HIGHLIGHTS
 OF SELECTED AIR POLLUTION
            RESEARCH GRANTS
U. S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
            Public Health Service
          Environmental Health Service

-------
        HIGHLIGHTS  OF  SELECTED
AIR  POLLUTION RESEARCH  GRANTS
                    Office of Research Grants
       U. S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
                     Public Health Service
                   Environmental Health Service
              National Air Pollution Control Administration
                     Raleigh, North Carolina
                         May 1970
    For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C., 20402 - Price 70 cents

-------
The AP series of reports is issued by the National Air Pollution Control Administration to report the results
of scientific and engineering studies, and information of general interest in the field of air pollution.  Infor-
mation reported in this series includes coverage of NAPCA intramural  activities and of cooperative studies
conducted in  conjunction with state and local agencies, research institutes, and industrial organizations.
Copies of AP reports may be obtained upon request, as supplies permit, from the Office of Technical Informa-
tion and Publications, National Air Pollution Control Administration, U. S. Department of Health, Education,
and Welfare, 1033  Wade Avenue, Raleigh, North Carolina 27605.
DISCRIMINATION PROHIBITED-Title VI of the Civil Rights Act of 1964 states:  "No person in the United
States shall, on the ground of race, color, or national origin, be excluded from participation in, be denied the
benefits of, or be subject to discrimination under any program or activity receiving Federal financial assist-
ance."  Therefore, the  Office of Research Grants, National Air Pollution Control  Administration, like every
program or activity  disbursing  financial  assistance from the Department of Health, Education, and Welfare,
must be operated in compliance with this law.
             National  Air Pollution Control Administration Publication  No. AP-70
                                                  11

-------
                                      CONTENTS

LIST OF PRINCIPAL INVESTIGATORS AND INSTITUTIONS	    v
INTRODUCTION         	     1
EFFECTS OF AIR POLLUTION ON HUMAN HEALTH, WELFARE, OR PRODUCTIVITY    ....    3
    Atmospheric Pollution by Aeroallergen Medical Phase   	         ....        .     3
    Biological Effects of Gaseous Ions	      .  .       	     3
    Clearance of Bacteria from Pulmonary Tissue	         	    4
    Sulfide Poisoning and Methemoglobinemia          	      . .        .    .   .    5
    Effect of Noxious Agents on Ciliated Epithelium      	     .   .          .     6
    Mechanics of Mucus Flow and Ciliary Action         .        .....          .        6
    Toxicity of Terpenes as Air Pollutants	      	    7
    Airborne Fungal Spores	  .         .        	       ....    7
    Atmospheric Pollution and Respiratory Disease	       	           8
    Pseudomonas in Tissue Cultures      .          .              .            	    9
EFFECTS OF AIR POLLUTION ON AGRICULTURE  	      	   11
    Photochemical Effects of Oxidants on Plants	      ....    11
    Biochemical Effects of Air Pollutant Oxidants	     .  .        	   11
    The Total Effect of Air Pollutants on Bearing Citrus .                 .  .         	   12
    Effects of Dusts on Vegetation       .       	          13
    HF—Air  Pollution and Intermediary Metabolism	         .   .   13
    Response of Plant Fruiting to HF Fumigation  ...        	                     13
    Air Pollution Effects on Plants 	                  .                    .14
    Cytogenetic Effects of Hydrogen  Fluoride on Corn  .     	   14
    Effects of Air Pollutants on Plant Growth ...      	        .    .       15
ECONOMIC AND POLITICAL STUDIES	       	           17
    Air Pollution and the Community Image       ....     	           	17
ANALYSES AND PHYSICOCHEMICAL INVESTIGATIONS	       	   19
    Photochemistry of Substances Present in  Urban Air	       	   19
    Mechanisms of Photochemical Reactions  in Urban Air            ....     	19
    Selenium and Its Significance as an Air Pollutant      	20
    Mechanisms of Photochemically Initiated Oxidations    ...      	        20
    Bioengineering Aspects of Air Pollution	      	      21
    Behavior of Aerosol Particles	21
    Controlled Source of Uniform Liquid Droplets	     ....   21
    Formation and Decay of Atmospheric Aerosols   .  .      . .       .  -        	    22
    Composition of Lead Halide Pollution Aerosols    	     ...       .23
    Influence of Aerosol Characteristics on Visibility	      	    23
    Primary Products of Photodissociation    	      25
DEVELOPMENT OF ANALYTIC METHODS AND EQUIPMENT   	       .    ...   27
    Generation and Decay of Small Ions	       	   27
    Particulate Sampling by Adhesive-Coated Material	27

                                           iii

-------
    Pollution Abatement by Process Gas Chromatography    	      .      	28
    Study of Atomizer Aerosol Generators     .       .   .      ...      .          ....  28
    Study of Odor Components of Industrial Exhaust           . .             ....  28
    Activation Analysis of Atmospheric Particulates    .   .         .      .      	   29
    Portable Spectrometric Analyzer for Air Pollutants    ....      . .      	     29
METEOROLOGY  .             ...      .          	31
    Travels of Airborne Pollen      	          .           ...      .      	31
    Visible Species of Algae and Protozoa in the Atmosphere	       .31
    Atmospheric Diffusion in the Inertial Subrange          .      	     	  32
    Mesoscale Wind System Around the Great Lakes      	      ....        .   32
    Investigation of Ice Fog Problems	      	   33
DESCRIPTION AND CONTROL OF AIR POLLUTION SOURCES  .       ...         .35
    Formation of Oxides of Nitrogen During Combustion   .                     .                 35
    Reduction of Polycyclic Aromatic Hydrocarbons                           .  .               35
    Particulate Emissions from Wood Waste           .            ...      .      	36
    Carburetors — Reduction of Engine Exhaust Emissions	      .       	37
    Chemical Aspects of Air Pollution from Kraft Pulping        	        ...     37
    Catalytic Mechanisms for Nitrogen Oxides Reduction     	         . .  38
    Interaction  of Flue Gases with Carbon Surfaces ...                        .38
    Crystal Structure Determination of Stable Ozonides               	   39
    Gas Phase Kinetics of Kraft Mill Pollutants        	                        .40
    Boundary Layer Flow in Electrostatic Precipitators     .   .            	      40
    Engine Emission Reduction by Combustion Control ...         ....                   .40
    Reversible Metal Complexes with Air Pollutants   . .         	           ...  41
    Air Transport of Pollutants to the  Marine Environment   .      ....         .             .41
    Fundamentals of Air Cleaning by Sorption Processes   .  .    .           	      42
COMMUNICATION                  ...       .     .       	         .45
    Manual of Methods for Sampling and Analysis of Air   .         ...         	45
    Audiovisual  Methods for Air Pollution Information    	      	45
    COMEX-Air Pollution Computer  Research Project  .  .    .      	     ...       .46
                                              IV

-------
            LIST  OF PRINCIPAL  INVESTIGATORS  AND INSTITUTIONS
Principal Investigator and Institution                Grant No.                                 Page
Ballenger, John V.
Evanston Hospital Assoc	AP 00321   	   6

Bolt, Jay A.
University of Michigan  	AP 00365	        	37

Boubel, Richard
Oregon State University	AP 00348	36

Calvert, Jack G.
Ohio State University	          . .          .AP 00131      	  20

Charlson, Robert
University of Washington       	AP 00336        	           .  .    .23

Darley, Ellis F.
University of California	AP 00272	  13

Douglass, Irwin B.
University of Maine   	AP 00383	                  . .        37

Dugger, William
University of California   	AP 00040   	  11

Friedlander, S. K.
California Institute of Technology   	AP 00680   	  21

Goetz, Alexander
Atmospheric Research Group	     	AP 00543      	22

Gruber, Charles
City of Cincinnati	AP 00370   	  27

Head, Murdock
George Washington University Medical Center    . . .  .AP00415	        ...     ....  45

Hendricks, Charles D.
University of Illinois   	AP 00511           	21

Hewson, E. Wendell
University of Michigan	AP 00380	  32

Hill, A. Clyde
University of Utah  	AP 00452  .	          	  15

Johnston, Harold
University of California 	AP 00104	  19

Krueger, Albert P.
University of California	AP 00002  . .     .     .        	   3

-------
Laurenzi, Gustave A.
New Jersey College of Medicine and Dentistry       .AP 00005

Leffland, Knud W.
University of Southern California  .       .     .   .AP 00508

Long, Ronald
University of Birmingham, England             .   .AP 00323

Low, M. J. D.
New York University                             .AP 00669

MacCready.Paul, Jr.
Meteorology Research, Inc.                       .AP 00359

McAtee, James L., Jr.
Baylor University               .                 .AP 00422

McFarland, A. R.
University of Minnesota                          .AP 00136

Mathews, A. R.
University of Michigan                           . AP 00001

Meyer, Wolfgang E.
The Pennsylvania State University        .        . .AP 00560

Miller, Calixtus E.
Manhattan College                              . .AP 00362

Miller, Gene W.
Utah State University               .         .  .   .AP 00276

Mohamed, Aly H.
University of Missouri            	AP 00586

Mudd, J. Brian
University of California    ...            .      .AP 00071

Murray, F. E.
British Columbia  Research Council           ...    .AP 00532
    46
    35
    42
    32
    39
    27
    40
    13
    14
. .   11
    40
Nolan, William J.
University of Florida    ...          .AP 00672

Ogden, Eugene C.
The University of the State of New York   	AP 00081

Ohtake, Takeshi
University of Alaska  .                .        .   .AP 00449

Pack, Merrill R.
Washington State University     .                  .AP 00341

Peters, Max S.
University of Colorado      .        ..           .AP 00388
    41
    31
    33
    13
 .   38
                                               VI

-------
Pitts, J. N., Jr.
University of California

Post, Roy G.
University of Arizona

Rankin, Robert E.
West Virginia University
Sage, B. H.
California Institute of Technology .  .

Schaer, Michael
Montana State University	
 Schlichting, H. E.,Jr.
 North Texas State University

 Sherwin, Russell P.
 University of Southern California

 Sholtes, Robert
 University of Florida	

 Smith, George T.
 University of Nevada

 Smith, Roger P.
 Dartmouth College.    .     .   .

 Snell, Robert E.
 Hospital for Sick Children .  .   .

 Soo.S.  L.
 University of Illinois
 Stern, A. C.
 University of North Carolina at Chapel Hill

 Thompson, C. Ray
 University of California          	
 Trieff, Norman
 Drexel Institute of Technology  ..

 Vaska, Lauri
 Clarkson College of Technology . .

 Walker, P. L.
 The Pennsylvania State University

 Weber, Darrell J.
 University of Houston    	

 West, Philip W.
 Louisiana State University  	
 .AP00109
 .AP00519
 .AP 00460
 .AP 00107
. .AP 00475
 .AP 00137
 .AP 00607
 .AP 00493
 .AP 00545
 .AP 00260
 .AP 00484
 .AP 00541
 .AP 00256
 .AP 00270
 .AP 00501
 .AP 00574
 .AP 00406
 .AP 00554
 .AP 00724
19
29
17
35
28
31
21
40
45
12
28
41
38
20
                                               VII

-------
Whitby, K. T.
University of Minnesota   .    .                  . .AP 00480    ...     .      	    28

Williams, David
University of Florida                   	AP 00591  ...                	    29

Winchester, John W.
University of Michigan               .      ..     .AP 00585               .           	23

Wilson, Kent R.
University of California      .  .          . .      .  .AP 00675        .      . .         ...         25

Wood, Francis A.
The Pennsylvania State University        .   ..     .AP 00436        .              	14
                                             Vlll

-------
                                        INTRODUCTION
      Air pollution is already a serious threat to health, and our continuing urban and industrial growth is
rapidly increasing the pollution of the air we breathe.

      The United  States Congress reacted  to the critical  air pollution problem by passing, in 1963, the
Clean Air  Act,  which gives to  the Federal government  the authority  to establish major research and
development programs. In  1965  and again  in  1967,  the  Clean  Air Act  was amended to broaden this
authority and to stimulate both control programs and research.

      The research grant program capitalizes on the expertise and imagination of  scientists in universities
and other nonprofit research institutions. In 1960 the Office of Research Grants of the National Center for
Air Pollution Control assumed from the National Institutes of Health the responsibility for administering
research grants in  air pollution. Since that  time, the number of research grants has grown from 22 in fiscal
year 1961  to nearly 220 in fiscal year 1968. Funds dispersed in these grants have increased from $456,237
in fiscal year 1961  to nearly $7,500,000  in fiscal year  1968. The  continuing increase in the number of
applications for research grants reflects the growth of national interest in abatement of air pollution and of
appreciation for the challenging technical problems involved.

      The  National Air  Pollution Control Administration is concerned with all aspects of research and
development  in the causes, effects, extent, prevention, and control of air pollution as it affects health,
welfare, and  productivity.  The research grant program covers eight major areas: human  health effects,
agricultural effects,  socioeconomic and political  studies,  analyses and  physicochemical investigations,
development  of  analytic  methods and   equipment, meteorology, air  pollution  source  control,  and
communications.  Research  in  these  and closely  related  areas  increases  our  understanding of the
fundamental nature and the complexity of the air pollution problem.

      Research  grant support, awarded to universities, foundations, and other  non-Federal  institutions
throughout the United States, provides an excellent opportunity for  scientists to challenge the difficult
technical problems in prevention and control of air pollution. Research grants are the primary responsibility
of the Office of Research Grants, NAPCA.

      This  booklet is intended to present  to the public as well as the scientific community some of the
recent accomplishments  of the research grant program and some of the ways that tax dollars are being used
to help solve  air pollution  problems. It is not a comprehensive account of all projects, but it does present
highlights  of selected, representative studies. Because of  space limitation many  equally worthwhile and
interesting research projects cannot be included in this first publication; however,  future publications will
include other projects as well as additional results of continuing projects. These  highlights are  meant to
improve communications among investigators and to provide information to the interested public.

      Since research is  a  continuing  process,  the reader  must  recognize that  the picture changes
progressively during the period that any report is being generated; therefore, the highlights contained in this
report are not completely current.

      Under the grants program the investigator not only  submits annual progress  reports to the Office of
Research Grants,  but as expeditiously as possible publishes the material  in the open scientific literature,
where it is available to the scientific community. Individuals interested in the results of specific research are
encouraged to communicate directly with the investigator.

-------
                  EFFECTS OF AIR POLLUTION ON HUMAN HEALTH,
                              WELFARE, OR PRODUCTIVITY
ATMOSPHERIC POLLUTION BY AEROALLERGEN MEDICAL PHASE
Kenneth P. Mathews
University of Michigan, Ann Arbor, Michigan
      At the University of Michigan Medical Center, medical researchers, botanists, ?nd meteorologists are
investigating the production and dissemination of living and non-living particles in the air and the human
allergic  response  when these particles are inhaled. By thorough  examination  of  ragweed pollinosis,  Dr.
Kenneth P. Mathews and  his  associates  are seeking  knowledge  of  basic  relationships having wide
applicability to a variety of aer6allergens.

      Human subjects sensitive to ragweed were studied during three consecutive pollen seasons. Multiple
daily clinical observations, objective ventilatory tests, studies of blood and nasal cytology, and subjective
reports  were used to define a broad seasonal parallelism of pollen concentrations and symptom severity.
The study has demonstrated that significant symptoms of rhinitis and asthma tend to persist into periods of
declining pollen levels and that diurnal patterns of symptom severity correlate  poorly with concurrent or
immediately preceding pollen concentrations.

      Other studies by this research team revealed fewer allergic  manifestations in families of non-native
university  students  than  in native groups.  Over  several years, the incidence of atopic  allergy among
foreign-born students was  observed to rise and finally equal that of native-born students. This observation
emphasizes the  importance  of exposure to potent allergens in  revealing a latent capacity for allergic
response.

      Several improved techniques for manipulating immunoglobulins have been developed in the course of
these studies. One technique is used to assess the properties of the human skin sensitizing antibody (SSA).
The studies have produced strong evidence of stoichiometric combination of SSA with specific antigens and
have  confirmed  the  incapacity of normal human  serum components to block passive transfer reactions
involving SSA.

      The importance of a multiplicity of sensitivities in determining the symptoms  of atopic persons led to
the  development  of comprehensive programs  using volumetric  techniques  to  sample  for  viable and
non-viable atmospheric particles.  Using newly developed samplers, the investigators collected volumetric
prevalence data for many types of viable  and non-viable particles in the air, some of which have previously
received little attention but which may be important to public health.


BIOLOGICAL EFFECTS OF GASEOUS IONS
Albert P. Krueger
University of California, Berkeley, California
     Dr.  Albert  P.  Krueger of the University of California School  of  Public Health, using advanced
instrumentation, is  investigating the possible biological effects  of small  air ions. Dr. Krueger  and his
associates  have found that physiological functions are indeed responsive both to-excessive numbers of ions
and to their virtual absence. Some findings of their studies are:

     1.   High concentrations of small positive and negative ions increase  the death rate of some types of
          microorganisms suspended in small droplets of water.

     2.   Small  positive ions  in excess  inhibit  the  efficiency of the respiratory  tract mucus escalator

-------
           responsible for removing inhaled particles and increase vulnerability of the tissues to mechanical
           trauma.

      3.    Negatively ionized air reverses the changes induced by positive ions.

      4.    The  powerful neurohormone  5-hydroxytryptamine (5-HT) has an important role  in air ion
           action on the respiratory tract. Positive C02  ions bring about an increase in tissue levels of
           5-HT. This neurohormone, in turn, directly influences many basic physiological functions, e.g.,
           permeability  of the  small blood vessels and rate of respiration. Negative 02 ions reduce the
           tissue levels of 5-HT  by speeding the rate at which it is oxidized and, in consequence, neutralize
           the effects of CO2+ ions.

      5.    Positive or negative 02 ions markedly stimulate the growth of higher plants while positive or
           negative  C02 ions  inhibit germination  and  growth,  seriously  curtail the  formation  of
           chlorophyll, and devitalize the young seedlings.

      6.    Reduction of the total small ion content of the ambient air to approximately 3 percent of the
           normal level inhibits  growth of plants and causes them to develop very soft leaves and to lack
           normal rigidity.

      7.    Exposure  of  silk  worm eggs to high densities of positive or negative ions accelerates hatching
           and the onset of spinning and  increases  the rate  of larval growth, the production of several of
           the ion-containing enzymes, and the weight of the cocoons.

      Dr. Krueger  points  out  that although information  about the biological effects of air ions is far from
complete, his research finding might  have practical applications. For example, the average electrical  space
heater and the ordinary  electrostatic precipitator are  excellent generators  of positive ions. With a normal
level of .05 percent C02  in the ambient atmosphere, the direct formation of C02+ ions and their indirect
production by charge transfer could lead  to an  ionic imbalance of potential physiological significance.
Higher C02 levels, frequently occurring in submarines, meeting halls, etc., increase the chances of C02+ ion
formation constituting a health hazard.

      Positive  or negative C02 ions can be  formed in  concentrations sufficient to affect plant growth also,
for CO2 concentrations in the ambient air  are artificially raised at times in whole geographic areas where a
variety of ionization energy sources exists.

      Dr. Krueger reports that laboratory  and  field evidence now  available indicates that  environmental
engineers of the future will include specifications for air ion density and ionic balance in their definitions of
optimal conditions for health.
CLEARANCE OF BACTERIA FROM PULMONARY TISSUE
Gustave A. Laurenzi
New Jersey College of Medicine and Dentistry, Jersey City, New Jersey
     Dr. Gustave Laurenzi is investigating the mechanisms whereby the normal respiratory tract is able to
rid itself of bacteria and the factors which upset these mechanisms so that bacteria are able to  take hold,
colonize, and cause  bronchial  infection. Studies of  human respiratory action or response are basic to
establishment of air quality standards.

     His studies with humans at the New Jersey College of Medicine and Dentistry have revealed that the
normal  lower respiratory tract  has a remarkable capacity to clear bacteria and to remain sterile despite
constant bacterial  challenge through inhalation  and  natural aspiration. In  the bronchitic, however,
impairment of this function allows respiratory pathogens to reside in his lower respiratory tract and to

-------
colonize during acute  chest illnesses. Such information helps the investigators to reconstruct the role of
bacterial infection in the acute exacerbation. Evidence indicates that a non-bacterial bronchial insult (viral
infection, air pollutions etc.) may set up circumstances which allow the parasitic bronchial pathogens to
colonize and produce secondary bronchopulmonary infection with all its serious sequelae. This information
further delineates the role of antibiotic therapy.

      A method has been developed for measuring quantitatively the clearance of bacteria from the lungs of
mice  implanted by exposure to  bacterial aerosols.  Bacterial clearance is rapid: 45 percent of bacteria
deposited disappear within 1  hour, and  95 percent  within 6 hours. The method serves as a bioassay for
determining the effect  of intrinsic conditions, meteorological changes, and respiratory irritants.

      Dr. Laurenzi's quantitative  studies have shown that  bacteria removal  by the respiratory  tract  is
adversely affected by  smoke inhalation, alcohol, cortisone, barbiturates, hypoxia, endotoxin. In addition,
he found that  specific pathogen-free mice,  free  of ordinary intestinal pathogens,  are  resistant to the
deleterious effect of smoke. The presence of these ordinary gram-negative organisms predisposes to smoke
interference with pulmonary disposal of inhaled bacteria.

      Investigators also have observed that oxygen inhalation has a deleterious effect on tracheo-bronchial
mucus flow and thereby interferes with the clearance of secretions.  In animals exposed to 10 percent and
100 percent oxygen sequentially, mucus flow rate was reduced 90 percent. Epinephrine and digitalis greatly
stimulated mucus flow; aerosolized racemic epinephrine, intramuscular epinephrine, and therapeutic doses
of intravenous  G-strophanthin enhanced nasal  flow and  prevented and reversed adverse hyperoxic and
hypoxic effects. These results suggest that the mucociliary system functions optimally at  ambient  oxygen
tension.

      In studies of the capacity of alveolar macrophages for  defending the respiratory tract against foreign
particles and  bacterial infections, macrophage yield significantly increased during 1 to 4 hours smoke
exposure. Smoke did not reduce macrophage viability or  alter macrophage mobilization following  an
airborne bacterial challenge.
 SULFIDE POISONING AND METHEMOGLOBINEMIA
 Roger P. Smith
 Dartmouth College, Hanover, New Hampshire
      Dr. Roger P. Smith, investigating methemoglobin and sulfide poisoning at Dartmouth Medical School,
 recognized  that hydrogen sulfide (a frequent air pollutant)  can  be a violent  poison  producing many
 symptoms in common with cyanide gas. Exploring the possibility that some treatment methods might work
 against poisoning by either gas, he has discovered at least one emergency procedure of potential value.

      In animals poisoned by hydrogen sulfide, methemoglobin avidly traps this poison and prevents it
 from attacking  vital sites in  the  brain.  Sulfide trapped  by methemoglobin can either undergo further
 transformation to harmless products or be  slowly released at a rate tolerable to the animal. Once it has
 served  this purpose,  methemoglobin is  spontaneously  reconverted to  oxyhemoglobin  in the blood.
 Although this treatment is still untried in humans, human methemoglobin injected into animals protects
 them as well as methemoglobin generated in their own blood.

      Dr. Smith's research has revealed other information about methemoglobin in addition to its potential
 value as an  emergency procedure in acute hydrogen sulfide poisoning. Since some kinds of methemoglobin
 can trap more sulfide than cyanide, previously unrecognized changes probably occur when oxyhemoglobin
 is converted to methemoglobin. Moreover,  methemoglobins generated by different chemicals appear to have
 different  chemical  properties. The systems  that spontaneously reverse a  methemoglobinemia have been
 found to reverse some changes, but not necessarily all. Eventually, such research may contribute to better
means of treating methemoglobinemia as well as hydrogen sulfide poisoning.

-------
EFFECT OF NOXIOUS AGENTS ON CILIATED EPITHELIUM
John V. Ballenger
Evanston Hospital Association, Evanston, Illinois

      Dr. John V. Ballenger is investigating the relationship of the mucociliary cleansing mechanism of the
human respiratory tract to selected air pollutants. The ciliary activity is quantitatively assayed by a rotating
explant method.

      Dr.  Ballenger's  work  on  the  ciliostatic  property of  nicotine has produced several  findings. A
considerable increase in the ciliostatic property of nicotine was observed when the ciliated explant was first
infected with  10,000 EID50's  of influenza B virus. Two hours after the nicotine perfusion (0.3-0.4 percent
by weight of oxidized nicotine), the  rotating speed of the infected explant was 41 percent less than that of
the nicotine perfused, uninfected explant. From the clinical point of view this suggests that air pollutant
exposure may impair the mucociliary cleansing mechanism of the respiratory tract more in an individual
with a myxovirus infection than in one free of the virus infection.

      Recent experiments in heat inactivation of influenza B virus  showed that exposure to 56°C for 1 hour
does  not  inactivate  the  ciliostatic effect  of the virus.  The  investigator found that adsorption of heat
inactivated virus by  guinea pig erythrocytes removed the ciliostatic substance  associated  with the virus
particle. High speed  centrifugation  (18,000 rpm for 1 hour)  of  the heat inactivated virus  produced
indications that the ciliostatic effect resided primarily in the virus particle.
      Rotation speeds  of human ciliated explants were increased by perfusion with nicotinamide adenine
dinucleotide (NAD) and with adenosine diphosphate (ADP). Perfusion with 100 mg%NAD was followed at
the end of 45 minutes by an increased rotation speed of 31.5%. Perfusion with 100 mg% of ADP produced
a  35% increase in  speed  within  15 minutes.  When 50 mg% each of NAD and ADP  were  perfused, an
increased speed of  52% was recorded almost immediately. The investigators concluded that in vitro both
NAD and ADP caused  increased activity of human respiratory cilia but the combination  of 50 mg% of each
caused a  greater increase in speed than either alone.
MECHANICS OF MUCUS FLOW AND CILIARY ACTION
Calixtus E. Miller
Manhattan College, New York, New York
      Dr. Calixtus E. Miller is investigating the effects of definite amounts of atmospheric pollutants upon
vital tissues of the body. Knowledge gained in this project might be used to determine a lower limit of air
pollutants which will not appreciably damage the mammalian system.

      At the Rheological Mechanics Laboratory of Manhattan College, mechanical apparatus analogous to
the mammalian mucociliary system was constructed and has been in operation for 2 years. The apparatus,
called a Rheociliometer, has  enabled Dr. Miller and his associates to measure and control  the speed of
particulate matter and other foreign bodies. They have shown the speed to be a function of the frequency
and  amplitude  of the  beating  mechanical  cilia and have  demonstrated the initiation of the flow of a
Newtonian fluid to be due only to the phasing of the ciliary beat.

      Dr. Miller's group  performed other experiments to predict the mechanical features of the flow which
may relate to the mammalian system. They found that the ratio of the frictional forces to the inertial forces
was  a function of the Reynolds number. This finding indicates that the Navier-Stokes equations and the
continuity equation form the  set  of  differential  equations that  must be solved to establish the fluid
dynamics of the entire system.

      A viscoelastic fluid similar to mucus  has been developed in the laboratory and is now used in all

-------
experiments previously carried out with Newtonian liquids. The ratio of the velocity of particulate matter
to the wave velocity of ciliary beat was found to be a linear function of the Reynolds number. This result
later was correlated with the mammalian mucociliary system.

      After mechanical features of flow in the Rheociliometer were established and described functionally,
the investigators studied the relationship  of these flow features to the mucociliary system of the cat's
trachea. Applying improved surgical techniques first developed by Dalhamn in Sweden, they measured the
frequency  and wavelength of ciliary beat in vivo. They found  that the ratio of the velocity of particulate
matter embedded in the mucus to  the wave velocity  of the ciliary beat was a linear function of the
Reynolds number. The linear function  had  different slopes for different animals, and the family of lines
drawn for  several  animals is directly correlated with the  linear function obtained with the Rheociliometer.
The investigators  thus developed a,theory of mucociliary system response to variations in frequency of
ciliary beat and in depth, viscosity, and density of mucus.

      With this theory, one  can predict  the action of toxic materials on the mucociliary system in terms of
these biomechanical factors. Using S02 as a toxic  material, Dr. Miller has validated  the theory. His
experiments  indicate that  chemical  changes took place in the lung system at  the area in  which gas  is
exchanged between the alveolar and vascular systems.

      The  uniqueness of the research lies in the fact  that effects of pollutants on vital  tissues are being
correlated  with the effects on the mechanism of the mucociliary system. This research should yield needed,
basic physiopathological knowledge.
 TOXICITY OF TERPENES AS AIR POLLUTANTS
 George T. Smith
 University of Nevada, Reno, Nevada
      Research by Dr. George T. Smith at the University of Nevada's Desert Research Institute suggests that
 terpene, the hydrocarbon that gives pine trees their smell and the Blue Ridge Mountains their color, may
 actually cause serious respiratory diseases such as emphysema and asthma. In one experiment, post mortem
 studies of cows forced to breathe terpene 3 to 7 days through a tube inserted in their nostrils, confirmed
 that all had emphysema, even though forced to breathe the terpenes only an hour  a day. More work is
 needed to definitely link asthma and emphysema  in man to exposure to terpenes; however, statistics do
 show a correlation between increased hospital  admissions from asthma and high levels of terpenes in the air.

      Dr. Smith and his associates first became  suspicious of the role of terpenes in bovine emphysema,
 which long has been a  common problem for ranchers in  the  Southwest. The  cause of  this condition,
 frequently called the "grunts" because  of labored  breathing by the affected cows was never clear,  but it
 ocurred  in the fall when the cows were brought  down into  the valley where terpene  concentrations were
 heavier. In the summer, grazing in the Sierra Nevada mountains where there was little terpene in the air, the
 cows never seemed to be troubled.

      The research group is now planning a pure  air chamber for humans and cows in order to investigate
 the effects of varied atmospheres in altering symptoms.
AIRBORNE FUNGAL SPORES
Darrell J. Weber
University of Houston, Houston, Texas

     The presence of fungal spores in the atmosphere is of serious concern because many of these spores
are inhaled and deposited in the lungs of humans and animals. Repeated exposure to certain fungal spores

-------
may result in allergic reactions with serious discomfort in some individuals. Furthermore, the waxy coatings
on these spores contain hydrocarbons which may be carcinogenic. Dr. Darrell J. Weber, of the University of
Houston, is investigating these waxy coatings to determine their effects in air pollution, allergic reactions,
and diseases.

      The spore populations in the atmosphere in various parts of Texas were sampled with a continuously
operating spore trap. The major spore types found in  the Houston area in very high concentrations were
Aspergillus, Alternaria, Cladosporium,  and Fusarium; the major spore type found in the El Paso area was
Alternaria. With continuing sampling and statistical analyses investigators will estimate the populations of
spores in the atmosphere and their role in air pollution over large cities.

      The waxy materials from spores of several types were extracted by lipo solvents and fractionated into
3 fractions with a silica gel column. Then the fractions were analyzed with a gas chromatograph using a
capillary column.  Unknown compounds that were separated on the gas chromatograph were characterized
with a gas chromatograph-mass spectrometer combination.

      The investigators found that the hydrocarbon pattern was distinct for each species of fungi analyzed
and  that the odd numbered hydrocarbons predominated in  every case. The predominant n-alkane peaks
were C27  for Ustilago rnaydis, C29 for Puccinia graminis, C29 andC31 for Ustilago agropyri, C27 andC31
for Ustilago  nuda, C2 9 and C31  for Ustilago avenae, and C2 9  for Splwcelotheca reiliana. All three fractions
of Ustilago rnaydis were analyzed. The hydrocarbon fraction  contained predominantly C25 ,C27, and C29
n-alkanes. The  benzene fraction contained natural methyl  esters, predominantly C]6  through C20, of
saturated and unsaturated fatty acids. This was the first report of naturally occurring methyl esters in fungi.
The  methanol fraction contained free fatty acids ranging in carbon number from C] 2 through C20. In both
the free fatty acids and the natural methyl esters, the distribution patterns of the carbon skeletons were
similar,  and  the  predominant  compounds  had even-numbered  carbon chains.  Investigators are  now
attempting to determine the biosynthesis of the waxy materials in fungi.
ATMOSPHERIC POLLUTION AND RESPIRATORY DISEASE
Robert E. Snell
Hospital for Sick Children, Washington, D. C.
     Dr. Robert Snell, at the Hospital for Sick Children in Washington, D. C., is working to define the role
of environmental agents such as air pollutants in the cause and perpetuation of asthma. The researchers are
                           Laboratory adjacent to the environmental control unit

using  a 600-square-foot environmental control unit in which  they  can carefully control  and monitor
atmospheric pressure, temperature, and humidity. The unit includes a  capability for strict control and
variation of the gaseous and particulate constituents of the atmosphere. A child can reside in this unit for
8

-------
                                                    up to  1 month, carrying out all his daily activities
                                                    in  the  unit.  Changes  in the child's status during
                                                    this period are  observed  by means ot repeated
                                                    measurements of respiratory function.

                                                          During construction of  the environmental
                                                    control unit. Dr. Snell and his associates have been
                                                    investigating emotional factors that may affect test
                                                    results  and training technical personnel who will
                                                    be in daily close contact with the children.

                                                          Investigators  hope to establish the concen-
                                                    tration-time  relationships  necessary to  produce
                                                    changes in respiratory function in  an individual
                                                    with   pulmonary  disease   who  is  exposed  to
                                                    specific  environmental  variations.   Such  infor-
                                                    mation is  urgently needed  for  establishment of
                                                    rational air   quality  criteria.  The  information
                                                    obtained also is valuable in the  diagnosis and care
                                                    of the children within the  unit.
                                                          Shown  here  is the interior of the environ-
                                                     mental control  unit  at the  Hospital  for Sick
Children in Washington, D. C. The unit is being developed by Dr. Robert  Snell under a research grant to
the hospital.
PSEUDOMONAS IN TISSUE CULTURES
Russell P. Sherwin
University of Southern California, Los Angeles, California
      At the University of Southern California, Dr. Russell P. Sherwin is investigating the response at the
cellular level of lung tissues exposed to air pollutants, in particular the interactions between bacteria (and
their  L forms)  and leucocytes.  Dr.  Sherwin found  that  macrophages  and alveolar wall cells increase
remarkably  in response  to  experimentally  applied  nitrogen  oxide.  Investigators  have measured  this
response which, they believe, has potential as a biologic indicator for air pollution.

      In another study,  Dr.  Sherwin found that nitrogen dioxide causes macrophages to be attracted to
epethelial  cells.  Both  the  frequency  of epithelial cell-macrophage interaction  and the  number of
macrophages present on  any  one  epithelial cell increase. This phenomenon may be another useful biologic
indicator for various types of insult to the lung.

-------
                    EFFECTS OF AIR POLLUTION ON AGRICULTURE
 PHOTOCHEMICAL EFFECTS OF OXIDANTS ON PLANTS
 William Dugger
 University of California, Riverside, California
      Investigating the photochemical effects of oxidants on  plants, Dr. William Dugger found that the
 sulfhydryl (SH) content of young primary leaves was considerably higher than that of leaves of plants 14 to
 17 days  old. He also found that  the  difference  in SH content between plants grown under normal
 photoperiod and those that had been in the dark for 24 hours was greater in the younger, more susceptible
 tissue. The plants lose their susceptibility to  peroxyacetyl nitrate (PAN) at 14 days, and at this stage there
 is little, if any, difference in the SH contents of the light and  pre-dark treated tissues. The SH content of
 10-day old plants pretreated with 24 hours darkness increases when the plants are returned to the light and
 reaches a maximum after 3 hours.  Previous results have shown that  plants given a 24-hour dark period
 become sensitive to PAN again after  a light period of 3 hours.

      Plant damage depends upon both the  intensity and the wavelength of the light. When exposed to PAN
 in the dark, plants grown under high light intensity will be damaged while plants  grown under low  or
 moderate light intensities will not be damaged. Irradiation of the plants with light of 660/u wavelength
 during the 15-minute exposure period results in typical PAN damage regardless of the light intensity under
 which the  plants are grown.  If, however,  the plants are exposed simultaneously  to  660^ and 700ju
 monochromatic light with the PAN  treatment, they will not be damaged.  Radiant energy of 700/u partially
 reverses the susceptibility to dark PAN damage of bean plants grown at high light intensity. Thus, radiant
 energy of 700/1 partially protects plants against PAN damage.

      Dr. Dugger found that leaf tissue from lemon seedlings fumigated with ozone takes up oxygen faster
 than the tissue from control plants. This increased uptake occurs several weeks prior to the onset of visible
 damage. The leaves show a considerable increase in reducing sugar content  and a decrease in starch content.
 These  two changes  may  be  related and may indicate  either  a stimulation  of starch hydrolysis or an
 inhibition of starch synthesis from hexose. The increase in reducing sugars may account for the increase in
 respiration observed in ozone treated tissue.

     In other experiments by Dr. Dugger's group, uniformly labeled C14-glucose was supplied to leaf discs
 from both ozone treated  and control lemon seedlings in order to determine the effect of ozone on cell
 permeability. In ozone treated tissues, the permeability to exogeneous sugars and the rate of decarbox-
 ylation of  the  labeled  glucose  increased considerably. Other experiments  using specifically  labeled
 C14-glucose showed  that ozone  did not induce changes in the pathway of glucose catabolism but did
 induce a two-to-threefold increase in the rate of decarboxylation or utilization of the glucose. Increased
 permeability to glucose was found to be the  first effect of ozone fumigation preceding the increase in the
 decarboxylation of glucose. These metabolic changes caused by ozone fumigation may  account for the
 citrus leaf drop observed in air containing low levels of oxidants. The increased decarboxylation stimulated
 by low levels of ozone over an extended period of time, however, might cause a premature starvation and
 subsequent abscission of citrus leaves.
BIOCHEMICAL EFFECTS OF AIR POLLUTANT OXIDANTS
J. Brian Mudd
University of California, Riverside, California
     In his research on "Biochemical Effects of Air Pollutant Oxidants," Dr. J. Brian Mudd determined the
primary reactions of ozone and peroxyacetyl nitrate with components of the living cell which give rise to
toxic responses.
                                               11

-------
     Compounds that play a catalytic role in metabolism were chosen for the study of chemical reactions
of air pollutant oxidants. The enzymes and co-enzymes are  in this category since they are responsible for
the transformation of many thousands of substrate molecules but remain unchanged themselves. Thus, the
inactivation  of one enzyme molecule prevents the metabolism of thousands of substrate molecules while
the destruction of one of the substrate molecules would have a negligible effect.

     Thorough investigation  of the  reaction of peroxyacetyl nitrate  with  thiol groups has revealed two
reactions: (1)  oxidation is always observed  and (2) acetylation is  sometimes observed. The experiments
show that enzymes which do  not require free thiols for their activity are resistant to peroxyacetyl nitrate.
Enzymes which alternate between thiol and disulfide forms are susceptible in the thiol form and resistant in
the disulfide form.

     Studies of the reactions of ozone have concentrated on the reactions with amino  acid residues. The
oxidation of these residues is much less specific than that of peroxyacetyl nitrate. The  susceptible amino
acid residues in decreasing order are: cysteine, methionine, tryptophan,  tyrosine,  histidine, cystine, and
phenylalanine. Decrease  in the biological activity of proteins after treatment with ozone is correlated with
the oxidation of one or  more of these amino acid residues. Dr. Mudd has started physiological experiments
to learn whether the reactions with proteins are really relevant.

     The subcellular particles  to  be studied, chloroplasts  and  mitochondria,  are complex lipoprotein
systems, and researchers do  not yet  know whether the protein  component is attacked before the lipid
component.  If  one of these is  much more susceptible than the  other, this fact  will be important in the
design  of a suitable chemical antagonist. The production of such  an antagonist would immediately benefit
agriculture and might eventually benefit human health.
THE TOTAL EFFECT OF AIR POLLUTANTS ON BEARING CITRUS
C. Ray Thompson
University of California, Riverside, California
     The objective of Dr. Thompson's project is to determine whether and how much air pollutants are
damaging citrus crops. Dr. Thompson first focused on lemon trees near Upland, California, and later added
navel  orange trees to the project.  Initially,  he enclosed  24 lemon trees individually in plastic-covered
greenhouses which could be provided with various fractions of the atmosphere, and he divided the trees
into 6 treatment groups of 4 trees each. Levels of total oxidants, levels of fluoride, and temperatures were
recorded in the air continuously.

     Within  a few weeks after the experimental treatments began, Dr. Thompson observed that trees
receiving filtered air  required  more  water than those getting  ambient air.  Measurement  of apparent
photosynthesis on the trees showed  that those receiving filtered air used more carbon dioxide than those in
ambient (smoggy) air. Fluoride caused no measurable effect.

     Preliminary evaluation of leaf  drop, fruit drop, and fruit yield indicates that trees receiving ambient
air  have  greater leaf drop (up to 30%) and yield less fruit than trees receiving carbon-filtered air. The
average yield in ambient air is often only one-half of that  in clean air. Fruit size, however, is not affected.
Photochemical smog, principally  from auto exhaust, seems  to be causing most of this damage. Atmospheric
fluoride is present in such small concentrations that it has no measurable effect.

     Some of the early fruit drop of navel oranges might be overcome by the antioxidants N,N'-diphenyl-
p-phenylenediamine and Ni-di-N-butyldithiocarbamate. Studies of the mechanism of this reaction continue.
12

-------
EFFECTS OF DUSTS ON VEGETATION
Ellis F. Darley
University of California, Riverside, California
      Investigating the effects of dusts on vegetation, at the Statewide Air Pollution Research Center, Dr.
Ellis F. Darley has been working on methodology to determine the effects of certain cement-kiln dusts.
Short-term experiments (dusting 10-day old plants  for 2 to 3 days) have  shown definitely that harmful
effects can be expected only when dusted leaves are wet with dew. Dusts from different sources vary in this
respect, but the relationship of chemical composition to injury has not yet been determined.

      Large chambers which  permit  dusting  plants to  maturity  (approximately  60  days) have  been
developed. The first experiment with these chambers showed no measurable effect on plant growth when
the dust was applied to dry leaves on alternate days. Dr. Darley has built a dew chamber large enough to
hold large plants in order to examine the effect of dew formation at regular periods  during dusting.
 HF-AIR POLLUTION AND INTERMEDIARY METABOLISM
 Gene W. Miller
 Utah State University, Logan, Utah
      Before his  investigation,  most plants  were thought to be unable to  synthesize fluoroacetate and
 flourocitrate; Dr.  Gene W. Miller, however, has now demonstrated that  fluorocitrate and fluoroacetate
 accumulate in common cultivated plants which are exposed  to atmospheric chloride or fluoride in the
 growth medium.  Fluoroacetate is  extremely toxic  to animals since  they  convert it  to fluorocitrate.
 Fluorocitrate is lethal to most animals at concentrations of 0.1 -to 5mg fluorocitrate per  1kg body weight.

      The  detection of these toxic  compounds in  forage crops in the vicinity of industrial areas is very
 significant. Fluoride injury to grazing animals may  be attributable in part  to organic fluoride. Dr. Miller is
 now  experimenting  to  determine toxic levels over a long period of feeding and is  considering possible
 effects on humans of fluoroorganic levels found in cultivated crops.
 RESPONSE OF PLANT FRUITING TO HF FUMIGATION
 Merrill R. Pack
 Washington State University, Pullman, Washington
      Dr. Merrill R. Pack is evaluating the effects of hydrogen fluoride (HF) on plant fruiting in  12 plant
 species representing a cross section of the major  crop plants grown primarily for fruit or seed. In initial
 tests, to determine the  effects and the plants affected, Dr. Pack subjected plants to unrealistically severe
 continuous exposure to 10 to 15 jug per cubic meter throughout the life  of the plants or from at least a
 week prior to flowering. The plants also were grown at a low calcium level (40 ppm) since such levels were
 found to favor maximum response to HF.

      The most common effect of the HF was reduction of the number of seeds produced and consequent
 distortion of fruit  due to lack of fruit development around the sterile ovules. These responses occurred in
 bean, pea,  tomato, and strawberry plants. Sweet  corn, grain sorghum, and pepper failed to produce  any
 fruit under continuous exposure to HF at about 10 jug F per cubic meter. Growth of the sweet corn  ears
 was  arrested prior to silk  emergence, and the sorghum produced no heads. On  pepper, flowering  was
 delayed and reduced, and the flowers fell off without producing fruit.

      An experiment with tomatoes revealed the relationship between calcium nutrition and the effect of
HF on plant fruiting. Plants growing at four levels of calcium nutrition (40,  80,  120, and 220 ppm) were
                                                                                               13

-------
exposed continuously to HF at 6 /ig F per cubic meter. The tomato fruits were smaller and contained less
seeds when the plants were exposed to the HF treatment or were grown with lower levels of calcium, and
the effects were additive. Continuous treatment with HF at 3 /ug F per cubic meter had no apparent effect
on tomato fruiting, even at the lowest level of calcium nutrition.

      The practical  significance of the effects of HF on plant fruiting is uncertain  at this point since the
minimum HF exposures at which effects on fruiting have been found are high in comparison to the levels of
phytotoxic fluorides found in the  ambient atmosphere,  except possibly near some fluoride sources. The
responses of additional plant species to lower HF concentrations will indicate the practical importance of
these effects.
AIR POLLUTION EFFECTS ON PLANTS
Francis A. Wood
The Pennsylvania State University, University Park, Pennsylvania
      Dr. Francis A. Wood, investigating the effect of air pollution on plants, has developed a fumigation
chamber for  exposing woody plants to various concentrations of ozone and peroxyacetyl nitrate (PAN)
under precisely selected temperature, relative humidity, and light regime.

      Dr. Wood  developed the fumigation  chamber  by modifying a Model M2 Plant  Growth Chamber
manufactured by Environmental Growth Chambers, Chagrin Falls,  Ohio.*  Major modifications include
treatment of interior surfaces to prevent corrosion by oxidants, use of Teflon insulation in internal wiring,
installation of an air exchange system, and installation of a charcoal filtration system through which air is
introduced. In this chamber, selected ozone concentrations can be maintained for indefinite periods with a
maximum fluctuation of ±5 percent.

      Using this chamber, Dr. Wood has exposed groups of 2- to 5-year-old seedlings of 22 tree species to 1,
25, and 50 pphm of ozone respectively for 8 hours at  temperatures between 70° F and 75° F, relative
humidities between  74 percent and 80 percent, and light intensities of approximately 1400 foot candles.
White ash, Japanese larch, tulip poplar, jack pine, Austrian pine, pitch pine, eastern white pine, Virginia
pine,  eastern  hemlock, and white oak showed acute symptoms after fumigation with 25  pphm. Symptoms
on conifers included ivory  flecking, chlorotic mottle, and tip neurosis. Hardwood leaves  developed dark
stipple on upper surfaces. Balsam fir, white fir, Norway spruce, white spruce, black hills spruce, blue spruce,
red pine, Douglas fir, eastern white cedar, sugar maple, European birch, and linden were resistant to 25
pphm ozone.

      Recent  fumigation experiments indicate that jack pine is the most sensitive of the species, probably
more  sensitive than eastern white pine.
CYTOGENETIC EFFECTS OF HYDROGEN FLUORIDE ON CORN
Aly H. Mohamed
University of Missouri, Kansas City, Missouri
     Since hydrogen fluoride (HF) is often a major gaseous component of atmospheric pollution, Dr. Aly
H. Mohamed of the Department of Biology of the University of Missouri is investigating the cytological and
genetic effects on plants of HF concentrations below those which produce detectable somatic damage. In
his recent experiments, Dr. Mohamed used corn seeds of the genotype Al AjC'R B Wx germinated in a
greenhouse in polyethylene pots containing a horticultural soil mixture.
*Mention of a company or product does not constitute endorsement by the U. S. Department of Health, Education and
 Welfare.
14

-------
      When the plants were about 2 feet high, eight plants were placed in a fumigation chamber and four
plants were placed in a control chamber. Before experiments began, plants were left in the chambers for 2
days to adjust to conditions in the chambers. Temperature was maintained at 24° C, relative humidity was
maintained  at about 60 percent, and light was closely controlled  for photoperiods of  14 hours. The
concentration of fluoride gas in the fumigation chamber was kept close to 3 ^g/m3. In the  10 days during
which the experiment was  conducted, four sporocyte samples were taken; the first sample after 4 days and
subsequent  samples at 2-day intervals. Control runs were always made simultaneously with treatment runs.
      The fumigated plants and the controls were moved back to the greenhouse after each treatment cycle.
Pollen grains collected from each fumigated plant and those collected from the controls, were used to
pollinate the recessive seed  plants of stocks yg2 C bz sh wx, a2 bt pr, and ai A2  sh2 C R dt. All of the
plants appeared healthy and  showed no visible injury.

      Meiotic analysis of microsporocytes of the treated plants showed the occurrence of heterozygous
reciprocal translocations  and inversions in the pachytene and bridges plus fragments in Aj. In a few cases
the  translocated chromosomes as well as  the  inverted ones were identified. These identifications are
summarized below.
      Type of aberration               Chromosome(s) involved             Breakage  position
      Translocation                            1-2                           1S.01.2L.31
      Translocation                            5-10                          5S.13, 10L.31
      Inversion (pericentric)                      1                             L.18,8.21
      Inversion (paracentric)                     7                             L.02,L.18
 EFFECTS OF AIR POLLUTANTS ON PLANT GROWTH
 A. Clyde Hill
 University of Utah, Salt Lake City, Utah
      Dr. A. Clyde Hill studied symptoms of ozone, PAN, and chlorine injury on a wide variety of crop and
 native plant  species.  Using several plant species  and pollutant  concentrations, he also studied the
 effectiveness of vegetation  such  as oats and  alfalfa in removing ozone and nitrogen dioxide from the
 atmosphere. Resulting  data indicate  that vegetation  might  be an important sink for these gaseous
 pollutants. Wind velocity above the canopy, light  intensity, extent of stomatal opening, and density of
 vegetation influence the pollutant uptake rate. The rate of pollutant uptake is related to plant injury as well
 as to atmospheric cleansing.

      By comparing plant responses under sunlight, standard fluorescent light, and  incandescent light, the
 investigator  found that the source of light can affect response of plants to air pollutants. Wind velocity also
 influences the response of plants to pollutants.

      PAN concentration of the ambient air was measured to determine the concentrations to which plants
 are exposed. PAN concentration in the ambient air is low in the early morning, builds up rapidly from 9:00
 to  11:00 in the morning to a peak, then decreases to a relatively low level by mid-afternoon. When
 concentrations average 2 to 3 pphm for about 2  hours, many sensitive plant species develop injury.

      After  an extensive study of the effect of ozone on plant growth, investigators concluded that a high
 concentration of ozone causes a temporary reduction in the growth rate of most species. Measurements of
stomatal openings  have  shown that  ozone causes  the  stomata to  close, reducing plant growth and
transpiration rates.
                                                                                               15

-------
        The technician is selecting oat seedlings to investigate the effect of air pollutants,
        particularity peroxyacetyl  nitrate and ozone  on  the  mechanism of  growth,
        specifically with respect  to  cell expansion in higher plant tissue. This work is
        conducted under grant AP 00213-06, entitled "Effect of Air Pollutants on Cell
        Growth," Dr. Lawrence Ordin, Principal Investigator.
16

-------
                           ECONOMIC AND POLITICAL STUDIES
AIR POLLUTION AND THE COMMUNITY IMAGE
Robert E. Rankin
West Virginia University, Morgantown, West Virginia
      In a completed  research project, Dr. Robert E. Rankin, of West Virginia University, investigated
public attitudes and reactions to air pollution where it constitutes a significant and constant part of the
environment. Dr. Rankin sought to determine (1) the public conception of air pollution and air pollution
control, (2) the  effect of air  pollution on  the public image of the  community,  and (3)  attitudes  and
personal characteristics influencing individual conceptions of air pollution and its control. Investigators
defined  five separate  population groups within the Kanawha  Valley chemical-industrial  area of West
Virginia and scientifically selected  samples for personal interviews. The samples included approximately
900 persons within the corporate limits of Charleston, 500 persons from three  separate communities
outside Charleston, and 800 graduating high school seniors from the Charleston area.

      A significant majority in every community were both aware of and concerned about air pollution. In
rating a number of typical urban problems according to seriousness, air pollution ranked first in all samples.
Over three-fourths of the respondents in all communities except Charleston expressed  some degree of
dissatisfaction with air conditions. In Charleston almost half were dissatisfied. Over 90 percent of every
population group agreed that air  pollution existed in the community. Dust and dirt, chemicals in the air,
and  odors  were  most  commonly associated  with  the term  air pollution. From  one-third to  over
three-fourths of the samples expressed some anxiety over the possible consequences of pollution.

      Despite these significant expressions of concern at the community level, many people did not seem to
feel personally affected by air pollution. In most areas people saw it as a much more serious problem in the
community-at-large than in their  own neighborhoods. Many appeared to consider pollution to be restricted
to the area near the source that is around the plants. Most people seemed  to feel personally affected only
when they perceived pollution as a health threat.

      Most people seemed to feel that air pollution could be greatly reduced, and even more favored action
to reduce it. When questioned about what would be done, however, most people were pessimistic. Less than
half of the respondents in all communities felt that there would be "noticeable improvement" in the next 5
years, while approximately 15 percent said that things would get worse. Knowledge about control programs
already in progress was slight. Asked about efforts of Federal or regional agencies to deal with air pollution,
two-thirds of those questioned were generally unaware of such action and  less than 10  percent could give
any substantive account of it.

      From 14 to 43 percent of the respondents, depending upon the  community, reported  that they had
felt, at times, like complaining about some aspect of air pollution, but in no community did  more than 10
percent report that they had translated this feeling into action.

      The interviews indicated that air pollution did have a significant  effect on general community
attitudes. Although satisfaction  with living in the area did not vary  much in relation to the perceived
seriousness of pollution in the total community, people who saw serious pollution problems in their own
neighborhoods  did tend to be  less satisfied.  Spontaneous remarks early in the interviews (prior to  any
mention of pollution by the interviewer), indicated great awareness of air pollution in the region. Even
though interviewees in Charleston seemed less  aware than those elsewhere, nearly  60 percent  of the
Charleston sample brought up the subject on their own. When asked what single thing they would most like
to change in their community, people ranked air pollution first everywhere except Charleston, where they
ranked  it second to the  streets and traffic problem. Few people spontaneously mentioned pollution  as a
factor in changing their residences, but many (from  17 percent in Charleston  to  47 percent in South
Charleston) reported having seriously considered moving because of it.
                                                 17

-------
      The graduating  seniors interviewed were significantly more concerned about air pollution than the
general  population. Twenty-two percent of those not wanting to remain in the Kanawha Valley gave air
pollution as their most important reason, and 59  percent of the total high school sampled said that air
pollution was the thing they disliked most about the region.

      Investigators are continuing work on the third research objective, determinations of general personal
characteristics influencing perception of air pollution and attitude toward the possibility of control. Thus
far  non-perceivers  have tended  to be more negative toward science,  to  have lower  incomes  and
educational  attainments, and to be older than perceivers. Those pessimistic about effective control were
more anti-scientific, had lower incomes and educational levels, were  younger, and were more alienated
from societal norms than their more optimistic neighbors.

      The relationship between the type and amount of pollution and  the awareness of and concern about
pollution has not yet been analyzed.
18

-------
                ANALYSES AND PHYSICOCHEMICAL INVESTIGATIONS
PHOTOCHEMISTRY OF SUBSTANCES PRESENT IN URBAN AIR
Harold Johnston
University of California, Berkeley, California
      Dr. Harold Johnston has developed a new method of following intermediates, such as free radicals, in
photochemical reactions. Utilizing long-path infrared absorption for direct observation of these free radical
intermediates, Dr. Johnston will attempt to determine the  mechanism of photochemical reactions which
cannot be unambiguously determined by mere observation of reactants and products. With this approach,
he  anticipates important breakthroughs in unraveling what actually happens in complex photochemical
systems, especially the photochemical oxidations that occur in air pollution. According to Dr. Johnston this
method, which measures optical densities as low as 1CT6 in an 80 meter path, is at least 100 times more
sensitive than any other infrared method.
 MECHANISMS OF PHOTOCHEMICAL REACTIONS IN URBAN AIR
 J. N. Pitts, Jr.
 University of California, Riverside, California
      In his research into photochemical reactions in urban air, Dr. J. N. Pitts is investigating the reactions
 of  excited  (singlet)  molecular  oxygen  with  hydrocarbons as possible  sources of  pollutants  in  the
 atmosphere. Using singlet oxygen in the gas phases generated by microwave  excitation of ground state
 molecular  oxygen, Dr.  Pitts  found  that  the reaction  of singlet oxygen with  certain unsaturated
 hydrocarbons in a flow system produces high yields of selected stable peroxides. Singlet oxygen has been
 found to react  with 2,5-dimethyl-2-methoxy-5-peroxyfuran. The  similar  reaction with 2,3-dimethyl-2-
 butene has produced only 2,3-dimethyl-3-peroxy-l-butene in better than 50 percent yield. Dr. Pitts and his
 associates are continuing  their study of the reactions of singlet oxygen with hydrocarbons that have been
 identified in polluted atmospheres.

      This group also is investigating the photochemistry of acrolein (CH2=CHCHO) in the vapor phase.
 Acrolein  is a  constituent of  photochemical  smog and  is stable  toward photo-decomposition. The
 investigators believe, however, that unstable intermediates such as methyl ketene (CH3CHCO), which might
 be formed during irradiation, may react readily with 02 (' Ag) in the atmosphere.

      Initial research  has  dealt  with the photochemistry  of acrolein at pressures between  1  mm  and
 approximately 50 mm. When that system is thoroughly understood, the investigations will be extended to
 include  the range 10~4mm to 10 mm, the atmospheric range. When these studies are completed, 02(1Ag)
 will be introduced in both pressure ranges.

      Dr. Pitts and his associates have developed a versatile chemical actinometer, suitable for field as well
 as laboratory studies, for the measurement of radiation  intensities in the near  ultraviolet range. The
 actinometer is a thin film  of polymethyl methacrylate in which the actinic material, 0-nitrobenzaldehyde, is
 dispersed. Aborption of light in the 28004100A range causes 0-nitrobenzaldehyde to  photoisomerise to
 0-nitrobenzoic acid with a quantum efficiency of 0.50. The extent of this reaction upon irradiation can be
 related to the intensity of the radiation source. This actinometer is suitable for measuring solar radiation
intensities within the region  30004100A, the photochemically  reactive wavelength  region for  the
production of photochemical smog.
                                              19

-------
SELENIUM AND ITS SIGNIFICANCE AS AN AIR POLLUTANT
Philip W. West
Louisiana State University, Baton Rouge, Louisiana
     Dr.  Philip West  is  conducting  two  research projects,  "Separation  and Estimation of Airborne
Particles"  and "Atomic Absorption Spectroscopy of Trace Pollutants." One important result of Dr. West's
research is the discovery of selenium  in papers and in the effluents from trash burning operations and
incinerator  stacks.  His  research  group  also  has contributed  numerous techniques for  separation,
identification, and  estimation  of  various  airborne particulates and  has developed atomic  absorption
spectroscopy for application to air pollution and related studies.

     Selenium, which may be associated with lung cancer, emphysema, and cardiovascular defects among
cigarette smokers, has been found in paper made from flax straw (cigarette paper) as well as papers made
from wood  pulp. Researchers have  developed three different methods for  determining  minute traces of
selenium.  They also are investigating the presence of selenium in tobaccos and in air, particularly in the
atmosphere around trash burning operations and municipal and apartment incinerators.

     The  research team is investigating methods for the study of airborne particulates in order to  develop
methods  that are  highly  sensitive,  selective, and reliable. The investigators  have concentrated  on the
development of ring-oven  methods  for  the highly specialized requirements  of  air pollution  studies.
According to Dr. West, the ring oven itself can be shop constructed or can be purchased for less than $200.
The ring-oven methods require no  special  training, and the  procedures are generally rapid, reliable, and
accurate. These  methods  are versatile  and are applicable to the  study of  complex mixtures. They can
determine pollutants in parts-per-million and parts-per-billion concentrations.

     Dr.  West's team has developed  reagent  crayons for   convenient  and  simple  field  detection of
pollutants. Selected reagents dissolved  in a low melting matrix are poured into small tubes such as drinking
straws. Upon cooling, the solutions solidify to form stable mixtures, like ordinary marking crayons, that
provide distinctive colors when streaked across test  surfaces on which pollutants are absorbed.

     An important part  of the  research program has been  the Development  of trace analysis methods.
Atomic absorption  spectroscopy holds  great promise because it is  inherently specific  and is extremely
sensitive. Methods have been developed which can determine pollutants in parts-per-million and parts-per-
billion  concentration ranges.
MECHANISMS OF PHOTOCHEMICALLY INITIATED OXIDATIONS
Jack G. Calvert
Ohio State University, Columbus, Ohio
     Dr. Jack G. Calvert is attempting to determine the complex mechanisms by which chemical reactions
occur in the polluted  atmosphere, especially  in  the  polluted  atmosphere irradiated  by sunlight.  He is
investigating the reactions of a variety of light absorbing compounds known to be present in the polluted
atmosphere. In studying the photochemistry of  several components of known importance in polluted
atmospheres, Dr. Calvert is employing a variety of quantitative physical methods, including flash photolysis,
long-path infrared spectroscopy, visible and  ultraviolet spectroscopy, emission studies, and electron spin
resonance spectroscopy.

     Extensive study of formaldehyde, the simplest of the carbonyl compounds, has yielded quantitative
data delineating the nature and extent of the primary  processes in the photolysis of this compound. These
data should be particularly useful  in  the calculation of rates of CH2O  photooxidation and H and HCO
formation in sunlight-irradiated polluted atmospheres. Efforts to establish what happens to the H and HCO
in the atmosphere continue.

-------
     Dr. Calvert has determined the relationship between structure and photodecomposition modes in a
variety of related ketones. He is studying the photochemistry  of the sulfur dioxide molecule and of its
photosensitized  oxidation in the presence of organic peroxy radicals. The reaction mechanisms of the
organic fragments (free radicals) formed in an oxygen rich media have been determined for a variety of
systems. Investigators have studied the methyl, acetyl, ethyl, propyl, tert-butyl, and n-butyl radicals, and
have determined probable mechanisms of their reactions in  the absence and presence of oxygen and nitric
oxide.

     Dr.  Calvert and his associates are continuing their  study on the  mechanisms and intermediates
involved in  the  photochemical oxidations sensitized at the surface  of metallic oxides and sulfides. They
intend to evaluate  the importance of  various inorganic particulates in  the chemical dynamics  of  the
irradiated polluted atmosphere.
BIOENGINEERING ASPECTS OF AIR POLLUTION
Sheldon K. Friedlander
California Institute of Technology, Pasadena, California
      Much of Dr. Sheldon K. Friedlander's research is concerned with the size distribution (the number of
 particles of any  given size) of the fine particles present in fumes, smokes, and smog. Since particle size is
 related to particle deposition in the human lung, such studies may yield important results. In addition, the
 designing of gas cleaning equipment such as filters and electrical precipitators requires reliable information
 on particle size distribution.

      As a result of their dancing motion, due to molecular bombardment, particles in a smoke or fume
 collide and  stick together, steadily increasing the number of larger particles and decreasing the number of
 smaller ones. Dr. Friedlander and his  associates have  discovered that this process leads to definite particle
 size  distribution, and they have worked out a mathematical theory that predicts the number of particles of
 each size. This theory enables one to determine from only a few measurements the size distribution of a
 fume or smoke, and thus to save considerable time  and money.
 BEHAVIOR OF AEROSOL PARTICLES
 Robert S. Sholtes
 University of Florida, Gainesville, Florida

      By observing aerosol particles through an image intensifying apparatus, Dr. Robert Sholtes is able to
 observe their  behavior via scattered  light without limitation of light intensity and rapidity of particle
 movement. The apparatus has been successfully assembled and its performance demonstrated.

      With a dust  counter installed in a light aircraft, Dr. Sholtes has experimented with the use of particle
 count to  trace a plume  in the downwind direction. The source of the plume was a power plant burning
 pulverized coal  without  any particulate controls. Since it was in an  isolated area on the Gulf coast of
 Florida, there were no interfering sources, and dispersion patterns could be examined over both land  and
 sea areas. Dr. Sholtes traced the plume for  40 miles downwind and established plume aerosol concentra-
 tions in both horizontal and vertical axes.
CONTROLLED SOURCE OF UNIFORM LIQUID DROPLETS
Charles D. Hendricks
University of Illinois, Urbana, Illinois

      Much air pollution research calls for reliable, controlled sources of uniform small particles, to serve as
models of polluting materials and as calibration sources. Professor Charles D. Hendricks is attempting to
                                                                                               21

-------
 develop such sources to deliver particles with diameters in the micron range and with size distributions of
 1CT2  or less standard deviation. Professor Hendricks is also investigating particle-particle and particle-surface
 interactions, and the ease with which he is able to control particle size and electric charge has led to studies
 of charged particle behavior.

      Since control  and dissipation of various types of air pollution require a knowledge of the behavior of
 liquid drops upon collision with other drops or with  solid particles, this  project particularly  has been
 concerned with collision and coalescence. The behavior  of colliding droplets is an important consideration
 in the design of systems to remove or control pollution from industrial sources.

      A droplet generator developed in Professor Hendricks' laboratory affords excellent control of size and
 charge and can produce uniform droplets down to a few microns in radius. Significant characteristics of this
 droplet generator are:
      1. The low pressures required to form liquid jets through narrow capillary openings
      2. The low power necessary to drive the quartz crystal, electromechanical transducers coupled to the
         liquid jets to disrupt them into droplets
      3. The high-speed electronic-pulse techniques employed for light synchronization  with the  droplet
         stream and  for separation of individual droplets for collision experiments

      A multiple-stream droplet generator is being constructed to produce large quantities of micron-size
 droplets.

      Professor Hendricks and  his associates also are studying an  emission  process  requiring only the
 collision of a small droplet  and a large  drop with an electric field at the surface. This electric field  may be
 produced by a charge  on the drop, which  is below the Rayleigh limit, or by the presence of an external
 electric field. If a small uncharged  droplet is collected  by  a large, charged drop, the  droplet touches the
 surface  of the drop  and remains there for a short time (the coalescence delay time) then begins to coalesce
 into the drop. If  the electric field at the drop  surface is high enough, the droplet coalesces, but a new,
 highly  charged  droplet is  emitted because  of instability  due to  the electric  stress  on  the surface.
 Investigators have verified the essential elements of this process analytically and experimentally.

      Although research so  far  has  produced relatively large particles, it is being extended to the  smaller
 sizes (a few microns or less). In preliminary investigations, ice particles were formed by freezing of water
 droplets  and lucite particles   by evaporation  of  a solvent.  Investigators  concentrated, however, on
 production of sodium nitrite particles by freezing of molten droplets because of the ease of working with
 this material. This process yielded uniform  particles less than 200 microns in diameter with more than 104
 coul/kg specific charge at a rate of 11,000 per  second. The techniques developed in this work  are being
 extended to small particle production.
FORMATION AND DECAY OF ATMOSPHERIC AEROSOLS
Alexander Goetz
Atmospheric Research Group, Altadena, California

      Dr. Alexander Goetz, of  the  Atmospheric Research  Group,  Altadena, California, is studying
aerocolloid formations of reactive hydrocarbons in the biosphere as part of his research into formation and
decay of atmospheric aerosols.

      Investigators  have revealed that,  depending on  time and location, the  number  and size  of the
particulates in  the  ambient air can  be considerably enlarged,  often by an order of magnitude, when the
sampled air flow, prior to precipitation of the aerosols, is briefly (<45 sec.) exposed to UV-irradiation at
2537 A. The precipitated particulates are very  sensitive to subsequent thermal or UV-exposure for extended
duration (>30 min.).

      This transformation of molecular-dispersed  hydrocarbons  into small particulates irradiation appar-
22

-------
ently  involves photochemical oxypolymerization and subsequent coagulation. The particles, apparently
mostly liquid and highly hydrophylic, appear to be active centers for H20-condensation.

      Dr. Goetz's findings offer a rapid and simple method for determination of the presence and quantity
of potentially reactive hydrocarbon traces in terms of their capacity to polymerize into particulates, and for
discrimination between these traces and the  aerocolloid matter that already has reacted under sunlight
irradiation.
COMPOSITION OF LEAD HALIDE POLLUTION AEROSOLS
John W. Winchester
University of Michigan, Ann Arbor, Michigan
      Professor  J.  W.  Winchester and  Dr. W. R.  Matson  of the Department of  Meteorology  and
 Oceanography,  University of Michigan, have  constructed  a  multiple anodic-stripping device that  can
 perform up to 20 analyses per  hour for nanogram quantities of lead, copper, cadmium, and bismuth in
 natural and pollution aerosols. These investigators have found that under certain conditions, between 10
 percent and 80 percent of the  lead found in 1- to  10-micron-radius particles in aerosols and in natural
 waters is bound to the  particles  and is released very slowly, half times of dissociation varying from 10 to
 100 minutes. The binding of trace metals to atmospheric particles may be a factor in the body's uptake of
 these materials through  the lungs and moist tissues.

      Professor Winchester and Dr. Matson are using a combination of anodic-stripping lead determination
 and neutron activation  analysis of the elements chlorine, bromine, and iodine to study the composition of
 lead halide pollution aerosols. Particles have been fractionated over the radius range 0.25 to 8 microns.
 Preliminary  studies  of  urban aerosols in Ann Arbor indicated that chlorine is enriched in the largest
 particles, bromine is enriched in the smallest,  and  iodine is variable. Some of the lead samplings show a
 pronounced  maximum  near  1 micron. These results are consistent  with the hypothesis that  bromine is
 condensed onto the  surfaces of  the small particles in the gas phase, whereas chlorine is associated primarily
 with the  large particles. If pollution iodine were added to the atmosphere mainly in an oxidized state, it
 would not be rendered  volatile by reaction with oxidants as are pollution bromide and natural iodine in sea
 water. Enrichment of pollution iodine in the smallest particles, therefore, is not expected.
 INFLUENCE OF AEROSOL CHARACTERISTICS ON VISIBILITY
 R. J. Charlson
 University of Washington, Seattle, Washington
      Decreased visual range, one of the most obvious effects of air pollution, is the result of light scattering
caused  by very small particles suspended in the atmosphere. In a research project directed  initially by
Professor A. T. Rossano and more recently  by Dr. R.  J. Charlson, investigators at the  University of
Washington, at Seattle, have discovered a relationship between the amount of particulate matter suspended
in the air and the visual range.

      Determination of this  relationship was made possible  largely by the development of an instrument for
measurement of the pertinent optical factor. This instrument, called an integrating  nephelometer, already
has been used  in pollution  monitoring as well as in research. One instrument built by the University of
Washington group has been used by the Puget Sound Air Pollution Control Agency for monitoring the
visibility degradation at the site of the 1962 Seattle World's Fair.

      Perhaps the most important application of a relationship between the amount of particulate pollutant
and the visual range is in the area of air quality standards. Results of this project indicate, for instance, that
maintenance  of the 5 km (3 mile) visual range for  aircraft operations under Visual Flight Rules, would
                                                                                               23

-------
require that particulate matter be kept at less than about 240 micrograms per cubic meter of air. Although
the amount does vary, 90  percent of all cases for a 5 km visual range should fall between 120 and 480
micrograms per cubic meter. Dr. Charlson has tested this result in extensive field experiments in New York
City,  in San Jose, and in Seattle. Similar  results  were obtained by an entirely different method by the
California Department of Public Health.	               	            	
                      The integrating nephelometer deveioped by R. J. Charlson
                        under a research grant to the University of Washington.
                            Integrating nephelometer mounted on aircraft.
 24

-------
PRIMARY PRODUCTS OF PHOTODISSOCIATION
Dr. Kent R. Wilson
University of California (San Diego), La Jolla, California
      Photodissociation,  the  breakup of molecules under  the influence of  light, is a basic  process  in
photochemical air pollution. The absorption of light  energy and the production of  molecular fragments
initiate complex chains of atmospheric chemical reactions leading to smog. Although photodissociation has
been  extensively studied, the details of the process, on a molecular level, have been difficult to determine.

      Dr. Kent R.  Wilson  and his associates  have  developed  a  new  procedure,  photodissociation
translational spectroscopy. They cross  a beam of molecules and a pulse of laser light inside a vacuum
chamber to cause some of the molecules to dissociate. By measuring the flight times of the fragments over a
several-centimeter  path to a mass spectrometer, the investigators determine their velocities, or translational
energies. The new procedure is being used in two studies.

      First, the research  group  is attempting to learn the details of the photodissociation of NO2, a basic
process in smog production. They already have made preliminary measurements of the partitioning between
translational energy and internal  energy  of the fragments in order  to determine the electronic states
involved in the dissociation.

      The  second study is to determine the  masses of  the  fragments of molecules, such  as  nitrates,
aldehydes, and ketones,  whose photodissociation is important  in air pollution. With their new procedure,
the investigators can measure the fragments directly, before they strike other molecules or walls.
                 Translational spectrometer used in studying the photodissociation of
                         nitrogen dioxide. The equipment has been developed
              by Dr. Kent R. Wilson under a research grant to the University of California.
                                                                                               25

-------
                               DEVELOPMENT OF ANALYTIC
                                METHODS AND EQUIPMENT
GENERATION AND DECAY OF SMALL IONS
A. R. McFarland
University of Minnesota, Minneapolis, Minnesota
      The initial objectives of the research directed by Dr. A. R. McFarland of the University of Minnesota,
were to study generation of small ions with a new sonic-jet ion generator, to study physics of decay of high
ion concentrations in flowing jets and in the presence of aerosols, and to develop systems for neutralizing of
electrostatic  charge on particles. Significant  products of these studies include a sonic-jet  ion  generator
which, when used to generate bipolar ion atmospheres, is also an effective aerosol neutralizer and a practical
electrical-particle counter for the submicron range.

      The sonic jet ion generator has been widely used as a research tool for ion generation, for charge
neutralization, and for  other  purposes. It is  an essential  part of several  aerosol  generators used for
calibration of aerosol-measuring instruments.

      The electrical particle counter is the first practical  in situ particle counter for the 0.01-to 1-micron
range. In combination with a condensation nuclei counter and an optical counter, it constitutes the first
automatic system for measuring aerosol size distribution over the complete range of sizes normally found in
the atmosphere.

      Dr. McFarland and his associates have also developed other charged-particle-measuring techniques and
devices,  including  a new electrostatic aerosol sampler capable of highly accurate sampling of aerosols on
electron-microscope grids and light-microscope slides simultaneously.

PARTICULATE SAMPLING BY ADHESIVE-COATED MATERIAL
Charles Gruber
City of Cincinnati, Cincinnati, Ohio
      Having successfully used adhesive-coated paper wrapped  around circular glass jars for monitoring
 windblown particles, the Cincinnati Division of Air Pollution Control wished to employ  this device in
 wide-scale air pollution studies. Charles Gruber's project comprised the evaluation of this device and the
 establishment of criteria for its use.

      Mr. Gruber  has  determined the best materials for the collectors and has  investigated the factors
 affecting  particle  collection. Cylinder diameter, wind  speed, total miles  of wind, and precipitation are
 important factors affecting  particle collection,  while electrostatic forces  are of little or no importance.
 Total particle loading  on the adhesive sampler  used in atmospheric surveys varies from 8 to 20 percent,
 depending upon the location of the sampler.

      Using a laboratory  wind tunnel designed for this project, Mr. GruBer found  the actual and the
 theoretical impingement  efficiencies of the adhesive sampler to be closely  correlated. He calculated the
 collection efficiency of the sampler to be 24 percent at 5 mph, 37 percent at  10 mph, and 54 percent at 15
 mph.

      Of the particles collected on the adhesive, 85 percent were greater than 11 microns in diameter, 60
percent were greater than 22 microns, and 30 percent were 22 microns to 44 microns in  diameter.

      A recommended  standard method for measuring windblown nuisance particles has been drafted, and
field application of the  method is in progress to verify its effectiveness.
                                                27

-------
POLLUTION ABATEMENT BY PROCESS GAS CHROMATOGRAPHY
Michael Schaer
Montana State University, Bozeman, Montana


      Dr. Michael Schaer, at Montana State University, has developed a process gas chromatograph using a
bromine microcoulometer detector sensitive to 1-ppm quantities of various sulfur compounds, such as H2S,
S02, and CH3SH. Lately,  he  has  been  attempting to solve  two problems with the detector, noise and
deterioration of the electrolyte  solution. Improvements in  cell design  have partially  solved the  noise
problem, and  improvements in  electrode design  may further reduce the noise.  Problems arising  from
deterioration of the electrolyte have been solved by the addition of a new electrolyte every 10 hours.

      Since the ordinary  strip chart output from a process gas chromatograph is not adequate in a modern
day  paper mill, Dr. Schaer is equipping the chromatograph to provide digital display of the concentrations
of the various sulfurous  gases. A standard teletype printer will provide the digital display. In addition, a
paper tape which can be  processed on  a digital computer  will be punched. The tape will allow  rapid
determination  of  the relationship between  plant operation  and  total  sulfurous  gas emission. This
information will provide management with a clear basis for corrective action to minimize air pollution.


STUDY OF ATOMIZER AEROSOL GENERATORS
K. T. Whitby
University of Minnesota, Minneapolis, Minnesota
      Dr.  K.  T. Whitby,  of the University of Minnesota, is attempting to develop a set of monodisperse-
aerosol generators that can be used for aerosol research, air cleaner testing, and  calibration of aerosol
sampling and measuring instruments.

      Some of the generators being studied in this project are:
      1. An improved atomizer-impactor aerosol generator for polystyrene latex in the O.Ol/n to 0.5^1 range
      2. An improved condensation aerosol generator for aerosols in the Q.Q3/J. to 1.3jU range
      3. An improved spinning disk generator
      4. Hollow-cone atomizers for monodisperse aerosol in the IM to 30/i range
In addition, preliminary experiments with specially prepared freon solutions of DOP in aerosol cans suggest
that they might be used to generate moderately monodisperse DOP aerosols of reproducible size.

      Dr. Whitby  also has been studying electric-charge distribution and residue-particle-size distribution,
on polystyrene latex (PSL) aerosols.

      He has  measured the relatively high electric charges on 0.8^ PSL. Since removal of this high charge is
necessary  for certain uses of the aerosol, the new PSL generator  incorporates a Krypton  85 charge
neutralizer.

      The investigator also found that  103  to  104  residue particles are generated for every PSL particle.
These residue particles are a significant source of spurious pulses in the calibration of optical counters.


STUDY OF ODOR COMPONENTS OF INDUSTRIAL EXHAUST
Norman M. Trieff
Drexel Institute of Technology, Philadelphia, Pennsylvania


      One of  the primary objects of Dr. Norman M. Trieff s investigations was to develop effective methods
of  sampling  and  analysis of industrial odors and  to analyze  emissions  from rendering  plants in the
Philadelphia area. Several sampling approaches have been successfully employed.
 28

-------
     In the first method, air was pumped from within or immediately outside the rendering plant through
a K2C03 drying tube and onto a U-tube. The U-tube was packed with glass beads or chromosorb W coated
with apiezon L and immersed in liquid N2. After sampling, the U-tube was attached to a chromatographic
column in  the chromatograph oven. The  U-tube served as a precolumn and released the  sample without
appreciable  fractionation.  Over  20 components  were  separated and  detected  in  the  chromatogram.
Reproducibility was good, but component size was too small to be  easily identified.

     In the second method, a larger sample was obtained by adsorption of odors on charcoal; heating of
the charcoal in a vacuum oven; and drawing of the odorous vapors through a drying tube onto  a packed
U-tube, cooled in liquid N2, which served as a precolumn for the gas chromatograph.

     Dr. Trieff is  now attempting to identify components  through retention times from  G.L.C., I.R.
spectra, and mass spectra.
ACTIVATION ANALYSIS OF ATMOSPHERIC PARTICULATES
Roy G. Post
University of Arizona, Tucson, Arizona
      Dr. Roy G. Post has employed neutron activation analysis for routine, rapid analysis of the elemental
 composition  of particulates obtained from air sampling stations. In Dr. Post's technique,  a  computer
 program automatically performs both qualitative and quantitative analyses.

      Only one sample spectrum is necessary for the qualitative analysis since this analysis is based only on
 gamma-ray peak energies, not  on half-life, To  perform quantitative analysis, this technique utilizes a
 permanent isotopic spectra  library  stored on magnetic tape for matrix unscrambling of the composite
 spectrum. Because the unscrambling scheme minimizes the amount of computer storage required, a 1024
 channel spectrum containing 20 components can be analyzed using only about 800 words of core storage.

      In this method,  the  sample is assumed to  have unknown composition but  a  limited number of
 possible  constituents. Program input consists  of raw data from  the spectrometer under a variety of
 experimental conditions. The output consists of both the isotopic and elemental sample composition in
 micrograms.  Errors  in  the spectrum unscrambling  are only  a  few percent for the most  abundant
 constituents.
 PORTABLE SPECTROMETRIC ANALYZER FOR AIR POLLUTANTS
 David T. Williams
 University of Florida, Gainesville, Florida
      The  effective  study  of air pollution  demands  rapid  and effective  measurement  of pollutant
concentrations. Molecular correlation spectroscopy, a new method developed by Dr. David T. Williams at
the University of Florida College of Engineering, measures these concentrations accurately, rapidly, and
conveniently.

      This method allows field measurement of concentrations of a few parts per billion of S02 , N02 , NO,
NH3, C6H6, C6HSCH3, and other pollutants, over path lengths of approximately 100 meters. Other
materials  in  the air do  not interfere with these quantitative measurements. Molecular  correlation
spectroscopy can be used to measure any gaseous chemical having a band or line spectrum, either visible or
ultraviolet. In  the field of air pollution, it can be used for  hitherto impossible quantitative studies of
atmospheric interactions.
                                                                                            29

-------
                                       METEOROLOGY
TRAVELS OF AIRBORNE POLLEN
Eugene C. Ogden
The University of The State of New York, Albany, New York
      Although pollen is a major air pollutant and an important cause of respiratory disease, little has been
 known about pollen dispersion and the factors that influence pollen concentrations. Dr. Eugene C. Ogden,
 State  Botanist of New York, is directing research to add to  the knowledge of these things. The basic
 accomplishments of this research include:
      1. Development and evaluation of samplers for airborne particles of pollen size
      2. Development of techniques for tagging pollen in living plants with radio isotopes and with dyes for
         artificial simultaneous dispersion from multiple point sources
      3. Determination of the influences  of  pollen  properties,  source  characteristics, meteorological
         conditions, surrounding terrain, and vegetative cover upon dispersion and deposition patterns of
         ragweed, timothy, and corn pollen from known sources over open terrain
      4. Accumulation of data on  the effects of forested areas  in removing  pollen from the air and
         comparison of removal rates in forests to those in non-forested areas
      5. Determination of the effects of height, time, source location, terrain, vegetation, and weather
         upon concentrations of naturally produced pollen
      6. Preparation  for  development and testing of mathematical models to predict dispersion and
         deposition from single and multiple pollen sources

      The project has added  to knowledge of the mechanisms of pollen dispersion and has facilitated
 adequate assessment of the variables that influence dispersion.

      The data acquired in  this  project  may be helpful in  the evaluation of proposed  weed-control
 programs. Since pollen sources are, in many ways, representative of area sources of airborne pollutants,
 results of this research into pollen dispersion also should  be  useful in the study of other air pollution
 problems.
 VISIBLE SPECIES OF ALGAE AND PROTOZOA IN THE ATMOSPHERE
 H. E. Schlichting, Jr.
 North Texas State University, Deaton, Texas
      Dr. H. E. Schlicting, Jr., of North Texas State University, has studied the numbers and species of
 algae and protozoa in the atmosphere and has conducted investigations in Michigan, North Carolina, and
 Texas. Using filters and bubblers containing soil-water extract, investigators collected  samples throughout
 the year under  environmental conditions  including freezing rain, heavy snow, fog, and summer tempera-
 tures up to 39.4°C and at heights ranging from 6 to 7,500 feet.

      To ensure uniform and valid results and to reduce the possibility of damage to the collecting medium
 or to the collected organisms, short sampling periods (1-2 hours) and a slow rate of sampling, usually less
 than 1 cubic foot per minute, were employed. Better correlations were made of the quality and quantity of
 algae in the air with vertical updrafts than with wind velocity or direction which often showed little or no
 correlation with the aerial biota.

     Preliminary investigations revealed that the aerial biota does include viable species of algae. Some of
the species identified are known to be toxic and to invade water supplies. Additional studies should provide
needed information on the survival and dispersal of these organisms in the atmosphere.
                                               31

-------
ATMOSPHERIC DIFFUSION IN THE INERTIAL SUBRANGE
Paul MacReady, Jr.
Meteorology Research, Inc., Altadena, California


     In the first phase of a study of fundamental relationships between turbulence and diffusion, Dr. Paul
MacCready, Jr., has investigated discrete particle tracer techniques that would approximate the motions of
neutral fluid particles. Dr. MacCready found that a small, helium-filled balloon with negligible superpressure
and zero net lift is an ideal tracer of turbulent motions down to  scale lengths comparable to the balloon's
diameter. The  balloons used were opaque, white, rubber balloons approximately 25 cm in diameter when
inflated. The effects of radiant heating on the balloon's buoyancy were found to be generally negligible.

     Elsinore  Valley and El Mirage Dry Lake in California were chosen as sites for the balloon experiments
because of their  smooth  and  uniform fetches and  their constant wind directions. The tracking system
consisted of a synchronized pair of phototheodolites oriented  crosswind on a 303-meter baseline. The
balloon tracers were carefully neutralized in a closed  van, carried aloft by a free-lift balloon, and released at
a preselected height by a  passive mechanism as either point source clusters or clusters with finite inertial
separations  in  the  crosswind  and vertical directions.  During the tracking of the  balloon  clusters,  an
instrumented aircraft  made along-wind and crosswind traverses in the vicinity of the balloons to measure
the turbulence dissipation  rate and, in the later experiments, to provide complete two-dimensional energy
spectra.

     The balloon data  are to be reduced and categorized on the basis of turbulence and meteorological
conditions.  Information gained  from this analysis  should  facilitate  meaningful comparisons between
observations and theoretical predictions.

     Dr. MacCready also  developed a method for the use of soap bubbles as a tracer technique. In these
investigations,  he  developed a technique  for generating permanent, buoyant soap bubbles and a method for
photographing the bubbles at considerable distances in the dark.


MESOSCALE WIND SYSTEM AROUND THE GREAT LAKES
E. Wendell Hewson
University of Michigan, Ann Arbor, Michigan

     Because  of the  great role that shoreline wind systems play in  the transport of pollutants in  the
industrialized Great Lakes area, knowledge of these  systems is vital for control  of pollution from lakeside
industries.  Research under the  direction of Dr. E. Wendell Hewson, at the University of Michigan,  has
provided new information about these wind systems.

     Using  triangulation  methods to track both freely rising  and neutral balloons, investigators have
learned that during the late spring and summer, the local wind from the lake to and over the land, known as
the lake breeze, often commences about 11 a.m.  and extends upward  from the surface l/i to 1 km. As it
advances over  the land, the cool lake air often has a clearly defined leading edge, known as the lake breeze
front. The  coo! air  may advance in  several steps: it may initially advance from 5 to 10 km inland, then
remain almost  stationary for as many as 3 hours,  and then move rapidly inland for distances up to 20 km.

     Aloft, from l/i to 2 km, there is often a return current with lighter  winds than the lake breeze.  Dr.
Hewson suggests that such pronounced return currents aloft occur more frequently near the lakes than near
middle-latitude sea and  ocean  shorelines, presumably because the circumscribed area of a lake constrains
the air flow. Neutral-balloon tracking in and near Chicago has revealed  looping patterns of air flow, with
similar pronounced patterns of smoke behavior, under low regional wind conditions.

     Increased knowledge of these local winds should facilitate  analysis of the transport of air pollutants
emitted by the rapidly growing industrial megalopolis south of the Great Lakes.


32

-------
INVESTIGATION OF ICE FOG PROBLEMS
Takeshi Ohtake
University of Alaska, College, Alaska
      Dr. Takeshi Ohtake, of the University of Alaska, has investigated ice fog, a kind of "low-temperature
air  pollution,"  in the Fairbanks, Alaska area. Ice fog is produced by the rapid  cooling of saturated warm
water vapor injected into a very cold atmosphere, —30° F or below, already near ice saturation. In subarctic
populated areas, such as Fairbanks, this phenomenon presents problems in transportation and in health.
      The three primary sources of ice fog are open water, automobile exhaust, and heating plant exhaust.
 In the formation  of ice fog, water vapor first condenses to form small liquid droplets. As these droplets
 diffuse away from the source, rapid cooling causes many of them to freeze. As further diffusion occurs, the
 remaining  droplets evaporate,  forming and adding to ice  particles by sublimation and maintaining the
 atmosphere near ice saturation.

      Dr. Ohtake  has investigated  the sources of water vapor  and its role in formation of ice fog, the
 relationship between concentration of ice fog particles and  concentrations of ice nuclei and condensation
 nuclei, and, using an electron microscope, characteristics of nuclei and crystals.

      Dense ice fog was found to be associated with large sources of moisture regardless of the number of
 nuclei. The total  concentration of ice fog particles increases as the ambient temperature decreases: the
 concentration  ranges from about 125 particles per cubic centimeter at —35°  C to about 225 per cubic
 centimeter at —42° C. The most common diameter decreases with the ambient temperature, from about 12
 microns at —36° C to about 3 or 4 microns at temperatures below —40° C.

      Dr. Ohtake  also  measured the temperature profile over open water, one of the major sources of ice
 fog, under  various air-temperature conditions. Although the water temperature was  near  0°  C,  the air
 temperature as low  as 2 meters above  the water surface was the same as the ambient temperature. At 5
 centimeters above the surface,  air temperatures were only a few degrees higher than ambient temperatures
 as low as —40° C. Because  of this very strong temperature gradient  near the open water surface, many
 supercooled water droplets can be expected to condense from the water vapor above the open water and to
 be frozen very quickly. Auto  exhaust vapors emitted into very cold air act similarly.

      Further investigation on  the measurements of ice nuclei, the freezing of water droplets, the electrical
 properties of ice fog particles, and the relationship  between ice fog and water vapor are continuing.
                                                                                                33

-------
                               DESCRIPTION AND CONTROL
                                              OF
                                AIR POLLUTION SOURCES
FORMATION OF OXIDES OF NITROGEN DURING COMBUSTION
B. H. Sage
California Institute of Technology, Pasedena, California
      Dr. B. H. Sage has completed investigations on the effects of oscillatory combustion on the formation
of residual partial oxidation products. An atmospheric combustor, approximately 13 feet long and 4 inches
in inside diameter, and a pressure combustor, approximately 2 feet long and 1 inch in inside diameter, were
used  in  this research. Each combustor consisted of  a  water-cooled copper tube with side ports  for
measurement of perturbations in normal stress and in monochromatic and total optical intensity.

      Investigators experimented primarily with flames produced by premixed air and natural gas in varying
ratios, although they did conduct limited experiments in the pressure combustor withinixtures of air and
methane,  ethane, propane, and n-butane. They insured close approximation of macroscopic steady state
since the  nature of the perturbations encountered in oscillatory combustion  are markedly influenced by
minor changes in experimental conditions.

      Early experiments  revealed that oscillatory combustion increases  residual oxide by  as much  as
fiftyfold and usually by at least thirtyfold. The increase  in the oxides of nitrogen as a result  of unstable
combustion underscores the importance of sufficient attenuating devices to avoid oscillatory combustion in
atmospheric combustors. Baffles and checkerbrick are  effective and practical attenuating devices.

      Studies of the perturbations in monochromatic intensity which occur at the same frequency as the
perturbations in normal stress indicate distinct perturbation in the mole fraction of both water and carbon
dioxide which may  supply the energy necessary to maintain the  oscillations. Over the wide range  of
conditions under which the  combustion of air  and natural gas was  investigated, the frequency of the
perturbation varies between 500 and 900 cylces per second. The waves are substantially sonic, although the
perturbations in normal stress deviate markedly from the conventional sign wave often ascribed to acoustic
phenomena. In the atmospheric combustor, the frequency  varies from approximately 700 cycles per second
below stoichiometric to approximately 900 cycles per second above the stoichiometric mixture ratio, and
approximately six nodes are encountered at different longitudinal positions within the combustor.

      The direct support of primary perturbations at frequencies in excess of 900 cycles per second appears
difficult to obtain at relatively low pressure. A tangential  traveling wave, however, is often encountered in
both combustors.

      In summary, the residual quantities of oxides  of nitrogen are increased many times by oscillatory
combustion. Such perturbations in normal stress and  in monochromatic and total intensity apparently are
associated with perturbations in the principal reactions  connected with combustion of natural gas and air.
REDUCTION OF POLYCYCLIC AROMATIC HYDROCARBONS
Ronald Long
University of Birmingham, Birmingham, England


     In his study of the formation of polycyclic aromatic hydrocarbons (p.c.a.h.), Dr. Ronald Long has
developed a relatively rapid method of identifying and measuring these hydrocarbons in soot samples. The
samples are extracted in  chloroform, and the soluble material is then chromatographed on a column of
silica gel with  benzene as eluent. The individual p.c.a.h.'s in the benzene eluate then are determined by


                                              35

-------
programmed-temperature gas chromatography using dual flame ionization detectors. Peaks in the gas
chromatogram are identified by comparison of the relative retention times with those of pure p.c.a.h. and
by ultraviolet absorption spectrophotometry of the fractions separated by gas chromatography.

      Dr. Long has determined the amounts  of chloroform-soluble  material, polycyclic  aromatic hydro-
carbons, and carbonaceous residue in the dry soot  recovered from  an ethylene-diffusion flame and has
investigated the  effects  on these materials  of  changes in the oxygen  index of oxygen-nitrogen and
oxygen-argon mixtures supplied to the flame.

      In the case of oxygen-nitrogen mixtures,  the amounts of  chloroform-soluble material  and of
polycyclic  aromatic hydrocarbons decrease rapidly as the oxygen index increases from 0.18 to 0.26. The
amount of dry soot reaches a maximum at an oxygen index of about  0.26; above this value, it decreases
rapidly in amount and is composed almost entirely of carbonaceous material.

      Substitution of argon for nitrogen leads to higher temperatures in the reaction and pyrolysis zones.
At lower oxygen indices, these higher temperatures favor the formation  of carbonaceous residue and reduce
the amount of polycyclic  aromatic hydrocarbons in the soot. At higher oxygen indices, the amounts of soot
(actually carbonaceous residue) are reduced.

      These results emphasize  the undesirability of  either a general or local depletion of oxygen in the
diffusion-flame combustion of hydrocarbons since such a depletion increases the formation of polycyclic
aromatic hydrocarbons, including the carcinogen 3:4-benzopyrene. Oxygen enrichment of combustion air
can greatly reduce the concentration of p.c.a.h. in the soot. If sufficient oxygen is added to the fuel itself,
p.c.a.h.  can be eliminated from the soot.

      This  research group also has studied  diffusion flames of ethylene and of propane burning in air and
the effects  of hydrogen, acetylene,  and oxygen  as additives.  The sooting rates of  the  flames both of
ethylene and of propane  increase with the addition of acetylene, and decrease slightly with the addition of
hydrogen. The addition of oxygen increases the sooting rate of the ethylene flame but decreases that of the
propane flame.
PARTICULATE EMISSIONS FROM WOOD WASTE
Richard Boubel
Oregon State University, Corvallis, Oregon
     In a study of particulate emissions from wood waste combustion, Dr. Richard W. Boubel, of Oregon
State University, has developed a rugged and reliable portable sampling train that  enables a field crew to
obtain  a particulate sample from the top of a 50- to 60-foot wigwam-type burner in approximately 1 hour.
Using this sampling train, investigators obtained several samples of particulates from representative sawmill
burners. The nature of the emissions  from these burners was  determined be means  of microscopic and
gravimetric analyses.

     Size distribution and mass rate of emission were found to vary greatly with  combustion conditions
within  the burners. These two factors, size distribution and  mass rate of emission,  greatly affect transport
properties, soiling properties,  and visibility reduction, which in  turn affect public reaction. Because of the
great number  of burners  (500 in Oregon alone) and the wide variation  in operating conditions, broad
categories probably will be necessary for cataloging the emissions from the wigwam burners.

     Standardized tests were run on many of the types and forms of fuel used in wigwam burners, and the
results  of  proximate analyses were  cataloged. This information should  be  valuable in research on
combustion characteristics of wood fuels.
36

-------
CARBURETORS - REDUCTION OF ENGINE EXHAUST EMISSIONS
Jay A. Bolt
University of Michigan, Ann Arbor, Michigan


      Professor Jay A. Bolt,  of the University of Michigan, has investigated factors affecting the fuel/air
mixture ratio in automobile carburetors. The fuel/air mixture ratio supplied to the engine by the carburetor
is the most important factor affecting the quantity of undersirable exhaust emissions from gasoline engines.
A leaner mixture (high in air) produces less undesirable unburned hydrocarbons and carbon monoxide. The
accurate control of this ratio by the carburetor is, therefore, very important in the control of air pollution.

      Professor Bolt's tests revealed that carburetor enrichment is quite close to that predicted by theory,
that is, the fuel/air mixture ratio varies in inverse proportion to the square root of the air density. Altitude,
however, does  affect this performance. Automotive carburetors run about 5.5 percent richer at mile-high
Denver than they do in Detroit, and an additional metering error is caused by earlier opening of the power
enrichment valve at high altitude. Researchers are considering ways to minimize or eliminate these errors in
metering.

      Professor Bolt has evaluated the effects upon  metering  of changes in  fuel properties, including
viscosity, gravity, and composition. In general, the effects are small.

      A fuel-flow stand constructed for Professor  Bolt's project permits precise measurement  of the fuel
and air passing through the fuel circuits of typical carburetor metering elements. This apparatus also allows
measurement of the air  passing into the  air bleeds. Research with the  fuel-flow stand  should provide a
fundamental understanding of the two-phase flow phenomena in  carburetors.  Two-phase  flow, resulting
from the presence of air bubbles in the fuel passages, greatly affects metering. A computer simulation of the
flow phenomena is being developed to predict the carburetor mixture ratio.

      Investigators also have studied the pulsing nature of the flow, caused by the irregular induction of the
piston engine, which also has important effects on carburetor performance.

      Professor Bolt and his associates have experimented with a constant volume bomb  to determine the
effect of the fuel/air-charge motion relative to the spark  plug upon the lean limit of combustion. They
learned that an enrichment of 17 percent  over the stagnant lean limit is required to ignite a mixture having
a velocity of 50  feet per second.  They have attempted to demonstrate these effects in a  single cylinder
research  engine. Through their research, these investigators have attempted to establish the leanest practical
mixture for automobile engines.
CHEMICAL ASPECTS OF AIR POLLUTION FROM KRAFT PULPING
Irwin B. Douglass
University of Maine, Orono, Maine


      The principal source of atmospheric emissions in the manufacturing of pulp and paper is the kraft
pulping process which accounts for more than  60 percent  of total U.S. pulp production. Dr. Irwin B.
Douglass, of the  University of Maine, has investigated chemical factors involved in the control of kraft
odors.

      Using a semi-micro pulping technique, Dr. Douglass has established several facts about the chemical
processes related to kraft  odors:
      1. The  release  of odors during  the pulping process is a direct  function of temperature, length of
        digestion, and concentration of sodium sulfide in the cooking liquor.
      2. Hardwoods  release more  methyl  mercaptan and  dimethyl  sulfide than softwoods  during  the
        cooking operation.
                                                                                               37

-------
     3. The primary reaction in the digester between sulfide ion and lignin produces methyl mercaptan.
        Dimethyl  sulfide  results from a secondary reaction between mercaptide ion and  lignin. The
        amount of methyl mercaptan present reaches a steady-state condition when mercaptide ion is
        consumed as fast as it is formed.

     A pyrolysis study  revealed that the organic material  in black liquor solids when pyrolized in the
presence of elemental sulfur, sodium sulfide, or sodium thiosulfate converts 30 — 60 percent of the sulfur
to hydrogen sulfide. This reaction helps to explain the release of great quantities of hydrogen sulfide from
the recovery furnace at times of heavy overloading.

     During the evaporation of black liquor in the multiple-effect evaporators, some methyl mercaptan is
formed. No appreciable amount of dimethyl sulfide, however, seems to be formed in the evaporators. Dr.
Douglass also has studied the destruction of the malodorous sulfur compounds by means of chlorine and
ozone.

     Another  aspect of the work has been concerned with the fundamental chemistry of low-molecular-
weight organosulfur compounds. Methyl  mercaptan, CH3SH, is converted by chlorine and other reagents
into  methanesulfenyl  chloride,  CH3SCL,  and other compounds  such as  CH3SCL3,  CH3SCL, and
CH3SOCH3. The spontaneous  decomposition of these compounds  and  their general mode of chemical
behavior have been under investigation.
CATALYTIC MECHANISMS FOR NITROGEN OXIDES REDUCTION
Max S. Peters
University of Colorado, Boulder Colorado
     Dr. Max S. Peters has been attempting to develop a selective and highly effective catalyst for nitric
oxide decomposition or reduction that could be used for abatement of air-pollution-causing nitric oxide in
waste gases.

     Research  has  concentrated  on the  catalytic activity of pyrolyzed  polyacrylonitrile, an organic
semiconductor with significant catalytic properties for reduction reactions. Dr. Peters has made a detailed
study of its heterogeneous  catalytic activity for the dehydration of tertiary butyl alcohol. The results of
this study interpreted on the basis of a Langmuir-Hinshelwood mechanism, show  that the  reaction rate is
affected  significantly by  adsorption  of the  products. A model  based  on a single-site or dual-site
reaction-controlling situation produced results correlating well with experimental results.

     Researchers  have investigated the decomposition of nitrous oxide over polyacrylonitrile and over
nickel  oxide and have  conducted conductivity  studies of various organic semiconductors to obtain
correlating factors for electron-transport mechanisms of catalysis.
INTERACTION OF FLUE GASES WITH CARBON SURFACES
P. L. Walker
The Pennsylvania State University, University Park, Pennsylvania


     The chemisorption of S02 on an oxygen-free carbon surface has been examined over the temperature
range 50° through 650° C in a research project under direction of Dr. P. L. Walker at Pennsylvania State
University.

     Charcoal chemisorbs approximately 1.0 percent of its weight in SO2 at all temperatures in the range
50°  through  300° C. Physically sorbed SO2 is  3.0 percent at 50°  C, 1.0 percent  at  100° C,  and
approximately 0.3 percent at  150° C.
38

-------
     After the charcoal is saturated with chemisorbed S02, temperatures in excess of 650° C are necessary
for  regeneration  of  the charcoal  in flowing helium to restore  completely the original  chemisorption
capacity. Regeneration at 500° C  results in S02 chemisorption capacity of no more than 0.3 percent;
regeneration at 650°  C results in a capacity of 0.8 percent. Chemisorption is 1.0 percent when the charcoal
is regenerated at 950°  C.  The major weight loss during regeneration occurs above 600°  C;  below this
temperature weight loss is no more than 0.2 percent, while at 950° C, it is approximately 1.0 percent.

     CO and C02 are the only gases evolved, apart from traces of S02 sometimes detected  from 300°
through 400° C.  Carbon monoxide first appears at about 300° C, and C02  at 500°  C. Although C02
predominates between 600° and 700° C, at 800° C it practically disappears, probably because  of reaction
with the  bed. Because only CO  appears at the higher temperatures, the  total weight  loss following
regeneration up to 950° C is mainly due to CO evolution. The apparent absence of any sulfur compound in
the gas evolved during regeneration is thought to be due to condensation of evolved sulfur on the cooler
surfaces of the absorption  column. Since the whole column is weighed in determining weight  loss, sulfur
loss from the bed would not be detected.

     Regeneration of  the  charcoal  at 650° C restores approximately 80 percent of original sorption
capacity. In a subsequent sorption  experiment at this temperature, S02 was continuously chemisorbed and
reduced to elemental sulfur which  freely condensed on the cooler surfaces of the adsorption column. The
experiment continued for 7 hours with complete removal of S02 from the gas stream and no indication of
any loss in bed reactivity. At this temperature, both C02  and CO were present in the gas leaving the bed,
the CO2/CO  ratio varying from 2.7 after 36 minutes to 4.0 at the end of 7 hours. The increasing C02/C0
ratio was attributed primarily to a  decreasing CO concentration leaving the bed. Most of the CO appearing
was considered a  primary product since the reaction between C02 and the bed to produce CO is very slow
at 650° C.

      Of the total weight  loss  observed during regeneration up to 950° C following  adsorption at 50°
through 300° C, approximately 63 percent occurs above 700° C. This stage of the regeneration, however,
apparently does not appreciably enhance the sorption capacity of the charcoal, which is already  80 percent
restored at 650°  C. Regeneration of  so much of the original capacity and reduction so readily of S02 to
elemental sulfur at 650° C, suggest  that  the essential stage in regeneration is the removal of sulfur from
active  sites on the charcoal surface.
 CRYSTAL STRUCTURE DETERMINATION OF STABLE OZONIDES
 James L. McAtee, Jr.
 Baylor University, Waco, Texas
      In his research into the physiological aspects of ozone in the air, Dr. James L. McAtee, Jr., at Baylor
University, has investigated crystal structures of organic ozonides of substituted indones. Determination of
these structures will increase understanding of the chemical and physical properties of such compounds
with regard to their physiological behavior.

      The organic ozonide,  di-tert butyl cyclopentene—1,2 dicarboxylate ozonide,  was the initial com-
pound  studied by crystal-structure methods.  Dr.  McAtee found that this material  crystallizes  in  the
monoclinic system with A equaling 15.39°, B equaling 10.40°, C equaling 11.19°  and  7 equaling 104.5°,
with the C-axis as the unique axis.  Each unit cell  contains four molecules. Utilizing crystal-graphic data
obtained from the Buerger precision camera and the Weisenberg camera, Dr. McAtee  determined the space
group to be P2/B. The atomic positions for this compound have been evaluated by means of a high-speed
computer.
                                                                                             39

-------
GAS PHASE KINETICS OF KRAFT MILL POLLUTANTS
F. E. Murray
British Columbia Research Council, Vancouver, British Columbia, Canada
     In his research into the reactions of sulfurous air pollutants, Dr. F. E. Murray, of the British Columbia
Research Council, found that  at about 800° C methyl mercaptan, dimethyl sulfide, and dimethyl disulfide
could be oxidized over iron that has been preoxidized on the surface of the particles. This finding was the
basis for a mill experimental reactor. Promising results achieved with the experimental reactor, in turn, led
to plans for a full-scale catalytic unit at a pulp mill.

     In  his laboratory work, Dr. Murray  has  studied the oxidation in  solution of methyl mercaptan,
dimethyl sulfide, and dimethyl disulfide. This work included studies of the oxidation of dimethyl disulfide
in alkaline  solution with molecular oxygen. These studies could lead  to a process for rendering contami-
nated kraft  mill condensates  suitable  for use in the mill's hot water system which would not emit  air
pollutants at the point of reuse.
BOUNDARY LAYER FLOW IN ELECTROSTATIC PRECIPITATORS
S. L. Soo
University of Illinois, Urbana, Illinois
     The research  directed by Dr. S. L. Soo concerns removal of ^articulate pollutants from air by
electrostatic precipitation. Aspects of this process under investigation include the nature of boundary layer
flow in an  electrostatic  precipitator passage, the effect of boundary layer flow on collection rate  and
reentrainment, the density distribution of particles in passages, and the interaction between electrostatic
forces and turbulent diffusion.

     Dr. Soo has introduced and verified a differential procedure of isokinetic sampling from a particulate
suspension. This procedure eliminates error due to holdup in the sampling system and corrects for depletion
in a finite system.

     This research  also has resulted in invention of an improved fiber optic probe with signal multipli-
cation. Simpler and more rugged than a photometer, this probe makes possible measurement of density of a
dilute aerosol  suspension on the basis of either absorption or scattering of light from a light source  to a
photocell.

     Formulation of electro-aerodynamics and correlation of experimental data on suspension should lead
eventually to rational design and scaling of electrostatic precipitators.

     In flow passages of a conventional electrostatic  precipitator, the secondary flow due to electric wind
was found to  be  a  basic cause of reentrainment in the conventional design.  Since this effect cannot be
eliminated  in the conventional plate-wire  system, a significant change in design is necessary  for further
improvement in precipitator efficiency.
ENGINE EMISSION REDUCTION BY COMBUSTION CONTROL
Wolfgang E. Meyer
The Pennsylvania State University, University Park, Pennsylvania


     In his study of engine emission reduction by combustion control, Professor Wolfgang E. Meyer has
concentrated on development  of experimental apparatus and  techniques. He has  made  progress  in
instrumentation  and has completed a unique exhaust gas sampling system designed to draw samples from
only those engine cycles which have specific characteristics.

40

-------
      The sampling system examines each cycle and decides whether to issue a command to a sampling
valve, in the exhaust line near the engine, to admit a sample to the gas analysis train. The system consists of
(1) the transducers, which sense  pertinent  cycle  characteristics (cylinder pressure, rate-of-pressure rise,
flame front speed, crank angle, etc.); (2) the logic components, which compare the signals generated by the
transducers to  preset values to determine whether to issue a command; and (3) a sampling, or diversion,
valve which is actuated by the commands.

      This system is designed to identify those engine cycles that produce higher than average emissions of
a  selected species and to determine  which cycle characteristics are associated  with the production of
particular  exhaust-gas species and what the relationships  are.  This  information should  be valuable in
designing the combustion process for minimum emissions, particularly during operation with lean fuel-air
ratios at which cyclic variations are large.
 REVERSIBLE METAL COMPLEXES WITH AIR POLLUTANTS
 Lauri Vaska
 Clarkson College of Technology, Potsdam, New York
      Professor L. Vaska has discovered that certain transition metal complexes react reversibly with some
 important air pollutants, such as sulfur dioxide, carbon monoxide, and unsaturated hydrocarbons. To learn
 about the factors involved in these unusual reactions, this investigator has undertaken a systematic kinetic
 and thermo-chemical study of the reversible uptake of these gases by the complexes in solution.

      These  studies have revealed that the affinity  of the molecules of these air-pollutants toward the
 complexes studied, e.g., IrCl (CO) (Ph3P)2, increases markedly in the order: C2H4{CO
-------
foaming characteristics of the black liquor suggested that saponified rosin might not be the principal cause
of foaming. Black liquor from hardwood digesters showed foaming characteristics identical to those of slash
pine liquors. In another experiment, hardwood chips, a mixture of oak and gum containing negligible rosin,
cooked in the laboratory digesters with kraft liquor, produced waste liquor just as foamy as all other liquors
tested. Professor Nolan planned additional tests to increase the sensitivity of the method for detecting
differences in foaming tendency.

      Rosin extraction had no  effect on neutral-sulfite  semichemical (NSSC) pulping except for a slight
increase in speed of pulping. After  a few sets of experimental cooks demonstrated this lack of  effect,
further NSSC pulping experiments were concentrated on unextracted chips.

      Physical strength of slash  pine pulps in the yield range of 50 to 55 percent are about 5 percent lower
in tear strength, but are comparable in burst and tensile  strength to  slash pine pulps of  45 to  50 percent
yield. Lignin content of these NSSC  pulps ranged between  11 and  15 percent while lignin content of kraft
was about 6 to 8 percent. Slash pine NSSC pulps of 60 percent or higher yield were weaker in all strength
categories than fully cooked kraft pulps, because of the very high lignin content (about 20 percent) of the
NSSC pulps.

      In this study, Professor Nolan found that an increase in the molal ratio of sodium sulfite to sodium
carbonate from 3:1 to 6:1 increases screened yield. He has planned further research involving liquors made
up  entirely of sodium sulfite or mixtures of sodium sulfite and bisulfite, which may result in more rapid
reaction, more selective lignin removal, brighter pulps, and, possibly, increased physical strength.
FUNDAMENTALS OF AIR CLEANING BY SORPTION PROCESSES
M. J. D. Low
New York University, University Heights, New York
      Dr. M. J. D. Low, of New York University, has established the feasibility of monitoring smokestack
effluents from distant ground locations by measuring the infrared emission spectra of the stack gases.

      The small optical system of a multiple-scan interference spectrometer was mounted on an 8-inch
reflecting telescope. Pointing the interferometer-telescope combination at a stack plume, investigators could
record in minutes, at night, the spectral distribution of infrared radiation emitted by the effluent. The
presence of SO2 was readily detectable.

      Such measurements, which can be carried out relatively easily, offer a novel instrumental approach to
studies in air pollution.

      Dr. Low also has developed techniques for recording of infrared spectra of samples of solids, liquids,
and gases using the multiple-scan interference spectrometer. One-microgram samples can be examined in 1
or 2 minutes.
42

-------
Mr. Dale A. Lundgren is shown with a Venturi scrubber, part of the apparatus used in the
"Basic Study of Air Pollution Control Wet Scrubbing," research grant AP 00723-01.
This particular  equipment aims at developing a definition of the performance of low-
pressure-drop gas scrubbing equipment for optimum efficiency.
                                                                              43

-------
                                      COMMUNICATION
MANUAL OF METHODS FOR SAMPLING AND ANALYSIS OF AIR
A. C. Stern
University of North Carolina, School of Public Health, Chapel Hill, North Carolina


      Professor  A. C. Stern heads an intersociety committee supervising preparation of a manual of
methods for ambient air sampling and analysis. The intersociety committee represents seven cooperating
organizations: the Air Pollution Control Association, the American Conference of Governmental-Industrial
Hygienists,  the  American Industrial Hygiene  Association,  the American Public Health Association, the
American Society of Mechanical Engineers, the  American Society for Testing and Materials, and the
Association of Official Analytical Chemists. This committee supervises the project and serves as an editorial
board.

      The committee plans to provide standard methods for examination of air comparable to those already
available  for examination of water and liquid wastes. Methods will be  detailed in a standard format: (1)
principle  of the method, (2) range and sensitivity, (3) interferences,  (4) precision and accuracy, (5)
apparatus, (6) reagents, (7) procedures, (8) calibration, (9) calculation, (10) effects of storage, and (11)
references. Pollutants to be  considered were classified arbitrarily into eight substance categories: (1) sulfur
compounds, (2) halogens, (3) oxidants and nitrogen compounds, (4) carbon compounds, (5) hydrocarbons,
(6) metals I, (7) metals II, and (8) radioactive substances.

      A seven-member substance subcommittee,  with one representative from each participating society
was appointed for each of  the eight  substance categories. An additional subcommittee is  responsible for
common  sampling procedures, common laboratory techniques and precautions, specifications for supplies
and  materials,  and guidelines for  evaluation of automatic  equipment.  Methods recommended by  a
 subcommittee are checked  by the editor and, if accepted,  are sent to the intersociety committee. If
approved by  the committee, the method is made available for publication as a tentative method and is
referred to  a separate coordinating organization for collaborative testing. Only after thorough testing by a
number of laboratories is  a  method  considered  standard. The intersociety committee  hopes to have
published in 1970 tentative methods for all listed compounds.

      The project is expected to provide a sound basis for improvement  of methodology over a period of
years. The most direct benefits of the manual, however, will be in field monitoring and evaluation. It will
make possible comparisons  of pollution levels in different areas and will  aid in the  development of air
quality  criteria and standards.
AUDIOVISUAL METHODS FOR AIR POLLUTION INFORMATION
Murdock Head
George Washington University Medical Center, Warrenton, Virginia
      A research project being conducted by Dr. Murdock Head, of the George Washington Medical Center,
is intended to facilitate public dissemination of air pollution information. Dr. Head is investigating current
air  pollution  information dissemination programs, the  measures of effectiveness being used, inter-
relationships among programs, quality of programs, intent and presentation of programs, and the breadth
and integration of information coverage. A second part of the project is a study of information collection
correlation, storage and retrieval, and distribution.

      The research group  produced a documentary film evaluated in cooperation with medical and civic
groups across the country  as a means of bringing air pollution information to the public. The film, "Beware
The Wind," achieved wide acceptance and was used by community leaders to develop air pollution control
                                               45

-------
groups. Requested  for  showing throughout the country, it  has been  used by  conservation  groups,
community  groups, and professional societies. As a television presentation, it was awarded the Television
Academy Public Affairs Emmy for the Best Documentary film of 1967.

      A second film, "Eagles Lament," treats air pollution as  viewed from the air through the  eyes of
professional pilots. The third film to be produced by Dr. Head's group, "Battle Below the Clouds," will
show what civic and professional groups can do about air pollution in a typical American city.

      The effectiveness of the films as a means of dissemination of information will be evaluated by means
of questionnaires, interviews, and critical reviews by professional critics and professionals in air pollution
control.
COMEX-AIR POLLUTION COMPUTER RESEARCH PROJECT
Knud W. Leffland
University of Southern California, Los Angeles, California
     Pollex,  a management-education game under development by the School of Public Administration,
University of Southern California, will be a major element in the Air Pollution Control Institute of the
School and  is expected  to  be used throughout  the country as it is developed and refined beyond  its
prototype stage.  The  Institute,  established to  prepare  students for  careers involving  the  planning,
supervision, and  management of air pollution control, deals with the decisions, operations, interpersonal
relationships, planning, supervision and management required of an air pollution  control executive/ad-
ministrator.

     The major  project of COMEX, Dr. Leffland's computor research project, the game Pollex compresses
realistic experience in the execution of responsibilities concerning air  pollution.  It takes into account the
social,  economic, demographic, and political factors  encountered in a  major  city. The compression of
experience takes  place through interaction with a computer  simulation of the environment into which
decisions are fed and from which  responses are received that reflect the critical changes effected by these
decisions. The simulation interlocks over 30 submodels of the general model. Each submodel, simulating
one component of the total  system, such as property tax base, per capita income, or demand and supply of
public  services, processes the new information of the last decision and signals inputs to other submodels
appropriately influenced. The submodel also may receive inputs from other submodels, either at a different
time or simultaneously.

     The modular structure provides unusual flexibility. Submodels  may be easily added to incorporate
more of the  ecological system or additional factors, such as the fouling of a river occasioned by installation
of a  scrubber. Earlier management games based upon the urban setting have been much simpler and have
lacked  the electronics  simulation  of Pollex. Dr. Richard D. Duke of the University of Michigan, who
developed Metropolis, one of the most widely used earlier games, is a co-investigator with Dr. Leffland of
the COMEX project.

     Inputs to the computer  simulation are provided not only  by the  role of an air pollution control
officer  but also by a politician and an industrialist. Personal interactions take place among  the three role
players as part of the decision-making experience. Numerous actions by each  role player  may be taken
during each cycle, or year, and several cycles are possible during a single day.
46

-------
Team players  in action.  Video-taped  pictures of an air pollution control officer and staff, Mayor and
council, and an industrialist team in the management-education  game "Pollex" now under experimental
development with a research grant to the School of Public Education, University of Southern California.
                                                                                              47

-------
            INFORMATION ABOUT THE RESEARCH GRANTS PROGRAM


    The National Air Pollution Control Administration provides support through research grants to assist
nonprofit institutions and individuals to establish, expand, and improve research in air pollution control.
No limitation has been established on the number or dollar value of research grants to an investigator or
institution. Although matching funds are not required, current legislation does require that the grantee
participate in the cost of the research project.

    The Administration is concerned with all aspects of research and development related to the causes,
effects, extent, prevention,  and control of air  pollution with  respect to human  health, welfare, and
productivity. Grants are available to support the  establishment of air quality criteria for all hazardous air
pollutants and the development of more effective means for prevention and control of air pollution.

    Research projects in the following areas of investigation may  be considered for research grant support:

    I.   Effects of Air Pollution.
         Includes  effects on man, crops, livestock,  materials,  and the ecology  in general.  Effects are
         categorized as follows:
         A.  Effects of Air Pollution on Man and  Experimental Animals.
             1.   Epidemiological  and statistical  studies on the  relationship between air pollution and
                 mortality and morbidity.
             2.   Effects of air pollution on broncho-pulmonary physiology and pathology.
             3.   Relationship  of  air pollution  to  broncho-pulmonary diseases  such  as lung cancer,
                 emphysema, asthma, chronic bronchitis, and other related respiratory disorders.
             4.   Studies  of  aeroallergens and  naturally occurring irritants and  their sources, prevalence,
                 seasonal variations, and effects on man.
             5.   Physiologic effects of specific known or suspected air pollutants.
             6.   Subjective and behavioral responses to air pollution.
         B.  Effects of Air Pollution on Agriculture and Livestock.
             Includes effects on livestock, on the  general ecology,  and on plants at the macroscopic,
             cellular, and molecular  levels.  Specific  pollutants of interest include sulfur oxides, ozone
             peroxyacyl nitrate, fluoride, and dusts.
         C.  Effects of Air Pollution on Materials.
             Includes effects on plastics, metals, textiles, rubber, and building materials.

     II.  Economic, Social, and Political Studies.
         Includes  estimates of damage  by  air pollution, cost of air  pollution control, studies of urban
         planning and land  use, political aspects of control programs, attitudes of people towards air
         pollution, and methods for influencing public opinion.

    III. Sources of Air Pollution and Their Controls.
         A.  Combustion.
             Investigation of the combustion process and of emissions from incinerators, open burning, and
             solid waste disposal.
        B.   Automotive Emissions.
            Studies of reactions of gases within combustion engines, of subsequent interactions in the
            atmosphere,  of  effects of operating conditions on emissions, and of methods for  reducing
            emissions.
        C.  Industrial Emissions.
            Includes investigations of industrial stack plumes, noxious odors, and particulate matter from
            industrial sources, such as paper mills, steel mills, rendering plants, chemical plants, nuclear
            fuel processing plants, and power generating plants.
                                                49

-------
        D.   Development of General Control Principles and Devices.
             Includes research into principles of control and development of devices applicable to control
             of air  pollution.  Control methods  include  static  precipitation,  scrubbing, sorption,  and
             catalytic removal.


    IV. Atmospheric Studies.
        A.   Physicochemical Characteristics of Air Pollutants.
             Studies of  gaseous,  liquid,  and  particulate  components of  the  atmosphere,  and of the
             chemistry, thermodynamics,  and kinetics of their formation and interactions as well as studies
             of the physics of aerosols.
        B.   Meteorology.
             Studies of transport and diffusion of air pollutants (includiagTadionuclides and pesticides), air
             pollution forecasting, biometeorology, and the influence of air pollution on visibility.

    V.  Analytical Technology.
        Development of methods for analyzing and characterizing gases, liquids, and particulate matter.

    VI. Communication.
        Support of grants aimed at providing detailed technical and scientific information for the buildup
        of a base of practical knowledge for all interested parties.
    A research grant  application should be  submitted  jointly by the investigator  and the institution
sponsoring his research. Responsibility for fiscal and administrative management should be assumed by the
institution.

    To  be eligible for  support, a  proposed project must receive favorable recommendation from a review
panel of experts in appropriate fields.  The panel considers scientific merit, qualification of the applicant,
and  adequacy  of facilities. Each  project  is further evaluated as to  its relevance to the program and its
consonance  with public policy. Approved projects are  funded in accordance with their assigned priorities
and the availability of funds. If not funded in a given fiscal year, an application may be carried over to the
next fiscal year or, if the applicant wishes,  may be withdrawn.

    Recently the program has  been expanded to  provide limited support for feasibility studies and for
young investigators who have stimulating  ideas but little research experience.  Applications are now being
accepted  for the  exploratory  support of appealing  but high risk ideas  and enthusiastic but untried
investigators. These  applications  require  the  same forms, processing, review,  and approval procedures
employed for regular research grants.

    In general,  exploratory grants will be awarded for a maximum of $10,000 (including indirect costs) and
18 months,  with a possible administrative extension to 24 months when warranted. Applicants may apply
for  a grant  in  this  exploratory category, or  the  review groups concerned may elect to recommend an
exploratory  grant in lieu of a regular research grant.

    Details  concerning application procedures,  application forms, and  dates for submission of applications
may be obtained from the Office of Research Grants, National Air Pollution Control Adminstration, P. 0.
Box 12055,  Research Triangle Park, North Carolina 27709.
50

-------