measurement as respirable particles.  However, it is difficult to



characterize the concentration of these particles because of complexi-



ties involved in precise species identification.  In the case of viruses



and bacteria, concentrations may go low as to cause problems in



measurement.



     Respirable biological particles have received low priority by EPA



because of lack of appropriate technology for their control that can be



applied to the general population.  However, biological respirable aero-



allergens, microorganisms and certain other substances that may interact



with biological tissues can be important in the etiology of immunologi-



cal respiratory disease.



     Certain paratoxic effects of gaseous atmospheric pollutants that



involve increased susceptibility to airborne microorganisms have been


                                        233
reviewed recently by Coffin and Gardner.     These effects may be related
                                   298

-------
to impaired pulmonary defensive capabilities and altered dynamics of



respiratory air flow that change the pattern of regional deposition



of inhaled particles.  Vfrth regard to the latter, see Fairchild224

                                  O?r
and Lippmann, Albert and Peterson.



5.1.7  Sulfur Oxides



5.1.7.1  Human Studies--The standards for SCL are shown in Table 5.30



and studies on which they were based when set on April 30, 1971 are



presented in Table 5.31. These studies represented the best informa-



tion available.  Their limitations and shortcomings were recognized,



but the Clean Air Act mandated that a standard be established.  Included



among this best available evidence for establishing an ambient air



quality standard for SCL in 1970 were the following reports:

                         7 "^ft
     (1)  Brasser, et al.    reviewed major episodes of air pollution



in London and Rotterdam between 1952 and 1962.  They indicated that



excess mortality resulted when 24 hour mean levels of SCL exceeded



500 yg/m  (0.19 ppm) for a few days.  Also, hospital admissions for


respiratory illness as well as absenteeism increased whenever 24 hour



mean levels of SCL reached 300-400 yg/m  for three-four consecutive



days.

                  737
     (2)  Joosting    studied data from London episodes and determined



that significant correlations between CL pollution levels and deaths



or disease occur with 24 hour mean SCL concentrations of 400-500 yg/m



(0.15-0.19 ppm) when there is a high soot content.


                        2 38
     (3)  Carnow, et al.    studied a group of patients with chronic



bronchitis.  Substantial increases in illness were reported by persons



55 years and older with more severe bronchitis when concurrent or
                               299

-------
proceeding daily SCL levels ranged from 119 to 249 yg/m  (.05-.09 ppm).


The relationship was not observed among persons with less severe bron-


chitis or patients less than 55 years of age.  During the period of


study, TSP levels exceeded the 24 hour standard on about 15% of the days.


So the effects observed may have been related to the combination of


materials that the patients were exposed to.

                         241
     (4)  Wicken and Buck    studied mortality in two communities in


England with contrasting pollution exposure levels.  They found increases


in lung cancer mortality in men and increases in bronchitis mortality in


men and women associated with long-term mean S02 of 115 yg/m  (0.040 ppm)

                                                 3
when compared with SCL exposure levels of 75 yg/m  (0.026 ppm).  The high


exposure community also experienced TSP levels of 160 yg/m  compared with


80 yg/m  in the low exposure area.

                            239
     (5)  Douglas and Waller    found increases in lower respiratory


disease in London children to be directly related to a pollutant gradient


that they were exposed to.  Upper respiratory disease did not show a


similar relationship.  LRD was increased in areas where annual mean SCL


concentrations were 130-148 yg/m  (.05-.06 ppm) or higher together with


TSP levels of 91-138 yg/m3 or higher.

                    243
     6)  Lunn et al.    observed increases in lower respiratory illness


in England children associated with exposure to annual mean SCL levels


of 194 yg/m  (.074 ppm) or higher and TSP levels of 177 yg/m  or higher


compared with S02 and TSP levels of 109-134 and 70-78 yg/m  respectively.


     To fill gaps in the information base as rapidly as possible, the


Environmental Protection Agency maintains a continuing program of research


to specifically assess adequacy of maximum permissible long-term or short-


term exposure levels.


                                   300

-------
      Table 5.30.  PRIMARY NATIONAL AMBIENT AIR QUALITY STANDARDS
                                 FOR SULFUR OXIDE
                  	National Primary Standard	
   Pollutant      Concentration (yg/m )            Averaging Time
Sulfur dioxide     80 ug/m  (0.03 ppm)      Annual arithmetic mean.

                  365 yg/m  (0.14 ppm)      Maximum 24-hour concentration
                                           not to be exceeded more  than
                                           once per year.
                              301

-------
    Table 5.31.  INFORMATION BASE FOR ESTABLISHMENT OF NATIONAL
                 PRIMARY AMBIENT AIR QUALITY STANDARD FOR SULFUR
                                     DIOXIDE
   Adverse Health Effect
 Concentration at Which Effect
         Was Observed
 Concentration   Averaging Time  References
    (yg/m3)
1.  Increased mortality.
2.  Increased hospital
    admissions with
    respiratory illness.

3.  Increased frequency and
    severity of respiratory
    illness.

4.  Increased specific
    mortality.
500 yg/m
(0.19 ppm)
300-500 yg/m3
24 hours
24 hours
224,225
226
(0.11-0,19 ppm)
130 yg/nT
(0.06 ppm)
130 yg/in
(0.06 ppm)
Annual mean
Annual mean
227,228
229
                                    302

-------
     One of the primary problems in determining health effects of S02



continues to be development of an understanding of the manner in which



this gas interacts with other substances in the atmosphere.  Laboratory



studies had demonstrated that the levels of S02 found in the ambient air



are innocuous in an experimental situation until combined with other



substances.  Similar studies with animals demonstrated the high toxi-



cities of sulfuric acid mists and various sulfate compounds that are



products of the atmospheric transformation of SCL.



     Observed associations of adverse health effects in epidemiologic



studies with ambient levels of suspended sulfates have supported these



laboratory studies.  Table 5,35 presents recent study results in a man-



ner that relates adverse health effects to S07 exposure and suspended



sulfate exposure.  The studies referenced in Table 5.32 relate to a



variety of health parameters.



     An analysis of daily mortality in the New York metropolitan



region between 1962 and 1966 indicated that S02 measurements contributed



significantly to prediction of deaths.  Mortality was 1.51 less than



expected on 232 days with levels below 30 yg S02/m  and 2% greater than



expected on 260 days with levels above 500 yg S09/m  after correcting
                                                Z<


for other factors.



     In each of three New York neighborhoods, cold temperatures were



directly related to increased symptom rates in persons with combined



heart and lung disease.  Elevated suspended sulfates were the only



pollutant consistently aggravating symptoms.  Daily sulfur dioxide and



total suspended particulate concentrations could not be associated with



symptom aggravation in the "heart and lung" panel that was most sensi-



tive to variations in daily pollutant concentrations.



                                303

-------
tO
to
CM
  •\
CM
to
CM
LO
tO
CM
to
CM
                oo
                to
                CM
to
CM
to
CM
O
**
CM
  •*

01
to
CM
OO
to
CM
to
CM









e

FH
Q
i — i

W

U
I-H
P-,
t-H
H
w
1 — 1
£_}
en

d
r^H
O

H
i— t
Q
r_


.
CM
tO
LO
CD
i — 1
•8
H














'•rj
P
CD
to
fi
0

1
3:
P
U
CD
4H
4-1
W

f|
O
•H
r^
§:
P
CO

Pi
O
•H
P
CO
£~t
4->
d
CD
O
r*j
5
U

1
H

•H
bo
rt

CD
^









to
e

bo

pj
O
•H
4_>
cO
P

CD
O

O




to
S

bO
~1

CO
CO



/B— ^
6
a


K1
C*
•^v^
bO
3.

CN
8






+-*
o
CD
4H
4H
W

r*|
4_j
rH
CO
CD
2C
CD
trt
rH
T3


SH
O
X!

^3-
CM









<£
>^i








LO
0 rH
O •
«* O
1 1
O rH
O rH
to •
o










•
fr
•H
rH
CO
P
%
P«
T3
CD
8
O


VI
o
X

r^j-
CM








O
t— 1
l
OO











f — ^
LO rf
\O rH
to •
o
^ — /





Pi
•H
j-
G
O
p

^^
(/}

4H
0
Pi ^N
•H r<
P CD
rt T)
CO CD
f-H
bO CD


£
o


^j-
CM








o
1— 1
1
OO







f — \
01
0 0
LO •
CM O
1 1
o r-
oo o
rH •
0








,


^
\f\
Co

4H
0
Pi
0
•H
P
1
bO
g
Q
£
rH
^j
p*
p
^^









rH
rH











f — ^
LO
o r~-
o o
CM
O






Pi
•H
_.
0
•H
P
O
3
4H

bO

rH
T)
CD Pi
3 £
CD TJ
>H rH
O -iH
g

s
rH
c8
3
pj
c
^^









o>










o
0
rH

O












f-l

g
rH

CD
P
O
cO
Tj
rease
o


























^— ^
to
0
•
0
1
T^
to
o

o
V 	 1






£
•H

to
CO
CD
tfl
•H
T3
S^
0 •
P  0 0
rH
O






o
p
4-1 cO
0 t-t
•H
CD O,
0 • t«
p| tn CD
CD -H ?-i
rH -P
CO -H CD
^> f* j-i
CD O 3
r< Pi 0
P< O cO
"^ o rcj
CD CD
tO O (/)
CO -H CO
CD pi CD
U rH O














































•
CD
•H
rH
ip-j
ri
4H

.s
CD
S
CD
c/)
        fi-S    ££43
                                  t-H TJ
to
          304

-------
     Best judgment estimates based on preliminary studies of 24-hour



mean threshold levels for aggravation of cardiopulmonary symptoms in



the elderly are 8-10 yg/m  of suspended sulfates.



     Studies of daily asthma attack rates in the Salt Lake Basin showed



that attacks were more consistently correlated with colder outdoor



temperature than with any measured pollutant.  An analysis of asthma



attack rates compared to daily pollutant concentrations was carried out



within two ranges of minimum temperature, 30 to 50°F and greater than



50°F.  Virtually no relationship between sulfur dioxide and attack rates



appeared.



     Total suspended particulates and suspended sulfates were positively



correlated with daily asthma attack rates.  A higher frequency of asthma



attacks was observed at the same daily total suspended-particulate con-



centration when a high sulfate fraction was present in the atmosphere.



It then appears that sulfate levels were a stronger determinant of asthma



attack rates than total suspended particulates.



     In New York, also, asthma attack rates were more consistently asso-



ciated with daily suspended sulfate levels than with either sulfur



dioxide or total suspended particulates.



     In the opinion of the authors, best judgment estimates of the 24-



hour mean levels of SCL that might serve as precursors of significant



ambient SO, concentrations were 180-250 yg/m .



     Ventilatory function of elementary school children diminished as



measured by 0.75-second forced expiratory volume in areas of elevated



exposure to sulfur oxides.  In New York only older children (ages nine



to 13 years) who had been exposed to substantially elevated pollutant
                                305

-------
concentrations for the first five to 10 years of life showed evidence of



reduced ventilatory function.  The best available estimates of these



previous annual average exposures were as follows:  sulfur dioxide, 131



to 435 yg/m ; total suspended particulates, 75 to 200 yg/m ; suspended



sulfates, 18 to 28 yg/m .  The best judgment estimate of a threshold



level for SCL was approximately 200 yg/m .



     In a Cincinnati study of ventilatory function in children, suspended



sulfates emerged as a pollutant of particular concern.  Sulfur dioxide



concentrations were at or below the moderate level of 57 yg/m  during the



time of testing permitting suspended sulfates to be assessed in the



relative absence of sulfur dioxide.  Ventilatory function in children



exposed to suspended sulfate concentrations of about 9.5 yg/m  was lower



than that of children exposed to concentrations of about 8.3 yg/m .  It



was the authors' best judgment that eight or nine years of exposure to



about 10 to 13 yg/m  of suspended sulfates might reduce ventilatory



function.  If these suspended sulfate exposures were accompanied by



exposures to about 200 to 250 yg/m  of sulfur dioxide and about 100 to



150 yg/m  of total suspended particulates, further reductions in FEV



0.75 might be expected.



     Lower respiratory disease studies conducted in the Salt Lake Basin



and Rocky Mountain areas found no significant association between total



lower respiratory disease and pollution for children whose parents had



been residents of their communities for less than three years.   For



single and repeated episodes of croup and repeated episodes of any lower



respiratory disease, families of children who had lived three or more



years in the high exposure communities reported more illness among all
                                   306

-------
ages of children from 0 to 12 years than did their counterparts in less



polluted communities.



     Best judgment estimates of the threshold levels for increases in



acute lower respiratory tract infections in children were three years of


                   3                            3
exposure to 95 yg/m  of sulfur dioxide, 102 yg/m  of total suspended



participates and 15 yg/m  of suspended sulfates.



     Chronic bronchitis rates in CHESS areas showed a consistent pattern



of excess among residents of more polluted communities.



     In the Salt Lake Basin, male smokers and non-smokers showed an



excess of chronic respiratory disease whether defined in terms of



bronchitis prevalence or severity scores.  Chronic bronchitis rates and



severity scores were higher among male and female smokers, non-smokers



and ex-smokers from more polluted areas than they were in comparable



groups from less polluted areas.



     Among young white military recruits in the Chicago area, the con-



tribution of air pollution was relatively much less than that of



cigarette smoking.  However, there was evidence that even among these



young inductees, respiratory symptoms were more prevalent among persons



from more polluted communities.



     Best judgment estimates of the threshold levels for increase in



prevalence of chronic bronchitis in adults were six years of exposure to



95 yg/m  of sulfur dioxide, 100 yg/m  of total suspended particulates,



and 14-15 yg/m  of suspended sulfates.



     Studies of total acute respiratory disease among family members in



Chicago and New York showed that, with the exception of fathers, who



often have greater occupational exposures and daily changes of exposure
                                307

-------
due to place of work, a consistent excess of acute respiratory disease

was reported among family members living in more polluted neighborhoods.

     Best judgment estimates of the threshold levels for increase in

frequency or severity of acute respiratory illness in families are three

years of exposure to 106 yg/m  of sulfur dioxide, 151 yg/m  of total

suspended particulates and 15 yg/m  of suspended sulfates.

     Best judgment estimates of the exposure threshold for adverse

health effects are given in Table 5.33.  The margins of safety are

included in the air quality standards in Table 5.34.  And estimates of

the population at risk are presented in Table 5.35.

5.1.7.2  Animal Studies--The health effects of sulfur oxides have recently

been critically reviewed in four major reports:

     1.  Summary report on adverse health effects related to sulfur
         oxides exposure, Environmental Protection Agency, Research
         Triangle Park, N. C., September, 1973.  Unpublished.

     2.  ERC/RTP Task Force report on sulfates and sulfuric acid
         aerosols, October, 1973.  Unpublished.
                                                                    253
     3.  Toxicology of sulfur dioxide decay products by Lewis  et al.

     4.  A review of the toxicology of oxidation products of sulfur
         dioxide by M. 0. Amdur.254

     Information in these documents help provide the basis for Air Qual-

ity Criteria for Sulfur Dioxide.  For information published before 1972,

readers should refer to the above referenced documents.  In the two

years since these documents were compiled, only a limited amount of new

information has been obtained that contributes significantly to under-

standing of toxicologic properties of sulfur oxides.

     Recent research on sulfur oxides has continued to demonstrate that

the respiratory tract is the principal organ system affected.   The
                                    308

-------
      Table 5.33,  BEST JUDGMENT THRESHOLD ESTIMATES FOR HEALTH
                             EFFECTS OF SULFUR OXIDES
                                    Best Judgment Threshold Estimate

1.
Adverse Health Effect
Aggravation of cardio-
Concentration yg/m Averaging Time
so2 ss
365 10 24 hours
    respiratory symptoms or
    lung symptoms in elderly
    patients with related
    illness.

2.  Increased mortality.

3.  Aggravation of asthma.

4.  Reduced lung function.

5.  Increased frequency or
    severity of lower
    respiratory illness.

6.  Increased prevalence of
    chronic bronchitis.

7.  Acute respiratory disease.
350

200

200

 91



 95


106
 NA        24 hours

8-10       24 hours

 11        Annual mean

9-12       Annual mean



 14        Annual mean


 12        Annual mean
                                 309

-------
Table 5.34.   SAFETY MARGIN INCLUDED  IN SULFUR OXIDE STANDARD
                               Threshold      Primary     Safety*
    Adverse Effect            Concentration    Standard    Margin
1.
2.
3.
4.
5.
6.

Aggravation of heart or
respiratory symtoms in the
elderly.
Increased mortality.
Aggravation of asthma.
Reduced lung function.
Increased lower respiratory
illness.
Increased chronic
bronchitis .
365 365
350 365
200 365
230 80
91 80
95 80

0
0
0
(-45)
187
14
19

*cnff^ M-^e-in - Threshold Concentration - Standard „ inn
                        Standard
                                 310

-------
         Table 5.35.  SIZE OF POPULATION AT POTENTIAL RISK
                          OF POLLUTANT-INDUCED EFFECT
      Adverse Effect
      Expected Frequency of
Adverse Effect in the Population
         (Rate per 100)
                               Potential
                               Size* of
                              Population
                                at Risk
Chronic bronchitis.

Asthma.

Chronic heart illness.

Susceptible to respiratory
  infection.
10% of adult population

           i&

 5% of adult population

          100
                                     8,400,000

                                     4,200,000

                                     4,200,000

                                   140,000,000
*Assumes a U.S. population of 200,000,000 and 70% of total population living
 in urban areas of increased pollution.
                                  311

-------
available data on comparative toxicity of sulfur oxides indicate that



sulfur dioxide is only a mild respiratory irritant, while specific



sulphate and sulfuric acid aerosols are more potent respiratory irri-



tants.  The importance of particle size as well as mass concentration



to toxicity of sulfur dioxide aerosols is of paramount importance.


                                                                 254
Experiments demonstrating this point have been reviewed recently.



     Most recent studies of sulfur-oxide toxicity have been concerned



with sulfur-oxide aerosols or sulfur dioxide in combination with an



inert particulate aerosol.  The importance of high relative humidity



to enhancement of the effect of sulfur dioxide and sodium chloride



aerosol has been demonstrated through sensitive repsiratory physiologic


          255                                                        3
responses.     These compounds (S0~- 1 ppm and sodium chloride 1 yg/m )



alone or in combination caused no effect on pulmonary airflow resist-



ance of guinea pigs at low relative humidity (40%).  However when the



relative humidity was increased to > 80%, a 50% increase in pulmonary



airflow resistance developed.  The increase in relative humidity



resulted in an increase in aerosol size and production of an acid



aerosol that are thought to be important events in the production of an



irritant aerosol leading to increased pulmonary airflow resistance.



     A concentration of3020ygm/m  H-SO. (1.8 u CMD size)  that has been



shown to increase pulmonary airflow resistance in guinea pigs also pro-



duces an increase in total respiratory particle deposition in guinea

     7 c A

pigs.     This increased particle deposition occurred primarily in the



nasopharynx, i.e., a proximal shift in the normal pattern of regional



deposition of radio-labelled bacterial aerosol occurred.   Dose-response



experiments revealed that even at a concentration of 30 ygm/m  (0.25 u



CMD size) a proximal shift in the pattern of respiratory particle


                                   312

-------
deposition occurred.  But in this instance the shift was to the trachea.



These results suggest where the site of action is of H-SO, aerosols of



this mass concentration and particle size.



     Particle deposition in the respiratory tract is correlated to air-



flow dynamics in this system.  The suggestion has been made that these



results reflect a subtle patho-physiologic consequence to altered



respiratory airflow resistance.  So these results provide added signifi-



cance to respiratory physiologic responses that are commonly used in air



pollution health effects studies.



     A concentration of 15 yg/m  of H-SO, (2.5 u CMD size) for 90 minutes



per day for four consecutive days induced a reduction in the physical



clearance of radio-labelled streptococcous particles deposited in the


                       245
nose and lungs of mice.     No effect was demonstrated on the clearance



of viable streptococci from these same tissues.  However, no effect on



physical clearance of streptococci was observed at a mass concentration



of 1.5 yg/m  H2S04 (0.8 u CMD size).  These data suggest that altera-



tions in respiratory particle deposition and path/physiologic conse-



quences of these alterations are a more sensitive index of response to



H^SO. inhalation than mucociliary clearance of particles.


                 258
     Busey et al.    have demonstrated that chronic exposure (78 weeks)



of guinea pigs to a combination of fly ash (0.55 yg/m ) and H2S04 aerosol



produced inflammatory lesions in terminal bronchioles of the lung



characterized as moderate hyperplasia of the epithelium.



     The only alteration in respiratory physiologic measurements was a



small increase in respiratory airflow resistance that might be associated
                                313

-------
with histopathologic lesions.  The results of this experiment are

important because a much higher concentration of sulfur dioxide did not
                          -^ rn
produce any health effect.         A combination of SCL (up to 5 ppm)

and fly ash (0.5 yg/m  - size 2.6 - 3.4 u MMD) exposure for 78 weeks

did not induce any respiratory physiologic or histopathologic effects

      ,                    262
in monkeys or guinea pigs.
            9 A T
     Zakower    has observed small changes in immunologic responsive-

ness of rats chronically exposed to sulfur dioxide and carbon dust.

These observations have not been confirmed or the pathophysiologic

consequence of this effect demonstrated.

5.1.8  Mercury

     Several recent animal exposure studies using methyl mercury given

in repeated oral doses over relatively long time periods show that a

"no-effect" level for development of neurological signs and/or histo-

pathological evidence of mercury poisoning is from 0.03 mg/kg body

weight (monkeys, cats) to 0.1 mg/kg body weight (calves).

     Daily oral doses of alkyl mercury compounds as small as 0.4 mg/kg

body weight have produced neurological disorders in rabbits, cats and

dogs.  Daily oral doses of 0.25 mg/kg body weight of methyl mercuric

chloride given throughout most of the gestational period caused increased

abortions and fetal abnormalities in cats.  Similarly, levels above 0.3

mg/kg given during gestation increased fetal abnormalities in rat fetuses.

     Most animal experiments were carried out with daily dose levels

much higher than the foregoing experiments and the most chronic exposure

found was that of monkeys that were exposed for two years.  Low level,

long-term exposures were notably absent.
                                    314

-------
     Behavioral changes; have been produced in rodents where no histo-


logical lesions were found from single oral doses of methylmercuric


chloride.  The relatively high 25 mg/kg dose level was required since


doses at 20 mg/kg level did not produce significant changes.

          264
     Ikeda    fed methyl mercuric chloride (MMC) to four groups of


five male monkeys each for two years.  Groups were made up of three


Macaca Mulatta and two Macaca Irus each.  Levels used were 0.01, 0.03,


0.1, 0.3 mg/kg/day plus a control level.  In the two highest levels


(0.1 and 0.3 mg/kg/day),  toxic neurological signs appeared at 62 and


182 days respectively when total amount of MVE ingested was 15.3 and


15.9 mg/kg.  No neurological signs were noted in the other groups


although animals fed at the 0.03 mg/kg level ingested a total of 18.4


mg/kg MC by the end of two years.  No significant alterations occurred


in hematological or biochemical parameters tested in the two lower dose


groups.  The mercury content of hair showed good correlation with the


daily dose of mmc.   This study is still in progress.

             *? f\ Q
     Takeuchi    reported on total amounts of methyl mercuric chloride


(MV1C) necessary to produce poisoning similar to Minamata disease.  In


cats, the total dose was 20.6 to 25.7 mg/kg at a daily level of 1.5 to


2.0 mg/kg.  In rats, total dose was 100 to 200 mg/kg at a daily level


of 5 to 10 mg/kg.  Extrapolating from these figures to man is a total


dose of 20 mg/kg.

          266
     Khera    fed pregnant cats orally with doses of methyl mercuric


chloride (MC) from the tenth day to the 58th day of induced (gonado-


trophin) pregnancy to determine teratogenic effects.  The results were:
                               315

-------
    Dose Level   Number                   Results
        0          7
    0.03 mg/kg     5      No signs of poisonii^ detected in dams.
    0.83 mg/kg     6      No signs of poisoning detected in dams.
    0.25 mg/kg     9      Increased abortions and fetal anomalies.
    0.75 mg/kg     4      Vomiting, ototoxia and death of dams
                            within 32 days post exposure.

Minimal or no embryopathic effects were noted at the two lowest levels.

The 0.03 mg/kg dose was considered the "no-effect" level.  This corre-
                         264
lates well with the IDEDA    experiment using monkeys where the feeding

period was two years.
          *7 f-\ "7
     Magos    studied cumulative effects of oral methyl mercury

dicyandiamide (MMD) on rats.  Female albino rats were divided into the

following three groups:

     I.   3.36 mg/kg for five days/week for 16 doses N=14
     II.  1.68 mg/kg for five days/week for 34 doses N=12
     III. 0.84 mg/kg for five days/week for 59 doses N=16

     Group I showed weight loss after the fourth dose and neurological

abnormalities after the twelfth dose.

     Group II lost weight after the 24th dose when four of the six ani-

mals remaining were ototoxic.

     Group III increased in weight throughout the experiment but two of

these animals showed slight ototoxia.

     All groups exhibited histopathological changes in the kidney and

cerebellum.
              268
     Irukayama    reported on short-term (10-90 days) multiple oral-

exposures to methyl mercury that produced neurological disorders in

rabbits, cats and dogs.  The daily intake of MM was 0.4 to 1 mg/kg and

the total intake in these species between 10 and 20 mg/kg.  To produce
                                   316

-------
similar signs in rats required a total dose of approximately 100 mg/kg



indicating the higher degree of resistance of this species.


         269
     Post    recorded behavioral changes in the following three groups



of young rats (force-fed a single dose of methyl mercuric chloride



[JMC]):



                   Group I    15 days old  20 mg/kg  N=15

                   Group II   21 days old  20 mg/kg  N=15

                   Group III  60 days old  25 mg/kg  N=45



     The differences in behavioral measurements in Groups I and II vs.



controls were small or statistically insignificant.  Behavioral changes



in Group III were significant, however.  The authors state that signifi-



cant behavioral changes in Group III could result from higher doses of



MC or age differences.  Since no histopathological changes were found



in any group, the authors conclude that behavioral testing was the more



sensitive indicator of mercury poisoning.


                         270
     In a study by Fukuda,   two of six rabbits that were exposed to



an average concentration of 4 mg/m  of mercury vapor for six hours a



day, four days a week, for 13 weeks, developed a fine tremor and clonus



in the fore- and hind-legs.  (This level is 4000 yg/m , a relatively



high exposure.)  Analysis of CNS tissue showed mercury levels of 0.8



to 3.9 yg/g wet tissue.



     Beliles    found fine tremors in the fourth week in rats repeatedly



exposed to mercury vapor at:  17 mg/m  for three hrs/day, five days/week



for four to five successive weeks.  Histological changes in the CNS were



also present.


                272
     Charbonneau    exposed two groups of cats to 0.25 mg/kg/day methyl



mercury for 12 to 14 weeks.  One exposed group received methyl mercuric
                                  317

-------
chloride in gelatin capsules.  The other group received methyl mercury-



contaminated fish.  A control group received uncontaminated fish.  Clini-



cal signs of neurological abnormality developed in both exposed groups



between 55 and 96 days.  At that time, total methyl mercury ingestion was



between 14 and 24 mg/kg.



     Tissue mercury content and pathologic changes were similar in both



exposed groups of treated animals.  Lesions were found in the cerebellar



vermis and the cerebral cortex.



     Pre-test blood mercury concentrations in the cats were considerably



higher than background value for humans, possibly reflecting the dietary



history of the cats.  Cats seem similar to other species, including man,



that develop clinical signs of methyl-mercury toxicity when brain concen-



trations are in the range of 10 ppm.


         273
     Gale    injected golden hamsters with mercuric acetate (inorganic



mercury) and phenylmercuric acetate (organic mercury) on the eighth day



of pregnancy and sacrificed them on the 12th or 14th day of pregnancy



to study potential teratogenic effects in this species.  Mercuric acetate



levels used were 2, 3 and 4 mg/kg, while  phenylmercuric acetate was given



at 5, 7.5, 8 and 10 mg/kg.  All levels of mercuric acetate and all but the



lowest level of phenylmercuric acetate produced resorption rates signifi-



cantly above control values.  Both compounds produced the same changes in



embryos.



     Embryonic growth rate was retarded one to two days and abnormal



fetuses had sub-cutaneous edema.  Finding of similar results from exposure



to organic and inorganic mercurials may be due to rapid metabolism of



organic mercury into inorganic form in both liver and kidneys.
                                    318

-------
         274
     Gale    injected pregnant hamsters intravenously with mercuric



acetate in combination with either cadmium sulfate or zinc sulfate on



the eighth day of gestation.  (Dose levels of each compound were either



2 or 4 mg/kg.)  On the 12th or 14th day of gestation, embryos and



implantation sites were examined for malformations and resorptions.  The



detrimental effects of Hg + Cd were much worse than those of the Hg + Zn



combinations.  Manifestations of toxicity in dams were directly propor-



tional to the mercuric acetate dose.  Animals that received the higher



mercury dose (4 mg/kg) showed more severe toxic effects than any of the



Hg + Cd or Hg + Zn combinations.


                         275
     In a study by Spyker,   methyl mercury dicyandiamide (MMD) was



injected into pregnant mice on the seventh or ninth day of gestation at



levels of either 4 or 8 mg/kg.  The number of apparently normal neonates



killed by the dam was significantly increased if offspring were pre-



natally exposed to WE).  Additionally, open-field testing at 30 days of



age revealed significant differences in latency, backings, defecations



and urinations.


                               77ft
     In another study by Spyker,   a total of 667 female mice of two



strains (129/Sr-Sl and A/J) were given I.P. injections of Methyl mercury



elicyandiamide (MMD) on one of days six to thirteen of gestation and



2,280 implantation sites were examined on day 15 or 18.  Dose levels



used were 0, 2, 4 or 8 mg MMD/kg.  The 8-mg/kg dose produced growth



retardation in both strains and was 88% embryo-lethal when given on



days nine to 13 in strain 129.



     This dose level was not embryolethal in strain A.  But it did cause



cleft palate in this strain when injected on days nine to 13.  Examina-



tions of fetuses from strain 129 on day 15 revealed 52% of embryos had



                                 319

-------
brain, palate or facial abnormalities.  Off-spring that appeared normal
showed significant behavioral differences when submitted to battery
tests.
          277
     Klein    exposed 25-day-old rats to sub-lethal oral doses of mer-
curic chloride at either 5 or 7 rag/kg daily for two weeks prior to
active-avoidance training.  Klein's results indicate that mercuric
chloride administration significantly impaired active-avoidance acquisi-
tion without influencing either escape latencies or general physiological
condition.
           278
     Kawabe    gave methyl mercury chloride orally to pregnant mice on
the tenth day of gestation at dose levels of 0.1, 0.2, 0.3, 0.5, 1.0,
1.5 and 2.0 mg/kg.  Fetuses were removed and examined on the 15th ges-
tational day.  At levels of 0.5, 1.0, 1.5 and 2.0 mg/kg the number of
dead fetuses and resorptions were increased.  Levels of mercury that
produced abnormalities in this experiment substantially agree with the
experiments of Spyker (mice) and Khera (cats).
          279
     Munro    gave groups of eight to 10 male Wistar rats daily oral
doses of methyl mercuric chloride (MMC) .  Clinical signs of mercury
intoxication appeared in all groups but the lowest dose level.  Patho-
logical changes occurred in the nervous system of all treated rats
involving Wallerian degeneration of sensory nerves, swelling with loss
of myelin in the posterior white column of the spinal cord, secondary
loss of nerve cells in dorsal root ganglia and atrophy of the cerebel-
lar vermis from loss of granular cells and some Purkinje cells.  The
results were:
                                      320

-------
            	Dose	    Appearance of Clinical Signs

            10    mg MC/kg/day                7 days
             5    mg MC/kg/day               14 days
             1    mg MC/kg/day               65 days
             0.5  mg MMC/kg/day              120 days
             0.05 mg MC/kg/day        No signs at 280 days

              280
     Herigstad    fed six four-week-old male Holstein-Friesian calves

methyl mercury that produced neurological signs and histopathologic

changes of mercury poisoning at levels as low as 0.2 mg/kg/day at 90

days exposure.
            281
     Iverson    induced overt clinical signs of mercury intoxication

in guinea pigs after daily dosing for nine days at 5 mg methyl mercury/

kg.
            28?
     Tatetsu    gave 5 mg/kg dimethyl mercuric sulfide orally daily

to pregnant rats during two to three weeks of pregnancy producing

degenerative changes in the brains of their newborn.

           283
     Suzuki    produced neurological signs in mice at dietary levels of

10 yg of methyl mercury per gram of feed.  This group did not show any

loss of body weight or neurological symptoms until the 41st day of

feeding.  The most sensitive neurological sign was noted at a methyl-

mercury concentration of 10 yg per gram of brain.
            284
     Iverson    found the LD5Q (14) for methyl mercuric chloride in

female guinea pigs to be 5.5 mg/kg I.P. and 16.5 mg/kg P.O.  The tissue

distribution of a single orally-given dose was studied with the follow-

ing results:  Kidney>Liver>Spleen>Heart>Brain.  A biphasic excretion

pattern was common to most organs except the kidney.  Half-times were

t, = two to three days and ^  = 15-16 days for most tissues.  Kidney

turnover rates were much slower.
                                 321

-------
     Newberne et al.    fed rats fish-protein concentrate (FPC) as part



of their diet to provide 20% protein for five generations.  Average



total mercury content of FPC samples was 0.22 ppm with more than 901 in



the form of methyl mercury.  Over the two-year feeding period, there



was no evidence of effects on growth, development, reproduction or



behavior throughout the five generations.  Histologic examination



revealed no lesions of the brain, kidney or liver caused by the diet.



The average weekly intake of the animals was 12 yg/kg per week.


                   286
     Singhal et al.    injected young male rats with 0.4 or 4.0 mg



methyl mercury/kg/day for 45 days and produced a significant decrease



in liver weights at both doses.  Gluconeogenic enzyme activities



increased in nearly all enzymes examined at both dose levels.  Elevated



blood glucose and urea along with reduced liver glycogen content occur-



red at both dose levels.   Withdrawal of mercury exposure to 4 mg/kg/day



for 28 days post-exposure generally failed to reverse observed metabolic



changes in hepatic and renal carbohydrate metabolism.


                  287
     Lucier et al.    found that subcutaneous injection of male rats



with methyl mercury hydroxide at 2.5-10.0 mg/kg/day for two days



decreased hepatic mixed-function oxidase activity and microsomal cyto-



chrome P-450 content by approximately 50%.  Oral administration with



drinking water of M£l of approximately 0.7/mg/kg/day for 30 days or 1.0



mg/kg/day for 17 days cytochrome P-450 and aminopyrine demethylase were



decreased by only 20% approximately.


                 288
     Klein et al.    injected rats daily for five days with 2-10 mg/kg



of methyl mercury hydroxide (NMI).  Only the highest dose group had



weight loss.  No CNS damage was noticed.  Focal necrosis of kidney
                                     322

-------
tubular epithelial cells were noted by day six.  These studies identify



the kidney as an early target in MM intoxication and suggest that bio-



transformation of MMH into inorganic mercury may produce part of the



pathological changes noted.


                  289
     Fowler et al.    gave rats 55 ppm Hg (as methyl mercury hydroxide)



in drinking water for four weeks.  Proximal tubule cells of kidneys



were found to contain swollen mitochondria with dense granual cytosomes.



Sodium phenobarbital, a microsomal enzyme inducer, given weekly during



MMH administration, prevented these histologic changes (possibly by



stimulating the metabolism of MM and reducing renal mercury levels and



attendant nephrotoxic effects).


                    290
     Hastings et al.    found that injection of 10 mg MMH/kg for two



days reduced serum cholinesterase activity by 501 in male and female



rats, but had no effect on brain acetylcholinesterase levels.


                 291
     Khera et al.    intubated pregnant mice with CH,, Hg Cl at doses



of 0.001 to 10 mg Hg/kg/day from day six to 17 of gestation.  Doses



of 5 mg/kg/day caused 100% stillbirths or neo-natal death but no



maternal toxicity.  Doses of 1 mg/kg/day caused a low incidence of



delayed cerebellar differentiation of progeny and depressed activity



of cerebellar enzymes.  Young female rats were fed methyl mercuric



chloride in the diet at levels of 0.002 to 0.25 mg Hg/kg/day until



sexually mature and then mated to untreated males.  Treatment con-



tinued throughout pregnancy, delivery and weaning.  At weaning, half



of the progeny remained on the experimental diet and others reverted



to a control diet.  All animals were subsequently mated and sacrificed



on day 20 of gestation.
                                 323

-------
     Long-term feeding of parent female rats with diets containing up



to 0.25 mg/Hg/kg/day for 122 days had no discernible effect on growth,



behavior or pregnancy.  No effects were seen at any dose level on the



F7 fetal weight, abnormalities, gross or microscopic histology of brain
 LJ


and spinal chord or viability.  A variable incidence of ocular lesions



was dose-related.



5.1.9  Beryllium



     Significant animal studies conducted since the classification of



beryllium as a hazardous pollutant are reviewed briefly.



     A soluble tissue extract prepared from animal and human lung con-



nective tissue sensitized normal guinea pigs to subsequent exposure of



beryllium as assayed by the skin reaction, macrophage migration inhibi-



tion factor and lymphotoxin production.  Greater than 50% of animals



with tuberculosis, berylliosis or coal pneumoconiosis exhibited some



evidence of cell-mediated sensitivity to appropriate soluble tissue


  *   ^292
extract.



     Mice and guinea pigs treated with metyrapone to alter adrenal func-



tion had a more severe reaction to beryllium (BeSO. or BeO via trans-



thoracic or intratracheal injection) than control animals as indicated



by weight loss, metal-ion shift and elevation of serum enzymes, all



signs of systemic disease.   Response to altered adrenal function has


                                                                   293

been seen in human cases, but never before demonstrated in animals.



     Injection (I.p) of 0.8 mg BeSCL/kg into rats induced a maximum



elevation of liver acid phosphatase after eight hours, and elevation



of the serum isocitric dehydrogenase, glutamic-pyruvic transaminase and
                                   324

-------
glutamic oxalacetic transaminase activities 48 hours after injection.
The serum lactic dehydrogenase was not elevated at any time.
                 295
     Clary et al.    studied the long latent period, sometimes 15 or
more years, between onset of the disease and last exposure to beryllium.
The latent period may be explained on the basis of beryllium accumula-
tion in a latent form in the lyosome.  This latent period could persist
for years until the general decline in adrenal output due to aging was
combined with adrenal stress.  Under these conditions, especially if
the adrenal reserve was also low, adrenal output may not be adequate to
meet all needs.  The lyosomal instability could result, initiating on-
set of beryllium disease.
                             7
     After i.v. injection of  Be the biological half-times were 1210,
890, 1770 and 1270 days in mice, rats, monkeys and dogs respectively,
                                                  296
compared with the 540 day value cited by the ICRP.
     Partially hepatectomized rats given 15, 30 or 60 y moles BeSO./kg
showed liver necrosis when examined 48 hours after i.v. injection.
The abolition of mitoses was observed after 20 or 16 hours in animals
treated with 30 v moles BeSO./kg 8, 12 and 22 hours after partial
            297
hepatectomy.
                        298
     Jacques and Witschi    found that beryllium did not prevent induc-
tion of aryl hydrocarbon hydroxylase by methylcholanthrene.  The
authors concluded that it is unlikely that beryllium could act as a
pulmonary cocarcinogen by interfacing with the metabolis of carcinogenic
polycyclic hydrocarbons in the lung.
     Delayed-type hypersensitivity bo beryllium was demonstrated in
guinea pigs sensitized with BeSO. by the skin test using BeSO. and Be-
                             325

-------
guinea pig albuminate, but not with beryllium hydrgencitrate or beryllium-


                     299
aurintricar-boxylate.



     Guinea pigs sensitized to beryllium by i.d. injections had skin



reaction to beryllium salts.  Sensitivity to beryllium was passively



transferable by peritoneal exudate and spleen cells.  Macrophage migration-



inhibitory factor (MIF) was produced in approximately 74% of guinea pigs



with positive skin tests.  Six out of seven chronic berylliosis patients



showed MIF production.  There was systemic involvement of the alveoli,



bronchiole muscles and spleen due to berylloisis.



     Schneider et al.    found that a nine-fold increase in the rate of



bone formation occurred in the beryllium-injected tibia during the first



four weeks.  The rate declined to normal during the last four weeks.



Pathological defects were prominent in newly-formed bone.  Some areas



were deficiently mineralized and had an increased number of resorption



spaces.


                  302 303
     Slonim et al.   '    found that the amount of beryllium concentrated



in guppies and fry was influenced by concentration of beryllium sulfate



in the surrounding solution, by fish size (inversely) and, to a lesser



extent, by exposure period; but not by fish age, solution buffering or



water hardness.  Beryllium uptake was highest in the gastrointestinal



tract and kidneys, but varied greatly among guppies exposed to the same



conditions.  Beryllium lethality in fish may not depend on amounts con-



centrated in fish, but on its effects on a particular target organ or



cellular or subcellular component.



     The variability in beryllium uptake observed in expired fish was



great, indicating that amounts absorbed in the body are not important



determinants of beryllium lethality.



                                  326

-------
     Vacher        found that contact of beryllium with skin produces



a delayed-type hyperserisitivity reaction in guinea pigs, while paren-



teral administration of beryllium produces tolerance.  The immune



response to beryllium is associated with different forms of beryllium,



i.e., immunogenic (bound to skin constituents) and tolerogenic (freely



diffusible).  Low dose tolerance was achieved by i.p. injection of a



very low dose of beryllium (4.78 yg/kg) and high dose tolerance by i.v.



injection of 400 pg/kg.  BeSO.-induced blockage of the reticuloendo-



thelial system (RES) is due to "non-diffusible" phosphate fraction



formed after i.v. injection of sulfate.  This blockage does not appear



to result from a cytotoxic effect since injected beryllium phosphate,



five times less toxic than BeSO., is active at doses 100 times lower



than toxic doses.  Blockage and cytotoxicity of beryllium do not



appear to be linked to the same mechanism.  RES blockage is thought to



occur as a result of saturation of absorption sites on phagocytic cells.



     Intravenous injection of beryllium phosphate and zymosan, before or



during development of adjuvant-induced polyarthritis in the rat,



decreased inflammatory reactions in the paw injected with adjuvant.



The observed effects appear to be related to a nonspecific activation of



the phagocytic cells with possible lyosomal changes that lead to produc-



tion of substances demonstrating the observed properties.


          307
     Vasil    found that the nucleo-protein fraction of lungs of rats



with experimental berylliosis contains six new antigens (as revealed



by immunoelectrophoresis).  Some of these antigens contain beryllium.



5.1.10  Asbestos



     The association of impaired human health with industrial exposure



to asbestos is well known.  Many hundreds of cases of asbestosis



                                327

-------
 (fibresis of the lung) and pulmonary cancer associated with mining,


milling and manufacturing of asbestos and asbestos products have been


documented.  The subject has been reviewed many times recently.


     An attempt will be made here to give a cogent story on the biologi-


cal experimentation, to discuss possible implication of air pollution of


general or point source exposure to commercial asbestos and the possible


hazard of exposure of human beings to asbestos-like fibrils that are


generated inadvertently from mining and quarrying.


     There is little evidence that light exposures such as might be


encountered in ambient air produce asbestosis or pulmonary carcinoma in


human beings.  These conditions have been consistently reported only


from heavy industrial contact with asbestos.  However, the discovery of


association of a unique tumor, mesiothelioma of the pleura of peritoneum,


with very low exposure, or after casual contact with chrysotile asbestos,


usually after a long period of latency, has raised a question about risk


due to air pollution.


     Many of these exposures had come from such things as living in


homes occupied by asbestos workers or living in vicinity of asbestos


factories and mills.  In some cases mesiothelioma developed as long as


30-40 years after any known contact.  While most of the South African

                                               314
cases were attributable to chrysotile asbestos,   mesothelioma was

                                                        315
found in the USA in workmen working solely with amosite.     In Finland


no mesothelioma is associated with the prevalent anthophyllite

         316
asbestos.


     The following summary points have been listed for the epidemiology


 r   v  *.   317
of asbestos:



                                     328

-------
      (1)  All major types of asbestos can cause lung cancer, although



there are clear differences in risk with type of fiber and nature of



exposure.  Since exposure and response to asbestos are related, there  is



no excess risk when occupational exposure has been low.



      (2)  All commercial types of asbestos except anthophyllite may



cause induction of mesothelioma.  The risk is greatest with crocidolite,



less with amosite and apparently less with chrysotile.  With the last



two, there seems to be a greater risk in manufacturing than in milling.



      (3)  There is evidence of an association of development of meso-



theliomas with air pollution near crocidolite mines and factories using



mixed fibers.  There is no excess risk from air pollution near chrysotile



and amosite mines.



      (4)  There is, a± present, no evidence of any cancer risk to the



general public from asbestos in air, water, beverages, food or in fluids



used for administration of drugs.



      (5)  Cigarette smoking enhances the risk of developing bronchogenic



cancer in workers exposed to asbestos.  No association between cigarette



smoking and development of mesothelioma has been demonstrated.



      (6)  Pleural plaques are associated with past exposure to all com-



mercial types of asbestos although not all pleural plaques are related



to asbestos.



     The amphiboles are an important group of rock-forming minerals



estimated to comprise as much as 31 of the earth's crust and associated



with both igneous and metamorphic rock.  They are divided geologically



into three sub-groups:  (1)  iron-magnesium amphiboles, (2) calcium



amphiboles and (3) alkali amphiboles.
                               329

-------
     The first sub-group contains grunerite, the commercial asbestos


form of that is termed "amosite."  Massive amounts of grunerite and



other amphiboles of non-commercial asbestos quality occur in the United



States and are mined inadvertently because of association with other


minerals that have commercial value, e.g., the Reserve Mining Company's


taconite ores from the Peter Mitchell Pit.  As a result since amphibole


ore is estimated to comprise about 3% of the earth crust, they are pre-



sent as matrices in many mining, quarrying, tunneling or other hard rock


activities where inadvertent exposure may occur both occupationally and

                                             318
environmentally in the surrounding community.


     It is possible that even agricultural processes in areas where


surface outcrops of asbestiform rock occur may pose a risk to human

       319
health.


     There is a growing body of evidence suggesting that health effects



associated with exposure to asbestos may not be unique to commercial


forms, but may also be associated with asbestos-like fibers found in



other rocks and even man-made fibers.         It is now known that the


external gross appearance of the mineral may not be the determinant.


It may be its microfibrillar nature after crushing or grinding.


     The toxicity potential of the silicate mineral may then be related


to their proclivity to form micro-crystals of a certain configuration


when crushed and ground.  It is likely, then, that a mode of toxicity



formerly thought to be associated only with asbestos may be present to


a greater or lesser degree in fibrous amphiboles of non-asbestos com-

           ,.325
mercial quality.
                                    330

-------
     Recent reports on exposure of rats to various forms of asbestos


indicate that, while there appears to be a time-dependent dose response


in tumor incidence, no significant difference was noted among various


amphibole asbestos when compared to chrysotile from both South African

                     326
and Canadian sources.


     It would appear possible that pleural and peritoneal mesothelioma


and possibly other disease of man can result from exposure to amphibole


of non-commercial asbestos quality.


     "Asbestos bodies" are prevalent in the general population of city


dwellers as is well know.  But the question of association of these


bodies with asbestos fibers is a moot point since it is known that simi-


lar fibers of other kinds can develop into these structures after resi-


dence in the tissue.  However, critical examination of 28 human lungs


from autopsy material obtained in N.Y.C. by means of appropriate E.M.

                                                      327
technique has revealed chrysotile fibers in all lungs.     Similar


studies in London have shown that chrysotile fibers are found in 80%


of the specimens of lung included in recent surveys of post-morten


material.  (See Tables 5.36 and 5.37.)


     The discovery of asbestos fibers in lungs of human beings not occu-


pationally exposed indicates potential risk to the general public.  More


surveys are needed to properly to assess this risk.  However, since


asbestos is a chemical now common only because of widespread commercial


use in the past 100 years or so and there has been a thousand-fold


increase in its use in the 20th century, the risk appears to be growing.


     Studies under way on occurrence of asbestos fibers in the ice cap


in Greenland suggest that there has been an increase in fiber deposition
                                 331

-------
since the 20th century began.  As such, the latency associated with prime



low- level lesion (mesotheliomi) and apparent increase of potential expo-



sure from air pollutants cannot be disregarded.



5.1.10.1  Biological effects of Asbestos --The principal effects of



asbestos exposure in people that are reproducible in experimental animals



include pulmonary fibrosis and carcinogenicity.



5.1.10.1.1  Fibrogenesis—Chrysotile asbestos was shown to produce


                          314
fibrosis as early as 1925.     Amosite and crocidolite have also been
shown to have this property.     It now appears that most types of asbes-



tos are fibrogenic.  Long fiber length is considered important to fibro-



genesis according to some investigators.  But others have found short



fibers to be fibrogenic.



     The exact mechanisms that initiate various asbestos lesions are



still unknown.  It is possible that the mechanisms for different lesions



(fibrosis, pulmonary, carcinoma and mesothelioma) are all different.



Fibrosis (asbestosis) is usually related to massive dose exposure and



has the shortest period of latency so that asbestos is associated with



all forms of asbestos fibers in industrial exposure.  The subject was


                  329
reviewed in 1972.



     There is some evidence that smoking increases the risk of asbesto-



sis.     Another variety of fibrosis (parietal pleural calcification)



appears to be strongly associated with industrial exposure to asbestos



and to residents in regions where asbestos is produced.  Such situations


                                                            314
have been reported in Finland from exposure to anthophyllite'   and in


                                           330
Czechoslovakia from exposure to chrysotile.
                                    332

-------
     Table 5.36.  CORRELATION OF INORGANIC FIBERS WITH ASBESTOS
                      BODIES IN LUNGS OF 3,000 CONSECUTIVE
                    AUTOPSIES IN NEW YORK CITY, 1966 TO 1968*
Percentage of cases showing asbestos bodies in
relation to occurrence of thin inorganic fibers.

             	Thin Inorganic Fibers
rtSUCSUUS
Bodies
0
1-4
5-14
15+
Total
No.
1,168
705
76
13
1,962
%
59.5
35.9
3.8
0.66
65 .,4
No.
332
424
89
20
865
%
38.3
49.0
10.3
2.3
28.8
No.
35
52
21
17
125
I
28.0
41.6
16.8
13.6
4.1
No.
16
13
6
13
48
%
33.3
27.1
12.5
27.1
1.6
Percentage of cases showing thin inorganic fibers
in relation to occurrence of asbestos bodies.
Asbestos Bodies
Thin
Inorganic
Fibers
0
1-4
5-14
15+
Total
* Correlation
0
No.
1,168
332
35
16
1,551
was done
1-4
% No.
75.3 705
21.4 424
2.3 52
1.0 13
51.7 1,194
%
59.0
35.5
4.3
1.1
39.8
by optical microscopic
5-14 15+
No.
76
89
21
6
192
study,
I No.
39.6 13
46.3 20
10.9 17
3.1 13
6.4 63
from Langer et
\
20.6
31.7
27.0
20.6
2.1
i 13
al.
   Table 5.37.  CHRYSOTILE IN 28 CASES STUDIED BY ELECTRON MICROSCOPY
                       No. of Chrysotile
         Group         Fibers + Fibrils      Cases     Male     Female
1
2
3
4
5
"Blank grids"
<9
10-50
51-99
100-200
>201
<9
4/28
11/28
6/28
4/28
3/28
--
3
5
1
4
3
--
1
6
5
0
0
--
                                  333

-------
     Most types of asbestos are fibrogenic.  The exact mechanism of

action is unclear at this time.  But there is evidence that lysosomal

                   331
injury is involved.    Long fibers stimulate more and quicker fibresis
                332
than short ones,    possibly because they are less well phagocytized

since transport begins with fibers of 20 y and increases as the fibers

become shorter.  Short fibers are engulfed by macrophage, long ones

        333
are not.

5.1.10.1.2  Pulmonary Carcinogenes is - - Exposure of animals by both inha-

lation and intra-tracheal instillation has produced pulmonary cancer in

animals.  In one study of rats given chrysotile, one-third of animals

surviving 16 months or longer had malignancies of the lung divided about

evenly between adenocarcinoma and other tumors consisting of squamous
                                                            *ZO A T 7 C
cell carcinoma and fibrosarcoma.  One mesothelioma was seen.   '     Of

interest is the authors' attribution of their tumor yield to concomitant

presence of trace metals from grinding methods since they contaminated

their asbestos with nickel, cobalt and chromium.  But other investi-

gators have produced tumors of the lung and related them to the influence

of asbestos alone.

     In a recent study of inhalation, S.P.F.  rats were exposed to three

types of amphibole asbestos (amosite, anthophyllite and crocidolite)
                                                      •TO £
and two types of chrysotiles (Canadian and Rhodesian).     The rate of

deposition and clearance of asbestos dust was studied.  Retention was

cumulative with length of exposure.  When animals were removed from

exposure, the amount of dust declined.  There appeared to be a better

retention of amphibole asbestos (amosite, crocidolite, anthophyllite)

than of chrysotiles  (Figure 5.6 and 5.7).
                                    334

-------
Weight of dutt
 In lunge (mg)
                                                     After removal
                                                     from exposure
                                                                24  Time (month•)
                       r
                     10000              20000
                    Cumulative dose (mg/m'hours)

                —Mean weight of dust in lungs of rat* in relation to dose and time.
314
         Figure 5.6.   Effects  of inhalation  of asbestos  in  rats
                                      335

-------
     3 MONTHS
                              6 MONTHS
                                                    12 MONTHS
24 MONTHS
    y>0    ?K>    IOOO


ANTHOPHYLLITE
    5OO    750    IOOO


CROCIDOUTE
_n
    XX)   ""f    'OOO

CHRYSOTILE   Conodion
    MO    /50    IOOO


CHXYSOTIIE  Rhodeiion
    500    fM    000



  Squomou! (orcinoma
                            nn
                                   7iO    IOOO
                                                          750    WOO
                             500    /yj    KOO        500    750    K)00       500    75O    KXX)
                                                                                      woo
                             500    750    IOOO        5OO    750    WOO       500    750    KXX)
                                                           li     n   M>
                             500    750    IOOO        500    750    KXX)       500    750    KXX)
                             5OO    75O    IOOO        500    75O    KXX)       500    750    KXX)
                       ffl AoVoocarcinoma      H Adenoma / odenomatotij      D Other causes

                       '—Distribution of survival times in days after first exposure.
         Figure 5.7.   Effects  of  inhalation of asbestos in rats
                                                                                 314
                                             336

-------
     Tumor induction was found in all forms of asbestos.  No tumors



occurred until 300 days or more after exposure began.  More tumors



occurred with 12 months; exposure than with six months exposure.  But



there was no difference; between 12 months and two years of exposure.



Of interest is the indication in this report that mesothelioma occurs



in two amphiboles (amosite and crocidolite) with only one day's expo-



sure to asbestos underscoring potential danger for brief exposure by



people.



     Tumor frequency relative to treatment is summarized in Table 5.36.



     Significant findings in the above study besides successful tumor



induction by inhalation routes include:  (1) difference in retention



rate for amphibole compared to chrysotile and (2) were the approxi-



mate equality in the ability of all asbestos tested to induce pulmonary



and mesothelial tumors.



5.1.10.1.3  Mesothelial Tumor Induction--Mesothelial tumor induction in



experimental animals has been previously mentioned.  Mesothelial tumors



are readily induced by all forms of asbestos via the inhalation route



(see Table 5.38) even though most experin. ats use intrapleural injection .



     A report in 1962 said that crocidolite and chrysotile produced



mensothelial tumors in mammals with intrapleural innoculation of the



fibers.     Since then, many reports have been published on other forms



of asbestos and their effects on mice, rats, fowl and hamsters.  Experi-



ments suggest that the fibrous nature of the material may have a bearing



on the tumorogenicity and a hypothesis could be advanced that carcino-



genicity of the material is realated to the ability of its fibers to



react with cell membranes without destroying the cells.  Also, the
                                337

-------
presence of trace metals or organics on fibers were not determinates.



Particle size and a relationship between the smallness of the fiber and



the number of mesotheliomas was more obvious.   '



     Other experiments promoted tumors (sarcomas) of mesothelial tissues



through use of non-asbestos fibers such as fiber glass and aluminum



oxide (AL?0,) when placed on a fiberglass mesh and implanted on the
         I* O


pleural surfaces of rats.  On the basis of this work, the theory was



advanced that a particular configuration of the crystal or fiber was



the determinant for tumorogenesis, i.e., diameters of 5 ym or less and



lengths of 20 ym or more.  However, other studies made with Canadian



chrysotile having extremely small fibers produced many mesotheliomas in


  *  320
rats.



     But the significance of these reports is somewhat in question



because the tumors induced were sarcomas rather than classical meso-



theliomas that are tumors of mesenchymal and epithelial characteristics.



The histogenesis of pleural and peritoneal tumors is complex.  The



earliest neo-plastic response often consists of small pedunculated



nodules with a central core of reticulin surrounded by a surface of



non-differentiate connective tissue.  These may spread diffusely over



the mesothelial surface as a sheet of connective tissue cells with



epithelial cells on the surface.  It is assumed that these tumors come



from undifferentiated mesenchymal cells in the submesothelial tissue



that become differentiated, giving rise to epithelial cells on the



surface and spindle-shaped connective tissue cells in the depths.



5.1.10.1.4  Intratracheal Studies--Intra-tracheal studies have been



promoted as a convenient method to test the potential of a chemical to
                                   338

-------
              •p  I
              •H  O
              5  CO
                  6  o>
                               r-l O O O O  i— 1         OOOi-HrH(Nl
                                                                                    rH i— ( O CM O
                                                                                                                   CD O O
WH
O
&.
oo
to

LO

 0)
&
          4-1
           O

           0)
                  S3
        u
        rt
        u
                  o  o
                  c  s
                  4) T-I
                     d
                     U
        co
        o
                    I
       s
                  bO
4H  oj *
 O     r^
    CO CO
  •  P -H
 O  nj 5*
2  rH
                               OOOOvOO
                                                         OOi— li— IvOOO
                                 rH       rH (XI


                              O rH O \O (XI CTl
                                                                                                                   O O  rH rH
                                                   to

                                                   vO
                               O O i— 1  i— 1 tO LO
                                                         O O r- 1 •* K) OO
                                                                                    i— 1  i— 1 O to CNI
                                               oo       o o i— 1 \o LO rsi        ofvirsi^)-LOto
                                                                          r— 1                         i— 1
                              to r-- i— i  LO
                                               tO
                                                                   CMrHLO
                                                         "3-tOrHrslr-lr}-
                                                                                                     CVJ
                                                                                                                      to
                                                                                                                      tO O
                                                                                                                   O O CM tO tO  OO
                                                                                                                   O LO (Nl rH
                                                                                                                                    O
                                                                                                                                    (X]
                                                                                                                   rH OO LO rH CD  LO
                                                                                                                   (Nl -^ 1^-- tO rH  t^
                                                                                                                   •^f- tO rH (Nl (XI  tO
                     e
                     3
                     CO
                     o
                    UU
                                                             co  to  oo to
^£r
                    efl
                    p
              •H
              (/)
              O
                                  tO
                                                      p
                                                      r-*
                                                      ^7
                                                         rH tO
                                                                                            CO  CO CO
                                                                    0)
                                                                    4-i
 O  cd O  O O
T3 T3 S  S E
•H
 (J i—I tO v£> 1X1
 O            rH
 nj

 O
H
                                                                                                                       10  CO CO  10
                                                                                                      rt
                                                                                                                       crj
                                                                                                                       +-'
                                                                                                                       O
                                                      !/)
                                                      X
                                                      rH
                                                           339

-------
                 o o o o o o
                                             o  o o  o
                 o o o vo LO
                                             0000
                     rH rH r-J (N) \O




                 rH K> t'O r-. LT) CT>
                                             o  o o  o
                 O tNl K) *d- rH O
                                             CD O O O
                                                                   §
                                                                   0
                     i— 1 (/)(/)
                      p)  pj  p;
                                    03
                                                        \O
           U ^
                                                     10
                                          rH  CO  Q  O O
                                           O "3  E  E H

                                          P rH fO ^t

                                           g        7
                                                                   (A  0

                                                                   fre
                                                                  O -iH
                                                                  O  |S
                                                                  tO


                                                                  •P  t/5


                                                                  Co  f!
                                                                  0 +3


                                                                      0
                                                                  -P  M
                                                                  CO  CO1



                                                                  0 p
                                                                   3  rH
                                                                   (/) .Q


                                                                  -6.3
0
                                                                  *  +
                                                           340

-------
induce pulmonary neoplasms and, in particular, to show response to a



co-factor in conjunction with a chemical carcinogen.  Comparative



studies were made using chrysotile and intratrachel inhalation and


                       337
intrapleural injection.



     Intra-tracheal Injection gives a dose-response according to the



frequency of injections.  The induction of BaP was required to elicit



tumors.  (Twenty-nine percent of the rats had tumors.)



     Inhalation for 13.5 months on a schedule of two hours a day, five



days a week, at 230 mg/m  produced pre-cancerous lesions in 20% of the



rats on chrysotile alone, 59% with BaP added and 38% with tobacco smoke



added.  A total of 29% of the rats had tumors.  Carcinoma of the lungs



occurred only in the chrysotile BaP group.  Previous experiments


                                                             338
demonstrated a slowing of the excretion of BaP with asbestos.



     Intrapleural Administ r ation was done by injection of chrysotile



three times per month into the right pleural cavity (20 mg fibers in



0.5 ml saline).  Almost all the rats experienced local proliferation



of the mesothelium that was presumably pre-neoplastic.  Mesothelioma



appeared after eight months and increased with time:  13 of 47 rats



at 8-17 months and 15 of 21 between 18 and 24 months.  Forty-six per-



cent of all rats showed mesotheliomas.



     As mentioned previously, qualitative differences in fiber size and



shape appear to determine induction of mesotheliomas.  Carcinogenesis



appears to be unrelated to trace metal content or presence of organic



matter on fibers.  The possible induction of tumors by material other



than commercial asbestos has also been considered.  And experimental



data suggest that a number of inorganic chrystals below 5 urn in diameter
                               341

-------
may be equally effective in inducing these tumors.  The implication of


these findings that small, fine particles are the effective component


for these tumors is important for industrial and community air pollution


control.


5.1.10.1.5  Synergistic Effects--Reference has been made earlier to the


remarkable association of asbestos and smoking in promoting bronchio-


genic carcinoma in exposed workers in the asbestos industry.  Animal


exposure by inhalation to chrysotile for 16 months has produced up to


33% pulmonary tumor adenocarcinomos, fibro-sarcomas, squamous cell car-

                            334
cinoma and one mesothelioma.     The carcinogens responsible for these


were thought to be contaminated by metallic substances from hammer


milling.


     The same author reported similar findings in a second inhalation

           335
experiment.     The role of BaP in promoting lung tumors with exposure


of animals to various forms of asbestos is known.  But the evidence for

                                                 337,338
such effect is at present mainly for chrystotile.         The other


forms of asbestos have not been sufficiently studied in connection with

            333
lung tumors.


     Contamination by organics including polycyctic hydrocarbons because


of geological and industrial factors has also been suggested as a causa-


tive factor in pulmonary carcinoma.  But the use of fibers after


extensive extraction and purification of the material have shown no

                          339
difference in this regard.


     Evidence now available suggests that either:  (1) some direct action


of the asbestos fiber or interaction with naturally occurring co-factors


is responsible for tumorigenesis of the lung in experimental exposure of
                                342

-------
animals; (2) the addition of BaP or tobacco smoke enhances tumorigenesis



with chiystotile; or (3) all forms of commercial asbestos are more or



less equally carcinogenic.



5.1.10.1.6  In-Vitro Effects- -Much about the basic biological effect of



asbestos can be learned from studies in vitro.  This work has been



reviewed in detail in reference    and will only be briefly summarized



here.



     Among actions reported for asbestos are many similar to silica.



These may be listed as follows:



     (1.)  Lysis of erythrocytes.



     (2.)  Cytotoxicity on pulmonary macrophages.



     (3.)  Stimulation of collagen synthesis.



The mechanisms involved are known in many cases and this information may



eventually have great value for basic understanding of lesions produced



by asbestos, asbestos-like minerals and airborne particles in general.



However, their detailed consideration is beyond the scope of this report.



5.2  MATERIALS



5.2.1  Nitrogen Oxide



     The damaging effects of atmospheric nitrogen oxides on materials



are mainly of concern to the textile industry.  Nitrogen dioxide (NO,,)



is the troublesome pollutant; nitric oxide (NO) appears to be harmless.



     Atmospheric N0? can react with a number of important textile dyes



and produce noticeable color change or fading.  This fading problem has



been a problem for the textile industry for decades.  A more recent



problem concerns yellow discoloration of un-dyed-white and pastel-colored



fabrics.  Chemists have traced this yellowing to the action of NO  on
                                     343

-------
certain additives applied to fabrics to enhance their marketing proper-


ties.  In the United States, annual gross damage to materials by NCL is


estimated to be three-quarters-of-a-billion dollars.


     These cause-effect relationships have been recognized for years.


What is lacking, however, is comprehensive dose-response information.


Such information would help  to  set secondary air quality standards and


make cost-benefit studies.


5.2.1.1  Field Studies--Sixty-seven dye-fabric combinations were exposed


to different types of urban and rural environments with no sunlight


involved.  Fading was observed in 43 fabrics.  The magnitude of fading


was greater in urban areas than in corresponding rural areas, but varied


among urban areas.  It was impossible to specifically attribute fading


to NCL since fading might have been caused by other pollutants as well.

                                                               340
However, NCL was a significant factor for seven of the fabrics.


5.2.1.2  Laboratory Studies--Controlled environment (no light) chamber


studies were conducted to assess individual effects of SCL, NCL and


ozone on 20 selected dye-fabric combinations.  NCL was the most potent


pollutant, producing the greatest amount of fading on 13 fabrics.

                                                                  341
Relative humidity was a significant factor in accelerating fading.


     Three randomly selected drapery fabrics were exposed to controlled


environments (with simulated sunlight) containing three pollutants


(SCL, NCL and ozone).  Direct and interaction effects of NCL caused


significant fading in one of the fabrics.  A relationship was developed


expressing the amount of fading as a function of time, NCL concentra-


tion and moisture content of the air.  A relationship also was developed


for the percentage life lost as a function of NCL concentration and

                         .334
moisture content of the air.
                                 344

-------
     Exposures in a controlled environment chamber showed that NO- had



no damaging effect on weathering steel, galvanized (zinc coated) steel,



stressed high-strength aluminum alloy, oil base house paint, acrylic or



vinyl coil coatings, rubber tire sidewalls, marble and concrete.



5.2.2  Sulfur Dioxide (S0?)



     S02 accelerates the deterioration of a wide variety of materials



as has been recognized for many decades.  Both field and laboratory



studies have shown that SCL-polluted environments (1) increase corrosion



rates of most metals, especially iron, steel and zinc; (2) damage a num-



ber of building materials such as limestone, marble, roofing slate and



mortar; (3) discolor and physically deteriorate statuary and other works



of art; (4) increase the erosion rates of oil-base paints; (5) degrade



textile fibers, especially cotton and nylon and fade dyed fabrics; (6)



embrittle and discolor paper and (7) weaken leather.



     Although these cause-effect relationships are well known, the



important need today is for comprehensive information on dose-response



relationships.  Such information is necessary to set secondary air-



quality standards and for economists to make cost-benefit studies.



     With this in mind, EPA has conducted both field and laboratory



studies.  The laboratory studies have included controlled environment



exposures using specially designed chambers that were scheduled to be



used in FY-75 to develop dose-response relationships for economically



vulnerable meterials.



5.2.2.1  Field Studies--Ambient levels of airborne S02 were major fac-



tors in control of rates of corrosion for zinc (galvanized steel) .  A
                                    345

-------
simple linear function of average S02 concentration and averaged rela-
tive humidity account for 92% of the variability in average zinc cor-
rosion rates.  The useful life of galvanized steel at various average
                                                                   342
annual S02 concentrations and relative humidities can be predicted.
     Ambient levels of airborne S02 were a major factor in accelerating
corrosion rates for steel.  Equations were developed for four types of
steel relating depth of corrosion to mean SCL levels and other fac-
     343,344
tors.
     Paints containing calcium carbonate extender pigments were found to
                                                          345
be particularly susceptible to attack by SO- environments.
5.2.2.2  Laboratory Studies--Direct and interaction effects of airborne
SCL accelerate corrosion rates of weathering steel, galvanized (zinc
coated) steel, stressed high strength aluminum alloy and erosion rates
                         346
of oil-base house paints.     Preliminary damage-predictive equations
were developed for weathering steel, galvanized steel, stressed aluminum
alloy and oil-base house paint, based on laboratory data and known physi-
                               346
cal and chemical relationships.
     Airborne SO- does not damage acrylic or vinyl coil (factory applied)
coatings, weaken rayon sidewall reinforcing cord in radial rubber tires
                                                             346
or produce fading in three randomly selected drapery fabrics.
     The effects of airborne SO- on marble, latex house paint and con-
                        346
crete were inconclusive.
5.::. 3  Ozone (07)
     Damage by atmospheric ozone occurs mainly to two classes of mate-
rials:  elastomers and textile dyes.  Not all elastomers, however, are
subject to ozone damage.  Synthetic elastomers with saturated chemical
                                346

-------
structures have inherent ozone resistance.  These elastomers are rela-



tively expensive and account for only a fraction of the market.  The



great bulk of the elastomers, including natural rubber and synthetic



polymers of styrere-butadiene, polybutadiene and polyisoprene, contain



double bonds that are prone to oxidation and therefore sensitive to



ozone attack.



     Researchers have developed anti-ozonant additives capable of pro-



tecting elastomers from ozone attack.  The protection, however, is not



permanent.  But for certain items, such as tires, it usually last for



the life of the item.



     Some important textile dyes fade when exposed to ozone.  Certain



blue dyes used on acetate and polyester/cotton fabrics and nylon car-



pets have been particularly troublesome.  To prevent or mitigate fad-



ing by ozone, the textile industry must use more resistant dyes and/or



inhibitors.  But these increase the cost of finished goods.



5.2.3.1  Field Studies--Sixty-seven dye-fabric combinations were exposed



to different types of urban and rural environments in the absence of



sunlight.  Two-thirds of the fabrics showed appreciable fading.  The



fabrics generally faded significantly more at urban sites than at cor-



responding rural sites.  Apparently, air pollutants were responsible for



the observed fading.  It was impossible, however, to separate the effects



of individual pollutants because they were mixed with effects of other


           347
pollutants.



     A number of paint types were exposed to different environments.



Oil-base house paint was the most sensitive.  The high smog environment



of Los Angeles produced the most damage.  It was not possible, however,
                                    347

-------
to identify what pollutant or combination of pollutants was respon-



sible.



5.2.3.2  Laboratory Studies--In controlled environment (no light) cham-



ber studies, low ozone levels (0.05 ppm) produced visible fading in



half of 20 dye-fabric combinations and high ozone levels (0.5 ppm) in


                          348
two-thirds of the fabrics.



     In controlled environment (including simulated sunlight) chamber



studies of different types of paint, high ozone levels (1.0 ppm) damaged



oil-base house paint, but low ozone levels (0.1 ppm) did not.



     In more sophisticated environmental (including simulated sunlight)



chamber studies of different types of paint, ozone levels up to 0.5 ppm



did not significantly damage any of the paint types.  Ozone produced



small cracks in rubber tire sidewalls.  But their rate of penetration


                                                            349
was not enough to significantly reduce the life of the tire.



5.3  WEATHER, VISIBILITY AND CLIMATE



5.3.1  Air Qualtiy Trends Analysis



     The importance of meteorology in interpretation of trends has been



recognized in the first annual report of EPA's Monitoring and Data



Analysis Division.  An a-typical pattern of significant upward trends in



total suspended particulate (TSP) was found over the Western U.S. for



1968-71.  This trend is apparently related to a decrease in rainfall



over the same period.



     TSP monitors are affected by contributions of particulate matter



from all sources, including natural dustiness.  There appears to be an



increase in fugitive dust emission (i.e., agricultural, upward roads,



construction, etc.) during drier periods.
                              348

-------
5.3.2  Atmospheric Turbidity



     Turbidity observations are made only when the line of sight to the



sun is free of cloud.  The measuring instrument used is called a sun-



photometer.  It is designed to measure the amount of light received



at wavelengths practically unaffected by water vapor absorption.  Mea-



surements are regularly made' at 80 stations, 50 of which are in the



United States.



     The Meteorology Laboratory provides the necessary number of instru-



ments and periodically recalibrates them.  Although the longest turbidity



record is only from 1961, it. appears that certain urban areas (Youngstown



and New York City) may have atmospheres that are less turbid now than in



the mid-60's.  The opposite trend may be occurring in some rural areas.



5.3.3  Visibility



     Reduction in visibility because of air pollution is, in most cases,



caused by scattering and absorption by aerosols.  Major progress has



been made in development of techniques to determine light scattering and



light absorption and to relate these parameters to meteorological range



and prevailing visibility or visual range.



     Light scattering, as measured by the integrating nephelometer, is



highly correlated with sub-micron aerosol volume measured by in-situ



techniques and reasonably well-correlated with sub-micron and total



aerosol mass.  Extensive tests in three California cities of relation-



ships between prevailing visibility, light scattering and aerosol mass



concentration indicate that light scattering, as measured by the inte-



grating nephelometer, is a good predictor of prevailing visibility.
                                  349

-------
     Progress has been made  in determining the contribution of various
 aerosol sources to visibility reduction.  Because of  their hygroscopic
 or deliquescent nature, secondary aerosols such as  (NH.)?SO., NH.HSO.,
 M-LNCL and oxidized organic  compounds grow as the relative humidity
 increases and cause more visibility reduction than  their dry weight
 • j-  <-   352
 indicates.
 5.4  ECOLOGICAL
 5.4.1  Introduction
     The over all effect of man's activities on terrestrial vegetation
 and ecosystems and cumulative effects of his activities on estuaries,
 coastal areas and the biology of oceans  are major  ecological concerns.
 Studies dealing with effects of toxic substances in the biosphere have
generally focused on toxic substance effects on individual plants and
 animals rather than total ecosystems.
     The studies usually deal with specific pollutants rather than
 interactions between and among pollutants.  This approach is used with
 the hope that effective control of specific pollutants and determination
 of costs of controlling them would be possible, particularly in agri-
 culture.  This approach is also used because it is  more difficult despite
 its importance to determine  the impact of pollutants on ecosystems in
 particular and the biosphere in general.
     Dr. G.  M. Woodwell,    however, has shown that disturbances to
 natural (i.e., non-anthropogenic) ecosystems from any cause produce
 changes that are similar and predictable.  The parameters most changed
 by pollution are diversity, structure and ratio of photosynthesis to
 repiration.
                                350

-------
     Pollution first affects an ecosystem by changing its diversity.



Sensitive flora and fauna are eliminated.  This results in shorter



food chains, fewer symbiotic relationships and less stability.  The



species affected are those with low reproductive rates, carnivores at


                                                                     353
the top of food chains and species with the most complex life cycles.



     The structure of an ecosystem is affected next.  The trend is toward



plants of lesser stature.  Taller plants are eliminated first.  Trees are



replaced by shrubs, shrubs by herbs, herbs by low-growing plants and in



some instances by mosses and lichens.



     The ratio of photosynthesis to respiration is involved in structural



change.  Chronic disturbance often damages the capability of plants to



carry on photosynthesis while not appreciably reducing the total amount



of respiration.  That makes plants use more energy than they produce.



Large plants with large respiration requirements are more vulnerable



than small plants.



     A reduction in nutrients is also a result of structural change in



an ecosystem.  A pool of nutrients is released by the decay of larger



plants.  These nutrients cannot be retained in the soil or recycled.



They are lost to aquatic ecosystems where they promote cultural eutro-



phication of rivers and lakes.  This process also points out the link


                                           354
between terrestrial and aquatic ecosystems.



     Crop agriculture involves complete replacement of a natural eco-



system with a highly simplified ecosystem composed of plants and ani-



mals wholly dependent on care and protection by people and requiring



energy inputs.  Historically, the continuing development of agriculture



has decreased diversity and increased artificiality.
                                   351

-------
     Since World War II, traditional farming with small fields growing


a variety of crops and interspersed with pasture and hedgerows or fence-


rows has been replaced by monocultural systems that are highly vulnerable


to pollution, pests and diseases because of low genetic diversity.


     Standards set for various substances are based primarily on effects


these pollutants have on man and man-made ecosystems.  But this is only


one aspect of the pollution problem.  Not considered is the threat to


maintenance of a biosphere suitable for life as we know it.  And it does


not underscore man's dependence of the integrity of diverse earth eco-


systems:  those living systems that probably built and now maintain the


biosphere.


     While toxic substances that are mutagenic to man, either through


inhalation or through the food chain, are of great importance, those


pollutants that affect components of earth's biota other than man present


a greater problem.  Effects of pollutants are often chronic and cumula-


tive over time rather than short-lived.  And the effects such pollutants


have on structure, biological diversity and mineral cycling in ecosystems

             353
is not known.


     Standards that were set have only superficially attempted to assess


effects of those levels on ecosystems.  In addition, they have only


dealt with pollutant interactions in a cursory way.  Little is known


about effects of pollutant interactions except for substances involved


in photochemical oxidant formation and with nitrogen oxides, ozone and


hydrocarbons.


     The National Primary and Secondary Standards are the same except for


sulfur oxides and particulate matter.
                               352

-------
5.4.1.1  Carbon Monoxide--The effects of carbon monoxide in the soil and
                                                             357
in aquatic ecosystems still need clarification.  Inman et al.    found
that soil takes up CO in large quantities.  But the changes brought
about in soil by CO up-take by microorganisms and subsequent production
                                       358
of methane have only been touched upon.
     Plants in general are relatively insensitive to carbon monoxide at
low concentrations toxic to animals.
5.4.1.2  Nitrogen Oxides--The primary importance of nitrogen oxides
involves their participation in photochemical reactions with formation
of peroxyacyl nitrates (PAN).  The photochemical reactions that produce
                                               359
oxidants have not yet been thoroughly examined.
     Evidence of damage to plants from direct exposure to NO  in the
                                                            J\.
atmosphere is usually confined to thproximity of specific industrial
sources.  For example, damage from high ambient levels of nitrogen
dioxide (NO-) are observed near nitric acid plants.  Direct damage by
nitric oxide (NO) and other NO  components or derivatives have not been
                              .A.
delineated in the field because effects on vegetation from the oxides
                                           359
of nitrogen per se are difficult to assess.
     Most research delineating the effects of NO  en vegetation was done
                                                J\.
in the laboratory.
     The biochemical-enzymatic mechanisms by which oxides of nitrogen
directly injure plants is not understood.
     No attempts have been made to determine effect of nitrogen oxide
emissions in formation of acid rainfall.
5.4.1.3  Photochemical Oxidants--Photochemical oxidants are products of
sunlight-initiated chemical reactions in the atmosphere that involve
                                353

-------
hydrocarbons and oxides of nitrogen.  Those that have been measured in the



atmosphere include ozone, peroxyacyl nitrates and nitrogen dioxide.  The



foregoing shows that photochemical oxidants are a variable mixture of com-



pounds.  Each component of this mixture may have a different degree of



phytotoxicity so that the composition of the mixture determines the extent



of the hazard.356



     Concentration of total oxidants may vary during the day.  While the



one-hour maximum may not be exceeded, chronic injury to vegetation may



occur because of long-term average concentrations.



     The presence of other pollutants and changes in environmental con-



ditions may affect tolerance of plants to photochemical oxidants.



     Little is known about the tolerance of plants under field condi-



tions.  Selection of a genetically uniform susceptible crop and plant-



ing it over large areas could end in large crop losses.



     Studies are currently under way to determine effects of photochemi-



cal oxidants on the San Fernardino Forest ecosystem.



     The primary standard of 160 yg/m  (0.08 ppm) for a one-hour average



may not protect all vegetation from adverse effects.  A secondary stan-



dard should recognize that both concentrations and duration of exposure



are important in determining effects on vegetation and ecosystems.



Various factors, e.g., soil and humidity, that affect plant sensitivity



have not been well-documented.



5.4.1.4  Hydrocarbons--Ethylene is the chief hydrocarbon gas that pro-



duces adverse effects at known ambient concentrations.  Plants are more


                                                      361
sensitive to ethylene than to other hydrocarbon gases.     Acetylene,



propylene and vinyl chloride all cause phyto-toxicity symptoms resembl-



ing those of ethylene.  But 60 to 500 times the ethylene concentration




                                    354

-------
is required to produce comparable effects.  Ranking according to toxi-



city is:  ethylene>acetylene>propylene>vinyl chloride.



     The effects of poly-nuclear aromatic hydrocarbons on higher plants



have not been adequately assessed.  There is some indication that the



aromatic hydrocarbons act as plant hormones.



     Studies have shown that gaseous hydrocarbons can be metabolized by



micro-organisms.     High traffic areas with high amounts of auto



exhaust have a soil microflora different from that in low traffic areas.



Studies have also shown that natural gas leaking into the soil, because



of its utilization by micro-organisms, can stimulate growth in that


                                                             364
soil.  Gaseous hydrocarbons, then, can affect soil fertility.



     Effects of these changes on the growth of higher plants and eco-



systems in general have not been assessed.  In addition, the effects of



hydrocarbons on the microflora of plant surfaces have not been assessed.



Changes in microflora of leaf, bark or stem could increase disease



susceptibility.



     Reactions between atmospheric hydrocarbons and sulfur oxides have



not been adequately assessed.



5.4.1.5  Sulfur Oxides--The Secondary Standard of 60 yg/m  (0.1 ppm)



annual arithmetic mean and the 24-hour guideline of 260 yg/m  (0.10 ppm)



for a 24-hour average were withdrawn in September, 1973.  The present


                     3

standard of 1300 pg/m  (0.5 ppm) for a three-hour average may not pro-



tect all vegetation against adverse effects as the standard is close to



exposure levels that pose a risk of detrimental economic effects and



discernible aesthetic injury to susceptible species of plants."
                                355

-------
     Chronic effects of sulfur dioxide and their interaction with other



pollutants such as ozone, nitrogen oxides and hydrocarbons require



further study to consider for the standard.  Since environmental condi-



tions not only affect the susceptibility of plants, but effect their



distribution, standards that are adequate for one geographic region may



not be adequate for another.



     The present standard is probably not adequate to control long-term



low-level exposure to sulfur dioxide, particularly as it relates to



chronic toxicity of sulfate accumulation in plant foliage.  The annual



average was an index of the concentration of sulfur dioxide and the



fraction of time that any measurable concentration was present.



     Of increasing concern, but not dealt with by the standards, is the



role of sulfur dioxide in acidic precipitation.  Long-term average



annual concentrations play an important role in the nature and severity



of this problem.



     The role of sulfur dioxide in changing the pH of plant surfaces has



not been studied in the U.S.  Studies in Sweden have indicated reduction



in growth of pine and spruce trees in areas of high S0~ emissions.  The



increased susceptibility to disease of plants so affected or the role of



SCL in changing ecosystem structure    have not been studied to any



extent.



5.4.1.6  Sulfates/Sulfuric Acid Aerosols--The sulfates that affect vege-



tation are formed by chemical reactivity of SCL as far as is known.



Sulfur dioxide reacting with moisture on the leaf, bark or stem surfaces



produces sulfuric acid and causes leaf damage and pH change in the bark.



Sulfuric acid mist, acid aerosols, acid rain or sulfate-bearing particu-


                                                       366
lates that dissolve in the dew produce similar effects.



                                    356

-------
     Sulfates are usually considered beneficial to soil and soil orga-



nisms except in those cases where they are attached to specific metallic



ions.  Changes in soil pH because of acidic precipitation may result in



soil reactions detrimental to plants and soil-living decomposer orga-



nisms.  Soils that are acidic or poorly buffered are particularly



susceptible.



     Sulfate that contributes to formation of acid rain is usually attri-



buted to S07 in the atmosphere.  The interaction of S07 and nitrogen
           tit                                          Lt


oxides, however, may also be involved.



     Studies by Likens, Borman and their co-workers deal with effects of

                                             "ZfL *T

acid rainfall on deciduous forest ecosystems.     Neither nitrogen oxide



nor sulfur oxide standards have dealt with this problem.



     Much overlap exists between the effects of SCL and sulfates.



5.4.1.7  Nitrates--The movement of nitrogen through the atmosphere uses



three separate cycles:  the N20 cycle, the NH, cycle, the NH, cycle and



the NO  cycle.  The NO  (nitrogen oxides) cycle has the greatest effect
      X               X


on plant communities and accordingly, other organisms that reside in



these communities.



     NO and N0~ from urban sources may move into the atmosphere where



reactions with 0, and water produce HNO, vapor and eventually nitrate-



salt aerosols.  Rain or dry particulate deposition eventually brings

                                                           'TfiO

nitrate down  to the earth's surface.  Robinson and Robbins    estimate



that the amount of nitrates brought down is 462 x 10  tons per year.



     The greatest amount of nitrate fallout occurs over oceans.



Nitrate fallout of the above-mentioned type has not been directly asso-



ciated with increasing acidity of rainfall in the Northwestern United



States.367



                                 357

-------
     The most significant and widespread effects of nitrogen oxides are



 indirect effects that occur because of involvement of nitrogen oxides in



 the formation of photochemical oxidants.  The nitrogen oxides from com-



 bustion processes  may enter into photochemical reactions and form



 peroxyacyl nitrates instead of moving off into the atmosphere in urban



 areas.  The formation of these compounds is discussed in greater detail


                                                                      369
 in the publication, "Air Quality Criteria for Photochemical Oxidants."



     The nitrogen oxide standard should help cut down formation of NCL



 and subsequent formation of nitrate aerosols through oxidation.  But



 reduction of atmospheric nitrates will not influence the problem of ter-



 restrial nitrate runoff and euthrophication that results from excess



 fertilizer application and barnyard runoff.



 5.4.1.8  Beryllium--Beryllium, like many trace elements, produces a varied



 reaction in plants.  Both beneficial and detrimental effects of beryllium


                                             370
 on plant growth processes have been reported.



     Studies show that be-yllium in the soil can be taken in and accumu-



 lated by plant roots.  Severe stunting of bush beans resulted when they



were grown in nutrient concentrations of 0.5, 1.0, 2.0, 3.0 or 5.0 ppm.



Abnormal symptoms were progressively more severe as beryllium concentra-


                370
 tions increased.



     Injury to higher plants from beryllium might occur if high levels



 of beryllium were dispersed in soil or ground water where plant roots



 could make contact.  Beryllium does not seem to inhibit formation and


                         370
 functions of chlorophyll.



     The present standard that prevents emission of high levels of beryl-



 lium should be adequate for protecting plants.
                                    358

-------
5.4.1.9  Mercury--In the Federal Register, Vol.  38, No. 66 - Friday,
April 6, 1973 p. 8825, the following statement is made:  "Current data
on the environmental transport of mercury do not permit clear assessment
of the effect of mercury emissions into the atmosphere on the mercury
content in the aquatic and terrestrial environments."  This statement
still holds true.  The standard set was intended to protect people from
effects of inhaled mercury.
5.4.1.10  Asbestos--Exposure of wild animals to asbestos is not likely
unless they are in the vicinity of a man-made source.  Then, the stan-
dards that protect man should protect them.
     Damage to plants is not likely unless the leaves of plants become
coated with asbestos to the point where photosynthesis cannot occur.
                                359

-------
                                   5.5  REFERENCES
 1.  Shy, C. M. et al.  The Chattanooga School Children Study:  Effects
     of Community Exposure to Nitrogen Dioxides.  Incidence of Acute
     Respiratory Illness.  J. Air Pollution Control Assoc.  20(9):582-
     588, September, 1970.

 2.  Shy, C. M. et al.  The Chattanooga School Children Study:  Effects
     of Community Exposure to Nitrogen Dioxides.  I.  Methods, Descrip-
     tion of Pollutant Exposure and Results of Ventilatory Function
     Testing.  J. Air Pollution Control Assoc.  2£(8):539-545, August,
     1970.

 3.  Pearlman, M. E. et al.  Nitrogen Dioxide and Lower Respiratory
     Illness.  Pediatrics  £7(2):391-398, February, 1971.

 4.  Chattanooga, Tennessee - Rossville, Georgia Interstate Air Quality
     Study 1967-1968.  U.S. Public Health Service National Air Pollu-
     tion Control Administration Publication No. APTD-0583, Durham,
     N.C., October, 1970.

 5.  Shy, C. M., L. Niemeyer, L.  Truppi and T. English.  Re-evaluation
     of the Chattanooga School Children Studies and the Health Criteria
     for N0? Exposure.  In-house technical report, Environmental
     Research Center, EPA.  Research Triangle Park, N.C.  March, 1973.

 6.  Galke, W. and D. House.  Prevalence of Chronic Respiratory Disease
     Symptoms in Chattanooga, Tennessee. 1971.  (Unpublished Data).

 7.  Hammer, D., and F. Miller.  Lower Respiratory Disease and Nitrogen
     Dioxide Retrospective Survey in Chattanooga, Tennessee.  1971.
     (Unpublished Data).

 8.  Riggan, W. et al.  Acute Respiratory Disease in Chattanooga, Tenne-
     ssee.  1972-1973.  (Unpublished Data).

 9.  Prevalence of Chronic Respiratory Disease Symptoms in the Los
     Angeles Basin.  1972.  (Unpublished Data).

10.  French, J. G., V. Hasselblad, R. Johnson.  Aggravation of Asthma by
     Air Pollutants.  1971-72 New York-New Jersey Metropolitan  Communi-
     ties .  (Unpublished Data).

11.  French, J. G., V. Hasselblad, R. J. Johnson.  A Study of Asthmatics
     in Two Southeast Communities  1971-72.  (Unpublished Data).

12,  Von Nieding, G. D., H. Krekler, R. Tuchs, H. M. Wagner, and K.
     Koppenhagen.  Studies of the Effects of NCL on Lung Function:
     Influence on Diffusion, Perfusion and Ventilation in the Lungs.
     Int. Arch. Arbeitsmed.  31:61-72.  1973.
                                    360

-------
REFERENCES (continued)


13.  Kennedy, M. C. S.   Nitrous Fume and Coal-Miners with Emphysema.
     Ann. Occup. Hyg.   15:285-300.   Pergamon Press,  1972.

14.  Report of the Expert Committee on Air Quality Criteria for Oxides
     of Nitrogen and Photochemical  Oxidants (Japan).  Central Council
     for Control of Environmental Pollution, Sub Council  for Air Pollu-
     tion Control.  June 20,  1972.

15.  Speizer, F. E. and B.  G.  Ferris, Jr.   Exposure  to Automobile
     Exhaust.  I.  Prevalence of Respiratory Symptoms and Disease.
     Arch. Environ. Health.   26_:313-318.  June,  1973.

16.  Speizer, F. E. and B.  G.  Ferris, Jr.   Exposure  to Automobile Exhaust.
     II.  Pulmonary Function  Measurements.  Arch. Environ.  Health.   26:
     325-329.  June, 1973.

17.  Burgess, W., L. DiBerardinis and F. E. Speizer.  Exposure to Automo-
     bile Exhaust.  III.  An  Environmental Assessment. Arch. Environ.
     Health.   26;325-329.

18.  Sprey, P.  Health  Effects of Air Pollutants and Their Interrela-
     tionships Contract No. 68-01-0471, Submitted to the  Environmental
     Protection Agency, Washington, D.C.  September, 1973.

19.  Air Quality Criteria for Nitrogen Oxides.   NATO/CCMS Document  No.
     15, June, 1973.

20.  Air Quality and Automobile Emissions Control.  MAS Documents Nos.
     93-23 and 24.  September, 1974.

21.  Adamson, I.A.R.,  and D.  H. Bowden.  The Type II Cells as Progenitor
     of Alveolar, Epithelial  Regeneration.  Laboratory Investigation.
     30:35, 1974.

22.  Weibel,  E. R.  Oxygen Effects  on Lung Cells. Arch.  Int. Med.   128:
     54, 1971.

23.  Freeman, G. and G. B.  Haydon.   Emphysema After  Low-Level Exposure
     to N02.   Arch. Environ.  Health.  8_:125, 1964.

24.  Riddick, J. H., K. I.  Campbell, and D. L.  Coffin. Emphysematous
     Changes Secondary to Nitrogen  Dioxide Exposure  to Dog Lungs.  Pre-
     sented at the Annual Scientific Assembly Am. Soc. Clin. Patholo-
     gists, Chicago, September 22-30, 1967.

25.  Blair, W. H., M.  C. Henry and  R. Ehrlich.   Chronic Toxicity of
     Nitrogen Dioxide:   II.   Effects of Histopathology of Lung Tissue.
     Arch. Environ. Health.   18:186, 1969.
                               361

-------
REFERENCES (continued)


26.  Freeman, G., R. J. Stephens, S.  C.  Crane and N. J. Furiosi.   Lesions
     of the Lung in Rats Continuously Exposed to Two Parts Per Million of
     Nitrogen Oxide.  Arch. Env.  Health.  17:181, 1968.

27.  Haydon, G. B., G.  Freeman,  and N. J.  Furiosi.  Covert Pathogenesis
     of NCL-Induced Emphysema in the  Rat.   Arch. Env. Health.   11:776,
     1965.L

28.  Freeman, G., S. C. Crane, R. J.  Stephens, and N. J. Furiosi.
     Environmental Factors in Emphysema and a Model System with N0?.
     Yale J. Biol. Med.  4£:566,  1968.                            L

29.  Freeman, G., S. C. Crane, and R. J. Stephens.  Pathogenesis  of
     Nitrogen Dioxide-Induced Lesion  in the Rat.  A review and presen-
     tation of new observations.   Am. Rev. Resp. Dis.  9_8_:429, 1968.

30.  Freeman, G., R. J. Stephens, S.  C.  Crane, and N. J. Furiosi.
     Lesions of the Lung of Rats  Continuously Exposed to 2 ppm of NCL.
     Arch. Env. Health.  17:181,  1968.

31.  Stephens, R. J., G. Freeman, S.  C.  Crane, and N. J. Furiosi.   Ultra-
     structural Change in the Terminal Bronchiole of the Rat Continuously
     Exposed During Continuous Low-Level Exposure to Nitrogen Dioxide.
     Exp. Mol. Pathol.   14:1, 1971.

32.  Stephens, R. J., G. Freeman, S.  C.  Crane, and N. J. Furiosi.
     Embedding
33.  Stephens, R.  J.,  G.  Freeman,  and M.  J.  Evans.   Ultrastructural
     Changes in Connective Tissue  in the Lungs of Rats Exposed to NO
     Arch.  Int. Med.   127:873,  1971.
2'
34.  Freeman, G.,  S.  C.  Crane,  and N.  J.  Furiosi.   Healing in Rat Lung
     After Subacute Exposure to NO-.   Am.  Rev.  Resp.  Dis.   100:662,
     1969.                        L

35.  Freeman, G.,  L.  T.  Juhos,  N.  J.  Furiosi, R. Mussenden, and T. H.  Weiss.
     Delayed Maturation of Rat  Lung in NO--Containing Environment.  (In
     Preparation).

36.  Bartlet, D.  Jr., C. S. Faulkner,  and K.  Cook.   Effect of Chronic Expos-
     ure (to 0, and N0~) on Young  Rats.

37.  Buel, G. C.,  Y.  Tokiwa, and P. K. Mueller. Lung Collagen and Elastin
     Denaturation in  vivo Following Inhalation of Nitrogen Dioxide.  Pre-
     sented at the 59th Annual  Air Pollution Control Assn. Meeting, San
     Francisco, June, 1966.  APCA  Paper No. 66-7.

                                   362

-------
REFERENCES (continued)
38.  Port, C., D. L. Coffin, P. B. Kane, and K. V. Ketals.  A Comparative
     Study of Experimental and Spontaneous Emphysema.  (In Preparation).

39.  Freeman, G., L. T. Juhos, N.  J.  Furiosi, R. Mussenden, R. J. Stephens,
     and M. J. Evans.  Pathology of Pulmonary Disease from Exposure to
     Interdependent Ambient Gases (Nitrogen Dioxide and Ozone).  Arch.
     Env. Health.  29_:203-210, 1974.

40.  Thomas, H. V., P. K. Mueller, and R. L. Lyman.  Lipoperoxidation of Lung
     Lipids in Rats Exposed to Nitrogen Dioxide.  Science.  159_:532, 1968.

41.  Estefan, R. M., E. M. Cause,  J.  R. Rowlands.  Electron Spin Resonance
     and Optical Studies of the Interaction between N0? and Unsaturated Lipid
     Compounds.  Environ. Research.  3^:62, 1970.

42.  Buel, G. C. Y. Tokiwa, P. K.  Mueller.  Lung Collagen and Elastin Denatura-
     tion in vivo Following Inhalation of Nitrogen Dioxide.  Presented at the
     59th Annual Air Pollution Control Assn. Meeting, San Francisco, June,
     1966.  APCA Paper No. 66-7.

43.  Buckley, R. D. and 0. J, Balchum.  Acute and Chronic Exposure to N0?.
     Arch. Env. Health.  14_:424, 1967.

44.  Buckley, R. D and 0. J. Balchum.  Effects of N07 on LDH Isoenzymes.
     Arch. Env. Health.  10:220-223.                 L

45.  Buckley, R. D. and 0. J. Balchum.  Enzyme Alteration Following N02
     Exposure.

46.  Ehrlich, R.  Effects of Nitrogen Dioxide on Resistance to Infection.
     Bacteriol. Review.  3£:604, 1966.

47.  Sherwin, R. P., S. Winnick, and R. D. Buckley.  Response to LEH-Positive
     Cells in the Lungs of Guinea Pigs Exposed to Nitrogen Dioxide.  Am.  Rev.
     Resp. Dis.  96:319, 1967.

48.  Buckley, R. D. and C. G. Loosli.  Effects of N02 Inhalation on Germ-
     free Mouse Lung.  Arch. Env.  Health.  18_:251, 1965.

49.  Menzel, D. B., J. N. Rhoem, S. D. Lee.  Vitamin E., the Environmental
     Antioxidant.  J. Ag. Food and Chem.  20_:481-486, 1972.

50.  Menzel, D. B., R. Slaughter, A. M. Bryant, and H. 0. Jauregeii.
     Heinz Bodies  Formed in Erythrocytes by Fatty Acid Ozonides.  Arch.
     Env. Health.   (In Press).

51.  Menzel, D. B., R. Slaughter, A. M. Bryant, and H. 0. Jauregeii.  Pre-
     vention of Ozonide-Induced Heinz Bodies in Human Erythrocytes by
     Vitamin E.  Arch. Env. Health.   (In Press).

                                   363

-------
REFERENCES (continued)
52.  Msnzel, D. B.  The Role of Free Radicals in the Toxicity of
     Air Pollutants (Nitrogen Oxides and Ozone).  In:  Free
     Radicals in Molecular Biology.  W. A. Prior (ed.), Academic
     Press.  (In Press).

53.  Charles, J. M. and D. B. Menzel.  Sulfate Stimulated Release
     of Histamine from Lung Fragments.  Environmental Research.
     (In Press).

54.  Coffin, C. L. and D. E. Gardner.  Interaction of Biological
     Agents and Chemical  Air Pollutants.  Ann. Occup. Hyg.  15:
     219-234, 1972.

55.  Coffin, D. L., E. J. Blommer, D. E. Gardner, and R. S.
     Holzman.  Effect of Air Pollution on Alteration of Sus-
     ceptibility to Pulmonary Infection.  Proceedings of 3rd
     Annual Conference on Atmospheric Contamination in Confined
     Space.  Aerospace Medical Research Lab.  71-80, 1968.

56.  Ehrlich, R.  Effects of Nitrogen Dioxide on Resistance to
     Respiratory Infection.  Bact. Rev.  30_:604-614, 1966.

57.  Coffin, D. L. and E. J. Blommer.  Acute Toxicity of Irra-
     diated Auto Exhaust.  Its Indication by Enhancement of
     Mortality from Streptoccal pneumonia.  Arch. Env. Health.
     15:36-37, 1967.

58.  Port, C. D., J. D. Fenters, R. Ehrlich, D. L.  Coffin, and
     D. E. Gardner.  Interaction of Nickel Oxide and Influenza
     Infection in the Hamster.  Abs. Env. Proceedings Conference
     on Heavy Metals in the Environment.  (In Press) .  Env.
     Perspectives.

59.  Maigetter, R. Z., J. Findlay, J. Fenters, and R. Ehrlich.
     Effect of Manganese  Dioxide on Resistance to Respiratory
     Infections.  Abs. Am. Soc. of Microbiology, Chicago, Illinois,
     1974.

60.  Blommer, E. J.  (Unpublished Data) .
                                    364

-------
REFERENCES (continued)


61.  Henry, M.  C.,  R. Ehrlich,  and W.  H.  Blair.   Effect of Nitrogen Dioxide
     on Resistance  of Squirrel  Monkeys to K.  pneumoniae infection.   Arch.
     Env. Health.   18:580-587,  1969.

62.  Coffin, D.  L., D.  E.  Gardner,  and R.  S.  Holzman.   Influence  of Ozone
     on Pulmonary Cells.   Arch. Env. Health.   1^:633-636,  1968.

63.  Gardner, E. D., R. S. Holzman, and D.  L.  Coffin.   Effects of Nitrogen
     Dioxide on Pulmonary  Cell  Population.  J. Bact.   9£: 1041-1043,  1969.

64.  Coffin, D.  L., D.  E.  Gardner,  and E.  J.  Blommeir.   Time/Dose Response
     for NO- Exposure in an Infectivity Model.   To  be  presented at  Soviet-
     American Symposium on the  results of the joint scientific work for
     1973-74, Riga  Lalvian SSR, December,  1974.

65.  Coffin, D.  L.  and  D.  E.  Gardner.   Influence of Mode of  Dose  on Toxi-
     city of NO-.   Australia-New Zealand  Clean Air  Conference, Rotorua,
     New Zealana, February, 1975.

66.  Aronow and Isbell:  Carbon Monoxide  Effects on Exercise-Induced
     Angina Pectoris.   Ann. Intern. Med.   79;392-395,  1973.

67.  Anderson,  Andelman, Strauch,  Fortuin and Knelson:   Effect of Low-
     Level Carbon Monoxide Exposure on Onset  and Duration of Angina
     Pectoris.   A Study of Ten  Patients with  Ischemic  Heart  Disease.  Ann.
     Intern. Med.   719:46-50,  1973.

68.  Aronow, Harris, Isbell,  Rohaw and Imperato: Effect of  Freeway
     Travel on  Angina Pectoris.  Ann.  Intern.  Med.  77:669-676, 1972.

69.  Aronow, Stemmer and  Isbell.   Effect of  Carbon Monoxide Exposure on
     Intermittent Claudication.  Circulation   49;415-417,  1974.

70.  Horvath, Dahms and Gray.   The Determination of Maximal  Aerobic Power
     Consequent to  Carbon  Monoxide Exposure.   J. Appl.  Physiol.   (In
     Press).

71.  Haak, Griggs.   Effects of  Low-Level  Carbon  Monoxide on  Exercise Per-
     formance,  Blood Lipids and Clotting  Factors.  (In Progress).

72.  Fodor and  Winneke.  Effect of Low CO Concentrations on  Resistance
     to Monotony and on Psychomotor Capacity.  Staub Reinhart. Luft.
     (English ed.)   32  (4) 46-54,  1972.

73.  Groll-Knapp, Wagner,  Hauck and Haider.  Effects of Low  Carbon  Monox-
     ide Concentrations on Vigilance  and  Computer Analyzed Brain  Poten-
     tials.  Staub  Reinhart.  Luft.  32:64-68,  1972.
                                    365

-------
REFERENCES (continued)


74.  Horvath, Dahms and O'Honlon.   Carbon Monoxide and Human Vigilance.
     A Deleterious Effect of Present Urban Concentrations.   Arch.
     Environ. Health.  23^:342-347, 1971.

75.  Beard, R. R.  and N. Grandstaff.  CO Exposure and Cerebral Function.
     Arch. Environ. Health.  2^:154-164,  1970.

76.  Wald, Howard, Smith and Kjeldsen:  Association Between Atheroscle-
     rotic Disease and Carboxyhemoglobin Levels in Tobacco Smokers.
     Brit. Med. J.  3^:761-765, 1973.

77.  Astrup et al.:  Effect of Moderate CO Exposure on Fetal Development.
     Lancet  2_: 1220-1222, 1972.

78.  Zorn, H.  The Partial Oxygen Pressure in the Brain and Liver at
     Subtoxic Concentrations of Carbon Monoxide.  Staub-Reinhalt.  Luft
     (English ed.)  32_:24-29, 1972.

79.  Rondia, D. Abaissement de 1 activte de la benzopyrine-hydroxylase
     hepatique in  vivo apres inhalation d'ozyde de carbone.  C. R. Acad.
     Sci.  (d)  771T6T7-619, 1970.

80.  Coburn, R. F. and P. B. Kane.  Maximal Erythrocyte and Hemoglobin
     Actabolism.  J. Clin. Invest.  £7:1435-1446, 1968.

81.  Adams. J. D., H. H. Erickson and H.  L. Stone.  Myocardial Metab-
     olism During   Exposure to Carbon Monoxide in the Conscious Dog.
     J. Appl. Physiol.   34:238-242, 1973.

82.  Debias, D. A., C.  M. Banerjee, N. C. Birkhead, W; V.  Harrer and
     L. A. Kazal.   Carbon Monoxide Inhalation Effects Following Myo-
     cardial Infarctions in Monkeys.  Arch. Environ. Health  27:161-
     167,  1973.

83.  Wells, L. L.   The Prenatal Effect of Carbon Monoxide  on Albino
     Rats  and Resulting Neuropathology.  Biologist.  L5_:80-81, 1933.

84.  Williams, I.  R. and E. Smith.  Blood Picture, Reproduction and
     General Condition During Daily Exposure to Illuminating Gas.
     Amer. J. Physiol.   110;611-615, 1935.

85.  Baker, F. D.  and C. F. Tumasonis.  Carbon Monoxide and Avian
     Embryogenesis.  Arch. Environ. Health.  24^:53-61, 1972.

86.  Baker, F. D., C. F. Tumasonis and J. Barren.  The Effect of Carbon
     Monoxide Inhalation on the Mixed-Function Oxidase Activity in the
     Chick Embryo  and the Adult Mouse.  Bull. Environ. Contam. Toxicol.
     9_: 329-336, 1973.

                                  366

-------
REFERENCES (continued)


87.  McGrath, J. J.  and J.  Jaeger.   Effect of lodoacetate on the Carbon
     Monoxide Tolerance of the Chick.   Resp.  Physiol.   12_:46-53, 1971.

88.  Jones, R. A., J. A. Strickland, J. A. Stunkard and J.  Siegel.
     Effects on Experimental Animals of Long-Term Inhalation to Carbon
     Monoxide.  Toxicol. Appl. Pharmacol.   19_:46-53, 1971.

89.  Ator, N. A.  Effects of Carbon Monoxide  on DRL Performance in  Rats.
     (Atstract of a paper to be presented at  American Psychological
     Association Meetings,  New Orleans, September,  1974).

90.  Gage, M. I., Y. Y. Yang., A. L.  Cohen and J. F. Stara.   Alterations
     of Wheel Running Behavior of Mice by Automotive Fuel Emissions.
     Paper presented at American Psychological Association Meeting, 1972.

91.  Particulate Polycylic Organic  Matter. National Academy of Sciences,
     Washington, B.C.,  1972.

92.  Aksoy, M., S. Erdem, K. Dincol, T. Hepyuksel,  and G. Dincol.
     Chronic Exposure to Benzene as a  Possible Contributary Etiologic
     Factor in Hodgkin's Disease.   Blut Band  XXVIII, Seite 293-298,
     1974.

93.  Ahmad and T. C. Whitson.  Formaldehyde:   How Much of a Hazard.
     Industrial Medicine and Surgery,  September, 1973.

94. Thorpe, J. J.  Epidemiologic Survey of Leukemia in Persons Poten-
     tially Exposed to  Benzene.  Journal of Occupational Medicine,  Vol.
     16, No. 6.  June,  1974.

95.  Rylander, R.  Toxicity of Cigarette Smoke Components:   Free Lung
     Cell Response in Acute Exposures.  American Review of Resp. Dis.
     108:1279-1282,  1973.

96.  Stedman, R. L.  The Chemical Composition of Tobacco and Tobacco
     Smoke.  Chem. Rev.  .68:153-207, 1968.

97.  Waltz, P. et al.   MeThodeu der Quantitativen Bestimmung des
     Brenzcatechins  in  Cigrettenrauch.  Beiter Tabakforsch.  _3:263-277,
     1965.

98.  Van Duuren, B.  L.  et al.  Carcinogenic Agents  in Tobacco Carcino-
     genesis.  J. Natl. Cancer Inst.  .51:703-705, 1973.

99.  Chemistry of Carbon Compounds  (Rodd,  E.  H., ed.), Vol. 3A.  Amster-
     dam, Elsevier Publishing Co.,  1956, p. 465.
                                    367

-------
REFERENCES (continued)
100.  Johnstone, R. A., J. R. Plimmer.  The Chemical Constituents of
      Tobacco and Tobacco Smoke.  Chem. Rev.  59^885-936, 1959.

101.  Figueroa, W. G.  et al.  Lung Cancer in Chloromethyl Methyl Ether
      Workers.  The New Eng. J. Med.  288_:1096-1097, 1973.

102.  Van Duuren, B. L., B. M. Goldschmidt, B. S. Catz, et al.  Alpha-
      haloethers:  A New Type of Alkylating Carcinogen.  Arch. Environ.
      Health  16^:472-476, 1968.

103.  Leong, B. K. J., H. N. MacFarland, W, H. Reese, Jr.  Induction of
      Lung Adenomas by Chronic Inhalation of Bis (Chloromethyl) ether.
      Arch. Environ. Health  22^663-666, 1971.

104.  Laskin, S. M. Kuschner, R. T. Drew, et al.  Tumors of the Respira-
      tory Tract Induced by Inhalation of Bis (Chloromethyl)  Ether.
      Arch. Environ. Health  23:135-136, 1971.

105.  Van Duuren, B. L., C. Katz, B. M. Goldschmidt, et al.  Carcino-
      genicity of Haloethers.  II.  Structure-Activity Relationships
      of Analogs of Bis (Schloromethyl) Ether.  J. Natl. Cancer Inst.
      48^1431-1439, 1972.

106.  Alvares, A. P. et al.  Inducibility of Benzo(a)Pyrene Hydroxylase
      in Human Skin by Polycyclic Hydrocarbons.  Chemical Pharm. and
      Thera.  1£: 30-40, 1973.

107.  Wiebell, F. J. et al.  Aryl Hydrocarbon (Benzo(a)Pyrene) Hydro-
      lase:  Inducible in Extraphepatic Tissues of Mouse Strains Not
      Inducible in Livei.  Archives of Biochem. and Biophy.  154:292-
      294, 1973.

108.  Federal Register, Vol. 36, No. 84, Part II, pp. 8186-8190,
      April 30, 1971.

109.  Air Quality Criteria for Photochemical Oxidants.  USDHEW, PHS,
      EHS, NAPCA, Washington, D.C., March, 1970, No. AP-63.

110.  Bates, D. V. et al.  Short-Term Effects of Ozone on the Lung.
      J. Appl. Physiol. 32(2), February, 1972.

111.  Hazucha, M., F. Silverman, C. Parent, S. Fields and D.  V. Bates.
      Pulmonary Function in Man after Short-Term Exposure to Ozone.
      Arch. Env. Health  27^183-188, September, 1973.

112.  Bates, D.  Hydrocarbons and Oxidants:  Clinical Studies Paper
      Presented at Conference on Health Effects of Air Pollutants,
      National Academy of Sciences, Washington, D.C., October 4, 1973.


                                368

-------
REFERENCES (continued)


113.  Hammer, D.  I., V.  Hasselblad,  B.  Portnoy and P.  F.  Wehrle.   Los
      Angeles Student Nurse Study.   Daily Symptom Reporting and Photo-
      chemical Oxidants.  Arch.  Environ.  Health  28;255-260, May,  1974.

114.  Challen, P. et al.  An Investigation of Some Health Hazards  in an
      Inert-Gas Tungsten-Arc Welding Shop.  Brit. J.  Indus. Med.   15:
      276, 1958.

115.  Young, W. A. et al.   Pulmonary Function in Welders  Exposed to Ozone.
      Arch. Environ. Health  ^:737,  1963.

116.  Kerr,  H. D., T.  J.  Kulle, M.  L.  Mcllhany and P. Swidersky.   Effects
      of Ozone Function in Normal Subjects.  An Environmental Chamber
      Study.  (In Press).

117.  Hackney, J. D.  Physiological  Effects of Air Pollutants in Humans
      Subjected to Secondary Stress.  Final Report, January 1, 1973,
      through June 30,  1974.  State  of California Air  Resources Board
      Contract No. ARB 2-372.

118.  Air Quality Criteria for Photochemical Oxidants  and Related Hydro-
      carbons.  Committee on Challenges of Modern Society.  NATO,  G.
      Hueter, Chairman,  1974, pp. 6-13.

119.  Pan, A., J. Belaud and Z Jegier.   Ozone-Induced  Arterial Lesions.
      Arch. Environ. Health  2_4:229-232,  1972.

120.  Goldstein,  E. and P. Hoeprich.  Influence of Ozone  on Pulmonary
      Defense Mechanisms of Silicotic Mice.  Arch. Environ. Health
      24_: 444-448, 1972.

121.  Goldstein,  E., D.  Warshaver, W. Lippert and B. Tarkington.   0., and
      N09 Exposure.  Arch. Environ.  Health  28:85-90,  1974.
        Lt                                   '—L—L
122.  Dowell, A., L. Lohrbauer,  D. Hurst, S. Lee.  Rabbit Alveolar
      Macrophage Damage Caused by .m vivo 0, Inhalation.   Arch. Environ.
      Health  21:121-127,  1970.

123.  Emik, L, R. Plata, K. I. Campbell,  and G. L. Clarke.  Biologi-
      cal Effects of Urban Air Pollution.  Arch. Environ. Health  25:
      335-342, 1971.

124.  Evans, M.,  W. Mayr,  T. Bils and C.  Loosli.  Effects of Ozone on
      Cell Renewal in Pulmonary Alveoli of Aging Mice. Arch. Environ.
      Health  22:450-453,  1971.
                                    369

-------
REFERENCES (continued)


125.  Hattori, K., N. Kato, M. Kinoshitan, S. Kinoshita and T.  Sunada.
      Protective Effect of Ozone in Mice Against Whole-Body X-Irradia-
      tion.  Nature (London), Vol.  198:1220, 1963.

126.  Matsumura, Y., K. Mizuno, T.  Miyamoto, T.  Suzuki and Y. Oshima.
      The Effects of Ozone, Nitrogen Dioxide and Sulfur Dioxide on
      Experimentally Induced Allergic Respiratory Disorder in Guinea
      Pigs, IV Effects of Respiratory Sensitivity to Inhaled Acetyl-
      choline.  Am. Rev. Respirat.  Dis.   1015:262-267, 1972.

127.  Fletcher, B. L. and A. L. Tappel.   Protective Effects of  Dietary
      Alpha-Tocopherol in Rats Exposed to Toxic  Levels of Ozone and
      Nitrogen Dioxide.  Environ.  Res.  6_: 165-175, 1973.

128.  Moorman, W. J., J. J. Chmiel, J. F. Stara  and T. R. Lewis.  Com-
      parative Decomposition of Ozone in the Nasopharynx of Beagles.
      Actue vs. Chronic Exposure.   Arch. Environ. Health  26:153-155,
      1973.

129.  Rochm,  N., J. G. Hadley and D. B.  Menzel.   Antioxidants vs.  Lung
      Disease.  Arch. Internal. Med.  1_28:88-93, 1971.

130.  Roehm,  J., J. Hadley and D.  Menzel.  Influence of Vitamin E  on
      the Lung Fatty Acids of Rats  Exposed to Ov  Arch. Environ.
      Health  24;237-242, 1972.

131.  Shakman, R.  Nutritional Influences on the Toxicity of Environ-
      mental  Pollutants.  Arch. Environ. Health   2,8:105-113, 1974.

132.  Kyei-Aboagye, K., M. Hazucha, I. Wyszogrodski, D.  Rubinstein and
      M.  E. Avery.  The Effect of Ozone  Exposure in vivo on the Appear-
      ance of Lung Tissue Lipids in the  EndobroncHTal Lavage of Rabbits.
      Biochem. Biophys. Res. Commun.  54_:907-913, 1973.

133.  Seto, K., M. Kawakami, M. Takeshima, M. Kon, K. Sugita and M.
      Shishido.  Influence of Short-Period Exposure to Ozone and
      Nitrogen Dioxide on the Formation  of Phospholipids in the Lungs
      of Rabbits.  Igaku to Seibutsugaku.  8^7:57-60, 1973.

134.  Castleman, W. L., D. L. Dungworth  and W. S. Tyler.  Cytochemi-
      cally Detected Alterations of Lung Acid Phosphatase Reactivity
      Following Ozone Exposure.  Lab.  Invest. 29^310-319,  1973.

135.  Castleman, W. L., D. L. Dungworth  and W. S. Tyler.  Histochemically
      Detected Enzymatic Alterations in  Rat Lung Exposed to Ozone.  Exp.
      Mol. Pathol.  19:402-421, 1973.
                                370

-------
REFERENCES (continued)
136.  Chow, and Tappel.   Activities  of Pentose Shunt and Glycolytic
      Enzymes in Lungs of Ozone Exposed Rats.   Arch. Environ. Health
      26:205-208, 1973.

137.  Dillard, C. J.,  N.  Urribarri,  K.  Reddy,  B.  Fletcher,  S. Taylor,  B.
      Delumen, S. Langberg,  A.  L.  Tappel.   Increased Lysosomal  Enzymes
      in Lungs of Ozone-Exposed Rats.   Arch. Environ.  Health 25:426-
      431, 1972.                                              ~

138.  Jegier, Z.   Ozone as an: Air  Pollutant.   Can.  J.  Public Health
      (Toronto).   64_: 161-166, 1973.

139.  Mustafa, M. G.,  A.  J.  Delucia, G. K.  York,  C. Arth and C.  E.  Cross.
      Ozone Interaction with Rodent Lung.   II.   Effects on Oxygen Consump-
      tion of Mitochondria.   J.  Lab. and Clin.  Med.  82^:557-565,  1973.

140.  Pan, A. S.  and A.  Jegier.  Trypsin Protein  Esterase in Relation
      to Ozone-Induced Vascular Damage.  Arch.  Environ.  Health   24:255-
      256, 1972.

141.  Pan, A. and Z. Jegier. The  Effect of Sulfur  Dioxide  and  Ozone on
      Acetylcholinesterase.   Arch. Environ. Health   21_: 498-501,  1970.

142.  Veninga, T. S.   Ozone-Induced  Alterations in  Murine Blood and
      Liver.  Preprint,  International Union of Air  Pollution Prevention
      Associations,  10P,  1970,  6 Refs.   (Presented  at the International
      Clean Air Congress, 2nd,  Washington,  D.C.,  December 6-11,  1970,
      Paper MB-15E.)

143.  Veninga, T. S.   Toxicity  of  Ozone in Comparison with  Ionizing
      Radiation.   Strahlentherapie (Munich).   134_:469-477,  1967.

144.  Yokoyama, Eiji.   The Effects of Low-Concentrations of Ozone on
      the Lung Pressure of Rabbits and Rats.   Preprint,  Japan Society
      of Industrial  Hygiene, pp. 134-135, 1973.  (Presented at  the
      Japan Society  of Industrial  Hygiene Annual  Meeting, 46th,  April,
      1975, Paper 225.)

145.  Yokoyama, Eigi.   A Comparison  of the Effects  of SO-,  NO-  and  0,
      on the Pulmonary Ventilation of Guinea Pigs.   Sangyo  Igaku (Jap.
      J. Ind. Health).  11^:563-568,  1969.

146.  Bloch, W. N.,  F. J. Miller and T. R.  Lewis.  Pulmonary Hyperten-
      sion in Dogs Exposed to Ozone.  Air Pollution Control Office,
      Cincinnati, Ohio,  Biological Research Br.,  10P., 1971.

147.  Goldstein,  E., W.  Tyler,  P.  Hoeprich and C. Eagle. Ozone and the
      Antibacterial  Defense Mechanisms of the  Murine Lung.   Arch. Internal
      Med.  128:1099-1102, 1971.

                                    371

-------
REFERENCES (continued)
148.  Goldstein, E., W. S. Tyler, P. D. Hoeprich and C. Eagle.  Adverse
      Influence of Ozone on Pulmonary Bactericidal Activity of Murine
      Lung.  Nature  229:262-263, 1971.

149.  Friberg, L., B. Holma, M. Piscator and R. Rylander.  Effects of
      Prolonged Exposure to Low Concentrations of Lead and Ozone in
      Rabbits and Guinea Pigs--with Special Reference to Lung Clearance
      and Alveolar Macrophages.  Karolinska Inst., Stockholm (Sweden),
      Dept. of Hygiene; National Inst. of Public Health, Stockholm
      (Sweden), Dept. of Environmental Health; Copenhagen Univ. (Den-
      mark), Inst. of Hygiene, PHS Grant AP 00212, Swedish Medical
      Research Council Proj. B69-14x-18, 26P., 1970.

150.  Fairchild, G. A.  Ozone Effect on Respiratory Deposition of Vesi-
      cular Stomatitis Virus Aerosols.  Am. Rev. Resp. Dis.  109:446-
      451, 1974.

151.  Gregory, A., L. Ripperton and B. Miller.  Effect of Neonatal
      Thymectomy on the Development of Ozone Tolerance in Mice.  Am.
      Ind. Hyg. Assoc. J.  28^:278-283, 1967.

152.  Gardner, D. E., J. Illing, F. Miller and D. Coffin.  1974.  The
      Effect of Ozone on Pentobarbital Sleeping Time in Mice.  EPA,
      NERC/RTP, EBL, PER, (in preparation).

153.  Schlipkoeter, H. and J. Bruch.  Functional and Morphological
      Alterations Caused by Exposure to Ozone Zentralbl.  Bakteriol,
      Parasitenk.  Infektionskr.  Hyg. Abt. l:orig, Reihe B, 156:486-
      499, 1973.

154.  Mizoguchi, I., M. Osawa, Y. Sato, K. Makino and H. Yagyu.
      Studies on Erythrocyte and Photochemical Smog, Part I:  Effects
      of Air Pollutants on Erythrocyte Resistance.  Taiki Osen Kenkyu
      J. Japan. Soc. Air Pollution.  8^:414, 1973.

155.  Matsumura, Y.  The Effects of Ozone, Nitrogen Dioxide, and Sulfur
      Dioxide on the Experimentally Induced Allergic Respiratory Dis-
      order in Guinea Pigs.  I.  The Effect on Sensitization with
      Albumin Through the Airway.  AM  Rev. Respirat. Diseases.  102:
      430-437, 1970.

156.  Roth, R. P. and M. F. Tansy,  Effects of Gaseous Air Pollutants
      on Gastric Secreto-Motor Activities in The Rat.  J. Air Pollu-
      tion Control Assoc.  22;706-709, 1972.

157.  Atwal, Onkar and T. Wilson.  Parathyroid Gland Changes Following
      Ozone Inhalation.  Arch. Environ. Health.  28:91-100, 1974.
                                372

-------
REFERENCES (continued)


158.  Nettesheim,  P., M.  G.  Hanna, Jr.,  D.  G. Doherty, R.  F. Newell and
      A. Hellman.   Effects of Chronic  Exposure  to Artificial Smog and
      Chromium Oxide Dust on the  Incidence  of Lung Tumors  in Mice.
      National Cancer Inst., Bethesda, Md.,  and Atomic Energy Commission,
      Oak Ridge, Tennessee,  Proc. Conf.  Inhalation Carcinogenesis,
      Gatlinburg,  Tennessee, 1969, pp. 305-320.

159.  Schlipoeter, H. W., G. G. Fodor, L. Ghelerter and R. Dolgner.
      Findings from Animal Tests  Concerning Synergism.  Proc. Int. Clean
      Air Cong., 3rd, Duesseldorf, West  Germany, 1973, P. A26-A30.

160.  Cortes,  R. and 0. Privett.  Toxicity  of Fatty Ozonides and Per-
      oxides.   Lipids.  7_: 715-721, 1972.

161.  Seto,  K, M.  Kawakami,  K. Sugita, M. Shishido, M. Yamaji and T.
      Tsuda.  Influence of Inhalation  of Ozone  and Nitrogen Dioxide
      on the Formation of Phospholipids  on  the  Lung.  Igaku to
      Seibutsugaku  86:317-320, 1973.

162.  Shakman. Nutritional  Influences on Toxicity of Environmental
      Pollutants.   Arch.  Environ. Health.   28.: 105-113, 1974.

163,  Trams, E., C. Lauter,  E. Brown and 0.  Young.  Cerebral Cortical
      Metabolism after Chronic Exposure  to  Ov  Arch. Environ. Health.
      24_:153-159,  1972.                      *

164.  Litt,  R. S., S. Vaughan, P. Birkinshaw, H. Coit and B. Sanders.
      Effects  of Low Concentrations  of Ozone on Temporal Discrimination.
      In: Air Pollution  Project:  An  Educational Experiment in Self-
      Directed Research,  1968 Associated Students of the California
      Inst.  of Tech., Pasadena, pp.  51-64,  1968.

165.  Xintaras, C., B. L. Johnson, C. E. Ulrich, R. E. Terrill and M. F.
      Sosecki. Application  of the Evoked Response Technique in Air
      Pollution Toxicology.   Toxicol. Appl.  Pharmacol.  8^77-87, 1966.

166.  Konigsbergs, A.  A  Study of the Measurement of Ozone and Some
      Effects  of Ozone and Nitrogen  Oxides  on the Activity of Rats.
      Syracuse Univ., N.Y.,  Eept. of Physics, Thesis (Ph.D.), January,
      1969, Ann Arbor, Michigan, Univ.  Microfilms, Inc., 1969.

167.  Reynolds, R. W. and R. R. J. Chaffee.  Studies on the Combined
      Effects  of Ozone and a Hot  Environment on Reaction Time in Sub-
      human  Primates.  In:   Project  Clean Air.  California University,
      Santa  Barbara, California,  Univ. Res.  Proj. 5-6 8P., September 1,
      1970.
                                   373

-------
REFERENCES (continued)


168.  Martin, A.  E.  and W.  Bradley.    Mortality,  Fog and Atmospheric
      Pollution.   Monthly Bull.  Ministry Health  19;.56-59,  1960.

169.  Lawther, P. J.  Compliance  with the Clean Air Act:  Medical Aspects,
      J.  Inst. Fuels (London)   36:341-344, 1963.

170.  Report of the  International Joint Commission, United States and
      Canada, on the Pollution of the Atmosphere  in the Detroist River
      Area.   International  Joint  Commission (United States and Canada).
      1960.   p. 115.

171.  Greenburg,  L., F.  Field, J. I.  Reed and C.  L. Erhardt.   Air Pollu-
      tion and Morbidity in New York  City.  J. Amer. Med. Assoc.
      182.: 161-164, 1962.

172.  Greenburg,  L., M.  B.  Jacobs, B. M.  Drolette,  F. Field  and M. M.
      Braverman.   Report on an Air Pollution Incident in New York City,
      November, 1953.  Public  Health  Reports.  77:7-16, 1962.

173.  Buck,  S. F. and D. A. Brown. Mortality from Lung Cancer and
      Bronchitis  in  Relations  to  Smoke and Sulfur Dioxide Concentration,
      Population Density and Social Index.  Research Paper No. 7.
      Tobacco Research Council, London, Fjigland.   1964.

174.  Lawther, P. J.  Climate, Air Pollution and Chronic Bronchitis.
      Proc.  Roy.  Soc. Med.   5.1:262-264, 1958.

175.  Winkelstein, W.  The  Relationship of Air Pollution and Economic
      Status to Total Mortality and Selected Respiratory System Mor-
      tality in Man.  Arch. Environ.  Health.  14_:162-169, 1967.

176.  Holland, W. W., D. D. Reid, R.  Seltser and R. W. Stone.  Respira-
      tory Disease in England  and the United States.  Studies of
      Comparative Prevalence.   Arch.  Environ. Health.  10:338-545,
      1965.

177.  Douglas, J. W. B.  and R. E. Waller.   Air Pollution and Respiratory
      Infection in Children.  Brit. J. Prevent. Soc. Med. 20^:1-8, 1966.

178.  Lunn,  J. E., J. Knowelden and A. J.  Handyside.  Patterns of
      Respiratory Illness in Sheffield Infant School Children.  Brit.
      J.  Prevent. Soc.  Med. 21^:7-16, 1967.

179.  Nelson, C.  J.  C.  M. Shy, T. English, C. R.  Sharp, R. Andleman,
      L.  Truppi and  J.  Van  Bruggen.   Family Surveys of Irritation Symp-
      toms During Acute Air Pollution Exposures.  J. Air Pol. Control
      Assoc.  23_(2):81-86,  1973.


                                 374

-------
REFERENCES (continued)


180.  Health Consequences of Sulfur Oxides:   A Report from CHESS,  U.S.
      Environmental Protection Agency (in press).

181.  Shy, C. M.,  V. HasselbLad,  R. M.  Burton, C.  J.  Nelson and A. A.
      Cohen.   Air Pollution Effects on Ventilatory Function of U.S.
      School Children.   Arch. Environ.  Health.  27:124-128, 1973.

182.  French, J.  G., G.  Lowrimore,  W.  C.  Nelson, J. F.  Finklea, T.
      English and M. Hertz.   The  Effect of Sulfur  Dioxide  and Suspended
      Sulfates on Acute  Respiratory Disease.   Arch. Environ.  Health.
      27:129-133,  1973.

183.  Chapman, R.  S., C. M.  Shy,  J. F.  Finklea,  D.  E. House,  H. E.
      Goldberg and C. G. Hayes.   Chronic  Respiratory  Disease in Military
      Inductees and Parents  of School  Children.  Arch.  Environ. Health.
      27:138-142,  1973.

184.   Galke, W.,  D. House,  et al.   Prevalence of  Chronic  Respiratory
       Disease Symptoms  in Adults:   1971-1972 Survey  of Two Southeastern
       United States Communities.   In-house Technical Report.   October  18,
       1974.

185.   Hammer, D.  I., F. J.  Miller, D.  E. House, K. E.  McClain, E.
       Tompkins and C. G.  Hayes.  Frequency of Acute  Lower Respiratory
       Disease in Children;  Retrospective Survey of Two Southeastern
       Communities, 1968-1971. In-house  Technical Report, May 8,  1974.

186.   Love,  G. et al.   Acute Respiratory Disease  in  Families in Two
       Southeastern Communities.

187.   Galke, W. A., D.  E. House, et al.   Prevalence  of Chronic Respira-
       tory Disease Symptoms in New York  Area Adults--1972.  In-house
       Technical Report, October  31, 1974.

188.   Hammer, D.  I., F. J.  Miller, A.  G. Stead and C.  G.  Hayes.   Acute
       Lower Respiratory Disease  in Children  in Relation to Sulfur
       Dioxide and Particulate Air  Pollution:  Retrospective Survey in
       New York City, 1972.   In-house Technical Report, September  13,
       1974.

189.   Fogleman,  E. et al.  Acute Air Pollution Exposures  in Two South-
       eastern Communities,  1971-1972.  Draft Report, March 11, 1974.

190.   French, J.  et al.  Aggravation of  Asthma Symptoms in Two South-
       eastern Communities,  1971-1972.  Draft Report.

191.   Stebbings,  J.  Frequency and Severity  of Cardiopulmonary Symptoms
       in Adult Panels,  1971-1972 New York Studies.   Draft Report.

                                     375

-------
REFERENCES (continued)


192.   French, J. et al.  Aggravation of Asthma Symptoms in the New York-
       New Jersey Area, 1971-1972.   Draft Report.

193.   Love,  G. J. et al.   Summary  and Conclusions.   Respirable Particu-
       late Monograph.   To be published.

194.  McJilton, C., R.  Frank and R.  Charlson.   Role  of Relative Humidity
      in the  Synergistic Effect of  a Sulfur Dioxide-Aerosol Mixture on
      the Lung.  Science.   182:505-504,  November,  1973.

195.  Morrow, P. E.  Experimental Studies on Inhaled Materials.  A Basis
      for Respiratory Models.  Arch.  Internal  Med.   126_:466-470, 1970.

196.  Task Group on Lung Dynamics.   Deposition and Retention Models for
      Internal Dosimetry of the Human Respiratory  Tract.   Health Physics.
      n:173-207, 1966.

197.  Air Quality Criteria for Particulate Matter, Chapter 9.   National
      Air Pollution Control Administration Publication No. AP-49, 1969.

198.  Amdur,  M. 0. and M.  Corn.  The Irritant  Potency of Zinc Ammonium
      Sulfate of Different Particle  Sizes.  Am.  Indust. Hyg.  Assoc. J.
      24_:326-333, July-August, 1963.

199.  Amdur,  M. 0. and D.  W. Underbill.   Response  of Guinea Pigs to
      Sulfur  Dioxide.   Arch. Environ.  Health.   16_:461-468, April, 1968.

200.  Amdur,  M. 0.  Toxicologic Appraisal of Particulate Matter, Oxides
      of Sulfur and Sulfuric Acid.   J. Air Poll. Cont.  Assn.   19_:639-
      646, September,  1969.

201.  Hatch,  T. and P.  Gross.  Pulmonary Deposition  and Retention of
      Inhaled Aerosols. Academic Press, New York, 1964.

202.  Dimmick, R. L.  and A. B. Akers.  An Introduction to Experimental
      Aerobiology.  Chapter 16.  Wiley-Interscience,  New York, 1969.

203.  Palm, P. E., J. M. McNerney and T. Hatch.  Respiratory Dust Reten-
      tion in Small Animals.  A Comparison with Man.   A.M.A. Arch.  Ind.
      Health.  13;355-365, 1956.

204.  Fairchild, G. A.   Measurement  of Respiratory Volume for  Virus
      Retention Studies in Mice. Appl.  Microbiology.   24:812-818,
      November, 1972.

205.  Lippmann, M., R.  E.  Albert and H.  T. Peterson,  Jr.   The  Regional
      Deposition of Inhaled Aerosols  in  Man.   In:  Inhaled Particles
      III. Vol. 1.  Ed. W. H. Walton, Unwin,  London,  1971.

                                376

-------
REFERENCES (continued)


206•  Lippmann, M.   Deposition and Clearance of Inhaled Particles  in the
      Human Nose.  Ann. Otology,  Rhin.  and Laryng.   79:519-529,  June,
      1970,                                         ~

207,  Casarett, L.  J.   The Vital  Sacs:   Alveolar Clearance Mechanisms
      in Inhalation Toxicology.   In:  Essays in Toxicology.   Ed. Wayland
      J. Hayes, Jr., Academic Press,  New York,  1972.

208.  Bates, D. V., G.  M.  Bell, C.  D. Burnham,  M. Hazucha, J. Mantha,
      L. D. Pengelly,  F. Silverman.   Short-Term Effects of Ozone on the
      Lung.  J. Appl.  Physiol.  32^:176-181, 1972.

209.  McCarroll, J. Measurements of  Morbidity  and  Mortality Related to
      Air Pollution. APCA Journal.   17:203-209, April, 1967.

210.  Thompson, D.  J.,  M.  Lebowitz, E.  J. Cassell,  D.  Wolter and J.
      McCarroll. Health and the  Urban  Environment. VIII--Air Pollution,
      Weather and the  Common Cold.  Am. J. Pub. Health.  6£:731-739,
      April, 1970.

211.  Ipsen, J., M. Deane  and F.  E.  Ingenito.   Relationships of  Acute
      Respiratory Disease  to Atmospheric Pollution  and Meteorological
      Conditions.  Arch. Environ. Health.  18^462-472, April, 1969.

212.  Finklea, J. F.,  D. C. Calafiore,  C. J. Nelson, W. B. Riggan  and
      C. B. Hayes.   Aggravation of Asthma by Air Pollution:   1971  Salt
      Lake Basic Studies.   Health Consequences  of Air  Pollution:   A
      Report of the CHESS  Program,  1970-71, EPA Technical Report.

213.  Lippmann, M.  and R.  E. Albert.  The Effect of Particle Size  on
      the Regional  Deposition of  Inhaled Aerosols in the Human Respira-
      tory Tract.  Am.  Indust.  Hyg. Assn. J.  30:257-275, May-June,
      1969.

214.  Morrow, P. E., F. R. Gibb and L.  Johnson.  Clearance of Insoluble
      Dust from the Lower  Respiratory Tract. Health Physics.  10:543-
      555, 1964.

215.  Morrow, P. E., F. R. Gibb and L.  J. Leach. The  Clearance  of
      Uranium Dioxide  Dust from the Lungs Following Single and Multiple
      Inhalation Exposures.  Health Physics.  12^:1217-1223,  1966.

216.  Gross, P.  The Processes Involved in the  Biologic Aspects  of Pul-
      monary Deposition, Clearance and  Retention of Insoluble Aerosols.
      Health Physics.   10_:995-1002,  1964.

217.  Mercer, T. T. On the Role  of Particle Size in the Dissolution of
      Lung Burdens. Health Physics.  13:1211-1221, 1967.

                                     377

-------
REFERENCES (continued)
218.  Kilburn, K. H.  Clearance Zones in the Distal Lung.  Ann. N.Y.
      Acad. Sci.  22^:276-281, February 28, 1974.

219.  Kanapilly, G. M. and C.  H. Goh.  Some Factors Affecting the in
      vitro Rates of Dissolution of Respirable Particles of Relatively
      Low Solubility.  Health Physics.  2_5:225-237, September, 1973.

220.  Bowden, D. H.  The Alveolar Macrophage.  Current Topics in
      Pathology.  5!5_:l-35, Springer-Berlag Pub.,  New York, 1971.

221.  Van Furth, R.  (Ed.)  Mononuclear Phagocytes.  Blackwell Sci.
      Pub., Oxford, 1971.

222.  Bingham, E., W. Barkley, M.  Zerwas, K. Stemmer and D. Taylor.
      Responses of Alveolar Macrophages to Metals.  Arch. Environ.
      Health.  25^206-414, December, 1972.

223.  Burrell, R. and M. Anderson.  The Induction of Fibrogenesis by
      Silica-treated Alveolar Macrophages.  Environmental Research.
      6_: 389-394, 1973.

224.  Waters, M. D., D. E. Gardner and D. L. Coffin.  Cytotoxic Effects
      of Vanadium on Rabbit Alveolar Macrophages  in vitro.  Toxicol.
      Appl. Phamacol.  2^:253-263, 1974.

225.  Brain, J. D. and P. A. Valberg.  Models of  Lung Retention Based
      on ICRP Task Group Report.  Arch. Environ.  Health.  28_:1-11,
      January, 1974.

226.  Lee, R. E. Jr., and D. J. Von Lehmden.  Trace Metal Pollution in
      the Environment.  APCA Journal.  23_: 853-857, October, 1973.

227.  Lee, R. E. Jr., R. E. Goranson and J. B. Moran.  National Air
      Surveillance Cascade Impactor Network II Size Distribution
      Measurements of Trace Metal Components.

228.  Kertesz-Saringer, M. E.  Meszaros and T. Varkonyi.  On the Size
      Distribution of Benzo(a)Pyrene-Containing Particles in Urban Air
      Atmos. Environ.  ,3:429-431,  1971.

229.  Rann, K. A., R. Dams, J. A.  Robbins and J.  W. Winchester.
      Diurnal Variations of Aerosol Trace Element Concentrations as
      Determined by Nondestructive Neutron Activation Analysis.
      Atmos. Environ.  5:413-422,  1971.
                                378

-------
REFERENCES  (continued)


230.  Harrison, P. R., W. R. Matson and J. W. Winchester.  Time Varia-
      tions of Lead, Copper and Cadmium Concentrations in Aerosols in
      Ann Arbor, Michigan.  Atmos. Environ.  5^613-619, 1971.

231.  Natusch, D. F. S. and J. R. Wallace.  Toxic Trace Elements:
      Preferential Concentration inRespirable Particles.  Science.  183:
      202-204, January, 1974.

232.  Natusch, D. F. S. and J. R. Wallace.  Urban Aerosol Toxicity:  The
      Influence of Particle Size.  Science.  186_: 695-699, November, 1974.

233.  Coffin, D. L. and D. E. Gardner.  Interaction of Biological Agents
      and Chemical Air Pollutants.  Ann. Occup. Hyg.  Vol. 15, pp, 219-
      234, 1972.

234.  Fairchild, G. A.  Ozone Effect on Respiratory Deposition of Vesi-
      cular Stomatitis Virus Aerosols.  Am. Rev. Resp. Dis.  109:446-451,
      1974.

235.  Lippman, M., R. E.  Albert,  and H.  J. Peterson, Jr.  The Regional
      Deposition of Inhaled Aerosols in Man.   Inhaled Particles III,
      Vol. 1.  W. H. Walton, ed.   Unwin Brothers Ltd., London,  1971.

236.  Brasser, L. J., P. E. Joosting and D. Von Zuilen.  Sulfur Dioxide--
      To What Level Is It Acceptable.  Research Institute for Public
      Health Engineering, Delft, Netherlands, Report G-300, July, 1967.
      (Originally published in Dutch, September, 1966.)

237.  Joosting, P. E.  Air Pollution Permissibility Standards Approached
      from the Hygienic Viewpoint.  Ingenieur.  79_(50) :A739-A747, 1967.

238.  Carnow, B. W., R. M. Senior, R. Karsh, S. Wesler and L. V. Alioli.
      The Role of Air Pollution in Chronic Obstructive Pulmonary Disease.
      J. Amer. Med. Assoc.  214(5):894-899, November 2, 1970.

239.  Douglas, J. W. B. and R. E. Waller.  Air Pollution and Respiratory
      Infection in Children.  Brit. J. Prev. Soc. Med.  20_:l-8, 1966.

240.  H. E. Goldberg, A. A. Cohen, J. F. Finklea, J. H. Farmer, F. B.
      Benson and G. J. Love.  Frequency and Severity of Cardiopulmonary
      Symptoms in Adult Panels:  1970-1971 New York Studies.  In:
      Health Consequences of Sulfur Oxides:  A Report from CHESS, 1970-
      1971.  U.S. Environmental Protection Agency, Research Triangle
      Park, North Carolina.  Publication No. EPA-650/1-74-004, 1974.

241.  Wicken, A. J. and S. F. Buck.  Report On a Study of Environmental
      Factors Associated with Lung Cancer and Bronchitis Mortality in
                                    379

-------
REFERENCES (continued)
      Areas of North East England.  Tobacco Research Council, London,
      Research Paper 8, 1964.

242.  Buechley, R. W., W. B. Riggan, V. Hasselblad and J. B. Van Bruggen.
      SO- Levels and Perturbations in Mortality.  A Study in the New
      York-New Jersey Metropolis.  Arch. Env. Health.  2^:134-137, 1973.

243.  Lunn, J. E., J. Knowelden and A. J. Handyside.  Patterns of
      Respiratory Illness in Sheffield Infant School Children.  Brit. J.
      Prev. Soc. Med.  21.: 7-16, 1967.

244.  Finklea, J. F., D. C. Calafiore, C. J. Nelson, W. B. Riggan and
      C. G. Hayes.  Aggravation of Asthma by Air Pollutants:  1971
      Salt Lake Basin Studies.  In:  Health Consequences of Sulfur
      Oxides:  A Report from CHESS, 1970-1971.  U.S. Environmental Pro-
      tection Agency.  Research Triangle Park, North Carolina, Publica-
      tion No. EPA-650/1-74-004, 1974.

245.  Finklea, J. F., J. H. Farmer, G. J. Love, D. C. Calafiore and
      G. W. Sovocool.  Aggravation of Asthma by Air Pollutants:  1970-
      1971 New York Studies.  In:  Health Consequences of Sulfur Oxides:
      A Report from CHESS, 1970-1971.  U.S. Environmental Protection
      Agency.  Research Triangle Park, North Carolina, Publication
      No. EPA-650/1-74-004, 1974.

246.  Shy, C. M., V. Hasselblad, J. F. Finklea, R. M. Burton, M. Pravda,
      R. S. Chapman and A. A. Cohen.  Ventilatory Function in School
      Children:  1970-1971 New York Studies.  In:  Health Consequences
      of Sulfur Oxides:  A Report from CHESS, 1970-1971.  U.S. Environ-
      mental Protection Agency.  Research Triangle Park, North Carolina,
      Publication No. EPA-650/1-74-004, 1974.

247.  shy, C. M., C. J. Nelson, F. B. Benson, W. B. Riggan, V. A. Newill
      and R. S. Chapman.  Ventilatory Functions in School Children:
      1967-1968 Testing in Cincinnati Neighborhoods.  In:  Health Conse-
      quences of Sulfur Oxides:  A Report From CHESS, 1970-1971.  U.S.
      Environmental Protection Agency.  Research Triangle Park, North
      Carolina,  Publication No. EPA-650/1-74-004, 1974.

248.  Nelson, W. C., J. F. Finklea, D. E. House, D. C. Calafiore, M. B.
      Hertz and D. H. Swanson.  Frequency of Acute Lower Respiratory
      Disease in Children:  Retrospective Survey of Salt Lake Basin
      Communities, 1967-1970.  In:  Health Consequences of Sulfur
      Oxides:  A Report from CHESS, 1970-1971.  U.S. Environmental Pro-
      tection Agency, Research Triangle Park, North Carolina, Publica-
      tion No. EPA-650/1-74-004, 1974.
                                 380

-------
REFERENCES (continued)


249.  Finklea, J. F., J. G.  French,  G.  R.  Lowrimore,  J.  Goldberg,  C. M.
      Shy and W. C. Nelson.   Prospective Surveys  of Acute Respiratory
      Disease in Volunteer Families, 1969-1970 Chicago Nursery School
      Study.   In:  Health Consequences  of  Sulfur  Oxides:   A Report from
      CHESS,  1970-1971.   U.S. Environmental  Protection Agency, Research
      Triangle Park, North Carolina, Publication  No.  EPA-650/1-74-004,
      1974.

250.  Love, G. J., A. A. Cohen,  J. F. Finklea, J. G.  French, G. R.
      Lowrimore, W. C. Nelson and P. B. Ramsey.  Prospective Surveys of
      Acute Respiratory  Disease  in Volunteer Families, 1970-1971 New
      York Studies.  In:  Health Consequences of  Sulfur  Oxides: A
      Report from CHESS, 1970-1971.   U.S.  Environmental  Protection Agency,
      Research Triangle  Park, North  Carolina, Publication No.  EPA-650/
      1-74-004, 1974.
              '                       \

251.  House,  D. E., J. F. Finklea, C. M. Shy, D.  C. Calafiore, W.  B.
      Riggan, J. W. Southwick and L. J. Olsen. Prevalence of Chronic
      Respiratory Disease Symptoms in Adults:  1970 Survey of Salt Lake
      Basin Communities.  In: Health Consequences of Sulfur Oxides:  A
      Report from CHESS, 1970-1971.   U.S.  Environmental  Protection
      Agency, Research Triangle  Park, North  Carolina, Publication  No. EPA-
      650/1-74-004, 1974.

252.  Finklea, J. F., J. Goldberg, V. Hasselblad, C.  M.  Shy, C. G.  Hayes.
      Prevalence of Chronic Respiratory Disease Symptoms in Military
      Recruits, 1969-1970.  In:   Health Consequences  of  Sulfur Oxides:
      A Report from CHESS, 1970-1971.  U.S.  Environmental Protection
      Agency, Research Triangle  Park, North  Carolina, Publication  No. EPA-
      650/1/74-004, 1974.

253.  Lewis,  T. R., M. 0. Amdur, M.  D.  Fritzhand  and  K.  I. Campbell.
      Toxicology of Atmospheric  Sulfur  Dioxide Decay  Products.  Environ-
      mental Protection  Agency Publication No. AP-111, National Environ-
      mental Research Center, Research  Triangle Park, North Carolina,
      July, 1972.

254.  Amdur,  M. 0. A Review of  the  Toxicology of the Oxidation Products
      of Sulfur Dioxide, Arch.. Environ. Health.  2^:459-468, 1971.

255.  McJilton, C., N. R. Frank  and  R.  Charlson.   Role of Relative
      Humidity in the Synergistic Effect of  a Sulfur  Dioxide-Aerosol
      Mixture on the Lung.  Science. 18^:503-504, 1973.

256.  Fairchild, G. A. and S. Stultz.  Sulfuric Acid  Effect on Deposi-
      tion of Radioactive Aerosol in the Respiratory  Tract of Guinea
      Pigs.  Submitted to Arch.  Environ. Health.   November 15, 1974.
                                   381

-------
REFERENCES (continued)


257.  Fairchild, G. A., P. Kane, B. Adams and D.  L.  Coffin.   Effect of
      Sulfuric Acid Inhalation on Clearance of Radioactive Aerosol from
      the Respiratory Tract of Mice.  In manuscript undergoing NERC
      clearance prior to submission for publication, October, 1974.

258.  Busey,  W. M.   Chronic Exposure of Cynomolgus  Monkeys  to Sulfuric
      Acid Mist and Fly Ash Mixtures, Project RP-74, Hazleton Labora-
      tories, Inc. report to Edison Electric Institute,  December,  1972.

259.  Alarie, Y., C. E. Ulrich, W. M. Busey, A. A. Krumm and H. N. Mac
      Farland.  Effects of Long-Term Continuous Exposure to  Sulfur
      Dioxide in Cynomolgus Monkeys, Arch.  Environmental Health.  24:
      115-128, 1972.

260.  Alarie, Y., C. E. Ulrich, W. M. Busey, H. E. Swann and H. N. Mac
      Farland.  Effects of Long-Term Continuous Exposure of  Guinea Pigs
      to Sulfur Dioxide.  Arch. Environmental Health.  2.1:769-777, 1970.

261.  Alarie, Y., W. M. Busey, A.  A. Krumm and C. E. Ulrich.  Long-Term
      Continuous Exposure to Sulfuric Acid Mist in Cynomolgus Monkeys
      and Guinea Pigs.  Arch. Environmental Health.   27^:16-24, 1973.

262.  Alarie, Y., R. J. Kantz II,  Charles E. Ulrich, A.  A. Krumm and
      W. M. Busey.  Long-Term Continuous Exposure of Sulfur  Dioxide and
      Fly Ash Mixtures in Cynomolgus Monkeys and Guinea Pigs.  Arch.
      Environmental Health.  27^251-253, 1973.

263.  Zabower, A.  Alterations in Antibody Response  Induced  by Chronic
      Inhalation of S09 and Carbon.  Arch.  Environmental Health.  25:
      45-50,  1972.    L

264.  Ikeda,  Y. et al.  Long-Term Toxicity Study of  Methylmurcuric
      Chloride in Monkeys.  Toxicology  lj61-375, 1973.

265.  Takeuchi, T.  Environmental Mercury Contamination.  Eds. R.
      Harting, B. D. Dinman.  Ann. Arbor. Sci. Pub.  1972, p. 247.

266.  Khera,  K. A.  Teratogenic Effects of Methylmercury  in the Cat.
      Teratology  8;293-304, 1973.

267.  Magos,  L. et al.  Cumulative Effects of Methylmercury  Dicyandia-
      mide Given Orally to Rats.  Fd. Cosmet. Toxicol.   1£: 513-17, 1972.

268.  Irukayama, K.  Cited by G. Lofroth in Methylmercury Bull. No.  4,
      Ecological Res. Comm. Swedish Natural Sciences Res. Council, 1970.

269.  Post. E. M. et al.  Behavioral Changes in Young Rats Force-Fed
      Methylmercury Chloride.  Proc. Soc. Exp. Biol. Med. 143:1115-16,
      1973.


                                  382

-------
REFERENCES (continued)


270.  Fukuda, K.  Metallic Mercury-Induced Tremor in Rabbits and Mercury
      Content of the Central Nervous System.  Brit.  J.  Ind.  Med.  28:
      308-311, 1971.                                              ~~

271.  Beliles, R. P. et al.  Tox.  Appl.  Pharmacol.   .12:15-21, 1968.

272.  Charbonneau, S. M.  Subacute Toxicity of Methylmercury in the
      Adult Cat.  Tox.  Appl. Pharmacol.   27_: 569-581, 1974.

273.  Gale, T. F. et al.  Embryopathic Effects of Mercury Salts.  Life
      Sci.  10:1341-1347, 1971.

274.  Gale, T. F.  The  Interaction of Mercury with  Cadmium and Zinc in
      Mammalian Embryonic Development.  Environ.  Res.  6_:95-105, 1973.

275.  Spyker, J. M. et  al.  Effects  of Methylmercury on Prenatal and
      Postnatal Development in Mice.  Teratology £:242, 1971.

276.  Spyker, J. M. et  al.  Behavioral Teratology of Methylmercury in
      the Mouse.  Pharmacol.  1.3:275, 1971.

277.  Klein, S. B.  Mercury Chloride Influence on Active-Avoidance
      Acquisition in Rats.  Bull.  Psychon. Soc.  1_:437-438,  1973.

278.  Kawabe, H. et al.  The Effect of Prenatal Methylmercury Poisoning
      on the Mouse Fetus.  Teratology  6:11, 1972.

279.  Munro, J. C. et al.  Toxic Effects of Methylmercury in the Rat.
      Tox. Appl. Pharmacol.  2_2:29,  1972, Abs. No.  53.

280.  Herigstad, R. R.  et al. Chronic Mercury Toxicosis in Calves.
      J.A.V.M.A.  16(3:173-182, 1972.

281.  Iverson, F.  Accumulation  and Tissue Distribution of Mercury in
      the Guinea Pig During Subacute Administration of Methylmercury.
      Tox. Appl. Pharmacol.  27_:60-69, 1974.

282.  Tatetsu, M. et al.  Psychiat.  Neurol. Jap.   7£:162, 1968.

283.  Suzaki, T. et al.  Neurological Symptoms and  Mercury Concentration
      in the Brain of Mice Fed with Methylmercury Salt.  Ind. Hlth.  9j
      51-58, 1971.

284.  Iverson, F.  Methylmercury:   Acute Toxicity,  Tissue Distribution
      and Decay Profiles in the  Guinea Pig.  Tox. Appl. Pharmacol.  24:
      545-554, 1973.
                                  383

-------
REFERENCES (continued)


285.  Newberne, P. M. et al.  Chronic Exposure of Rats to Methyl Mercury
      in Fish Protein.  Nature  237;40-41, 1972.

286.  Singhal, R.  L. et al.   Metabolic Alterations in Liver and Kidney
      Following Chronic Msthyl Mercury Treatment and Withdrawal.  Environ.
      Res.  7; 220-229, 1974.

287.  Lucier, G. W. et al.   Methyl Mercury-Induced Changes in Rat Liver
      Microsomes.   Environ,  Hlth.  Perspect.  4:102, 1973.

288.  Klein,  R. et al.  Methyl Mercury Intoxication:  Early Functional
      and Morphological Changes in the Rat Kidney.  Environ.  Hlth.
      Perspect.  1_:100, 1973.

289.  Fowler, B. A. et al.   Phenobarbital Protection Against Methyl
      Mercury Nephrotoxicity.  Environ. Hlth. Perspect.   4_:100, 1973.

290.  Hastings, F. L.  Methyl Mercury-Cholinesterase Interactions in
      Rats.  Environ. Hlth.  Perspect.  4_:101, 1973.

291.  Khera,  K. S. et al.  Effects of Methylmercuric Chloride on the
      Progency of Mice and Rats Treated Before or During Gestation.  Fd.
      Cosmet. Toxicol.  11_:245-254, 1973.

292.  Gate, C. C.  and R. Burrell.   Lung Antigen Induced Cell-Mediated
      Immune Injury in Chronic Respiratory Diseases.  Amer. Rev. Resp.
      Dis.  109_: 114-23, 1974.

293.  Clary,  J. J., C. R. Hopper and H. E. Stokinger. Altered Adrenal
      Function as  an Inducer of Latent Chronic Beryllium Disease.
      Tox. Appl. and Pharmacol.  23_:365-375,  1974.

294.  Clary,  J. J. and D. H. Groth.  Comparative Changes in Serum Enzyme
      Levels  in Beryllium- or Carbon Tetrachloride-Induced Liver
      Necrosis.  Proc. Soc.  Exp. Biol. Med.  143:1207-1210.

295.  Clary,  J. J. and H. E. Stokinger.  The  Mechanism of Delayed
      Biologic Response Following Beryllium Exposure.  J. of Occ.
      Med.  15^:255-259.

296.  Furchner, J. E., C. R. Richmond and J.  E. London.   Comparative
      Metabolism of Radionuclides  in Mammals.  VIII.  Retention of
      Beryllium in the Mouse, Rat, Monkey and Dog.  Health Physics
      24_: 293-300,  1973.

297.  Goldblatt, P. J., M. W. Lieberman and H. Witschi.   Beryllium-
      Induced Ultrastructural Changes in Intact and Regenerating Liver.
      Arch. Environ. Health   26^:48-56.

                               384

-------
REFERENCES (continued)


298.  Jacques, A. and H.  R.  Witschi.   Beryllium Effects  on Aryl Hydro-
      carbon Hydroxylase  in JRat Lung.   Arch Environ.  Health  27:243-
      247, 1973.                                             ~~

299.  Krivanek, N. and A. L. Reeves.   The Effect of Chemical Forms  of
      Beryllium on the Production of the Immunologic Response.   J.  Amer.
      Indust. Hyg. Assoc.  33:45-52,  1972.

300.  Marx, James J.  and  R.  Burrell.   Delayed Hypersensitivity  to
      Beryllium Compounds.  J.  Immunol.  11^:590-598, 1973.

301.  Schneider, M.,  M. I. Resnick and K. F. Wellman.  Increased Bone
      Formation in Rabbits Following Intravenous and Intra-Osseous
      Injection of Zinc Beryllium Silicate.  Clin.  Orthop.  Relat. Res.
      92^251-259, 1973.

302.  sionim, A. R. and F. C..  Dann.   Beryllium Uptake by the Common
      Guppy Using Radioactive Beryllium-7.  II.   Beryllium Concentration
      in Fish.  U.S.  Nat. Teca.  Inform. Service, Iss. No.  758815, p.  29,
      1972.

303.  sionim, A. R.  Acute Toxicity of Beryllium Sulfate to the Common
      Guppy.   J. Water Pollut.  Contr.  Fed.  4_5:2110-2122,  1973.

304.  Vacher, J.  Immunological Responses of Guinea Pigs to Beryllium
      Salts.   J. Med. Microbiol.   5>:91-108, 1972.

305.  Vacher, J., R.  Deraedt and J.  Benzoni.  Compared Effects  of Two
      Beryllium Salts (Soluble and Insoluble):  Toxicity and Blockade
      of the Reticuloendothelial System.  Toxicology and Applied
      Pharmacology 24_:497-506,  1973.

306.  Vacher, J., R.  Deraedt and J.  Benzoni.  Influence  of a Change in
      the Activity of the Reticuloendothelial System on  the Development
      of Adjuvant-Induced Polyarthritis in the Rat.  J.  Reticuloendothel.
      Soc.  13:579-588, 1973.

307.  Vasil,  E.  Changes  in the Antigenic Composition in the Lungs  in
      Experimental Berylliosis.   Byull. Eksp.  Biol. Med.  73:76-80, 1972.

308.  Criteria for a  recommended standard.  Occupational Exposure to
      Asbestos, NIOSH,  HEW,  1972.

309.  EPA National Emission Standards  for Hazardous Air  Pollutants,
      Asbestos, Beryllium and Mercury.   Federal Register,  Vol.  38,
      No. 66, April,  1973.
                                  385

-------
REFERENCES (continued)


310.  Proceedings of the Second International Conference on Biological
      Effects of Asbestos, Dresden, 1968 Proceedings.

311.  International Conference on Pneumonoconiosis,  Johannesburg, 1969,
      Oxford University Press, 1970.

312.  Proceedings of the Working Group Meeting on Biological Effects of
      Asbestos.  Lyon, 1972.   Preprint 30 Int. Agen. Res. Cancer, Lyon,
      France.

313.  Williams, S.  Asbestos.   A Bibliography of the World's Literature
      Abstracted and Indexed (a thesis).  Pneumonconiosis Research Unit
      CSIR, 1969.  P.O. Box 1038, Johannesburg.

314.  Wagner, J. C.  Brit. J.  Ind. Med. 20,  1963.

315.  Selikoff, I. J., E. C. Hammond and M.  Seedman.  Working Group
      Meeting on Biological Effects of Asbestos.   Preprint 33, Int.
      Agency Res. Cancer, Lyon, France, 1972.

316,  Meurman, L. 0., R. Kiviluoto and M. Hakama.  Int. Conf. Bio.
      Effects Asbestos.  Preprint 31.

317.  Cilson, J. C.  Asbestos  Cancer Report  of the Advisory Committee
      to Director Int. Agency  Res. Cancer, Lyon,  France, 1972.

318.  Bragg,  L. W. and G. F. Claringbull. Crystal Structure of Miner-
      als.  Bell, London.

319.  Kiviluoto, R.  Pleural Calcification as Roentgenologic Sign of
      Nonoccupational Endemic  Anthophyllite  - Asbestos.  Radial Supp.
      194, pp. 1-67. 1960.

320.  Wagner, J. C. and G. Berry.  Brit. Jour. Cancer   23^:567, 1969.

321.  Harrington, J. S.  In Working Group on Biological Effects of
      Asbestos.  Preprint 45,  Int. Agency Res. Cancer, Lyon, France,
      1972.

322.  Stanton, M. F., R. Blackwell and E. Miller. Amer. Ind. Hyg.
      Assoc.  J.  30_:236, 1969.

323.  Stanton, M. F. and C. Wrench.  J. Ntl. Cancer  Inst.  48_:797,
      1972.

324.  Stanton, M. F.  In Working Group Meeting on Biological Effects
      of Asbestos.  Preprint 43A.  Int. Agency Res.  Cancer, Lyon, 1972.
                                 386

-------
REFERENCES (continued)
325.  Davis, J. M. G.   Histogenesis and Fine Structure of Peritoneal
      Tumors Produced in Animals by Injection of Asbestos.  J.  Ntl.
      Cancer Int.  52^1823, 1974.

326.  Wagner, J. C., G. Berry, J. W.  Skidmore and V.  Timbrell.   The
      Effect of the Inhalation of Asbestos in Rats.   Brit, of Cancer
      2£:252, 1974.

327.  Selikoff, I. J., W. J. Nicholson and A. M. Langer.   Arch. Env.
      Hlth.  2,5:1, 1972.

328.  Vorworld, A. J., T. M. Durkan and P. C. Pratt.   Arch. Ind. Hyg.
      Occup. Med.  _3:1, 1951.

329.  Smither, W. J. and H. C. Ldwinsohn.  In Working Group Meeting on
      Biological Effects of Asbestos.  Preprint 26,  Int.  Agency Cancer,
      Lyon, France, 1972.

330.  Naviatil, M. and F. Trippe.  Prevalence of Pleural  Calcification
      in Persons Exposed to Asbestos  Dust and in the General Population
      in the Same District.  Env. Res.  5_:210, 1972.

331.  Miller, K. and J. S. Harrington.  Brit. J. Exp. Pathol.  55:397,
      1972.

332.  Davis, J. M. G.   Brit. J. Exp.  Pathol.  5_3:190, 1972.

333.  Harrington, J. S., A. C. Allison and D. V. Badomi.   Mineral Fibers
      Chemical, Physiochemical and Biological Properties  Advances in
      Pharmacology.  (In Press.)

334.  Gross, P., R. T. P. de Treville, E. B. Talker,  M. Kaschak and M. A.
      Babyah.  Arch. Env. Health.  15:343, 1967.

335.  Gross, P, R. T.  P. de Treville and L. J. Cralley.  In Pneumono-
      coniosis (H.A. Shapiro ed.).  Oxford University Press, London and
      New York, 1970.

336.  Wagner, J. C.  Nature (London).  196:180, 1962.

337.  Shabad, L. M., L. N. Phlev, L.  V. Krivosheeva,  T. F. Kulagina and
      B. A. Nemenko.  Expermental Studies on Asbestos Carcinogenecity.
      J. Natl. Cancer Inst.  52;1175, 1974.

338.  Pylev, L. M., F. J. Roe and G.  P. Warwick.  Elimination of Radio-
      activity after Intratracheal Instillation of 3.4-BP in Hamsters.
      Br. J. Cancer  23:103, 1969.
                                    387

-------
REFERENCES (continued)
339.  Wagner, J. C.  Recent Results.  Cancer Research  39_:37, 1972.

340.  Beloin, N. J.  Fading of Dyed Fabrics by Air Pollution:  A Field
      Study.  Text. Chern. Color.  4^43-48, March, 1972.

341.  Beloin, N. J.  Fading of Dyed Fabrics by Air Pollution:  A Cham-
      ber Study.  Text. Chem.  Color.  5^:128-133, July, 1973.

342.  Haynie, F. H. and J. B.  Upham.  Effects of Atmospheric Sulfur
      Dioxide on the Corrosion of Zinc.  Materials Protection and
      Performance.  9;35-40, August, 1970.

343.  Haynie, F. H. and J. B.  Upham.  Effects of Atmospheric Pollutants
      on Corrosion Behavior of Steels.  Materials Protection and Per-
      formance.  10_: 18-21, November, 1971.

344.  Haynie, F. H. and J. B.  Upham.  Correlation Between Corrosion
      Behavior of Steel and Atmospheric Pollution Data.  In:  Corrosion
      in Natural Environments, ASTMSTP 558, American Society for Testing
      and Materials.  Philadelphia, 1974.  pp. 33-51.

345.  Campbell, G. G., G. G. Schurr, D. E. Slawikowski and J. W. Spence.
      Assessing Air Pollution  Damage to Coatings.  J. Paint Technology.
      46_(593): 59-71, June, 1974.

346.  In Preparation, to be published.

347.  Beloin, N. J.  Fading of Dyed Fabrics by Air Pollution:  A Field
      Study.  Text. Chem. Color.  4_: 43-48, March, 1972.

348.  Beloin, N. J.  Fading of Dyed Fabrics by Air Pollution:  A Chamber
      Study.  Text. Chem. Color.  5_: 128-133, July, 1973.

349.  In Preparation, to be published.

350.  Charlson, R. J., A. H. VanderPol, D. S.  Covert, A.  P. Waggoner,
      N. C. Ahlquist,  Sulfuric Acid-Ammonium Sulfate Aerosol:  Opti-
      cal Detection in the St. Louis Region.  Science.  184:156, 1974.

351.  Samuels, H. J., S. Twiss, E. W. Wong.  Visibility,  Light Scatter-
      ing and Mass Concentration of Particulate Matter.  Report of the
      California Tri-City Aerosol Sampling Project, State of California
      Air Resources Board, 1973.

352.  Covert, D. S.  A Study of the Relationship of Chemical Composition
      and Humidity to Light Scattering by Aerosols.  Phd. Thesis, Uni-
      versity of Washington, Seattle, Washington.
                                388

-------
REFERENCES (continued)


353.  Woodwell, G.  M.   Effects of Pollution on the Structure and Physi-
      ology of Ecosystems.   Science  168_:429-433,  1970.

354.  Likens, G. E. and F.  H.  Borman.   Linkages between  Terrestrial and
      Aquatic Ecosystems.   Bio Science.  24_:447-456,  1974.

355.  Smith, R. L.   Ecology and Field Biology.  2nd.  ed., Hoper § Row,
      New York, New York.   1974.

356.  McCune, D. C. and W.  W.  Heck.  Health Effects of Air  Pollutants.
      In:  Air Quality and  Automobile Emission Control - Vol. 2.   Com-
      mittee of Public Works,  United States Senate.  Pp. 503-511.  1974.

357.  Inman, R. E., R.  B.  Ingersol and E. A. Levy.  Soil:   A Natural Sink
      for Carbon Monoxide.   Science.   172:1229-1231,  June 18, 1971.

358.  Air Quality for Carbon Monoxide, N. 10.   A Report  by  the Expert
      Panel on Air Quality  Criteria,  NATO Committee on the  Challenges
      of Modern Society. Research Triangle Park,  North  Carolina, pp. 1-9
      to 1-11.  1972.

359.  Air Quality Criteria  for Nitrogen Oxides, N. 15.  A Report by the
      Expert Panel on Air Quality Criteria.  NATO Committee on the Chal-
      lenges of Modern Society.  Research Triangle Park, North Carolina,
      Chapter 7.  1973.

360.  Miller, P. L.  Oxidant-Induced Community Change in a  Mixed Conifer
      Forest.  Adv. in Chem. Series No. 122.  Air Pollution Damage to
      Vegetation,  pp.  101-117.  1973.

361.  Air Quality Criteria  for Photochemical Oxidants and Related Hydro-
      carbons.  N.  29.   NATO Committee on the Challenges of Modern
      Society.  Research Triangle Park, North Carolina.  Chapter 4.  1974.

362.  Heck, W. W. and E. G. Pires.  Growth of Plants Fumigated with
      Saturated and Unsaturated Hydrocarbon Gases and Their Derivative.
      The Agricultural and Mechanical College of Texas,  Texas Agr. Expt.
      Station.  MP603.   p.  12.  1962.

363.  Andelman. J.  B.  and M. J. Suess.  Polvnuclear Aromatic Hydrocarbons
      in Water Environment.  Bull. World Health Organization.  4J5:479-
      508, 1970.

364.  Garner, J. H. B.   The Death of Woody Ornamentals Associated with
      Leaking Natural Gas.   Proc. j9  Intl. Shade Tree Conf., Boston,
      Massachusetts,   p. 13-17.  1973.
                                      389

-------
REFERENCES (continued)
365.  Westman, Lars.   Air Pollution Indications and Growth of Spruce
      and Pine Near a Sulfite Plant.   Arnbio.   3_:189-193.   1974.

366.  ERC/RTP Task Force Report on Suspended Sulfates and Sulfuric
      Acid Aerosols.   Research Triangle Park, North Carolina. March,
      1974.

367.  Likens, G.  E. and F. H. Borman.   Acid:   A Serious Regional
      Environmental Problem.   Science.  1M: 1176-1179, 1974.

368.  Robinson, E. and R. C.  Robbins.   Gaseous Nitrogen Compound Pol-
      lutants from Urban and Natural Sources.  J.A.P.C.A.  20:303-
      306, 1970.

369.  Air Quality Criteria for Photochemical  Oxidants. AP-63.
      Washington, B.C.  1970.

370.  Romney, E.  M.,  J. D. Childress and G. V. Alexander.  Beryllium
      and the Growth of Bush Beans.  Science.  135:786-787, 1962.
                               390

-------
                          6.  CONTROL TECHNOLOGY





6.1  STATIONARY SOURCES VS.  POLLUTANTS



     Stationary combustion sources contribute more to ambient atmospheric



loading of SO , NO  and total suspended particulates (TSP) than any other
             J\.    X


anthropogenic source category.  These sources are responsible for (1)



approximately 80% of the SO  emissions, 50% of the NO  emissions and
                           .X                         «X.


(2) over 501 of ambient fine particulates.



     Industrial processes and open sources (e.g., open burning, mining,



incineration, fugitive emissions) are responsible for (1) approximately



161 of the SO  emissions, 441 of the hydrocarbon emissions, 22% of the
             A.


CO emissions and (2) over 25?. of ambient fine particulates.  They are



also responsible for most of the hazardous air pollutant emissions (i.e.,



asbestos, beryllium and mercury), vinyl chloride and other potentially



hazardous carcinogenic pollutants.



6.1.1  Particulate Control



     The most pressing need in particulate control technology is for



development of commercially available and widely applicable fine particle



(less than 3 microns) control technology to support the establishment of



Fine Particulate standards to provide control of secondary particulate



precursors, catalysts and hazardous trace elements.  Such technology is



inadequate and only just undergoing development under EPA sponsorship.



     Scrubbers, electrostatic precipitators and fabric-filter particle



collectors are principal particulate collection devices.  They are being



upgraded by projects concerned with decreasing costs, increasing appli-



cability of devices to a wider range of sources and extending their range
                                   391

-------
of particle collection capability to smaller particle sizes.  In addi-



tion, entirely new concepts of particle collection are being investi-



gated.



      System studies have been completed for each of the conventional



devices.  These define potential areas of improvement and new applica-



tions.  Long-range projects include development of generalized models



for existing collectors, indentification and laboratory scale testing



of totally new concepts in particle control technology and pioneering



work in small-particle detection and small-particle generation equip-



ment.



6.1.2  Sulfur Oxides Control



      For Sulfur oxides control, achievement of Ambient Air Quality



Standards require control of industrial combustion, industrial pro-



cesses and area sources, including utility combustion.   There is only



enough natural low-sulfur fuels to satisfy about 40% of the demand of



State Implementation Plans.   The remainder must be supplied by con-



trol technology in the form of effluent desulfurization, fuel cleaning



or process modification.



      Although the currently defined sulfur oxides control technology



program contains developmental projects of sufficient diversity to



ensure achievement of Ambient Air Quality Standards, a substantial EPA



research and development investment will be required to bring this



technology to commercial fruition.  Only in the case of effluent de-



sulfurization technology for electric utility applications should con-



trol technology achieve widespread commercialization the next few years.



      The program has emphasized stack-gas cleaning systems with five or






                                392

-------
six such processes to be demonstrated before 1976.  It has also included



work in such areas as fuel modification and desulfurization, industrial



process modification and advanced combustion processes.



     Most of EPA's early coaL de-sulfurization work involved improving



and evaluating physical cleaning methods for coal.  With the over all



potential of physical de-sulfurization and de-ashing of coal reasonably



well established, this approach should have moderate applicability in



reducing sulfur by 30 to 70% in specific coals.  On-going work in this



area includes washability testing, coal de-sulfurization and cleaning



and pollutant control evaluation and optimization.  The most recent work



is aimed at chemical de-sulfurization of coal and problems of hazardous



pollutants in fossil fuel.



     Laboratory-scale technology developments are under way on processes



to remove sulfur from coal, producing a clean fuel for combustion.  The



two processes under development are unique since one is completely



selective to inorganic sulfur in coal, the other is being developed for



preferential organic sulfur removal and both produce a solid fuel that



retains the basic physical characteristics of coal.



     The technical feasibility of the inorganic sulfur-removal system



has been proven in the laboratory and on the bench scale.  It is under-



going scale-up design to a pilot plant size operation.  Construction of



this plant is scheduled to begin in early 1974.  The degree of sulfur



removal that can be obtained from the organic sulfur-removal process is



currently being quantified in a laboratory apparatus.



     This system could be well enough developed by mid-1974 to initiate



scale-up design to continuous pilot operation by September, 1974.
                                   393

-------
The two systems will be examined in detail for their capatibility for



integration into one process scheme for complete removal of sulfur from



coal.  After successful pilot-plant operation, plans call for scale-up



to a demonstration size plant.



      Two factors--the major contribution of small coal and oil-burning



sources (area sources) to degradation of ambient air quality and the



severely limited supplies of low-sulfur fuels--indicate a need for clean



fuel or coal conversion processes.  CSL has provided funds to both the



Bureau of Mines and the Office of Coal Research to assist in development



of conversion and gasification processes that can provide clean fuels



and to determine what environmental controls will be required for these



techniques.



      The work on advanced processes primarily involves development of



fluidized-bed combustion.  Fluidi^ed-bed combustion process options



being investigated include:  pressurized coal combustion, coal gasifi-



cation for production of low-sulfur and low-Btu fuel gas and oil gasi-



fication.  System studies also have been done on development of advanced



power cycles.



      Work is being conducted to control emissions from smelters, iron



and steel operations, refineries, iron foundries, secondary aluminum



furnaces and other industrial sources.



6.1.3  Nitrogen Oxides Control



      On a national basis, 98% of the nitrogen oxides (NO ) from sta-
                                                         X


tionary sources are from combustion processes.  For this reason, the



NO  control program is oriented heavily toward combustion control.  Con-
  J\,


trol technologies under investigation to provide near-term solutions to
                                394

-------
the problem include:  combustion modifications such as flue gas recircu-



lation, off-stoichiometric combustion and low excess air operation;



identification of alternate or novel combustion systems with inherently



low NO  emission levels; changes in burner design and the use of alter-
      A.


nate fuels.



     Although flue-gas cleaning processes and advanced power cycles are



also being investigated, they may offer longer-term solutions to the



problem.  Major emphasis in this program has been on coal combustion in



utility and industrial boilers since that poses the most difficult



problem.



     The main approach has been modification of the combustion process



to reduce NO  formation.  Bench-scale work and field testing indicate



that control for the immediate future can be achieved by this method.



In addition, promising stack-gas cleaning processes are being evaluated



and investigated on a small scale.-  Results of this research, however,



have not been encouraging so far.



     A complicating factor in developing effective control technology



is that NO  are formed during combustion through two separate mechanisms -



the fixation of nitrogen in combustion air and the conversion of fuel-



bound nitrogen contained in fuels.  Although some control of both types



of NO  has been achieved by combustion modifications, it is not known



if combustion modification alone will adequately control the NO  from



fuel nitrogen.



6.1.4  Hazardous and Other Control



     As EPA regulatory programs develop, the number of pollutants requir-



ing control has expanded to include more than 30 potentially hazardous





                                  395

-------
and annoying air pollutants.  Since a majority of the hazardous pollu-



tants are likely to be emitted as particulate matter, there is strong



interaction between these two programs.



      Examples of specific hazardous and other pollutants under con-



sideration include asbestos, beryllium, cadmium, carbon monoxide,



fluorides, hydrocarbons, lead and mercury and odorous materials from



rendering plants, pulp mills, sewage treatment plants and chemical pro-



cess industries.  Because of the paucity of data currently available,



many problem definition and source characterization studies are required



to deal with these pollutants on a rational basis.



6.2  STATIONARY SOURCES VS. CONTROL



      Significant advances in development and demonstration of technology



to control SO , NO  and primary particulates have already been achieved.
             X    X.


Additional improvements in the state of the art are projected for coming



years.  A brief summary of proven and promising technology under develop-



ment to control various combustion emissions are described below.



6.2.1  Combustion



6.2.1.1  Fuel Gas De-Sulfurization--Consistent with Congressional guide-



lines, major concern has focused on control of sulfur oxides from fuel



combustion.   Expenditures for this have been about 80% of the NERC/RTP



Control Systems Laboratory's expenditures to date.  And flue-gas de-



sulfurization (FGD)  technology development has comprised a major portion



of this work.



      Flue-gas de-sulfurization systems have been installed on several



major commercial power plants in the U.S.A.  At least 80 more such



systems will be installed by 1980.  With the exception of use of clean
                                 396

-------
fuels, flue-gas de-sulfuriza.tion is the only sulfur oxides control
technology that will have widespread application in the next 15 years.
With the expected shortage of clean fuels (amounting to about 20% of
the coal demand), flue-gas de-sulfurization will be needed to off-set
that shortage.
     The need to develop techniques that permit use of eastern and
midwestern coal is urgent since only about 7% of this coal is now
usable under New Source Performance Standards.  And a domestic resource
about equivalent in value to the GNP will not be available for use
without FGD technology.
     Flue-gas de-sulfurization is a technically sound solution that is
also economically acceptable.  The cost of flue-gas de-sulfurization
for coal-fired power plants should be 2 to 3 mills/Kwbr^ ' compared to
2 to 4 mills/Kwhr^- ' for naturally-occurring clean fuels delivered to
the power plant site and even higher costs of approximately 8-13 mills/
Kwhr^ ' associated with coal gasification technologies.
6.2.1.1.1  Sodium hydroxide scrubbing with electrolytic regeneration
(Stone § Webster/Ionics)--In July, 1972, EPA and Wisconsin Electric
Power Company (WEPCO) initialed a 3-1/2 year, three-phase program involv-
ing the Stone $ Webster (SWI) sodium hydroxide scrubbing process.
     In Phase I, recently completed, an integrated pilot plant was
built.  Operating tests were performed for about a one-year period and
a prototype-scale electrolytic cell system was designed, fabricated and
tested.  Preliminary design of a 75 MW prototype system and development
of detailed test programs and operating schedules for the prototype
system were also completed.  The Phase I final report was scheduled for
publication in late 1974.
                                    397

-------
      Based on favorable assessment of Phase I results and continued



technical and economic viability of the process, a 16-month-long Phase



II effort is being considered for the detailed design, procurement and



installation of the 75-MW prototype.  This would be followed by Phase



III, a 12-month start-up and operational period for the 75-MV prototype.



Assuming a decision to proceed, EPA and WEPCO would co-fund the $7 mil-



lion program.



      Chief advantages of the process, expected to apply to both exist-



ing and new power plants over a broad range of sizes, are:  highly



efficient removal of SO ; production of easily handled non-slurry flow
                       Jv.


streams; no solid waste; and recovery of SCL for subsequent processing



into liquified SO-, sulfuric acid or elemental sulfur.



      Potential disadvantages of the process include:  power require-



ments for electrolytic regeneration, adverse influence of particulate



and flue-gas trace constituents on reliability of the electrolytic cell



and need to remove from the system any sulfates produced by oxidation



in the scrubber.  The Phase I final report will evaluate and assess



these potential disadvantages.



6.2.1.1.2  Catalytic oxidation (Monsanto Cat-Ox)--The catalytic oxida-



tion (Cat-Ox) process is an adaptation of the contact sulfuric acid



process.  Monsanto Enviro-Chem Systems, Inc. has developed this adap-



tation through work on a pilot-scale unit and a 15-MW prototype.  EPA



and Illinois Power Company (sharing a $7 million total funding require-



ment) prepared to demonstrate the process on a 100-MV coal-fired boiler



at Illinois Power's Wood River Station by late 1974 with accompanying



commencement of the one-year test program.





                                398

-------
     The Cat-Ox system is available in two configurations:  the Reheat



system for retrofitting existing plants and the Integrated system for



incorporation into new power generating facilities.



     The Reheat system operates with flue gases passing first through a



high efficiency (99.6%) electrostatic precipitator.  Then, in prepara-



tion for catalytic conversion of the S0? to SO,, the temperature is



raised to about 850°F.  This heat is added in three increments by:  a



primary input from an external combustor, a gas heat exchanger and a



secondary input from the external combustor.



     After heating, S02 contained in flue gases is converted to SO, by



the catalyst.  Leaving the converter, the hot flue gases pass through



the high-temperature side of the gas heat-exchanger to the acid produc-



tion section.  The sulfuric acid is formed by the standard SO,-FLO



absorbing tower contact process.



     The acid product is cooled and sent to storage while the flue gases



pass through a fiber-packed mist eliminator (where residual traces of



sulfuric acid mist are removed) and on to the stack where clean gas



exits to the atmosphere.  At this point, essentially all particulate



matter and 85% of the SO- have been removed from the gas stream.



     Trace and hazardous element analyses account for an important



portion of the over all Cat-Ox test program.  A complete characteriza-



tion of Wood River Unit No. 4 (prior to Cat-Ox equipment tie-in)



included analyses for some 30 trace elements in the coal, hopper ash



and slag.  Other analyses included fly ash, where elemental analysis



has been done for a complete range of size fractions.  These tests will



be repeated during the one-year test program (after the Cat-Ox system
                                     399

-------
becomes operational) to determine effects of the system on concentration



and distribution of trace elements.



6.2.1.1.3  Sodium ion scrubbing (Wellman-Lord)--EPA has high confidence



for success of this first coal-fired boiler demonstration system in



meeting guarantees for pollution control, product quality and material



and utility requirements.  This confidence is based on the already



large amounts of successful operating experience to date for W-L Systems



on various applications, including acid plants, Glaus plants and oil-



fired boilers.  Seven systems are now in operation in the U.S. and



Japan.



      The knowledge gained from operating these systems has produced a



series of process improvements (reducing costs and purge requirements)



that are incorporated in the EPA/NIPSCO demonstration (115 MW coal-fired



power plant for 90-95% SO- removal efficiency).  CSL is considering



expansion of the Wellman Power Gas Demonstration to achieve 98-99%



removal efficiency.  This could be done with little interruption of the



current project and at an incremental cost of approximately $400,000-



$2,000,000, depending on the length of the high efficiency trials.



      As an on-going project with high efficiency potential, the Well-



man Power Gas System (Sodium base scrubbing) could be the first tech-



nique available to achieve eventual SCL-sulfate standards.  Data from



the Wellman Demonstration could be available prior to 1978.



      The S0~ product from the W-L Process is suitable for recovery in



three forms:  liquid SO-, sulfuric acid and elemental sulfur.  For pur-



poses of the EPA/NIPSCO demonstration, the Allied Chemical S02 Reduction



Process will be applied to generate a most salable and environmentally





                               400

-------
sound product elemental sulfur.  The Allied Process uses natural gas as



a reductant in a novel catalytic reactor system.  The process has been



demonstrated on a large scale with treatment of a 12% SCL gas stream



from a nickel ore roaster at Sudbury, Ontario.



6.2.1.1.4  Citrate process--EPA and the U.S. Bureau of Mines are coop-



erating and pool ing funds and technical talents to demonstrate the



Citrate Process developed through pilot scale by the Bureau of Mines.



A concurrent development program by an industrial consortium headed by



Pfizer Chemical Company also led to a successful pilot operation using



the process.  Based on the success of these two pilot programs, EPA and



the Bureau of Mines decided to demonstrate this technology at the 30 to



60 MW scale.



     Current plans call for two separate demonstration plants:  one to



treat oil-fired flue gas and the other, coal-fired flue gas.  Negotia-



tions are currently under way with prospective host sites and process



vendors.  Contracts were to be signed in the Spring of 1975 for these



two projects that will include substantial cost sharing by the host site.



     The Citrate Process consists of five steps:  gas cleaning and cool-



ing, sulfur dioxide absorption, sulfur precipitation and solution regen-



eration, sulfur separation and hydrogen sulfide generation.  Although a



number of reactions take place in the reactors, the net reaction is com-



bining of sulfur dioxide and hydrogen sulfide to form elemental sulfur.



     Based on favorable projected economics for the Citrate Process and



encouraging results at the Pfizer and Bureau of Mines pilot plants, the



process is considered a candidate for commercial application of a second



generation flue-gas de-sulfurization process.
                                    401

-------
6.2.1.1.5  Ammonia scrubbing with bisulfate re generation--Stack gases



have been commercially de-sulfurized with solutions of ammonium sulfite



and bisulfite since the mid 1930's.  The early processes recovered SCL



in pure form by acidifying the scrubbing liquor with such acids as



sulfuric, nitric and phosphoric.  The resulting ammonium salt of the



acid was further processed for use as a fertilizer.



      Because of the enormous tonnages of SCL involved in de-sulfurizing



power-plant stack gases, fertilizer markets will not support wide-scale



use of fertilizer-producing ammonia processes.  So CSL, in a joint



venture with TVA, is developing a completely cyclic ammonia scrubbing/



bisulfate regeneration process that has a concentrated stream of SCL



as its major product.



      The process (shown below) removes SO  from stack gases by absorp-



tion in a solution of ammonium sulfite and bisulfite.  Scrubber product



liquor is acidified with ammonium bisulfate to produce SCL and form



ammonium sulfate.  After condensing out most of the water, a pure stream



of SCL can be further processed to sulfuric acid, elemental sulfur or



liquid SCL.



      Three purge methods can be used.  If a fertilizer market exists



for ammonium sulfate, ammonium sulfate crystals can be purged prior to



decomposition.  It there is no fertilizer market, ammonium bisulfate



can be reacted with lime to form gypsum and regenerate the ammonia.



And ammonium bisulfate can be injected into the utility boiler where it



will be decomposed into nitrogen and SCL.



      In 1973, attention focused on eliminating an objectionable plume



of ammonia-based salts in scrubbed gas leaving the stack.   Based on
                                402

-------
visual observation, this plume was eliminated or reduced to an accept-



able opacity by quenching the flue gas with water prior to introducing



the gas into the ammoniacal scrubber.  Other explanations can be offered



for elimination of the plume, but they are considered less likely.



     During FY 74, the pilot plant was modified.  A venturi-type pre-



scrubber was added to humidify and cool the incoming gas and remove



particulates and chlorides.  Two marble-bed stages were replaced with



Koch valve trays and another valve tray was added.  An evaporator/



crystallizer was installed to produce solid ammonium sulfate in the



regenerator section.  The pilot plant was operated for two periods



totalling about four months of operating time.



     The pre-scrubber reduced particulates and chlorides by about 93%



(average) and essentially 1001 respectively.  Typical sulfur dioxide



removal efficiencies in the scrubber were 90% or greater.  Observed



plume opacity was about 5% or less and ammonia losses were in the 10-



30 ppm range.



     CSL's efforts during FY 75 focus on improved sulfur dioxide recovery



from rich scrubber liquor, improved scrubber performance through reduc-



tion of inter-stage mixing and better control and improved mist elimina-



tion.  In addition, an electrical decomposer is being designed and



fabricated.  The decomposer regenerates ammonium bisulfate and ammonia



and is expected to be operational early in FY 76, allowing integrated



operation of the pilot plant.



6.2.1.1.6  Magnesium oxide (Chemico Mag-Ox) scrubbing--A two-year stack-



gas scrubbing demonstration funded by EPA/CSL using a magnesium oxide



slurry has been successfully completed on Boston Edison's oil-fired,






                                   403

-------
155 MW steam electric plant, located at Mystic Station, Massachusetts.



The chief advantage of the process is its wide applicability to both



existing and new steam-electric plants and its highly efficient removal



of both sulfur oxides and particulates with no interference to boiler



operation.  Sulfur removal efficiencies in excess of 93% have been



achieved.



      During final months of the demonstration phase, the control system



availability approached 90%.  This level of availability is significantly



better than in previous periods of operation.  Removal efficiencies cited



above are adequate to meet existing sulfur oxide emission standards.  The



ability of the process to produce high-quality sulfuric acid for marketing



was clearly established.



      This control technology is of special importance because it is



environmentally clean.  There is no disposal of waste products after



processing the magnesium oxide slurry for sulfur recovery and marketing



and recycling of recoverable magnesium oxide.  Industrial support is



evidenced by new construction planned by other utility companies imple-



menting this process.



6.2.1.1.7  Activated carbon--The use of multi-stage, dry fluidized beds



of recycling activated carbon appears attractive both for sorption of



SO  from flue gases and for converting removed SO  to elemental sulfur.
  J\.                                              J\.


Under an EPA contract, development of the activated-carbon-based flue-



gas de-sulfurization process has advanced to a stage where three major



process units--sorber, sulfur generator and carbon regenerator--are



integrated for continuous and cyclic operation.



      Integrated pilot plant operation, a culminating point in efforts



to determine over all technical feasibility of the process, is complete.


                               404

-------
Cyclic operation of the approximately 300 scfm capacity pilot plant has



produced encouraging preliminary results.  Estimated process economics



based on such results compare favorably with those of other flue-gas



de-sulfurization processes.  Westvaco, EPA's contractor, was to provide



a detailed final report early in 1975 on this process development.



6.2.1.1.8  Lime/Limestone wet scrubbing--Lime/Limestone scrubbing is the



prevalent FGD technology in the U.S. today.  Eleven of 16 operational



facilities are either lime or limestone scrubbing systems.  And 13 of 18



FGD facilities currently (November, 1974) under construction are lime or



limestone systems.



     In 1972, EPA initiated a program to test a prototype lime and lime-



stone wet-scrubbing system to remove sulfur dioxide and particulates from



stack gases.  Three scrubbers (10 MW equivalent each) of different design



were connected to stack-gas ducting of a coal-fired boiler at the TVA



Shawnee Power Station, Paducah, Kentucky.  Bechtel Corporation was the



major contractor.



     Major goals of the program are to:  (a) characterize effects of



important process variables on sulfur dioxide and particulate removal;



(b) develop mathematical models for design of full-scale systems for



installation at other power plants; (c) perform long-term reliability



testing; and (d) conduct a sludge disposal evaluation program.



     Reliability of both the limestone and lime scrubbers has been



improved.  The scrubbers can be operated continuously for three months



before shut-down is required to clean the mist eliminator.  Present



efforts focus on solving the mist eliminator pluggage problem.  That



would allow reliable operation for periods of six months and longer.






                                  405

-------
       During system testing,  over  all  particulate removal  efficiencies



 of 98.4 to 99.4%  and SO  removal efficiencies  of 77  to  99% were obtained.
                        X.


 System tests continue with modification of various operating parameters



 to determine effects that such changes have on system reliability and



 system performance.



       The  sludge  disposal evaluation program has recently  been initiated.



 This program will evaluate disposal  of both untreated and  treated



 (fixated)  lime  and  limestone  sludge  materials.



 6.2.1.1.9   Double alkali--The double-alkali process,  like  lime/limestone



 wet-scrubbing processes, produce a throwaway product consisting of fly



 ash and calcium sulfite/sulfate.   The  process was developed  in various



 forms  in an effort  to avoid problems associated with use of  absorbent



 slurries in lime/limestone processes.   The Double Alkali Process uses



 a clear scrubbing liquor containing  soluble alkali species rather than



 absorbent  slurries.



       Although  less  thoroughly researched and  developed than lime/lime-



 stone  wet-scrubbing  processes,  double-alkali systems have  the  potential



 to attain  high  sulfur-oxide removal  efficiency and good reliability at



 competitive costs.   One problem associated with these systems  is the



 potential  for ground and surface-water pollution by  solubles in the



waste product.   However,  there are  ways to reduce or  eliminate  this



 potential  secondary  problem.



 6.2.1.2 Combust ion  modificat ion--Combus t ion sources  contribute about



 98% of NO   emissions from stationary sources.   Studies  to  date indicate
         A


 that combustion modification  is the  principal method available in the



 near future to  control  NO emissions from combustion of fossil fuels.
                          J\.
                             406

-------
The most promising combustion modification techniques include combustion



with low excess air, recirculation of flue gas in the fuel/air mixture,



staged combustion and burner/combustor re-design.



     So far, flue gas recirculation has been the most effective combus-



tion control technique for NO  emission from nitrogen fixation of atmos-
                             J^


pheric nitrogen.  Staged combustion is the most effective control method



for NO  emissions from fuel nitrogen conversion.  The development of
      X


this technology by EPA has allowed control of NO  emissions from gas-
                                                X.


and oil-fired utility boilers to a level of 150-250 ppm.  In short-term



testing, combustion modifications have also resulted in NO  reductions
                                                          jC


of up to 50% in commercial coal-fired utility boilers.



     Also, burner and furnace design variables cause widely varying NO
                                                                      Jk.


emission levels in all boiler categories.  Current efforts are directed



at continued development and demonstration of modified operating pro-



cedures for NO  control in pilot- and commercial-scale demonstrations of
              X


combustion control of NO  for existing and new combustion sources in all
                        J\.


size categories.



     In addition, R§D efforts will be extended to develop control tech-



nology applicable to combustion of additional fuel types (including



coal-derived fuels such as low Btu gas, mixed fuels, waste fuels,



mathanol, etc.) and covering a wider range of combustion equipment (e.g.,



stationary gas turbines, internal combustion engines, industrial process



furnaces, etc.).



     EPA/CSL has recently completed a field test program to study method



of reducing NO  formation in coal-fired steam generating units.  Intro-
              J\.


duction of biased firing has developed as a product of this study.  Under
                                 407

-------
these conditions, fuel-rich first-stage firing is followed by delayed



introduction of the total combustion air supply.  In actual measurements,



the NO  emission level was 1.04 gms NO /10   , or 17.5% lower than the



New Source Performance Standard.



6.2.1.2.1  Utility boilers--



      Control Limitations--Although general techniques are well known,



results of application of these techniques to practical combustion



systems are still uncertain.  Most applications to now have been retro-



fits to existing equipment and they do not approach optimum levels of



NO control that should be achieved.



      Application of techniques is difficult because they must be applied



in a manner that prevents increases of other pollutants (i.e., - CO and



smoke) and losses of system efficiencies.  Further development work is



needed, particularly for heavy oil and coal-fired systems.  The impact



of various alternate fuels on the control techniques must also be



assessed.



      Control Application Experience--Implementation of combustion modi-



fication techniques to date have been almost exclusively used with



utility boilers.  The Los Angeles APCD has had standards for existing



gas- and oil-fired utility boilers for some time (until December 31,



1974, 225 ppm for gas and 325 ppm for oil).  These standards are being



met using combinations of staged combustion, low excess air and flue



gas recirculation.



      In addition, the Los Angeles APCD has a regulation limiting new



units, regardless of size, to 140 Ibs. per hour.  That means that a



315 MW boiler can emit about 40 ppm NO (@ 31 07).  A unit (Scattergood
                                              b




                               408

-------
3) has been installed that is expected to meet this limit firing natural
gas.  This unit uses the full range of available combustion modification
techniques and if successful, will significantly advance the state of
the art of application to gas-fired utility boilers.
     Federal standards have been set for new (ordered after August, 1972)
utility boilers greater than 25 MW for all fuels.  The approximate levels
are:  168 ppm NO for natural gas, 230 ppm for oil and 500 ppm for coal
(all concentrations are at 31 CL dry basis).
     Boiler manufacturers are currently selling units guaranteed to meet
these standards.  Staged combustion, low excess air and burner design
changes are being combined to meet these regulations.  The main uncer-
tainty is how to achieve the standards on coal wall-fired boilers.
     As previously mentioned, combustion modification techniques used
to control NO  may adversely affect emissions of other pollutants (i.e.,
             A,
- CO, HC and particulates) and system efficiency.  However, since much
of the data from existing field equipment is not designed for applica-
tion of these techniques, the significance of these adverse effects
must be carefully assessed.  There is good evidence that a system
initially engineered for NO  control can also achieve emission standards
                           J\
for other pollutants at equal or greater efficiency.
6.2.1.2.2  Industrial/residential/commercial boilers--For other sources--
industrial and commercial boilers, residential heaters, industrial pro-
cess furnaces and stationary internal combustion engines--no standards
have been proposed.  The Rfp for each of these sources is in various
stages of progress and will influence both standards and implementation
schedules.

                                  409

-------
      The residential and commercial boiler field tests were initiated



by Battelle-Columbus Laboratories in October, 1970 under sponsorship of



the American Petroleum Institute (API).  To expand EPA's in-house stud-



ies in this area, a follow-up program jointly sponsored by API and EPA



was awarded to Battelle and completed in September, 1973.  The tests



were primarily with oil-fired equipment, but some gas-fired boilers



were included.



      The equipment used ranged from 80,000 to about 20,000,000 Btu's



per hour.  The major conclusion reached was that combustible emissions



from residential equipment can be greatly reduced by proper servicing.



By replacing old, worn-out units, CD emissions were reduced by more



than 65%, HC emissions were reduced by 87%, filterable participate by



17% and total particulate (filterable and condensable) by 33%.  Tuning



the burner by proper service methods further reduced CO emissions for



a total reduction of more than 81%.



      The Bacharach smoke number was reduced by 59%.  Even these reduc-



tions are conservative since Battelle only included burners that were



under a burner service contract.  The findings strongly indicate that



emissions from residential sources could be reduced to insignificant



levels simply by proper maintenance that identifies units in need of



replacement and by tuning the remainder.  Significant NO  reductions
                                                        J\.


should result from burner re-design programs described elsewhere in



this Report.



      The major results from commercial boiler operations were that



emissions are mainly affected by boiler and burner design and fuel



type.  Also, for commercial boilers operating at steady state





                              410

-------
conditions, Bacharach smoke numbers showed consistent trends in rela-
tionship to filterable participates when firing different oil in the
same boiler.
     Earlier studies have indicated that the most important source of
polycyclic organic matter, particularly benzo(a)pyrene, was inefficient
combustion of coal in small hand-fired residential furnaces.  At present,
a study is under way to evaluate emissions from combustion of coals of
various types in a stoker-fired system and to assess combustion of smoke-
less coal.  The ultimate aim of this work is to provide improved low-
emission technology for operation of this class of residential and small
commercial coal-burning furnaces.
6.2.1.2.3  Gas turbines--Publication of New Source Performance Standards
for stationary gas turbines was planned for December, 1974.  Standard
setting was planned for the first half of 1975.  It appears that dif-
ferent standards may be established for gas and oil-fired units.  Cur-
rent target levels for stationary gas turbines of over 1.5 million Btu/
hr. (about 125 HP) are 77 ppm NO  (15% excess oxygen) for oil-fired
                                .A.
units and 55 ppm NO  (15% excess oxygen) for gas-fired units.
                   J\.
     Combustion modification experience has centered chiefly on methods
to reduce peak temperature.  Although interim methods such as water or
steam injection and exhaust gas recirculation offer potential for sig-
nificant reductions in NO  emissions, advanced combustor concepts will
                         Jv.
be needed to achieve optimum control of all pollutants.  Turbine manu-
facturers are developing low NO  combustors since they think that "dry"
                               Jv
controls will be more economical and attractive to users.  At present
EPA is conducting surveys and field tests of gas turbines to establish
                                  411

-------
the state of the art of control technology and to identify R§D require-



ments for these sources.



6.2.1.3  Primary Partidilate Control Devices--Initial work has empha-



sized characterization of conventional control equipment.  Prior to



January, 1975, sufficient data should have been available to learn about



the actual control capability in terms of fractional efficiency of



electrostatic precipitators, fabric filters and wet scrubbers.  A series



of tests are under way to determine relative collection difficulty asso-



ciated with specific industrial dusts.  Plans to accomplish this call



for use of standardized control equipment (pilot scale) with accompany-



ing measurement systems available on mobile mounting.  This will facili-



tate comparison of numerous sources.  The standardized equipment include



a fabric filter, two scrubbers and an electrostatic precipitator.



      In the past year, CSL has been involved in a program designed to



find acceptable methods to control emitted fine particulate matter.



Program results so far indicate that several conventional devices, such



as fabric filters, high efficiency electrostatic precipitators and cer-



tain high-energy scrubbers, are able to control fine particulate emis-



sions on particulate matter as small as 0.01 microns in diameter.  These



devices, to be effective, must be designed, operated and maintained to a



very strict standard.  Much additional work is necessary to reduce capi-



tal and operating costs associated with these devices when they are used



as fine particulate control devices.



      CSL is conducting field tests of industrial ESP's to determine fine



particle collection and economics of ESP systems.  Recent results indi-



cate that properly designed and operated ESP's can control fly ash from





                                412

-------
coal-fired utility boilers at an over all mass efficiency in excess of



991.  These same efficiency measurements indicate that these ESP's are



more than 90% efficient on a mass basis in collecting all particle size



fractions as small as 0.01 microns.



     Last year, full-scale fabric filter systems on combustion sources



were characterized as to their ability to remove particulates as small



as 0.01 ym.  Test results show that the filter systems typically oper-



ate at 99.8% over all collection efficiency and at greater than 99%



efficiency even for sizes as small as 0.1 ym.



     Work is also being done on particulate collection at elevated



temperatures and pressures as required to meet the needs of coal-



combustor-gas turbines and coal gasification processes.  Development



has started on high-temperature electrostatic precipitation.  Granu-



lar filters, special inertial separators and other high temperature



devices are being evaluated for particulate clean-up on a fluidized



bed coal reactor.



6.2.1.4  Novel Combustion Systems



6.2.1.4.1  Fluid bed combustion--Under contract to EPA/CSL, Exxon R§E



is investigating sustained operation parameters of a coal-fired pres-



surized (10 atmos) 630 KW mini-plant at their Linden, N. J. headquar-



ters.  Sustained operation attainment has been delayed for about six



weeks to correct minor technical problems.



     Significant increases in combustion efficiency and improved pol-



lution control are attainable by fluidized bed combustion.  This offers



the greatest potential for producing electrical energy from fossil



fuels within present environmental constraints and at a lower cost than



conventional power plants using low-sulfur fuel or stack gas cleaning.



                                   413

-------
6.2.1.4.2  Refuse firing for steam generating--A CSL study to evaluate



technical aspects, cost effectiveness and environmental benefits of



burning municipal refuse in utility grade boilers was completed by the



Envirogenics Company in 1971.  Cost analyses indicated that, in most



cases, solid waste disposal costs would be significantly less than the



cost of disposal in a municipal incinerator.  In some instances, sav-



ings were $2 to $5 per ton of refuse burned.  Analyses also indicated



that if all available refuse in a selected large metropolis were to



replace coal in power plants not currently having SO- control, SCL



burdens in that air pollution region would be reduced by about 7%.



There would also be a moderate reduction in atmospheric particulates.



      The feasibility of burning shredded municipal wastes as a sup-



plementary fuel in coal-fired utility boilers is being demonstrated in



a program sponsored by EPA, the City of St. Louis and the Union Electric



Utility Company.  A waste processing plant has been constructed and fir-



ing facilities have been constructed at a power plant 18 miles away.



      Initial tests were conducted by Union Electric of St. Louis,



Missouri, to determine effects of combined firing of shredded refuse



and coal on pollutants emitted from a boiler, boiler operating



characteristics, efficiency of the electrostatic precipitator and com-



bustion efficiency of solid waste as fuel.  Tentative conclusions



indicated that increased refuse firing rates produce increased combus-



tion efficiencies.  No significant changes were noted in gaseous



pollutant levels when refuse and coal are fired together under test



conditions.  However, there is an apparent decrease in electrostatic



precipitator efficiency.





                                414

-------
     This drop in ESP efficiency is probably the result of increased



gas flow-rates and changes in ESP operating characteristics.   Additional



tests are being undertaken to further investigate effects of refuse pro-



cessing and firing on emissions and energy recovery.  Successful comple-



tion of this project will help solve solid waste disposal problems and



add an increment of fuel to meet industrial needs.



6.2.1.5  Catalytic reduction--In a contract with Environics.  Inc.,



selective noble metal reduction of NO  with ammonia is being explored



on a pilot scale.  The experimental system uses a side stream equiva-



lent to 2 MV from a gas-fired utility boiler as a flue-gas source.  The



flue gas, containing around 225 ppm of NO, is mixed with ammonia and



then contacted with a catalyst bed at elevated temperature.  NO  reduc-



tions of 90% have been achieved.  However, equal or greater amounts of



NH7 (e-g-> 25-30 ppm) are also present in the exhaust.



     The pilot scale unit has accumulated about 2000 hours of testing



with natural gas firing with essentially no performance degradation of



the catalyst.  Current plans, made necessary by recent natural gas cur-



tailment for utility use in the Los Angeles area, are to test with sul-



fur-containing flue-gas beginning in the Winter of 1974.  In preparation



for testing with flue-gas from oil combustion, an electrical pre-heater



has been installed to raise flue gas temperature prior to entering the



catalyst bed.  A report on pilot plant results with gas firing and oil



firing should be available in Spring, 1975.



     TRW Systems has done a technical and economic assessment of vari-



ous catalytic schemes for NO  control for stationary power plants.  The



purpose was to review catalyst technology for NO  abatement,  assess
                                                J\.




                                  415

-------
technical and economic feasibility of various schemes, evaluate appli-




cability to power plants and recommend the most promising schemes.  A




comprehensive data bank was developed with about 250 articles and patents




on pertinent NO  catalysts and catalytic processes.
               -A.


      On a lab scale with simulated flue-gas (without fly ash), cata-




lytic reduction of NO was investigated over space velocities ranging




from 5,000 to 20,000 hr   STP and at temperatures from 200 to 450°C.




Approximately 45 catalysts were screened to determine nonselective NO
                                                                     A.



reduction with H~ and CD and selective reduction with NH,, H2 and CO.




Identified as being most promising (because of their activity) for




selective reduction with NH, are iron-chromium, venadium, copper-lead,




molybdenum and platinum catalysts.




      Parametric investigations of best catalyst systems with major




emphasis on selective NO  - NH, non-noble systems have been completed.
                        A.     O



These parametric studies indicated NO conversions of about 60-95% with
NH
  _ stoichiometry about 1.0, temperature of 400°C, space velocities of



5000 to 20,000 hr"1 and inlet NO concentrations of 250-1000 ppm.



      Preliminary capital and operating cost estimates for application



of this process on an 800 MW power plant are $6.15/Kw and .88 mills/Kwh



respectively.  These estimates assumed fly ash removal prior to NO



removal and that the SO  present did not affect the catalyst.  This
                       A.


latter assumption was verified in preliminary screening of Fe-Cr and



vanadia catalysts.



6.2.1.6  Fuel Cleaning



6.2.1.6.1  Coal--The goal of the coal-cleaning program is to determine



the impact that coal cleaning could have on control of sulfur oxide by
                              416

-------
increasing supplies of low sulfur coal.  The approach taken here has



been to identify qualities of U.S. coals, potential sulfur reduction



attainable by physical methods and improvements in coal-cleaning



techniques that would maximize sulfur reduction.



     So far, this program has achieved many of its objectives.   The



vast coal float-sink testing program initiated in 1965 is 75% com-



pleted.  Evaluations and applicability of existing physical cleaning



techniques are complete.  And modification of froth-flotation to



obtain sulfur reductions not achievable before have been piloted.  The



emphasis placed on R/D in coal and coal-cleaning programs by EPA has



stimulated interest in additional efforts by other organizations.



     The work supported at TRW on chemical extraction of pyrite involves



an approach that would achieve 95 to 100% pyrite removal.  The full



development of this approach would enable coal processors to guarantee



sulfur reduction to levels that would meet new performance standards.



     In the Appalachian coal states (Alabama, Maryland, Ohio, Pennsyl-



vania, Tennessee, Virginia and West Virginia), much of the coal cur-



rently mined could be reduced to a 0.75% sulfur level or less by



application of the Meyers' process.  The combination of mechanical and



chemical cleaning techniques would enhance the over all applicability



of coal-cleaning technology and should improve coal-cleaning economics.



     A shift in production to specific coal beds could make an even



more significant impact.  The coal-cleaning plant in the near future,



then, would most likely involve an integrated physical and chemical



removal process that would produce a coal of lowest sulfur and lowest



ash with a minimum of trace metallic constituents.
                                 417

-------
      CSL has recommended that a prototype coal cleaning demonstration
plant not be built.  They think that EPA can have the greatest impact
through technical support in engineering systems for coal cleaning (in
conjunction with other control techniques where required) that would
result in the most appropriate control strategies.
      Such an approach has been initiated with the state of Iowa.  CSL
will provide a technical data base for coal cleaning (mechanical and
chemical) and other control methods that will allow for development of
strategies to meet Iowa's short-and long-range programs.  In this study,
it is evident that coal cleaning will not only be an initial technique
to meet current state standards, but may be a necessary step to meet
long-range sulfur emission levels.
      An integrated coal cleaning development program would result in
the earliest availability of a process that could have maximum impact
on all users of coal.  In the Appalachian coal region, use of this com-
bined approach on coals now being mined for combustion purposes would
result in 50 to 60% of the coals having a sulfur level less than 0.75%
and 70 to 80% of the coals having a sulfur level less than 1.0%.  The
use of these lower sulfur-level coals could achieve the following
results:
      1.  Residential users (normally the lowest income group)  would
not have to switch to other fuels.  In many cases (such as in Phila-
delphia, Detroit, Chicago, etc.),  this user group could not financially
afford to switch from coal to gas  or oil.
      2.  Industrial and commercial users (using about 15% of the com-
bustion tonnage)  could meet existing standards and avoid requirements
to switch to alternate fuels.
                              418

-------
     3.  Large utility users, in the majority of cases, should be able



to meet state standards for existing units and many new or planned



stations could use coal instead of gas or oil.  The continued use of



coals would aid in and prevent increased use of gas and oil by the



utility industry.



     So over all, there would be an increase in the use of coal by the



utility industry and an increase in availability of gas and oil to area



source users who have few alternative control strategies available to



them.



     EPA/CSL is currently negotiating for construction of a chemical



coal de-sulfurization pilot plant.  This technology will not be avail-



able for commercial application until the mid-1980's.



6.2.1.6.2  Liquids--Much of the oil currently available in the U.S. for



fuel is high sulfur, high metal content residual oil.  Even if these



oils could be economically de-sulfurized, high vanadium and nickel con-



tent would probably present environmental problems and would certainly



cause equipment problems in combined cycle operations.  Nitrogen contents



of these oils can also be a problem especially with combined cycle



operation.



     Because of the inter-related and dependent nature of these con-



taminates, EPA/CSL has programs to study separate and combined effects.



For example, both enhancing and inhibiting effects of simultaneous



hydro-de-sulfurization and hydro-de-nitrogenation reactions have been



observed.  Additional discussions of liquid fuel cleaning are presented



in the section on Coal Conversion.



6.2.1.7  Fuel Gas Production
                                  419

-------
6.2.1.7.1  CAFE--The Chemically Active Fluid Bed  (CAFB) process for



gasifying and de-sulfurizing heavy oil has been demonstrated in a 0.75-



Mtf continuous pilot unit at Esso Research Center, Abingdon, England



(Esso, England).  The CAFB process involves injection of heavy fuel



oil into a shallow (about two feet deep) fluidized bed of lime/lime-



stone particles to partially oxidize, gasify and de-sulfurize the oil.



The continuous pilot unit fires a commercial boiler rated at 10 million



Btu/hour and demonstrated a service factor of 95% in the latest run of



about 400 hours duration.



      In addition to 90% sulfur removal at a calcium-to-sulfur feed



ratio of 1.5 to 1, the CAFB has completely removed vanadium and has



removed 75% of the nickel and 36% of sodium.  A reduction in the NO
                                                                   A.


emissions from 263 ppm (when the boiler was oil-fired) to 160 ppm



(when fired on the CAFB product) has been demonstrated.



      Economic studies continue to show that CAFB is a viable com-



mercial process.  The effluent from the limestone regenerator is



5-10% SCL and can be reduced to sulfur using existing technology.



Demonstration of a 50-MW unit is planned at Providence, R. I.   New



England Electric System (NEES, a private utility) is participating in



a process design effort with Stone and Webster Engineering Company



(SWEC), Esso England and Westinghouse Research Laboratories, under EPA



sponsorship, to design the demonstration unit.  The sulfur removed by



CAFB will be reduced to elemental sulfur using a modified Glaus process.



      An atmospheric pressure CAFB gasifier demonstration plant will be



constructed and ready for integrated operation by 1977.  Simultaneously



with demonstration of the atmospheric pressure gasifier, a pressurized






                               420

-------
CAFB facility will be constructed and operated in conjunction with a gas



turbine.  The thinking is that a pressurized CAFB can reduce costs of



power generation by gas turbines by 30%.



6.2.1.7.2  Fuel pollutant characterization--As a first step in any



program involving fuels, a certain minimum amount of data on fuel is



necessary.  Today, this must be broadened to include all potential pol-



luting constituents.  Recognizing this, EPA/CSL has issued a report on



an extensive literature survey that presents data on potential pollu-



tants (e.g., lead, cadmium, beryllium, mercury, sulfur, nitrogen, etc.)



in fuels.



     Since coal is to be a major energy source and existing data are



inadequate for many constituents, CSL's interest is both in developing



analytical techniques for trace elements and in the analyses themselves.



Techniques used include neutron activation, x-ray fluorescence, atomic



absorption, ion-specific electrode, direct reading optical emission and



others.



     Since the form of a constituent in coal may effect its pollution



potential, an effort is also under way to better define the nature and



composition of coal's mineral matter.  These combined studies are pro-



viding information that will be helpful in determining the quantity and



fate of potential pollutants in coal's use, processing or conversion to



clean fuel.



6.2.1.7.3  Coal conversion



     Liquid Fuels



     Technology for conversion of coal to liquid fuels is being developed



in the United States at an accelerated pace.  This technology represents





                                  421

-------
the major alternative to increased dependence on imported petroleum



fuels because of present domestic demand and inability of the domestic



supply to meet this demand.



     Various methods are under development to produce liquid fuels from



coal.  Fuel products include all ranges of low-sulfur oil that can be



burned directly in utility and industrial boilers, heavy oils that can



be processed through a conventional refinery and naphtha.  The heavier



liquid fuels produced from coal retain significant (up to 2%) quanti-



ties of coal nitrogen and usually less than 1% sulfur.  Control of 98+%



of the inorganic coal constituents (trace metals, ash) is projected.



Technologies to produce liquid fuels from coal will not be commercially



available before 1980.



     EPA/CSL has several activities under way to obtain data on liquid



fuel from coal processes.  One of these activities involves study of



catalyst materials for selective removal of contaminates such as



vanadium, nickel, nitrogen, sulfur and others from coal-derived oils.



Such a ctalyst material must be developed to control the relatively



high nitrogen content of the oil.  And it must perform satisfactorily



in the presence of the sulfur content of the oil.



     Study of competing reactions and removal of these contaminates



will increase the usefulness of these liquids (e.g., combined cycles)



and result in a cleaner environment.  Another data acquisition task



that CSL has under way is directed toward obtaining quantification of



the pollutant potential of the Solvent Refined Coal (SRC) process.



Determination of material balances for sulfur and nitrogen in the SRC



process was included and is currently in the process of being reported.





                               422

-------
Work is also in progress on preparation of engineering designs of over
all coal-processing complexes based on the SRC process that will pro-
duce optimally clean gaseous and liquid fuels.
     A program for total environment assessment of liquid fuel from
coal technologies is currently under way and is being expanded by EPA/
CSL.  This type of environmental assessment activity is required because
of the importance of insuring that coal liquefaction technologies will
include adequate environmental safeguards.  Their use otherwise to meet
domestic energy needs may be severely restricted because of potential
environmental impact.
     Liquid fuel from coal complexes of 30,000 and more tons of coal
per day are projected.  Obviously, technologies that treat such large
quantities of coal for liquid-fuel production will also handle and pro-
cess enormous quantities of sulfur, nitrogen, trace constituents and
polynuclear aromatics under conditions that could lead to significant
pollutant discharges without adequate process control.
     This environmental assessment activity will determine those con-
trols required for liquid fuels from coal technologies or will identify
additional information that must be obtained to identify control needs.
After defining process pollutant control requirements, appropriate
solutions can be pursued,
     Gasification
     Coal conversion to a gaseous fuel is an important way to provide
environmentally clean energy when done properly.  A significant
increase in coal gasification activity by the private sector has not
taken total environmental impact into account.  HPA/CSL has done studies
that address this need.
                                 423

-------
     Using currently available information and engineering estimates,

coal conversion processes are being evaluated to determine associated

environmental problems.  Reports have already been issued on Koppers-

Totzek, Synthane and Lurgi processes.  And reports on other processes

will be issued soon.

     Although there are many potential problems with elements and com-

pounds of sulfur, nitrogen, mercury, lead, cadmium, vanadium, particu-

lates, etc., there is an urgent need for quantifying constituents in

all output streams.  As a result, use is being made of new environmental

data obtained or planned for from existing commercial gasification com-

plexes overseas and pilot plant operations in this country.

     Through a planned and integrated effort to obtain data, do environ-

mental assessment, identify needed environmental safeguards and research,

develop and demonstrate environmental controls, energy processes that will

be efficient and environmentally sound can be commercialized.

     The preceding basically applies regardless of final gas Btu con-

tent.  However, use of low or intermediate Btu gas presents additional

problems.  EPA/CSL is studying this in relation to environmental aspects

of combined cycle power generation and retrofit of existing commercial

and industrial facilities to use this alternate fuel source.  Results to

date indicate that over all gasification and power generation efficiencies

will be improved with proper integration of environmental controls while

developing environmentally sound systems.

     These studies also help to identify alternatives and environmental

needs.  And some users of clean premium fuels could switch to an alterna-

tive gasified fuel with proper environmental planning and free premium

fuels for premium needs.
                                 424

-------
6.2.2  Industrial Processes
6.2.2.1  Coke Making--Production of coke in conventional coke oven bat-
teries has traditionally been a major source of particulates, sulfur
oxides, odors, carcinogens and hazardous trace metals.  Until recently,
emissions from this source have been relatively uncontrolled.
     The majority of existing coke-making facilities will be operable
for the next 25 years.  And most facilities built in the next 10 years
are expect to feature conventional batteries.  As such, CSL has studied
developing control technology for conventional batteries to meet pollu-
tion control guidelines until the end of the century.
     Indications are that pollution control technology developed for
conventional batteries, whatever it is, will probably be expensive,
have high-maintenance cost arid still not control all pollutants.  The
expected long-term solution to the coking problem is a continuous cok-
ing process that emits pollutants in a more controllable form.  CSL's
involvement in coking should ultimately include continuous coke-making
when it's more feasible.
     Specific coke oven emission-control projects with CSL involvement
includes smokeless coke charging, enclosed coking pushing and quenching,
smokeless coke pushing and improved coke oven door seals.
     Coke oven projects obviously concern pollutants other than hydro-
carbons.  Nevertheless, these projects will have a significant impact
on stationary source hydrocarbon emissions.
6.2.2.1.1  Coke oven charging emission control program--EPA/CSL jointly
funded an emissions control program with the American Iron and Steel
Institute to improve coke oven charging techniques and abate the large
                                    425

-------
volume of particulates and gases released during charging operations.



The program operation was managed by Jones and Laughlin Steel Corpora-



tion at their Pittsburgh Works.  The program culminated in design and



construction of a new type of larry (coal charging) car that was both



functional and smokeless.  It also incorporated an environmentally



controlled cab for safety and comfort of the operator.



     The Mitre Corporation concurrently did an emissions test and



evaluation program.  Measurements of major gases emitted and reductions



attained using the new larry car are tabulated below:



TSP (total suspended            120 gms/charge            85% reduction

     particulate)



THC (total hydrocarbon)         20.43 scf/charge          40% reduction



CO                               6.28 scf/charge          64% reduction



CCL                              3.82 scf/charge          87% reduction



NO                                .021 scf/charge         82% reduction
  J\.


     Favorable response of the coke industry to development of this



improved technology is demonstrated by their commitment of $10,000,000



for new installations incorporating these and other features.



6.2.2.1.2  Enclosed coke pushing and quenching--EPA and the National



Steel Corporation are funding a demonstration of an enclosed coke push-



ing and quenching system on National's new Weirton Steel Division



Brown's Island coke plant.  Construction was completed and the system



placed into operation in May, 1973.  The demonstration unit is presently



being brought up to full production status.  This will be followed by a



one-year emission testing and system evaluation phase to be completed



in 1975.
                                426

-------
     In this system, the coke is completely enclosed from the moment it



leaves the oven until after it is quenched.  Emissions produced in the



push and transfer to the quench station are drawn off and removed with



a high-energy scrubber on the gas cleaning car.  Emissions produced by



hot coke in the underground track hoppers are also controlled by a high-



energy scrubber.  The relatively low-volume continuous steam plume



generated in the continuous quenching operation is contained by hoods



and controlled by a vapor suppressor in the stack.



     Current information indicates that this system will apply to nearly



all new coke batteries.  This is particularly significant because half



of the existing coke batteries are at least 20 years old.  Based on an



average life of 30 years, nearly half of the 250 existing batteries will



have to be replaced in the next 10 years.



     Since continuous coke-making processes may not be available until



the end of that period, most new batteries will be conventional slot



ovens with useful lives extending well into the next century.  Demon-



stration of this system will provide proven emission control technology



that can be integrated into the initial plant design.



6.2.2.1.3  Smokeless coke pushing--CSL contracted with Ford Motor Company



to test and evaluate the coke pushing emission control system developed



by Koppers Company and installed at Ford's River Rouge Plant.  Principal



features of the system, now in operation at Ford's River Rouge Plant,



Dearborn, Michigan, include a fume-collecting hood, a fume main-gas



cleaning unit and a modified quench car.



     Since the control system will apparently fit most, if not all, exist-



ing installations, demonstration of the Ford system will make available to
                                    427

-------
 industry a relatively low-cost device that can significantly reduce coke



 oven emissions.  It will serve as an interim solution to existing bat-



 teries  (more than 15 to 20 years old) until these batteries can be



 replaced (average battery life is 30 years).  At that time, a more com-



 plete control system can be installed.



 6.2.2.1.4  Coke oven door seals--Leakage of gases and condensible hydro-



 carbons from coke oven doors contribute significantly to typical poor



 air quality in the vicinity of coke batteries.  These emissions contain



 high levels of carcinogenic materials such as benzo(a)pyrene.  They are



 potential health hazards to workers and surrounding communities.  The



 solution to this problem has a relatively high priority within EPA and



 the steel industry.



     The major technical objective of this research effort is to create



 and develop practical solutions to sealing coke oven doors to eliminate



 or reduce emissions from this source to the lowest extent practical.



Another objective is development of methods to measure emissions from



 coke oven door seals as installed on an operating commercial battery.



     Work on this project is being done by Battelle Columbus Labora-



 tories.  It is co-funded by the American Iron and Steel Institute (AISI).



The work was initiated in July, 1974.  The primary work done to date



 includes problem definition, review of technology and technology transfer.



     About 17 coke-producing facilities have been visited.   That includes



most U.S. batteries with door seal development programs or new sealing



techniques being tried.  New systems have been cataloged and appriased.



     Arrangements have been made to conduct tests that will define the



operating conditions that a door seal will encounter.   These measurements
                                428

-------
include temperature, fluid pressures, warpuge, material stress and com-



position.  Other difficult sealing problems in such areas as nuclear



reactor, power boilers and spacecraft are being analyzed for possible



technology transfer.



6.2.2.2  Basic oxygen process (BOP) charging emission control--Primary



operations to produce steel by the basic oxygen process (BOP) include



charging scrap, charging hot metal, oxygen blow, chemical tests and



tapping.  In charging, particularly with hot metal and during oxygen



blow, large quantities of emissions are produced.  There is no proven



technology at present to control charging emissions.



     A project was initiated in June, 1973, with National Steel Corpora-



tion's Research and Development Center to develop technology for control



of particulates, gases and fumes emitted in charging of basic oxygen



steel-making process vessels.  This development program focuses on pro-



cess modifications that will allow emissions to be collected.  Considera-



tion will also be given to suppressing emissions in the vessel.



     Specifications will be developed for a prototype emission-collection



system.  Additional specifications will be developed for a gas-cleaning



system to be added to the prototype collection system.  The development



program is structured so that results will be applicable to the total



industry.



6.2.2.3  Iron foundry--The iron foundry cupola system is the predominant



U.S. process for melting and refining iron.  The principal drawback of



the conventional system is that effluent must be cooled by air dilution



to remove particles from exhaust gases so that it can be treated by



lower temperature gas-cleaning devices.  This requirement produces more
                                     429

-------
gas to be treated, higher gas cleaning costs and loss of heat that other-



wise could be a source of non-polluting energy.



     The control system that is being demonstrated to overcome the above



problems involves a new water-cooled un-lined cupola coupled to a com-



plete emission control system consisting of an afterburner, a dry media



heat exchanger, a pair of cyclones and a fabric filter (the filter to be



installed later).  The system has been operating in the Flynn and Emrich



Foundry at Baltimore.



     All carbon monoxide is converted to carbon dioxide in the natural-



gas-fired afterburner.  The heat exchanger extracts heat from the after-



burner exhaust gases, cools the gases so that they are compatible with



the dust-collecting unit and does this with minimal air or water dilu-



tion.  Transferring this heat to the blast air-stream reduces the amount



of coke used that, in turn, reduces both coke particulate blown from the



cupola and over all emissions from the coke manufacturing operation.



     The dry media heat exchanger minimizes such problems as fouling of



the heat transfer surfaces by contaminated cupola exhaust gases.  This



problem results in frequent and costly maintenance with conventional



tube-type heat exchangers.  The expected slight fouling of the dry media



in the heat exchanger will produce only negligible performance deterio-



ration.



     Dust particles in the cooled heat exchanger exhaust-stream are



removed by the cyclones and fabric filter.  Since only about two-thirds



of heat exchanger capacity is required for blast air heating, the



remaining one-third is available as a non-polluting heat source for



other foundry functions.





                                  430

-------
6.2.2.4  Sinter plant windbox emission control--The sinter plant takes
ore fines, mill scale, iron-bearing particulate matter from control
devices, etc. and agglomerates them into large pieces suitable for
blast-furnace feed.  In that way, their iron values can be recovered.
This is done in a sinter machine where iron-containing material is
mixed with limestone and coke breeze and fed in a thick layer on a long
slow-moving continuous belt.
     Coke at the top of this layer is ignited at the front end of the
machine.  Ambient air is drawn down through this slow-moving bed to
provide oxygen for maintenance of coke combustion.  The products of
combustion are collected in a windbox and exhausted to the atmosphere.
     As the mixture proceeds,, the flame front goes deeper and deeper
into the layer until it readies the belt at the discharge end of the
machine.  The heat given off by the burning coke is sufficient to make
other materials tacky and stick to each other.  But the heat is not
great enough to completely liquify it.  The fused material being dis-
charged from the machine is then broken into large pieces in a sinter
breaker and screened.  The screened product is used as blast-furnace
feed.
     The emissions contain particulates, S02, other gases and hydrocar-
bons derived from oils that are driven off by distillation on some com-
ponents of the charge material.
     CSL's current contract with National Steel Corporation calls for
identification of windbox emissions versus feed characteristics on a
conventional sinter machine and design of a windbox gas-recirculation
system.  The second phase, now in final stages of negotiations, calls
                                   431

-------
for an extensive test and evaluation of a sinter machine fitted with a



windbox gas-recirculation system.



     In this approach, part of the windbox gases are returned to a hood



located above the sinter bed instead of being discharged to the atmos-



phere.  Enough ambient air is mixed with recirculated gases above the



bed to provide oxygen for the process.



     The recirculation approach promises several advantages, including:



     1.  Reduced volume of gases to be cleaned.



     2.  Reduced hydrocarbon emissions by using the sinter bed as an



afterburner.



     3.  Reduced particulate emissions by using the sinter bed as a



filter.



6.2.2.5  Ferro-alloy furnaces



     Characterization.  The Office of Air Quality Planning and Standards



(OAQPS) has conducted extensive source emission tests over the past



three years on a number of ferro-alloy furnaces here and abroad to



establish the basis for a Standard of Performance for new ferro-alloy



plants.  Facilities tested included all principal ferro-alloy products



along with calcium carbide that are smelted in submerged arc-furnaces.



     Since many of these samples still exist, CSL's program obtains



these samples and results of the analysis performed by OAQPS and does



more detailed and exhaustive analysis where indicated.  And in those



cases where there is enough sample, the samples will undergo toxicologi-



cal screening tests.



     This effort will result in maximum use of available samples to



detect those smelting operations posing the greatest danger of hazardous





                              432

-------
element emissions.  The samples would also be used for any further emis-



sion testing and R§D on improvement of control technology.



     So far, samples from five different furnaces have been analyzed for



60 elements and screened for polynuclear aromatic hydrocarbons (PNA's).



The elemental analyses agree well with the limited analyses performed by



OAQPS.



     The PNA screening that was not done previously on these samples



showed high levels in some samples.  The next step will be to collect new



samples with recently developed procedures that guarantee preservation



of the true character of samples (PNA's are susceptable to light and



heat).



     The submerged arc-electric furnace is the principle source of emis-



sions in the ferro-alloy industry.  Smelting of ferro-alloys is usually



accomplished by reducing ore with carbon that produces desired metallics



as well as substantial quantities of CO.  In some cases, the quantity of



CD produced actually exceeds the production of metallics.  The gases



evolved from ferro-alloy furnaces carry large quantities of particulates



that, because of high temperatures in the reaction zone, are primarily



in the submicron size range.



     Conventional practice has been to leave the furnace top open.  This



allows the CO to mix with large volumes of air and burn above the furn-



ace.  The mixture is then collected and treated with conventional par-



ticulate control equipment before being vented to the atmosphere.



     More recently, furnaces have been used in Europe and Japan that



are hooded tightly so that no excess air is carried in the furnace off-



gas.  And combustion does not take place above the furnace.  When this





                                 433

-------
type of system is used, the volume of gas is decreased by 20 to 50 times



since excess air is not included.



     This decreased amount of emissions can be cleaned to the same



degree as emissions from an open furnace.  So total particulates emitted



are decreased by approximately the same factor of 20 to 50 times.  Also,



the gas that is no longer burned over the furnace can be used as a low



Btu fuel after cleaning.



     U.S. ferro-alloy producers hesitate to install totally enclosed



furnaces because they think it may reduce their product flexibility.



To solve this problem is the project goal.  Specific objectives of this



study include:



     1.  To compare flexibility of open and totally enclosed ferro-



alloy furnace to learn about the true significance of the flexibility



problem.



     2.  To identify current practices that minimize any flexibility



problem that may arise in totally enclosed furnaces.



     3.  To develop, where warranted, recommendations for an additional



program that could be undertaken by EPA to develop or demonstrate tech-



niques and systems to minimize the problem.



6.2.2.6  Smelters--Because of substantial SO- emissions from non-ferrous



smelters and lack of available control technology, CSL has initiated a



set of development projects.  Two new projects currently in operation



have as their respective objectives:



     a.  Providing information to EPA on a smelter-by-smelter basis



about optimum application of currently demonstrated technology to con-



trol all smelter streams with SCL and particulates at the same time.






                               434

-------
The output will be in a form currently acceptable to the courts as
demonstration by means of technology transfer.
     b.  The assessment of environmental considerations of emerging
technology for metal-winning in the primary non-ferrous industry.  In
this project, consideration will be given to hydrometallurgy as new
smelting processes.
     CSL and Phelps Dodge Corporation started a cost-sharing study in
July, 1971, of a new sulfur-oxide control method based on reacting SO-
with H^O and recovering the sulfur involved as elemental sulfur.  Ini-
tial attempts to generate needed H~S by roasting available copper ore
with steam at 800°C showed that it was technically feasible but the
economics were prohibitive.
     Emphasis has now shifted to leaching the concentrate with hydro-
chloric acid that decomposes pyrite and pychloric in the concentrate
and releases ample quantities of H2S.  Preliminary results are promis-
ing.  Tests are required, however, to understand the observed variations
in H2S generation as a function of the concentrate source.
     EPA has entered into two separate Public Law 480 agreements (excess
foreign currency programs) with Yugoslavia.  One program is with the
Institute for Copper, in Bor and the other program is with the Lead and
Zinc Institute, in Trepca.  The Bor p   ject is a three-year investigation
(begun in May, 1971) at an American-engineered copper smelter (the
largest in Europe).  The Trepca project is a similar three-year effort
(started in October, 1971) at a lead and zinc smelter.
     Objectives of both projects are:
     a.  Qualitative and quantitative characterization of all air pol-
lutant emissions from this type of smelter.
                                   435

-------
     b.  Relating air pollutant emissions to the feed and to feed changes
so that data will apply to other smelters.
     c.  Relating air pollutant emissions to operations changes (changes
in smelter configuration) so that data will apply to other smelters.
     d.  Determining the effects of controlling sulfur dioxide and par-
ticulates on emission of all other pollutants, especially "hazardous"
heavy metals.
     The relationships being developed in these two PL-480 projects
should be applicable to the domestic non-ferrous smelting industry.
Additionally, two smaller studies on potentially hazardous materials
have been done.
     The first was to develop methods to remove mercury from smelter
gases.  The results show promise.
     The second was to determine the fate of various pollutants (such
as As, Cd, Se, Hg and Pb) when a sulfuric acid plant is used as a S0_
control process.  Those pollutants ending up in the acid pose a poten-
tial hazard.  About half of the acid manufactured domestically is used
for acidulation of phosphate rock.  It could be transferred to foods
when used as a fertilizer.
6.2.2.7  Kraft pulping--The Pulp Mill Indirect-Contact Evaporator
Conversion project at Hoerner-Waldorf Corporation is a first-of-a-kind
demonstration of retro-fitting an existing furnace to eliminate the
standard practice of direct contact between furnaces gases and incom-
ing liquor.  The direct contact portion of the furnace is a major
source of furnace emissions.
     EPA is demonstrating viability of the retrofit concept by support-
ing a detailed emission-testing program for both the retrofit and the
                                436

-------
new boiler.  Also, capital and operating cost requirements, startup



experiences and operating capabilities are being documented.  And the



testing program is designed to establish optimum boiler conditions for



low-odor SCU and particulate emissions.



     Preliminary indications are that a retrofitted boiler can be



operated successfully.  EPA's complete documentation of retrofitted



furnace capability to control noxious emissions efficiently and eco-



nomically will provide existing mills with a viable option for meeting



local as well as anticipated Federal emissions standards.



6.2.2.8  Alfalfa dehydration--In the alfalfa industry, dehydration of



harvested "raw" alfalfa is a necessary step in processing the crop to



the standard final product of pelletized alfalfa.  This dehydration is



done in a continuous system rotary-drum dryer where gas temperatures



may reach 2000°F.  Because of the non-homogeneity of moisture content,



however, some of the alfalfa may be so dry when introduced into the drum



that it burns, producing significant particulate emissions.



     The American Dehydrators Association (ADA) investigated this serious



problem in 1971.  EPA joined in the effort in July, 1972, by providing a



grant to help the ADA further its studies.  The final report on the pro-



gram, finished in December, 1973, is now available.



     Results of the first test phase (1971) indicate that the drying



operation causes 75% of total emissions.  Results of the second test



phase (1972) indicate that medium-efficiency wet scrubbers have the



potential to bring alfalfa dryer emissions into compliance with process



weight and rate standards.  Results of the third phase (1973) indicate



that it is possible for each dehydrator to plan and schedule a technically






                                     437

-------
and economically sound strategy to control particulate emissions so as



to meet the Bay Area Process Weight Rate Standard.  The report includes



capital and operating costs applied to a representative control model



for control schemes investigated.



6.2.2.9  Nitric acid plants--CSL is involved in a joint demonstration



with the U.S. Army of the capability of molecular sieves to abate NO
                                                                    A.


from nitric acid plants.  This effort includes testing and evaluation



of a molecular sieve system retrofitted to a 50-ton per day ammonia



oxidation process (AOP) unit.



     The objective of this program is to determine economics and oper-



ating characteristics of molecular sieves for this specific application.



The program will include a thorough evaluation of the efficacy of this



pollution control method.  This method has the potential to allow the



present NO  performance standard for new nitric acid plants (3 pounds/
          J\.


ton of acid produced, expressed as NO-) to be reduced, perhaps by as



much as a factor of 10 to 20.  System start-up was planned for March,



1974.



6.2.2.10  Refineries--Petroleum refinery catalytic-cracking feedstocks



contain varying amounts of sulfur that are distributed between the



cracked products and carbonaceous matter laid down on the catalyst dur-



ing the cracking reaction.  Although distribution depends on many fac-



tors, about 5% of the total sulfur generally ends up with the catalyst



to be regenerated.



     In 1970, estimated refinery SO  emissions (containing 15-60% S0»)
                                   J\.                                *J


from catalytic cracker regenerators amounted to 359,000 tons (1% of the



total SO  emitted in the U.S.).  The regenerator is recognized as an
        1\.




                               438

-------
important source and should be more significant as refiners process



more higher sulfur crude oils.



     CSL has developed a program to identify and evaluate techniques for



reducing SO  emissions from regenerators by 901.  The program will
           j\.


include laboratory and pilot plant studies as needed to confirm the most



advantageous process identified.



6.2.2.11  Plastics and petrochemicals--The ethylene oxyhydrochlorination



vent is the main source of hydrocarbon emissions associated with manu-



facture of ethylene dichloride, a five-billion pounds per year business.



At present, there is no practical way to eliminate the oxyhydrochlorina-



tion vent from existing processes.  The gases are too dilute for direct



incinceration and addition of natural gas to make the gases burn is an



extravagance.  Furthermore, incineration will produce hydrochloric acid



that must be controlled by scrubbing.



     It is believed that hydrocarbon control can be done with only a



modest increase in cost because anticipated benefits of increased raw



material yields will off-set control costs to a great extent.  Unit cost



increases of 0.05<£ per pound of EDC are projected.



     The objective of this 12-month project is to demonstrate technical



and economic feasibility of a process to produce ethylene dichloride by



ethylene oxyhydrochlorination characterized by a hydrocarbon emissions



rate-reduction of 90% or greater.  Current processes use air as the



source of oxygen and vent the resultant inerts along with about 0.03 ton



hydrocarbons per ton of EDC to the atmosphere.



     The proposed process, feeding oxygen with recycle vent-gas, will be



applicable to existing facilities to the extent that it will be compatible





                                     439

-------
with other units of the over all process to produce vinyl chloride from



ethylene and chlorine.  The proposed process will probably be economi-



cally competitive with existing ethylene oxyhydrochlorination processes.



6.2.2.12  Asbestos mining--Phase I of this program involved problem



definition.  One asbestos-milling tailings pile and two asbestos cement-



manufacturing waste piles were sampled with hi-vol samplers and the fil-



ters analyzed for asbestos.  Ambient asbestos concentrations in air were



evaluated using dispersion models.  It was concluded that asbestos min-



ing -and- mi 11 ing waste probably did not have serious impact on public



health because of remoteness of sites.  It seems that asbestos cement



waste probably did have high public health impact because of ambient



levels calculated as present in populated areas.



     A competitive procurement now in process is entitled "Field Test-



ing of Control Concepts for Abatement of Emissions from Asbestos



Manufacturing Waste."  This project will involve selection of control



options to reduce emissions from manufacturing waste-piles and field



testing these options for technical and economic viability.



6.2.2.13  Enclosed asbestos operations--Phase I of this program



involved problem definition.  Five sites processing asbestos were



visited and baghouses were typically 99% efficient, baghouse effluent


                          7       9
gases contained between 10  and 10  fibers/cubic meter.  It was con-



cluded that further improvements in control efficiency may be required



to protect public health.



     Phase II of the program is a laboratory study to optimize baghouse



performance for asbestos fibers.  Various options will be tested for



technical feasibility and a cost-benefit relationship established for



options.

                                 440

-------
6.2.2.14  Asphalt roofing manufacturing--The primary objectives of this
program are to characterize atmospheric emissions of particulate poly-
cyclic organic matter (PPOM) from asphalt roofing manufacturing pro-
cesses and to describe general demographic parameters of this industry
such as size, location and growth patterns.  This characterization of
PPOM includes:  quantitative measurements of effluent gas streams to
determine concentration and. emission rates of total particulate, concen-
trations of selected polycyclic organic compounds and particle size
distribution.
     Emission rates are related to various process variables to provide
a basis for estimating emissions from other plants in this industry.
Measurements are made before and after use of emission control systems.
     Specific polycyclic compounds identified are listed below:
     7,12-Dimethylbenz (a) anthracene
     Dibenz (a,h) anthracene
     Benzo (c) phenanthrene
     3-Methylcholanthrene
     Benzo (a) pyrene (C-OH,-)
     Dibenzo (a,h) pyrene
     Dibenzo (a,i) pyrene
     Dibenzo (c,g) carbazole
     The secondary objectiAre of this project is to characterize other
atmospheric emissions from these manufacturing processes such as alde-
hydes, gaseous hydrocarbons and inorganic particulate.
     The following specific processes were sampled to determine emission
rates:
                                     441

-------
     Asphalt blowing



     Felt saturating



     Mineral coating



     The blowing and saturating operation are, by far, the largest



potential sources of PPOM.  Mineral handling and coating operations are



potential sources of particulate, but not PPOM.  Where possible, each



process was sampled while saturating felt for shingles and then roll



roofing and under two operating conditions with two different asphalts.



     When the PPOM and other pollutants have been characterized, a pro-



gram to develop and demonstrate a control technique will be initiated



if needed.



6.2.3  Particulate Control Technology



     For the most part, fine particulate control is in a very early



stage of development.  Recently, however, actual source tests have



shown that both electrostatic precipitators (ESPs) and baghouses



should be capable of controlling fine particulate from a limited number



of sources emitting fly ash.



     An ESP has been shown to be effective on a utility boiler emitting



fly ash with a resistivity conducive to electrostatic collection.  On



this utility boiler, burning a relatively high sulfur coal, a high



efficiency ESP (99+% over all mass efficiency) was more than 90% effi-



cient in mass removal of all particulate fractions as small as 0.02



microns.



     Preliminary tests indicate that a baghouse is effective on a



utility boiler if close operating limits are maintained on a number of



critical variables.





                                  442

-------
     It is quite possible that applicability of conventional ESPs over
a broad rnage of sources to fine particulate control can be extended by
developing dust-conditioning techniques and by modifying the design of
charging sections and collecting electrodes.  Considerable research
and development will be needed before either method can be put to prac-
tice.  The development of special operating techniques and filter fabrics
seems to offer the best hope of extending the useful operating range of
baghouses.
6.2.3.1  Electrostatic precipitation--In an electrostatic precipitator
(ESP), dust suspended in gas streams are electrically charged and passed
through an electric field where electrical forces cause particles to
move toward a collection electiode.  The dust, separated from the gas
by being retained on the collection electrode, is later removed from the
device.  In a conventional ESP, the dust is removed mechanically.  In a
wet ESP, the dust is removed by continuous washing of the collection
electrode.
     A systems study of conventional ESPs has been completed.  Its
results are published in an ESP handbook.  A systems study of wet ESPs
was scheduled for completion in late 1974.  A mathematical model that
quantitatively describes ESP operation under all conditions and indi-
cates potential performance limitation- and design improvements has been
developed and is being up-graded to improve agreement between predicted
and measured performance--especially for fine particles.
     CSL is conducting field tests of industrial ESPs to determine fine-
particle collection and economics of ESP systems.  Recent results indi-
cate that properly designed and operated ESPs can control fly ash from
                                     443

-------
coal-fired utility boilers at over all mass efficiency in excess of 99%.



These same efficiency measurements indicate that these ESPs are more



than 90% efficient on a mass basis in collecting all particle size



fractions as small as 0.01 microns.



     A theoretically-sound method of sizing ESPs has been developed



based on the mathematical model and field test results.  A report



describing the design method and presenting equations and figures neces-



sary to use the method was scheduled for publication in late 1974.



     ESPs are being re-designed to improve their particulate collection



efficiency, especially foi fine particles and high resistivity dusts.



This work includes development of dust-conditioning methods and special



particle-charging and collection section designs.  Reports on fly ash



conditioning have been published.  The work on conditioning has resulted



in discovery of the current carrying mechanism in fly ash at high tem-



peratures and demonstration of a new conditioning agent.



6.2.3.2  Fabric filtration--A typical fabric filter consists of a flexi-



ble layer of porous cloth through which a dusty gas is passed to sepa-



rate particles from the gas stream.  Because accumulating particles



increase the filter's resistance to gas flow, deposits are removed



periodically by cleaning the cloth to maintain pressure drop across the



filter within practical operating limits.  The ability to clean the



fabric without removing it is a distinguishing characteristic of this



class of gas filter.



     In the last year, full-scale fabric-filter systems on combustion



sources have been characterized as to their ability to remove particu-



late as small as 0.01 ym.  Test results show the filter systems to
                               444

-------
operate typically at a 99.81 over all collection efficiency and at



greater than 991 efficiency even for sizes as small as 0.1 ym.  Experi-



ments have shown that fiber and fiber characteristics can be manipulated



to improve filter performance.  Manufacturers are producing fabrics



that filter at higher efficiencies and lower pressure drops than before.



     Laboratory work both in-house and by contract is continuing to



determine parameters and interactions that most affect filtration per-



formance (dust, gas, fabric, process variations and baghouse operation).



Specific programs to be pursued over the next year include:  development



of filtration theory for needle-punched fabircs, testing of filter bags



made with various special fibers, optimization of cleaning parameters,



investigation and use of electrostatic phenomena, high-velocity filtra-



tion and continued characterization of existing industrial filter-



systems.



6.2.3.3  Wet scrubbing--In a wet scrubber, both gaseous and particulate



pollutants are transferred from the gas to a scrubbing liquid.  Avail-



ability of a wide variety of scrubber types and scrubbing liquids gives



wet scrubbers potential for satisfactorily removing many pollutants.



(Details of many gaseous scrubbing systems are described elsewhere in



this Report:  See Section 6.3.1.)



     Results of a wet scrubber system study have been published as a



handbook.   It is an authoritative and comprehensive reference source on



wet scrubber technology.  A system study of wet-scrubber entrainment



separators is underway.  The results of this study will also be published



as a handbook.  The first section of the handbook was scheduled for publi-



cation in late 1974.



                                    445

-------
     The Control Systems Laboratory is conducting field tests of indus-
trial wet-scrubber systems to better define fine-particle performance
and economics of conventional scrubber systems.  The data from these
tests will also be used to improve and develop scrubber design equations.
     A feasibility study of using condensation effects to improve fine-
particle collection has been completed.  Based on results of this study,
CSL is developing a new class of scrubber systems called Flux Force/
Condensation (FF/C) scrubbers for collecting fine particles.  A pilot
scale demonstration of FF/C scrubbers is under way.
     Study of liquid and energy use in conventional scrubbers is also
sponsored by CSL.  Results of the first phase of this work have already
been published.
6.2.3.4  Novel particulate collection devices--All known novel devices
and new collection concepts are being reviewed by EPA.  Those with poten-
tial for fine-particle collection are being evaluated for performance
and related cost.  Systems showing promise of high-efficiency fine-
particle collection at reasonable cost and meriting further development
will, if necessary, be further supported by CSL.
     Evaluation of four novel devices has been completed.   The Lone Star
Steel Company Steam-Hydro scrubber installed on an open hearth furnace
had 99.9% collection efficiency, the best efficiency of the devices
tested.  This scrubber has greatest potential where waste heat is avail-
able for steam generation since energy requirements range from 8250 to
12,750 Btu/1000 scf.
     The Aeronetics two-phase scrubber has similar power requirements.
Tests on an Aeronetics scrubber installed on a ferro-alloy plant gave
collection efficiencies of 95.1 to 96.7%.
                               446

-------
     The RP Industries Dynactor scrubber was tested in the laboratory



using re-suspended fly ash and iron oxide.  It did not give high effi-



ciency collection of submicron particulate, but in applications that a



venturi scrubber might be suitable for, the Dynactor scrubber may be



an economical alternative.



     The Braxton Corporation sonic agglomerator was tested in the labora-



tory using re-suspended cupola dust and fly ash.  The collection effi-



ciency with this device was not adequate to justify further EPA



development of sonic agglomeration.



     Test programs are now under way to evaluate four additional novel



devices, i.e., the Purity Pentapure Impinger, the Entoleter Centrifield



Scrubber, the Johns-Manville CHEAP Filter and the Rexnord Granular Bed



Filter.  Annual evaluations of four to six devices are expected through



FY 80.  Laboratory pilot-scale development of one-to-three novel collec-



tion systems will be initiated in FY 75.



     A feasibility study on use of charged droplets to collect fine



particulate matter has been completed.  Research in critical areas of



charged-droplet technology, identified in the feasibility study has also



been completed by M.I.T.  Problems related to scale-up of the charged-



droplet scrubber and eventual commercialization are to be solved under



a program with TRW.  Pilot demonstration of the charged droplet scrubber



is scheduled for completion in 1975.



     Feasibility of collection of charged particles in fiber beds has



been demonstrated by Battelle Northwest.  They will continue with efforts



to model the collection mechanism and scale-up the device.
                                   447

-------
     Other new concepts using electrostatics are being assessed.  The



University of Illinois is studying the electric curtain and Carnegie-



Msllon University is studying electrostatic effects in fabric filtration,



both under grants.



     The feasibility of foam scrubbing to collect fine particles will be



assessed under a contract with Monsanto Research Corporation.  Demonstra-



tion of these concepts is expected in 1976.
                               448

-------
                                   6.3  REFERENCES
1.  OAWP Data Files of Nationwide Emissions.   1971.

2.  Contribution of Source Categories to Man-Made Ambient Fine Particu-
    lates.   T. Ripberger:   Internal Report.   Industrial Environmental
    Research Laboratory.  U.S.  Environmental  Protection Agency,
    Research Triangle Park, N.C.  October 26, 1974.

3.  Sulfur Oxide Throwaway Sludge Evaluation  Panel Vol. 1:  Executive
    Summary, Unpublished EPA Report, p.  18.   September, 1974.

4.  Ponder, W. H.  Status  of FGD Technology for Power Plant Pollution
    Control.  Thermal Power Conference,  Washington State University,
    p. 12.   October, 1974.
                                    449

-------
                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
 1 REPORT NO.
  EPA-600/1-76-023
 4. TITLE AND SUBTITLE
  SCIENTIFIC AND  TECHNICAL DATA BASE FOR CRITERIA AND
  HAZARDOUS POLLUTANTS - 1975 ERC/RTP Review
                                                           3. RECIPIENT'S ACCESSIOf*NO.
                                                           5. REPORT DATE
                                                             January  1976
                                 6. PERFORMING ORGANIZATION CODE
7 AUTHOR(S)
                                                           8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
  Health  Effects Research Laboratory
  Office  of Research and Development
  U.S.  Environmental Protection Agency
  Research Triangle Park, North Carolina
                                 10. PROGRAM ELEMENT NO.

                                   1AA601	
                                 11. CONTRACT/GRANT NO.
                  27711
 12. SPONSORING AGENCY NAME AND ADDRESS
                                                           13. TYPE OF REPORT AND PERIOD COVERED
                                                             Yearly Review 1976	
                                                           14. SPONSORING AGENCY CODE
                                                             EPA-ORD
 15. SUPPLEMENTARY NOTES
 16. ABSTRACT

   This  report is a review and evaluation  of the current knowledge  of  the criteria and
   hazardous  pollutants:  oxides of  nitrogen; carbon monoxide; hydrocarbons; photo-
   chemical oxidants; suspended particulates; sulfur oxides; asbestos;  beryllium; and
   mercury.   Primary emphasis is on  results  achieved from the ERC/RTP  research program
   since publication of the criteria documents,  which were used as  the data bases for
   the National  Ambient Air Quality  Standards.   This document is  the first in a series
   of annual  reviews to be conducted by  the  Environmental Research  Center in the
   Research Triangle Park, U.C. on the results  of on-going research.

   The document attempts to assess the adverse  effects of the criteria and hazardous
   pollutants on health, vegetation, climate, visibility, and materials.   Information
   on instrumentation, measurement,  pollutant characterization, transformation and
   transport, and control technology for the specific pollutants  is also  given.
17.
                               KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
   Pollution
   Chemical Analysis
   Abatement
   Distribution
   Lnviron. Biology
   Oxides  of  Nitrogen
I'l. Ol^TRIHUl 11'N SI AftMt NT

  Release  Unlimited
Carbon Monoxide
Hydrocarbons
Photochem. Oxidant;
Particulates
Sulfur Oxides
Asbestos
Beryl!iun
Mercury	
                                             b.IDENTIFIERS/OPEN ENDED TERMS
Environmental  Pollution
Air Pollution
                                                 COS AT i Field/Group
13B
06A
13B
04B
0GB
07B
07C
07C
07D
07D
07B
07B
07B
                    19. SECURITY CLASS (fins Report/
                     Unclassified
                          21 NO. OF PAGES

                           449
                                              20. SECURITY CLASS (Tliispafc)
                                               Unclassified
                                                                        22. PRICE
EPA Form 22JO-' (9-73)

-------