INTERSTATE  AIR  POLLUTION

                                            STUDY
 BI-STATE DEVELOPMENT
        AGENCY

ST.  LOUIS DEPARTMENT OF
 HEALTH AND HOSPITALS
ST. LOUIS  -  DIVISION OF
 AIR POLLUTION  CONTROL
     PHASE  II PROJECT REPORT
  EAST ST. LOUIS - AIR
   POLLUTION  CONTROL
      COMMISSION


   ST.  LOUIS  COUNTY
  HEALTH DEPARTMENT

   EAST  SIDE HEALTH
      DISTRICT


   MISSOURI DIVISION
      OF HEALTH

  ILLINOIS DEPARTMENT
   OF PUBLIC  HEALTH

CHAMBER  OF COMMERCE OF
METROPOLITAN  ST. LOUIS
VI.  EFFECTS  OF  AIR  POLLUTION
ILLINOIS AIR POLLUTION
    CONTROL  BOARD

        DHEW
 PUBLIC HEALTH SERVICE

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            INTERSTATE AIR POLLUTION STUDY
                PHASE II PROJECT REPORT
            VI.  EFFECTS  OF AIR POLLUTION
                       prepared by

                      J. D. Williams
                      F. D. Maddox
                      T. O. Harris
                    C. M.  Copeley, Jr.
                  W. Van Dokkenburg,  Jr.
            U.S.  Environmental Protection Agency
            Region  5, Library {5PL-16J
            230 S.  Dearborn St-eet, Room 1670
            Chicago, IL   60604
U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
                   Public Health Service

    Bureau of Disease Prevention and Environmental  Control
           National Center for Air Pollution Control
                      Cincinnati, Ohio

                      December 1966

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      Copies of this report are available from the cooperating agencies listed on
the cover of this  report and from the Technical Assistance Branch, Division of Air
Pollution, Robert A. Taft Sanitary Engineering Center, 4676  Columbia Parkway,
Cincinnati, Ohio.

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                                   FOREWORD
      The Interstate Air Pollution Study was  divided into two phases.  Phase I, a
general study of the overall air pollution problems in the St. Louis - East St. Louis
metropolitan area, was conducted to determine specific activities  that would require
further study  in Phase II of the project.  The effort was divided into two phases to
provide a logical stopping  point in the event that interest and resources  for proceed-
ing further might not materialize.  The necessary impetus did continue, however,
and the Phase II operation was also completed.

      The Phase I operation resulted in a detailed report,  designed primarily for
use of the Executive Committee members and their agencies in making  decisions
concerning the Phase II project operation. A Phase I summary report was also
prepared; it received wide distribution.

      Numerous papers, brochures, and reports  were prepared during  Phase II
operations, as  were some 19 Memorandums of Information and Instruction concern-
ing the project. All of these documents were drawn upon in the preparation of the
Phase II project report.  The Phase II project  report consists  of eight separate
volumes under the following titles:

              I.  Introduction
             II.  Air Pollutant Emission Inventory
            III.  Air Quality Measurements
            IV.  Odors  - Results of Surveys
             V.  Meteorology  and Topography
            VI.  Effects of Air Pollution
            VII.  Opinion Surveys and Air Quality Statistical Relationships
           VIII.  Proposal for an Air Resource Management Program.

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                                   CONTENTS
INTRODUCTION	    1
   Methods Available  for Setting Air Quality Goals	    4
SULFUROUS COMPOUNDS	    6
   Sulfur Oxides  	    6
   Hydrogen Sulfide	   12
CARBON MONOXIDE	   13
   Acute Effects	   14
   Sensitive Groups	   15
OXIDANTS	   15
OXIDES OF NITROGEN	   17
EFFECTS OF PARTICULATE MATTER	   19
   Introduction	   19
   Health-Related Effects	   20
   Vegetation Damage and Related Effects	   21
   Soiling	   22
   Visibility	   22
ODORS	   29
ASTHMA - A PILOT STUDY	   30
AEROALLERGENS	   31
VEGETATION DAMAGE	   31
   Fluoride Effects  on Vegetation	   32
   Fluoride Effects  on Farm Animals	   33
   Sulfur Dioxide	   33
   Photochemical Smog	   34
   Ethylene	   34
   Miscellaneous  Pollutants	   35
VEGETATION DAMAGE IN STUDY AREA	   35
   Historical Development	   35
   Tobacco Plant  Oxidant Study	   36
MATERIALS DETERIORATION	   39
   Steel Corrosion Study - 3-Month	   39
   Steel Corrosion Study - 16-Month	   39
   Effects on Exposed Nylon  Fabric	   41
   Effects on Exposed Cotton Fabrics	   44
EFFECTS OF AIR POLLUTION ON PROPERTY VALUES	   46
   Economic Effects of Open Burning	   49
PUBLIC OPINION SURVEY - EFFECTS REPORTED	   50
HEALTH EFFECTS -  A SUMMARY STATEMENT	   51
ECONOMIC EFFECTS - A SUMMARY  STATEMENT	   52
REFERENCES	   55

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                       VI. EFFECTS OF  AIR  POLLUTION
INTRODUCTION
     The Air Quality Goals Subcommittee, appointed under provisions of item 5-A-5
of the Interstate Air Pollution Study Phase II Project Agreement, reviewed litera-
ture, met with consultants in the air pollution effects field, and selected air  quality
goals for consideration by the Project Executive Committee.  The Committee lim-
ited its consideration to goals because it does not have authority to adopt air quality
standards, a function restricted to legally constituted governmental agencies.  The
Committee does, however, by approving this report, accept the  consensus of pro-
fessional and technical personnel.  The  explanations of effects levels presented
herein were prepared by the staff of the Public Health Service Technical Assistance
Branch who utilized the advisory resources  available within the Division of Air
Pollution.

     The effects of air pollution,  as a program element,  is  only one part of an air
resource management program; the relationships among the several elements are
shown in the diagram in Figure  1.  Air pollution effects, air-quality levels,  and
pollutant emissions are the major program elements that provide the basis for air
quality goals.  Actually,  if no consideration were given to  the length of time  needed
to reach goals  or to the priorities of community needs,  air pollution effects would
be the  only program element to be considered in establishing  goals.  The suggested
goals listed in  Table 1,  however,  are based on the air quality (indicating major
                                       QUALITY
                                        GOAL
                         AIM QUALITY
                       GOAL SETTING PROCESS






ORDINANCES

RULES a
REGULATIONS

PLANNING
Decisions

COMMUNITY
PURPOSES
a
POLICIES







LI
LI
T?


T"
CHANGED
EFFECTS

CHANGED
AIR QUALITY

                                                                     CHANGED
                                                                     EMISSIONS
              Figure  1.  Air resource management flow diagram.

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             Table 1.   SUGGESTED AIR  QUALITY GOALS
         FOR  INTERSTATE AIR POLLUTION STUDY AREAa
Sulfur oxides
   Sulfation, measured by lead peroxide candle method
      Maximum annual average 0.25 mg 803 per 100 cm^ per day
      Maximum month 0. 5 mg 803 per  100 cm^  per day

   Sulfur dioxide, measured by West-Gaeke or conductometric methods
      Maximum annual average 0. 02 ppm
      24-hr average 0. 1 ppm not to be exceeded over 1 percent of the days in any
        3-mo period
      1-hr  period not to exceed 0.20 ppm more than once in any 4 consecutive days
      5-min period not to  exceed 0. 50 ppm more than once in any 8 hr

   Suspended sulfate, measured by high-volume sampler
      Maximum annual average not to exceed 4 jig per  m^
      Not to exceed 12 (ig  per rrH over 1 percent of time

   Sulfuric acid
      Maximum annual average not to exceed 4 jig per  m^
      Not to exceed 12 ug  per m^ over 1 percent of time
      Not to exceed 30 ug  per m^ hourly average over  1 percent of time

Hydrogen sulfide, measured by AISI spot sampler using lead acetate impregnated paper
   0. 05 ppm 1/2-hr average not to be exceeded over 2 times per yr
   0.03 ppm 1/2-hr average not to be exceeded over 2 times in any 5-consecutive-day
      period

Oxidant (total), measured by potassium iodide colorimetric method
   0. 15 ppm for 1 hr (not  to be exceeded)

Carbon monoxide, measured by nondispersive infrared method of measurement
   30 ppm for 8 hr
   120 ppm for 1 hr

Dustfall, measured by settled particulate accumulated in dry jars for 1 mo
   10 tons per mi^ per mo,  3-mo average above background in all areas except those
      zoned heavy industrial
   (Use 5 tons per mi^ per mo background)
   25 tons per mi^ per mo,  3-mo average above background in zoned heavy industrial
      areas
   (Use 5 tons per mi^ per mo background)

Suspended particulate, measured by high-volume sampler
   75 ug per m , annual geometric mean
   200 ug per m^, annual  99th percentile

Soiling index, measured by AISI spot sampler
   0.4 Coh per 1,000 lineal ft, annual geometric mean
      mg  = milligram            ug  =  microgram
      cm  = centimeters           m  =  meter
     ppm  = parts per million     mi  =  mile
      hr  = hour                  ft  =  feet
      mo  = month               Coh  =  function of optical density - see reference 1
Note:  All goals, unless otherwise stated, apply to any place where people live or an
       undesirable  effect could result from levels above the goal.

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 types and amounts of pollutants present) as  well as actual and anticipated effects of
 air pollutants in the  Interstate Air Pollution Study area.  They do not provide a great
 factor of safety in health matters,  nor do they include the time that might be needed
 to reach those goals without undue disruption  of normal community life.  Timing
 should be specified,  however,  in provisions of suggested ordinances that will imple-
 ment the air-use plans.

     The effects of air pollution, have been considered  in this  report from the view-
 point of  a consultant •whose  task has been the development of a set of goals that  will
 meet the future needs  of the area.  Some of the quantitative relationships between
 effects  and air quality levels have not yet been established, but enough is known that
 a guide for a constructive air resource management program  has been provided for
 the Interstate Air Pollution Study area.  This  guide (Table 1) is intended to serve
 the needs of the Study  area  only, and is not  intended to have general application.

     The frame of reference in which this report has been prepared recognizes  that
 approaches of  the past are not always valid  in the  present. For example,  in the
 field of public  health,  past successes  have stemmed from the  control of epidemics.
 These successes have been based on single-cause, single-effect  relationships.   Few,
 if any,  of these simple or direct relationships seem to exist in the complexities of
 community air pollution problems.  A  departure of public health  programs from the
 orientation of epidemic control  has been recognized for those  modern programs in
 health that are being oriented toward a relatively new priority need, the control of
 chronic  diseases and the conditions causing them.  In the  air pollution field com-
 parable  situations  are represented by multiple types, combinations, and levels of
 air pollutants, which,  combined -with other stresses on individuals or groups,  cause
 undesirable  effects.   Program needs in both instances  only remotely resemble  the
 old priority  need established for control of epidemics.   This report's frame of
 reference  also recognizes that community capability has changed and that this  in-
 creased capability holds  the promise of effective action toward improving air qual-
 ity.  An example of the importance of increased community capability is apparent
 from a  quick review of the air pollution problems  in London,  England,  and other
 manufacturing centers.  As long ago as 1907,  deaths  associated with sulfur dioxide
 •were reported,  but little if any action was  taken to alleviate this admittedly unde-
 sirable situation until  community competence  in many activity areas had advanced
 and  met the  established priority needs of these cities and  their citizens.


     The frame of reference recognizes that metropolitan areas have decided to
 develop their central city areas for new purposes.  By  way of  example,  the old
 purpose  might very well be  compared with an  extractive operation such as mining
 or lumbering.  The new metropolitan central city  area's purpose contrasted with
 the old,  emphasizes  people  rather  than production or even sales.  In effect, these
 metropolitan areas have, -without consideration of air pollution and probably many
 other important factors,  committed themselves to a mixed and varied land use,  at
 least in their central areas.  Major decisions  left for the future pertain to how
 these many mixed and  varied land uses can be made to  function in a compatible
 manner.

     Recognition has  been given  to the  competition  between major metropolitan
areas for people,  money,  and talent; in effect, viability of the  total metropolitan
 area as contrasted with competition among  the  area's  several parts,  as has often
been the case in the past.

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     Last, but not least, recognition has been given to the beginnings  of attempts to
come to grips with  the urban  environment.   Those attempts are directed toward
shaping  the urban environment so that it develops the best in its citizens, while
making living  in this urban environment worthwhile, and imparting beauty and a
sense of well being to not only those people who live there,  but also to those who
visit.  For example,  Oscar Sutermcister,   in a paper presented at the annual con-
ference  of the American Institute of Planners in 1961, said: "The planner may ask
the health officer to consider such questions as 'Does mixture of land uses  along an
arterial road bounding a residential neighborhood promote well being7  Does the
existing level  of traffic noise promote well being? '  " To these it would be easy to
add many more, such as:  Does  the existing quality of air in our cities promote
well being9  Do community decisions made now adequately  consider future  air
quality?

     In the preparation of this report the folio-wing guidelines selected by the Sub-
committee  on Air Quality Goals  have been used:

     1.   The quality of the  air should not adversely affect the health of even the most
          sensitive or susceptible groups in the population.

     2.   Pollutants should not be allowed to reach concentrations that would cause
          a nuisance, such as  the sensation of unpleasant tastes or odors.

     3.   Pollutant concentrations should not reach levels that would be damaging to
         animals, ornamental plants, or agricultural crops.

     4.   Pollutants  should not reach concentrations that would significantly reduce
         visibility,  especially visibility reductions that would,  or could, be a
         hazard to transportation.

     5.   Soiling, corrosion, and damage to materials, as well as adverse  economic
         effects, should not occur to any great extent.  (These effects have been
         considered in a way  that points toward the  economic savings that could re-
         sult from improvement in air quality. )

    A few words indicating the differences among standards,  goals, and criteria
are in order.  Goals relate to objectives that are not necessarily legal standards,
nor need they be linked to obvious health effects  or  vegetation damage.  They should
relate to what is best for  the total development of the human resources of the com-
munity.   This does  not mean complete freedom from air pollution,  or no stress on
the citizens, but does dictate  an  approach  directed toward what is best for the
citizens'  total development. Standards,  by contrast,  are specified by lav/.   They
may be as broad in  their meaning as goals, or they may be  limited to some effect
such as health or vegetation damage.   Criteria refer to relationships bet-ween air
quality and various  effects  of pollution, -word meanings equated with numerical values.


Methods Available for  Setting Air Quality  Goals

    Many methods have been  used in the developing air pollution field for establish-
ing air quality goals for particular kinds of pollutants.  Much of this work has been
based  on knowledge of the effects of single pollutants, often under conditions and
with populations that are not typical of those exposed to air  pollution.   Unfortunate-
ly,  little is known of the synergistic effects of combinations of pollutants, although

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it is known that such effects exist.  Generally, in goal setting relating to the  effects
of air pollutants on health, as knowledge became more detailed from research and
experience, the standards of maximum permissible human exposure have had to be
progressively lowered.   The acute  effects on human beings have been much easier
to evaluate than the  chronic effects, particularly those chronic effects that may
evolve after a great many years of  exposure to low levels of air pollution.  Long-
term effects  are extremely hard to evaluate,  and not much effort has been put forth
for their definition since the least productive part  of the population is most affected.
Most of the people suffering from long-term exposure have already  lived the  major
part of their lives and carried out their reproductive function to sustain society.
The effects of air pollution on them, therefore,  arouses less attention than similar
effects upon young and vigorous persons.

     The Russian philosophy in establishing maximum permissible exposures  to air
contaminants is perhaps  the most rigorous  currently proposed.   It takes the posi-
tion that any detectable effect upon  the human organism that can be measured by
any known method in an average group of  exposed individuals should establish the
maximum  allowable standard.  These levels are frequently far below that which the
individual  can recognize  by sensory perception, and they may or may not have long-
range or chronic effects  on the individual.  The methods  include testing  exposed
individuals for such hidden effects as changes in optical chronaxy in the  eye, changes
in brain waves,  threshold odor,  and any other measurable effects  for which there
are test procedures.  The standard is set by the most sensitive measurement that
first shows the effect of  exposure to an air  pollutant.  At the other end of the
philosophy spectrum, some persons advocate that  standards should  be established
only upon the basis of proved damage to the human organism.
     A reasonable approach to the establishing of air quality goals would apparently
demand that  such goals be sufficiently low so that no adverse health effect or im-
pairment of bodily function -would occur, even in the most susceptible or sensitive
group in the  population.   As an example,  goals would not be based on currently
established threshold limit values applicable to the  active male -working population
exposed for 8 hours a day.  Instead, they would be based on the older part of the
population suffering from chronic health problems that would predispose them to
the effects of acute air pollution episodes to which such people have been  shown to
succumb in the past.

     In summation, air quality goals for those contaminants that affect health should
be based upon concentrations at -which sensitive groups of individuals in the popula-
tion would not be affected.  This would not, however,  preclude all effects upon all
hypersensitive individuals.

     Where health effects are not believed to exist,  other criteria must be used to
set goals.  Where sensory effects to humans are involved,  it would appear that
the public would wish that the standards would not allow the sensory threshold to
be exceeded  as related to irritation, taste,  or odor, at least  in the residential and
general-public-use types of environment.  When economic  effects serve as the
basis for goals, the public would probably wish  that resulting  standards would
not allow demonstrable damage to animals or to ornamental plants or  crops,  and
that corrosion and other  damage not appreciably shorten the usable life of building
materials, instruments,  and fabrics.  Obscuration  of vision should not be so se-
vere that transportation is affected or rendered more hazardous.   Where  nuisance

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effects  are the primary concern, it would seem that the public would readily ac-
cept standards that would prevent the filth in the environment from being objection-
able to  most individuals.

    Aesthetic values such as the beauty of an unobscured view are difficult to
assess,  but may be important under certain circumstances.   Certainly the Los
Angeles and Denver areas have  lost much of  their natural beauty from smog  ob-
scuring the mountain ranges around them.  Certainly St.  Louis will lose much in
addition to economic costs if visitors to the  Arch and the residents of the fashion-
able high-rise apartments frequently look out upon a sea of air pollution instead of
the suburbs to the  west and  the bottom land and  bluffs to the  east.

SULFUROUS COMPOUNDS

    The effects of sulfurous compounds are summarized in Table  2.  The  sulfur-
ous compounds in the atmosphere are primarily from the sulfur oxides group,
which consists of sulfur dioxide, sulfuric acid,   and sulfate salts.  Hydrogen
sulfide,  mercaptans, and other  such compounds occur occasionally,  but  generally
in small amounts or in limited parts of urban atmospheres.  The effects of sul-
furous compounds  reported  herein  are related to pollutant concentration  and  to
exposure time.  Although expressed in  terms of sulfur  dioxide, concentrations
are reported with the assumption that normally  occurring amounts of sulfuric
acid and suspended particulates  are also present.


Sulfur Oxides
     The suggested goals for sulfur oxides (determined by measuring sulfur di-
oxide) in the Study area are dual.  On the basis of observed effects, an annual
arithmetic mean concentration not to exceed 0. 02 part per million is recommended.
In addition to this annual goal,  the sulfur dioxide  concentrations  shoiald not exceed
0. 1 part per million more than 1 percent of the time in any 3-month period.  Both
of these goals are to relate  to 24-hour sulfur dioxide measiirements based on the
West-Gaeke or  equivalent method of analysis.  These concentrations are not to be
exceeded  in any place where people live, or where an undesirable  effect may occur.

     The sulfur  oxides group is one of the most prevalent man-made pollutants  in
the United States and is concentrated in  major metropolitan areas.  This wide-
spread condition results from the abundant use of fossil  fuels, such as coal and
oil,  used  for power and heat.   (See report Volumes II - Air Pollutant Emission
Inventory and III - Air Quality Measurements. )

     The effects of sulfur oxides reported in Table 2,  with the exception of those
in the "brief exposure"  section, do not ordinarily derive solely from the presence
of any one sulfur oxide or, necessarily, the sulfur oxides as  a group.  They are
for the most part observed effects associated with sulfur oxides  when various con-
centrations of these pollutants  and other pollutants (the normal situation), have
been present in urban atmospheres.  Because of the interreactions among pollu-
tants and  the reactions of pollutants with oxygen and water in the atmosphere,  as
well as the influence of sunlight and temperature  on these reactions, the effects
of sulfur oxides pollution in a total atmosphere may be quite different from  the
effects of sulfur oxides  under laboratory conditions.  The effects reported,  there-
fore, are not primarily expressions of cause and effect that can  be duplicated pre-

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        Table 2.    SUMMARY OF  EFFECTS OF SULFUROUS COMPOUNDS
        Sulfur dioxide
     concentration, ppm
              Exposure period
                 and effect
Measurement
  method*5
                                                                   Reference
Trace
0. 01 to 0.02
0. 02 max annual avg
0. 02 to 0.03
0.07 to 0.25

0. 20 to 0. 30 for 3 days


0. 20 to 0. 86 for 3 days
0. 21
0. 1 not to be exceeded
 over  1% of time in any
 3-mo period
0.25
0 28
0. 04

0. 08

0. 10
0. 20 for  I hr not to be
 exceeded over  once in any
 4 consecutive days
0. 30
0. 50
0. 50 for  5 mm not to be
 exceeded over  once in any
 8-hr period
0 5 for 1 sec
0. 5 for 4 hr
0. 5 for 7 hr
1 0 for 10 mm
1 6 for 1 to 5  mm
              Yearly exposure

Metal corrosion beginsa
Significant metal corrosiona
Impaired pulmonary functiona
Increased cardiovascular morbiditya
Air-quality goal for Study area
Increased respiratory death rates for
  area studied3
Detectable chronic injury to perennial
  vegetation3

            2 - to 4-day exposure

Hospital admissions for cardio-
  respiratory diseases increase3
Rhinitis, sore throat,  cough,  and eye-
  imtation rates increased3
Mild to acute sensitive vegetation injury
Cardio-respiratory mortality increased3
Acute vegetation injury

             24-hr exposure

Bronchitic patients'  health deteriorates3
Air-quality goal for  Study area
Increased total death r-ates3
Detectable injury to sensitive vegetation

             Brief exposures

Visibility reduced to  10 mi at 70% relative
 humidity
Cortical conditioned reflexes  produced.
 Repeated 10-sec exposures
Visibility reduced to  4 mi at 70% humidity
Air quality goal for Study area
Taste threshold
Visibility reduced to 0. 85 mi at 70% humidity
Air.-quality goal for Study area
Odor threshold
Detectable injury to sensitive vegetation
Acute injury to trees and shrubs
Respiration and pulse rates increase
Threshold for inducing measurable broncho-
 constriction  in healthy  people
Pb02
PbO2
Pb02, W.G.
Pb02, W.G.

PbO2

T. A.
H2°2
P.G.
H2°2
P.G.
H2°2
H2°2



C

NMI

C
P.G.
C
P.G.
P.G.
P.G.
P.G.
P.G.
                         5
                         5
                       6,7
                       6,7

                         8

                         9
                        10

                    1 1, 12

                        13
                        14
                    13, 15


                        16
                        16
                        13
                        17
                                                                        18
                        19
                        13
                        15
                        20
                        21
 Effect determined for ambient air-quality conditions.  Other effects are calculated or determined by
 laboratory experiment.
 PbO2 - lead peroxide candle method
 T, A. - by Thomas autometer
 E  - by electroconductivity
 C  - calculated effect
                       W.G.  - West-Gaeke method
                       H2O2  - hydrogen peroxide method
                       P.G.  - pure gas used
                       NMI - no method indicated

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cisoly from one location to another, but rather they are useful values derived
from what has actually been taking  place in urban atmospheres.

     Each of the sulfur oxide compounds -  sulfur dioxide,  sulfuric acid,  and sul-
fate  salts - contributes individually to the  effects of sulfurous pollution.  The pro-
portions of the compounds, of course, vary in a  complex manner over any geo-
graphical area, both in regard to the proportions of the compounds and the  time
or times during which they occur.  Over a long period,  it is  expected that the pro-
portions of the compounds would remain roughly the same from place to place
and season to season.  Studies involving volumetric and sulfation measurement
methods during two winter seasons in the St.  Louis area tend to confirm this ex-
pectation.

     Since the methods of measuring the sulfur dioxide component have been more
fully developed than methods of measuring other pollutants, and since most in-
vestigations reported from other places have relied heavily on measurements of
sulfur dioxide, concentrations of this gas have been used to express the  concen-
trations of sulfur  oxides.  Considering  that the sulfur dioxide measurements are
an index of effects,  the higher-than-normal sulfation levels in the Study area may
be found at some time to have some major significance,  such as  indicating  the
presence of significant levels  of sulfuric acid.

     In the documented air pollution disasters in  Belgium (1930),    Donora,
Pennsylvania  (1948), 23 New York City (1953 and 1963), 12 and London (1952  and
1962), 24, 25 large numbers of people became ill,  and  many died.  All of these
episodes occurred in heavily industrialized areas during relatively brief periods
of weather conditions that prevented dispersal of air pollutants.  Sulfur  dioxide
concentrations were abnormally high, as were the concentrations of other gaseous
and particulate pollutants.  Although  the pattern  of effects -was not uniform  in all
these episodes, generally speaking, the elderly, the very young, and  those with
preexisting cardiorespiratory disease were affected most.

     The evidence is considerable that sulfur  oxides pollution  aggravates existing
respiratory disease in humans and contributes to its development.   Sulfur dioxide
gas alone irritates the upper respiratory tract.  Adsorbed on particulate matter,
the gas can be carried deep into the respiratory system to injure lung tissue.
Sulfuric acid in a  certain particle size, when inhaled, penetrates deeply into the
lung to damage tissue.

     Epidemiological, as well  as clinical,  study substantiates the evidence that
certain portions of the population are more sensitive than others to sulfur oxides
pollution.  For example, prolonged exposure to relatively low concentrations of
sulfur dioxide  has been associated  with increased cardiovascular morbidity in
older persons.  Prolonged exposure to higher concentrations  of sulfur dioxide has
been associated with an increase in respiratory disease death rates and an in-
crease in complaints  by school children of such symptoms as nonproductive cough,
mucous membrane irritation,  and mucous  secretion.  Furthermore, the residual
air in the lungs of emphysema patients  has been significantly reduced when the
patients breathed  outdoor  air that had been filtered of its pollutants.   Alveolar
elasticity is  apparently restored somewhat, or airway resistance is decreased
by the cleaner air.  The most important single factor in improving the feeling of
well-being in  chronic bronchitis patients has  been decreases in the amounts of
smoke and sulfur  dioxide pollution.

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     Sulfur oxides pollution can also adversely affect the most robust persons  of
the population.  Experiments in which human volunteers were exposed to sulfur
dioxide concentrations several times higher than the 0. 3-ppm taste threshold
indicate that such exposure will produce pulmonary function changes,  including
increased respiration rates,  decreased respiratory flow rates,  and increased air-
way resistance.  The impairment of function is greater when the sulfur  dioxide
gas is administered along with particulate matter. *-"> ^ ' The  latter appears to in-
crease the penetration of sulfur dioxide into the lung.  Sulfur dioxide and partic-
ulates would be a normal combination found in urban atmospheres.

     In other experiments involving sulfur dioxide concentrations below the taste
threshold,  cortical conditioned reflexes were produced. Tests  made -with concen-
trations at the taste threshold desynchronized the predominant wave in electro-
encephalograms  and  increased the sensitivity of the dark-adapted eye.
             studied the incidence of respiratory illness lasting more than 7 days
in female employees in five cities.   Results of this  study showed a very high
correlation (0. 964) of the average concentration of suspended sulfate in the air in
these cities with the  rate of respiratory illnesses.  The average sulfate concen-
trations for the cities ranged from 5 to 20 micrograms per cubic meter.  During
the non-influenza-epidemic years, the incidence of  respiratory disease was more
than twice as great in the city with the highest sulfate concentration than it was in
the city with the lowest sulfate concentration.  As one would expect,  the incidence
of total respiratory disease during the Asian flu  epidemic  of 1957-1958 was great-
er than in the same  cities  during nonepidemic years.  In the city with the lowest
concentration of suspended sulfates, the incidence of respiratory illness increased
about 20 percent during the epidemic year, whereas in the city with the highest
concentration of suspended sulfate,  the incidence of respiratory illness increased
approximately 200 percent.  This was 10 times as great an increase in the city
with the highest sulfate concentration as in the city with the lowest sulfate concen-
tration.  In absolute  terms rather than percent increase, during the influenza year
the incidence of respiratory diseases in  the city with the highest sulfate pollution
was more than five times as high as that in the city -with the lowest sulfate pollu-
tion.   There is, of course, the possibility that the sulfate concentrations mea-
sured  indicate  the presence of other pollutants that increase simultaneously with
sulfate concentrations and that are contributory to adverse health effects or are
even more damaging to health than the sulfurous compounds producing  the sulfate.

    Sulfuric acid mists and sulfates in the atmosphere scatter light and thus re-
duce visibility.  Because sulfuric acid and sulfate are hygroscopic,  they tend to
cause  fogs.  These fogs  decrease the amount of solar energy reaching  the ground
and, therefore, tend to stabilize the atmosphere so that pollutants are  held in the
affected area.

    Prolonged exposure of all but the most resistant metals to any quantity  of
sulfuric acid accelerates corrosion.  The  corrosion rate increases  rapidly as the
pollution level  rises.  The effects of sulfur oxides on nylon and cotton fabrics
have been studied to  some extent during  the Interstate Air  Pollution Study.   In
fact, these studies have  been some  of the first of this type  ever made.   (See
Materials Deterioration  in the Study Area  section of this  report. ) The effects of
sulfur  oxides corrosion on  stone  statuary and buildings has been recognized
throughout the  world. Damage to art objects, paper,  leather,  textiles, and paint
is also a widespread problem.

-------
     Vegetation is  acutely damaged by a few hours oi exposure to concentrations
of sulfur dioxide in excess of 0. 25 ppm,  and injury may be detected in many areas
that have yearly average concentrations of 0. 02 to 0. 03 ppm.  Vegetation  sensi-
tive to sulfur oxides disappeared many years ago in several parts of the Study
area.  Decreases  in measured sulfur dioxide concentrations during  the past 20
years, however,  have allowed  some species to reappear in the central part of the
Study area  (see Vegetation Damage section of this report).

     Table 3 reports effects caused by different amounts of sulfuric  acid (criteria).
For the most part these criteria are derived from laboratory investigations and
do not,  like sulfur dioxide criteria  (Table 2),  represent conditions found in urban
atmospheres.   This is undesirable, but is understandable  because of the major
difficulties  encountered  in the measurement of sulfuric acid in  urban atmospheres.

     It has been postulated that the presence of sulfuric acid aerosol can be shown
by comparison of sulfation candle results and West-Gaeke results.  Correlations
of results from paired samplers located at the same sites can be expected to differ
for the two methods from site to site and city to city because the West-Gaeke method
is specific  for sulfur dioxide and the nonspecific,  sulfation  method shows the pres-
ence of all  sulfurous compounds that react with lead dioxide to  form lead sulfate.
The relative importance of sulfuric acid aerosol  at any site, therefore,  may be
determined by comparing the difference in the  sulfation and sulfur dioxide  levels
with the  cliffcrences found for other sites.  Volume III - Air Quality Measurements
rc'ports in some detail on the high  sulfation levels found in the Study area.   These
levels were five times higher than those found in  Nashville, Tennessee, and in the1
same range as those found in London, England.   Sulfuric acid aerosol may, there-
tore, be more important in the  Study area than sulfur  dioxide levels would indicate.

     The following quotation from  the book,  Air Conservation, ^ 9 reports the prin-
cipal effects of sulfuric-  acid  on man and animal:

     "Sulfuric  acid must have been the principal cause1 of the air pollution
     disasters of the Meuse Valley, Donora,  and  London.  It (sulfuric acid)
     produce's  on a molar  basis  from 4 to 20 times the physiological response
     in animals as sulfur dioxide does.  The  effect of sulfuric  acid mist is
     greatly influenced by the size  oi the mist particles.  Those of interme-
     diate size (about 1 micron in  mean  diameter) appear to be  most injurious. "

     Sulfuric acid  mist causes  spots on the surface of leaves exposed to falling
droplets.  Discrete spots appear  only when the drops arc  large enough to settle
upon the1 leaf and wet its surface.   Such damage occurs most often during  foggy
weather, which is conducive to both coalescence  of droplets and to leaf wetting.
As one would expect, nonwaxy leaves are more susceptible to this type of  damage.

     Sulfuric acid  mist promotes corrosion  and materials  deterioration.   Especial-
ly damaging to certain cloth materials, such as nylon,  sulfuric acid causes the
formation of pinholes and weakens cloth as  a whole.  Participate matter in the air,
depending upon its characteristics, may detract  from or enhance the acid-mist
effect.

     A goal of 0. 004 milligram  per cubic meter for a maximum annual average1
(4 ug/m ) and 0.030 milligram per cubic meter (30 |o.g/m  ), not to be exceeded as
an hourly ave^rage over  1  pc'rcent of the1 time,  is  sugge'sted for the' Interstate- Air
10

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Pollution Study  area.  These- concentrations would not entirely eliminate mate-
rials deterioration,  but  would, based on current information,  provide  reasonable
protection oi the- public health.


Hydrogen  Sulfide

     Hydrogen sulfide is easily identified by its distinctive rotten egg odor.  Its
effects include gastrointestinal disturbances,  damage to lead-base paints, and
emotional stress  caused by its odor.   Table 4 shows that concentrations greater
than 500 ppm cause  death;  lower concentrations cause respiratory irritation re-
sulting in  nausea,  vomiting,  discomfort, loss of sleep, shortness  of breath,  and
headache.  Concentrations  of 10  to  100 ppm can cause eye effects including con-
junctivitis and keratitis.

     The odor threshold for sensitive individuals is about 0.01  ppm and ranges up
to 0. 10 ppm,  depending  upon individual olfactory  sensitivity.  At higher concen-
trations the odor  becomes  progressively stronger and more disagreeable; it
reaches intolerable  levels  at about  30 ppm.

     Damage to lesid-based or pigmented paints and paints containing mercury-
based fungicides can be  caused by hydrogen sulfide.  Discoloration occurs when
the metallic  oxides react with the hydrogen sulfide  to form metallic sulfides.   The
occurrence  of this type  of damage depends considerably upon the presence of water,
which hastens the  reaction and allows it to occur  with smaller  amounts of hydrogen
sulfide.  When the paint surface  is  moistened, damage may occur  with exposures
of less than  1 hour and concentrations as low  as  0.  1 ppm.  Figure 2,  a photograph
of a garage  in the  Study area, shows  the type  of damage caused by hydrogen sulfide.
  Table 4.    EFFECTS OF HYDROGEN SULFIDE FROM BRIEF EXPOSURES
      Concentration, ppm
                                                   Effects
                                                                             Reference
0. 003

0. 001 to 0. 10

0. 03 for 1/2 hr not to be exceeded
 more than twice in any 5 days
0. 05 for 1/2 hr not to be exceeded
 more than 2 times/yr
0. 01 to 0. 3 for 30 mm

1. 0 for 30 mm
3 to 5

4 to 30
20
20  to 30
20  to 40 for 5 hr
50  to 500
>500
Tarnishing of silver and copper occurs
  slowly
Odor threshold depending upon olfactory
  sensitivity
Air quality goal for Study area
Air quality goal for Study area

Paint blackening in presence of water mist
Paint blackening under dry conditions
Offensive intense odor

Eye effects noted by most people
Industrial hygiene threshold limit value
Strong odor, intolerable at about 30 ppm
Damage to sensitive vegetation
Respiratory irritant subacute poisoning
Systemic poisoning,  death
   34

35-37
   38


    4
39-43
   44
45, 46
   47
12

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    Odors and tarnishing of metals are other specific effects found in the Study
area.  These effects are found within small areas and are intermittent in occur-
rence.  The hydrogen sulfide upper limit goal of 0.05 ppm,  1/2-hour average, not
to be  reached or exceeded over two times a year at any place where people live or
an effect maybe objectionable,  is  suggested.  This concentration would be  detected
as odors by some people, and some tarnishing of metals  would occur; but if the
goal is met, the frequency of such occurrences  would be  low.

CARBON MONOXIDE

     Table 5 presents carbon monoxide  criteria.  The toxic  action of carbon mon-
oxide is related primarily to its affinity for hemoglobin,  the oxygen-carrying com-
ponent of blood.  Human hemoglobin has an affinity that is about 200 times  greater
for carbon monoxide than it is for oxygen;  therefore,  a relatively small concen-
tration  of carbon monoxide in the inhaled air can tie up significant quantities of
hemoglobin as carboxyhemoglobin. Hemoglobin is then unavailable for the trans-
port of  oxygen to the various body tissues.  Secondary, though probably important,
effects  of carbon monoxide result  from carboxyhemoglobin inhibiting the dissocia-
tion of oxygen and hemoglobin molecules.  This  further reduces the body's oxygen
supply.  Carbon monoxide in the blood also reduces the partial pressure of oxygen,
as a gas,  in the blood, and thereby lessens the  moving force that causes the oxygen
to diffuse into the tissues.

     The amount of carbon monoxide within the body is related to both its concen-
tration  in the air and the length of time the individual is exposed.  Unless  the
concentration in the air is sufficient to  bring about death, an equilibrium condition
is established between the carbon  monoxide in the  air breathed and that in the blood.
              Figure 2.  Example of paint damage caused by hydrogen
                        sulfide  in Study area.
                                                                              13

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                 Table 5.   EFFECTS OF CARBON MONOXIDE
Concentration ,
ppm
5
5 to 10
30
30
45

70 to 100

120
200
500

1,000
2, 000
Exposure
time
20 mm
-
8 hr or more
8 hr

-

1 hr
2 to 4 hr
2 to 4 hr

2 to 3 hr
1 to 2 hr
Effects
Reflex changes in the higher nerve centers
Average levels of CO in St. Louis and most
large cities
Impairment of visual and mental acuity
(5% carboxyhemoglobin)
Air quality goal for Study area
Peak concentration at St. Louis CAMP
Station
Maximum levels occurring in some large
cities
Air quality goal for Study area
Tightness across the forehead, possible
slight headache
Severe headache, weakness, nausea, dimness
of vision, possibility of collapse
Rapid pulse rate, coma with intermittent
convulsions, and Cheyne-Stokes respiration
Death
Reference
4
48
49-51
48

49

52
52

52
52
  All effect levels pertain to healthy individuals.  Specific effect levels for individuals who for
  other reasons are approaching the levels of tolerability are not available.
In the concentration range of 0 to  100 ppm carbon monoxide, after sufficient time
has elapsed to establish equilibrium, each  1 ppm of carbon monoxide has inactivated
approximately 0. 17 percent of the body's hemoglobin.   The time necessary for
equilibrium to be reached is a matter of hours,  however,  Both time and concentra-
tion must, therefore, be considered in determining  effects.


Acute Effects

    The oxygen deficiency that results from exposure to carbon monoxide is a re-
versible chemical asphyxia, a type of asphyxiation or  oxygen deficiency.   There
is no  satisfactory evidence  to indicate that  permanent  ill effects occur from single
acute carbon monoxide exposures that do not result  in a loss of consciousness;
however, when poisoning is severe enough  to cause  loss of consciousness,  some
damage to the  brain,  central nervous  system, and circulatory system may occur.
The degree of damage incurred is related to the length and severity of the asphyxia. ^

    Impairment  of body function is detectable at carboxyhemoglobin levels as low
as  5 percent in the blood.  Such levels could  result  from exposure to 30 ppm car-
bon monoxide for an 8-hour period. 49-51   Effects caused by such exposure involv-
ing higher nerve centers include impairment of  the  ability to think and see clearly,
a faculty very important to  motor vehicle drivers.   Detectable effects caused by
 14

-------
levels of 1. 7 ppm for 24 hours affect the reflex actions in the higher nerve centers
(such as light sensitivity of the eye,  optical chronaxie, and the cerebral biocur-
rents). "*


Sensitive Groups

     For persons with certain types of preexisting physical  disabilities or illnesses,
the concentrations required to produce effects  can be considerably less than those
causing effects in healthy people.  Included among this group would be persons
with one or more of the following conditions: anemia,  certain forms  of heart
disease, emphysema, a high metabolic rate (e.g.,  those with thyrotoxicosis or
fever),  and bronchial asthma.

     In addition to those having an increased susceptibility because of certain
disease conditions, there are others, who,  because of  where they are or what
they have been doing, may exhibit an increased susceptibility.  For example,
those people  at high altitude,  in high temperature and high humidity,  or  persons
with significant preexisting amounts  of carboxyhemoglobin in their blood result-
ing from their occupation, from  smoking (which has been found to produce carboxy-
hemoglobin levels of up to 8 percent), 53 or frOm traffic may be thought to be suf-
fering from chronic effects of  carbon monoxide when in fact they  have accumulated
acute levels  of carboxyhemoglobin in the blood.  Traffic exposures in St. Louis
inside vehicles alone, for example, have been  found to be over 30 ppm,  or about
twice the levels measured by the  Continuous Air  Monitoring Program station. 54

     As far as healthy humans are  concerned,  numerous experiments  conducted
under carefully controlled conditions have demonstrated that repeated exposures
to low but significant amounts of carbon monoxide do not result in any permanent
ill effect. 52

     The goal of 30 ppm,  not to be  exceeded for any 8-hour  exposure period, in-
cludes some  consideration of the persons within special groups, but is not unduly
governed by the needs of  these groups.  Some researchers  believe this goal should
be as low as  5 ppm for  8  hours. -*->


OXIDANTS

     Oxidant levels,  as  measured in urban atmospheres, record the results of a
complex atmospheric interaction that apparently  involves the primary air pollu-
tants as reactants and catalysts.  Photochemical smog is the term used to describe
the resulting group of secondary air  pollutants.  Measured  levels of urban air
oxidants are  compared  in Table 6 with  results  from experiments  using ozone under
laboratory conditions.  The complexity of urban-air-measured oxidants as com-
pared to the  simplicity  of the laboratory-measured ozone must be kept in mind in
assessing the effects attributable to oxidants.

     Oxidants  measured in urban atmospheres indicate  effect levels  of photochem-
ical smog.  Photochemical  smog,  as explained by Haagen-Smit, "° is  associated
•with a considerable increase in concentrations  of ozone and  other oxidant mate-
rial.  In smog formation  sulfur dioxide, nitrogen dioxide, and aldehydes are be-
lieved to absorb ultraviolet radiation and react chemically •with molecular oxygen
to produce atomic oxygen (ozone).  These reactions  are irreversible  for sulfur  di-
                                                                              15

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                         Table 6.   EFFECTS OF OZONE
    Concentration, ppm
              Observations
                                                                                Reference
0. 01

0. 02 for 8 hr

0. 03 for 8 hr

0. 05

0. 05 for 1 hr

0. 10 for 1 hr


0. 05


0.15b


0. 15 maximum allowable for
 1 hr average (total oxidant)
0. 10
0. 1 to 0.25 long term


0. 10 for 8 hr

0.20 for 3 hr
0.60


1 for 1-1/2 hr
3 to 12 for few hr
Ozone considered radiomimetic - no safe
 level

Odor threshold of ozone
Damage to tobacco leaves begins

Significant damage to tobacco leaves

Nose and throat irritation threshold
Damage to tobacco leaves begins

Significant damage to tabacco leaves Pine
 tree needle tips burned

Threshold for eye irritation in sensitive
 people (ambient oxidant)

Generally stated eye-irritation threshold
 for normal people (ambient)

Air quality goal for Study area (ambient
 oxidant)

Reduction in oxygen consumption and blood
 oxygen tension (concentration) levels of
 emphysema patients, compared to effects on
 some patients breathing filtered air (ambient)
Shortens life span, increases mortality of
 guinea pigs

Definite symptomatic effects in sensitive people

Decrease of visual acuity

Cough irritation threshold, pronounced nose and
 throat irritation
Coughing, irritation, severe exhaustion
Lethal to small laboratory animals
   56


   57

   58

   58

   56

   58

   58


   59
                                                                                     60
   61


57,62
   63
   63

   64
   65
  As determined from laboratory experiments using ozone except where otherwise noted.
  Ambient measurements are for "total oxidants. "
  0.25 ppm by the phenolphthalin method.
oxide and aldehydes, but the nitrogen dioxide reaction is cyclic unless the nitrogen
dioxide is  converted to nitric acid or is used up in organic reactions.  In the sulfur
dioxide reaction, the sulfur dioxide is  oxidized to sulfur trioxide, with subsequent
formation  of sulfuric acid aerosol.  Hydrocarbons and other organic pollutants
react in varying degrees with the ozone and oxidant formed to yield compounds
that cause eye irritation,  vegetation damage, and reduced visibility.


     Most researchers  agree that eye irritants  are produced by photochemical oxi-
dation of hydrocarbons in the presence of sunlight and nitrogen oxides.   Research-
ers further agree that eye irritation is directly and consistently correlated with
formaldehyde, acroletn, and PAN concentrations  in the air.   Ozone, the compound
16

-------
with which most laboratory studies were made,  constitutes the major proportion
of oxidant in the atmosphere of most cities during all seasons.  Concentrations,
however, vary from season to season,  being highest in the summer and fall as a
result of the greater photochemical  activity associated with the greater amount of
sunlight. The percent ozone portion of oxidant concentrations is highest in the
winter,  often being 95 percent or more of the total oxidant.  In the summer and
fall, the relative proportion of ozone may drop to 80 percent or less because of
the production of other oxidants in the photochemical  reactions and the increased
conversion  of nitric  oxide to nitrogen dioxide, the latter being an oxidant itself.

    Eye irritation,  although possibly not the most important effect of the constitu-
ents measured as oxidants,  is the most troublesome and most commonly recog-
nized effect in urban atmospheres.   This major problem of photochemical-type
air pollution varies greatly  in the effects caused, not  only because of differences
in the sensitivity of the individuals affected but also because of variations in light,
humidity, haze,  and wind currents.   Although the eye-irritation threshold level
is usually placed at 0. 15 ppm total oxidants  as measured by the potassium  iodide
method, it appears that the  total oxidant is not directly responsible for this effect. ° '
It is attributed to specific chemicals  associated with or among the measured oxi-
dants,  in particular the ozone-olefin reaction products.


     The goal of  0.  15 ppm,  not to be exceeded for over 1 hour, is based upon the
California standard. This  goal measured as total oxidant will be  equivalent to
approximately 0. 13 ppm ozone.  As  seen from Table  6, this concentration  is
somewhat higher than those concentrations causing significant damage to sensitive
plants  and producing symptomatic effects in sensitive people.
OXIDES OF NITROGEN

    Seven oxides of nitrogen are known, but only nitric oxide and nitrogen dioxide
are thought to play an important role in the formation and action of photochemical
smog.  Of the other five oxides,  only nitrous oxide  is normally present in signifi-
cant concentrations (0. 5 ppm) in the atmosphere.  It is  chemically inert at am-
bient  temperatures.  As described in the discussion of oxidants, the complex
reactions that produce smog are initiated by the photolysis (breakdown) of nitrogen
dioxide.  In sufficient concentrations nitrogen dioxide is toxic to humans and vege-
tation; under some conditions it gives the atmosphere a yellowish-brown color.

    Nitrogen oxides are formed primarily during combustion.  In  most communi-
ties power plants and  motor vehicles are the primary sources,  and space heaters,
water heaters, and industrial processes contribute  varying but lesser amounts.
In the St.  Louis area, motor vehicles emit an estimated 32 percent of the total
nitrogen oxides and fuel combustion by power and industrial  sources contribute
about 55 percent.   (See Volume II - Air Pollutant Emission Inventory.)

    Nitric oxide and nitrogen dioxide are the only nitrogen oxides found in the  at-
mosphere that reach concentrations sufficiently high to be  of concern.   Since nitro-
gen dioxide is five  times as toxic as nitric oxide and is  most active in promoting
photochemical  smog,  most research on determining effects of nitrogen  oxides
has been based upon nitrogen dioxide.  Table 7  shows some of its effects.
                                                                               17

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    Since neither gas is very soluble in water,  they pass through the upper res-
piratory tract and are hydrolized to nitric and nitrous acids in the high-humidity
atmosphere of the alveoli.  Nitrous acid is a potent mutagen,  and nitric acid dena-
tures human tissue and makes it leathery and brittle.   These two acids promote
the development  of emphysema by destroying  the lung alveoli and by decreasing
resistance to other stresses such  as airborne infectious microorganisms.  A con-
centration of 3 ppm by volume of nitrogen dioxide for  1 hour may be serious
enough to cause acute effects in sensitive people.   Prolonged exposures to nitrogen
dioxide concentrations of 0. 5 to 1.0 ppm have been shown to be detrimental to the
health of animals.

    Data  on phytotoxic effects indicate that exposure to 2 to 3 ppm by volume of
nitrogen dioxide  may cause acute damage to sensitive plants.  Long-term ex-
posure to concentrations  of nitrogen dioxide below 1 ppm by volume may lead to
growth suppression,  chlorosis, and premature abscission of leaves.  Exposures
to 1 ppm by volume for 8 hours produce significant growth reduction, but no
visible lesions.
    Nitrogen dioxide absorbs light in both the ultraviolet and the visible spec-
trums.  In sufficient concentrations  it reduces the brightness and contrast of
                  Table 7.  EFFECTS OF NITROGEN DIOXIDE
   Concentration,
        ppm
                     Effect
Reference
  0. 1
  0.25
  0. 5  3 mo

 <0. 5  12 to 19 days



   1 to 3
  2.5  7 hr or more

  3    4 to 8 hr

  3.5  2 hr

 13
Limit of acceptability for coloration effect
 in aerosol-free air with viewing distance
 of 10 miles.
Limit of acceptability for coloration effect
 in normal metropolitan area air with view-
 ing distance of 10 miles when the visibility
 is 20 miles.

Increased susceptibility to infection  in mice
 by certain aerosolized bacteria.
Significant growth reduction in tomato and
 bean seedings.  No visible lesion damage.
 Chlorosis of leaves reported.
Odor threshold.
Bean,  tomato,  and nicotiana glutinosa leaves
 damaged with white lesions  occurring.

Pinto bean leaf damage.
Increased susceptibility to infection in mice
 by certain aerosolized bacteria.
Nasal and eye irritation noticeable.
     68


     68




     68

  69,70


     68
     71

  71,72
  73,74

     75
  18

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distant objects and imparts a yellow-brown color to the horizon sky and distant
white objects.   These coloration effects are enhanced as aerosol concentrations
in the  atmosphere decrease.   Objectionable coloration effects can be expected to
occur  on days of good visibility (20 miles) with concentrations  of about 0. 25 ppm
by volume of nitrogen dioxide.

     At present  authorities disagree as to whether reductions in hydrocarbon con-
centrations alone will produce the desired reduction in photochemical smog prod-
ucts.    In Los  Angeles, for example,  two eye irritation peaks have been ob-
served. The earlier of the two peaks occurs at approximately 9 to  10 a.m. and
seems  to coincide with the maximum daily nitrogen dioxide concentration.   The
later peak occurs between about noon and 4 p. m.  and corresponds to the peak
total oxidant measurement.  Some authorities believe that  a reduction in hydro-
carbon emissions alone may lead to a prolongation and intensification of the earlier
peak.   This presumably •would  occur because of a lack of hydrocarbons with which
the nitrogen dioxide and other intermediate photochemical  products  react to form
the materials causing the  second eye irritation peak.  Both hydrocarbon and nitro-
gen  oxide emissions may thus have to be reduced to alleviate smog conditions that
cause  eye  irritation.

     No goal for nitrogen dioxide for the Study area has been chosen because of the
uncertainty of authorities  concerning the health effects of concentrations in the
range  of those occurring in the Study area.  Adopting an  ambient-air-quality
standard such as that adopted by the California Department of Health (3  ppm for
1 hour  =  serious level) is considered unnecessary since this level is over  10
times  higher than the 5-minute maximum levels recorded in St. Louis by the Con-
tinuous Air Monitoring Program.  The mutagenic and denaturing effects of low
concentrations of this pollutant in the lungs as •well as the sky coloration and
phytotoxic effects may,  however, call for ambient-air -quality  goals of less than
1 ppm.
EFFECTS OF PARTICULATE MATTER

Introduction

     The effects of particulate matter vary widely, depending on particle size and
composition as well as numbers.  For example, less than 1 microgram per cubic
meter of beryllium presents a health hazard, whereas inert dusts could be present
in quantities several hundred times that without comparable danger.  In their
present stage of development, particulate collection and analysis do not make
nearly all the tests desirable, but are limited primarily to finding total weight of
particulate  matter per unit volume of air.  For this reason, many of the effects
reported in Table 8 are  based on the opinions of experts in the field of  air pollu-
tion.  These opinions  relate to urban air, and the effects  are attributed to or
related to particulate  matter combined with other pollutants in that environment.
Reported visibility reductions and results from public opinion surveys,  however,
do stem from quantitative relationships.

    The effects of particulate matter include  contributions to reduced visibility,
increased health effects  (including cardiorespiratory diseases and eye irritation),
increased vegetation damage,  soiling,  and increased materials damage.
                                                                               19

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                  Table 8.   EFFECTS OF PARTICULATE MATTER
         Concentration
                                                      Effect
                                                                                  Reference
ug /m

     25 to 50
     75 to 100
over 100

     150 to 200
over 200
     100
     140
     75, geometric mean
     200, 99 percentile

Cohs/ 1 , 000 lineal ft
over 0. 3
    0. 4  60% relative humidity
    0 4  > 90% relative humidity
    0. 4
    i. 6  60% relative humidity

 tons/mi  /mo

      5
     15
     10  3-mo average above
         background in all areas
         except those zoned heavy
         industrial.
     25  3-mo average above
         background in zoned
         heavy industrial areas.
     30
Background levels
Considered satisfactory air quality by most people
Increased mortality from all causes, increased
 mortality from chronic respiratory diseases
Considered dirty by most people
Considered excessively dirty by most people
Visibility reduced to about 5 mi
Visibility reduced to about 3 mi at humidity > 60%
Residential Air quality goal for Study area
Increase in total morbidity and incidence of
 cardiovascular diseases among middle-class
 individuals 55 years of age or older
Increased mortality from respiratory diseases
 among the middle socioeconomic class
Visibility reduced to about 9 mi
Visibility reduced to about 3 mi
Air quality goal for  Study area
Visibility reduced to about 3 mi
Background level
Considered satisfactory for residential areas
76

77
78
78
79
79
79
                                   Considered dirty by most people
 Health-Related Effects
      Health effects associated with  airborne particulate matter vary with the  particle
 sizes and the chemical activity of the pollutant, and its sites  of toxic  action.   Since
 air pollutant effects  are associated primarily with action upon the respiratory sys-
 tem, consideration of the mode of entry and action  -will be  limited to that system.
 Particles larger than  10  microns in diameter are practically all  removed  in  the
 nasal passages.   Upper respiratory efficiency in  removing particulate matter de-
 creases  as the size  of particles decreases  and becomes practically nil for 1-micron-
 diameter particles.   The  efficiency of particle removal is  high in the pulmonary air
 spaces,  being approximately 100 percent for all sizes above 2-micron diameter.
 Below this  size,  the efficiency  decreases to a minimum at about  0. 5 micron  and
 then  increases again as the force of precipitation by diffusion becomes more ef-
 fective on these smaller  particles.   The percentage penetration of particles into
 20

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the pulmonary air spaces increases from practically zero at 10 microns to a
maximum at and below 1 micron,  where it is equal to the percentage of tidal air
that reaches the  lungs.  The percentage of inhaled particles that are deposited in
the pulmonary air spaces has  a maximum value between 1 and 2 microns.   The
relative amount of particulate matter deposited and its  distribution in the respira-
tory system,  however, does change with breathing frequency and tidal volume.
Upper respiratory trapping  increases with faster breathing as the rate of inspired
airflow increases.  The amount of deep lung deposition of particulates increases
with slow,  deep breathing because of the larger amount of tidal air reaching the
                                                                    Q f\
pulmonary air spaces and the  longer transit time of air in the  lungs. °


     The  effects of particulate matter deposited in the lungs depend upon the chem-
ical and biological action that  the  material may have  on the exposed cell tissue
and the body's defense mechanisms.  Acid mists,  silica,and beryllium as well as
certain other metals are especially  damaging to the  lungs and  human health.
Beryllium,  -which was not found in samples collected during the Study, is a serious
health hazard.  Certain carcinogenic materials, which  also occur in particulate
form,  can be a serious health hazard.  Measurements of benzo(a)pyrene, one of the
potential cancer-causing air pollutants, made during the Study, showed the pollu-
tant concentration in the  St.  Louis area to be comparable, in a general sense,  with
those in other  United States  cities of similar size and composition.  The sample
average was 10.2 |ag/l,000 m  during the winter of 1964, -with the  range bet-ween
sites from 1.4 to 28.0 jig/1,000 m^. The United States urban average value is
5 |j.g/l, 000 m^.  In addition, samples analyzed  indicated the possibility that other
potential cancer-producing airborne particulates may be present  in the Study
area's atmosphere.   In 1959 an abnormally high concentration of  54 micrograms
of benzo(a)pyrene per 1, 000 cubic meters,  over 10 times the urban average, was
recorded.  Report Volume III, Air Quality Measurements, presents the benzo(a)py-
rene data in  detail with interpretation regarding occurrence and sources.  Present
knowledge of this pollutant is inadequate to  explain the variation found in the Study
area, but its occurrence emphasizes the need for continuing to measure the con-
centrations  of this pollutant  and supporting  research to better  define its importance
in the environment.   Most authorities agree that although a large  proportion of the
increased rate of lung cancer  in c  ities  can be attributed to the  smoking habits of
city dwellers,  a certain part of the excess cancer  rate  in urban areas is due to air
pollut ion . " 1


     As mentioned previously, laboratory experiments  with human subjects have
demonstrated that particulate  matter penetrating the pulmonary air spaces exerts
additional effects when present with certain gaseous pollutants in the  air.  In other
words, when the gas is  adsorbed  on the particulate matter, it has a greater detri-
mental effect than if it were present in its natural state. ° ' °  In addition, free
soluble gases are largely absorbed  in the upper respiratory tract,  -whereas gas
adsorbed on particulates may pass through the upper respiratory tract and be
deposited in the alveoli.


Vegetation Damage  and  Related Effects

     Gaseous matter adsorbed or  absorbed  on particulate matter may also produce
vegetation,  animal, or materials  damage.  Vegetation  damage can be caused by
chemically  inert particulate matter  building up on the leaf until sunlight cannot
                                                                                21

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penetrate the layer.  If the particles are not inert, damage may occur as the
result of direct burning by acid,  caustic,  or other active droplets or by absorp-
tion of biologically injurious compounds.  Animals eating pollutant-covered
forage or forage having the pollutant within  its leaves are particularly endangered.
Fluoride damage to bones and teeth of cattle is an example of this type  of effect.
     Particulatcs soil many surfaces and increase the costs of cleaning buildings,
laundry, and dry cleaning.  Figures 3 and 4, showing cleaning of the Old Post
Office Building and an office building in downtown St. Louis,  illustrate these ef-
fects.  Damage to  building exteriors caused by particulates and by gaseous com-
pounds in the air decreases building life and increases building maintenance costs.

     A study conducted in the upper  Ohio River valley in 1959 and I960 revealed
important differences in the  cost of four categories  of cleaning in  communities
subjected to different levels  of air pollution."   The activities examined were care
of the exterior of homes, interior of homes,  clothing,  and hair and face.  Three
communities having distinctly different  air quality,  but similar weather and in-
come levels were compared.  With  few  exceptions,  greater frequency of cleaning
and maintenance operations  was found  necessary in areas  of higher air pollution.
Estimates of the costs of 28  household and personal chores (Table 9) show that a
family living in air containing an average of 383 micrograms per cubic meter of
suspended particulates spent from $47 to $829 per year more than a family living
in air containing an average  of 115 micrograms per cubic meter.  The third city
included in  the study had an average air quality of 178 micrograms per cubic
meter, and, as expected, the cleaning costs for its  citizens were  greater than
those for the cleaner city and less than  those for the dirtier city.  The large range
in cleaning  costs is due to the differences in standards of living.   The range is
considerably less for any one selected standard of living.  The table also shows
an increase in laundry and cleaning  costs of about 25 to 30 percent for the people
living in the dirtier atmospheres.
Visibility

    Visibility is reduced appreciably by particulate matter in the atmosphere.  At
relative humidities  of approximately 70 percent or greater,  visibility may be re-
duced primarily by  -water vapor.   At lower humidities,  the decreases in visibility
are due primarily to the effect of particulate matter in  the air.   Of major impor-
tance in the relationship between air pollution and decreased visibility are particle
sizes and numbers.   Particles having approximately the same diameter as the
•wavelength of light (0. 4 to 0. 7 micron) reduce visibility more effectively per unit
quantity than do other sizes - a fact related to light-scattering properties and total
area available to block light.  Burt, ^9  using St. Louis, Missouri,  data from 1954
through 1958, showed a semilog relationship between visibility and soiling index
at 60 percent relative humidity (Figure 5).  Day-to-day or other single-event pre-
dictions of coefficient of haze (Coh) values based on visibility, or vice versa, may
be highly inaccurate, however, since the variables concerned cause a wide scatter
of data.  ^ In part,  this lack of small-number correlation may be  due to difficul-
ties in making field measurements of visibility and particulate concentrations as
well as the influence of the variable particle densities along  any visibility measure-
22

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Figure 3.  Post Office Building during sand-blast cleaning.
                                                                  23

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                Figure 4.  Office building during sand-blast cleaning.
ment trajectory.  In spite of these difficulties, correlations based on long-term
relationships have been determined for visual range and pollutant concentrations,
both by calculations and experiment. ^° Figure 6 shows a corresponding range of
visibility for specific water droplet and iron sphere sizes at various concentrations.
This figure further emphasizes that for a fixed weight of particulates per cubic
meter of air, the point of maximum visibility impairment occurs as particle di-
ameters approximating the wavelength of light. 85

     Visibility trends  are affected not only by air pollution control efforts, but also
by general changes that occur  in the community.  An analysis made in Salt Lake
City, Utah,  utilizing number of hours with visibility of 3 miles or less  due to
smoke,  shows a sharp rise caused by rapid industrial expansion during  World War II.
An  investigation of visibility conditions in the Salt Lake Valley by the Utah State
climatologist revealed that visibility was much better during the 1930' s than during
the years after World War II.  Contrary to the experience at Salt Lake  City,  visi-
bility has improved in many cities during these years as a result of conversion
from steam  to diesel  locomotives and from coal to gas and oil for heating.   This
improvement in visibility pertains to the Study area also.  As indicated  in Table 10,
visibility has improved the most during the winter  months.  The improvement re-
flects both regulatory activity  and changes in fuel use.
24

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         Table 9.   ADDED COSTS OF LIVING IN DIRTY ENVIRONMENT
          (DOWNTOWN STEUBENVILLE,  OHIO, 383 ug/m3 VERSUS
          UNIONTOWN, PA. ,115 (.ig/m3) FOR  28 ACTIVITIES,  1960

Inside
maintenance
Outs ide
maintenance
Laundry and
cleaning
Hair and
Facial care
Totals, per family
In private homes

In apartments
(no inside painting or
decorating, no outside
maintenance)
Income
g r oupa
(1)
(2)
(1)
(2)
(1)
(2)



(1)
(2)
(1)
(2)


Per family
Do-it-
yourself
$ 29
44
21
337
27
129

9

86
519
47
158


Non-do-it-
yourself
$ 162
227
49
368
79
186

48

338
829
263
423


    (l)  Annual income under $8,000.
    (2)  Annual income $8,000 or more.
Table 10.   PERCENT FREQUENCIES OF ALL VISIBILITIES LESS THAN 7 MILES
            AT WEATHER BUREAU AIRPORT STATION (ST.  LOUIS)
Dates
(month/year)
1/35 to 12/41
1/58 to 12/60

Jan
50
34

Feb
45
18

Mar
39
28

Apr
32
10

May June
18 14
12 8

July
14
13

Aug
17
11

Sept
22
9

Oct
33
20

Nov
40
13

Dec
52
22
                                                                            25

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                                        DAT* A*C FOR FEDERAL BUILDING IN JT LOUIS
                                        WO WCRC TAKEN »T LtSS THIN 60% RELATIVE
                                         IOITY
                                        SUSPENDED PARTICULATE SAMPLING 1030 TO 1330 C5T
                                        VISIBILITY OBSERVATION  IZOO CST
                         1.0       2.0      3.0       4.0      5.0
                         SUSPENDED  PARTICULATE ,   Cohs / IpOO feel
                      Figure 5.  Soiling index versus visibility.
    Figure 7 reports the hours per month that visibility is  restricted at Lambert
Field.  These 10-year-average figures, varying from. 55 hours in July to 160 hours
in January, show that restricted visibility occurs a considerable portion of the
time as a result of air-pollution-associated conditions.

    Figure 8 is a wind  rose of the wind directions and speeds  associated with
visibility of less than 3 miles at Lambert Field.  Such visibility occurred during
11 percent of the total Lambert Field wind observations during the  1941  to  1950
period.  Low visibility  is associated primarily with low wind speed since calms
and wind speeds less than 4 miles per hour occur during 37 percent of the low
visibility observations.  Such winds are reported for only about 15 percent of the
total wind observations; therefore, about  27 percent of these low wind speeds
(0. 37 x  11/15) are associated with low visibility.   In other words,  low visibility
can be expected to occur during about  3 out of 10 such low wind speed occurrences.
Winds from the east to  southeast,  from the direction of the urban area,  account
for about 32 percent of  the  occurrences of low visibility, a higher percent than is
associated with all three other quadrants  together when allowance is made  for the
37 percent low visibility that occurs during calms.  Winds  from the east to south-
east quadrant occur only about 23  percent of the total time; thus low visibility does
 26

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 - 10
5 oe
CD
tn 06
         a =2r K PARTICLES RADIUS -r LIGHT WAVELENGTH
   001     002     004  006 OO6 Ol      02       04   06 0.8  I

                             WEIGHT OF PARTICLES, mg/m'
                                                                          6  8  10
     Figure 6.   Range of visibility as a function of particle concentration
                 by weight in the atmosphere.




1600
§ I&OO
" 1400
3
* I30O
MEAN MAXIMUM MIXING DEPTH, m«terj i
* A U o* -4 a Ifi O — h)
3OOOOOOOOO
DOOOOOOOOO
160
150
• ^ I4O

130
VISIBILITY LESS THAN 7 MILES.hr/
*J>lPV-^ai
-------
                                        N
  W
             Figure 8.  Wind rose for visibility less than 3 miles for
                        all causes,  Lambert Field,  St. Louis, Mo. ,
                        1941-1950,  percent frequency of occurrence.
occur more frequently than the general wind pattern would lead one to expect.
This can be attributed to weather patterns and air pollutants from the metropolitan
area.

    Information on visibility at the Bi-State Parks Airport south of East St.  Louis
is not available.  Since visibility is restricted by air pollutants at Lambert Field,
reduced visibility can be expected to be more frequent at the Bi-State Parks  Air-
port because of the greater frequency of low wind speeds at its location,  its prox-
imity to many major pollutant sources, and its location within the St. Louis -
Cahokia Bottom area of high  inversion frequency. ° '
 28

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    Decreased visibility levels cause a direct economic loss when airports must
be closed because of limited visibility.   Three miles is the visibility distance
needed for aircraft to land by visual approach.  Instances of air-pollutant-caused
reduction of visibility causing  disruption of air service at Lambert Field have been
reported by the Weather  Bureau Station situated there.  Reduced visibility is also
reported to have  significant effects on people who find  their view of some cherished
scene obstructed by air pollutants.

    One of the criteria for particulate goals in the Study area is  the 3-mile visi-
bility needed by aircraft  for visual landing approach.   The goal of 200 micrograms
per cubic meter not to be exceeded over 1  percent of the times would, according
to present knowledge,  correspond with the 3-mile  sight distance  when the relative
humidity is below 70 percent (See  Figure 6).
ODORS

     The effects of odors are not limited to nuisance conditions; they also include
human physiological  effects such as nausea and psychological stress. Odors can
result in economic effects because people  tend to leave odorous areas.  Odor prob-
lems in the Study area are documented in Volume IV, Odors - Results of Surveys.
Some severe odor problems and an odor episode are reported in that volume.  The
downtown area of St. Louis is subjected to a pervasive odor that permeates hotel
rooms, clothing,  and certain items  of merchandise.  Persons visiting the area
detect the odor on their clothing long after they have left the St. Louis area. Some
merchants in the  area have considered the installation of special filtering devices
to remove the odorous material from the air as it comes into the buildings.

     The report,  Public Awareness and Concern With Air Pollution in the St.
Louis Metropolitan Area, "" indicates that 53 percent of the respondents who said
there was air pollution in their neighborhoods defined air pollution as odors.
Odors were consistently the highest definitional item for air pollution.   The same
report also indicates that 46 percent of all respondents in the Study area are
bothered by air pollution.  Although the effects  of air pollution on cleanliness are
most frequently mentioned,  Table 22 of this same report indicates that  15 to 25
percent of the people feel the value of their homes is affected and 20 to  35 percent
feel that the  reputation of their residential area is damaged by air pollution.  The
report goes on to point out that those individuals having lung trouble, heart trouble,
or allergies  are more likely to indicate that they  are bothered by air pollution.

     Public awareness of odors caused by motor vehicle exhaust is reported in
Table 27 of Public Awareness and Concern With Air Pollution in the St.  Louis
Metropolitan Area. 88  This table shows that in St. Louis County, motor vehicle
exhaust is named  more frequently (approximately 25 percent) as a definitional
item for air pollution than it is in any  of the other political subdivisions  of the
Study area.


    A review of complaint records,  reported in detail in Volume I,  reveals that
objectionable odors cause more complaints than any other type of air pollution.
The good agreement among the several reports  and surveys indicates that people
notice the effect of odors more than those  of any other type of air pollution  in the
Study area.
                                                                               29

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ASTHMA - A PILOT STUDY
    There have not been any recent community-wide epidemiological studies  or
investigations relating air pollution to effects on human health in the St.  Louis
Metropolitan Area.  In 1964, however, the Public Health Service, Division of Air
Pollution,  Field Studies Branch,  initiated a pilot project study to investigate  the
occurrence of asthma attacks in the St. Louis area and their relation to  air pollu-
tion.  Because the  study is still in progress, the data relating to asthmatic attacks
presented in this report are only  a  fraction of those planned for  the above-men-
tioned study.

    The pilot project data consisted of records of asthma patients admitted or
treated  during 1961 and 1962 in the emergency rooms of the two East St. Louis
hospitals,  St. Mary's and Christian Welfare.  During the  2-year span,  739 cases
of acute asthma attacks were recorded in the emergency room logs of the two
hospitals.   These cases accounted for 2. 1  percent of the total number of emer-
gency room visits recorded.  The maximum number of  asthma patients  reported
in any 1 day during this time was six.

    The seasonal distribution of  asthmatic patient visits recorded during both 1961
and 1962, as shown in Figure 9,  indicates  a significant  increase during  the months
of September,  October, and November.  Similar autumnal increases in  the fre-
quency  of asthmatic attacks have  been observed in other cities. °9, 90  Suggestions
explaining the cause of these increases include:  onset of  cold weather with ac-
companying metabolic adjustments;  resuspension of settled allergens in the home
heating  systems at the beginning  of a heating season; increased  atmospheric stag-
nation during this period with associated increases in pollutant levels;91 and
prevalence of mold  spores,  particularly those  associated with decaying  vegetation.
                                                                                 89
   60
   4O
85
Q.
en
    20
                  r     i
                       _L
                                            1961
                             i      I	I	I	L
                                                          J_
                                                               J	L
                                                                           _L
           JAN   FEB   MAR   APR   MAY  JUNE  JULY  AUG   SEPT   OCT   NOV  DEC
                                         MONTH

      Figure 9.  Emergency room visits  by asthma patients in East St.  Louis
                 hospitals during  1961 and  1962.
 30

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AEROALLERGENS

    Pollen grains discharged into the atmosphere by weeds, grasses,  and trees
are the major cause of hay fever; certain molds, spores, and plant rusts also add
to the problem.  As measured by the American Academy of Allergy method,  25 to
30 pollen grains per cubic meter  of air are considered sufficient to cause a reac-
tion in allergic individuals. "   Estimates of the  proportion of populations affected
by hay fever in various areas of the United States vary from 2 to 10 percent. "<--94
An estimated 100, 000  people in the St. Louis Metropolitan Area suffer from  hay
fever.   Most patients have an uncomplicated type of hay fever in which the symp-
toms disappear at the  termination of the  pollen season, but sinusitis, catarrh,
bronchitis,  bronchial asthma,  and both acute and chronic dermatitis may develop
from ragweed sensitization. °^  The most important effect is the development of
bronchial asthma, which increases debilitation and decreases life span in cases
•where  sensitivity has extended to the mucous membranes of the lungs.

    Hay fever is most often seasonal in  character.  Spring hay fever (March to
June) is associated with tree pollens; summer hay fever is attributed to  grass
pollens; and autumn hay fever  is usually due to weed pollens.  August and Septem-
ber are the worst hay fever months in the St.  Louis area, with the greatest part
of the problem caused by ragweed pollen.  This  weed,  although not an aggressive
invader, rapidly takes over neglected land and land  that has been denuded or dis-
turbed, and thus  begins a succession of plant types that ultimately ends with grass.

    Each ragweed plant may produce millions of pollen grains.  Although most
pollen pollution occurs in the immediate  area  of origin, pollen grains, because of
their  small size (10 to 50 microns)  and buoyancy, may be carried long distances
by the wind. Actual clouds of pollen are known  to occur.  In  1873,  pine  pollen
from  400 miles away deposited in St.  Louis made the ground appear as though it
had been sprinkled with sulfur. 92  Pollen clouds may explain increases in hay
fever symptoms after  sunset even though ragweed plants  usually release their
pollen early in the morning.  With sunset, cooling of the  air concentrates clouds
of pollen at ground level.

    Although local ragweed control programs have been found effective in some
areas,  other ragweed  control programs have proved ineffective because  of trans-
port of pollen from nearby  areas  having no ragweed control. °4 Eradication  of
ragweed in  a limited area may not,  therefore, reduce hay fever incidence.   An
approach toward  solution of the problem  seems  to be control on a metropolitan-
wide basis through  (1) mowing,   (2) use  of soil  sterilizers,  (3) use of herbicides,
and  (4) maintenance of ground cover.

    Such a program should be accompanied by research that would evaluate  results;
determine threshold response  levels; determine the importance of various pollens,
spores, molds,  and plant rusts; and establish the degree of control needed to re-
duce hay fever incidence by known amounts.


VEGETATION DAMAGE

    The effects of air pollution have long been known to cause serious damage to
vegetation.   For  example,  agricultural losses from photochemical smog in the
belt from Washington, D. C. ,  to Boston are estimated at  some $18 million a year.
An additional annual loss of approximately $10 million  is attributed to this same
                                                                             31

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 pollutant in California, and the characteristic markings of smog have been found
 on vegetation near practically every metropolitan area in the country.  Other
 commonly occurring pollutants such as sulfur dioxide result in additional losses.
 When air  quality standards and goals are being  established, the vegetation  effects
 associated with these pollutants should be considered both from an economic and
 an aesthetic standpoint.


 Fluoride Effects on  Vegetation

     The concentration  of  gaseous fluoride required to cause  injury in susceptible
 plants is exceedingly low.   For example, gladiolus  plants incur appreciable injury
 in a few days when exposed to concentrations of 1 to 2  parts per billion. "-'  A list
 of some of the  more susceptible species is  presented in Table  11.
       Table  11.   SENSITIVITY OF SOME CULTIVATED PLANTS AND
          FARM ANIMALS TO INJURY BY HYDROGEN FLUORIDEa
Sensitive
class 1
Plantsb
Gladiolus
Apricot
Prune
Sweet potato
(some varieties)
Corn
Grapes
(some European varieties)
Peach

Buckwheat
Animals
Cattle

Intermediate
class 2

Alfalfa
Barley
Buckwheat
Carrot

Clover
Lettuce, head

Sweet potato
(some varieties)
Wheat

Swine
Sheep
Resistant
class 3

Cabbage
Cotton
Dandelion
Squash

Sweet pea






Horses
Poultry
       Data from references 95 and 96.
       Concentrations  required to cause slight injury to plants in 7 to 9 days:
         Class 1=5 ppb or less
         Class 2  = 5 to 10 ppb
         Class 3  = more than 10 ppb; higher concentrations require
                   proportionally less time.
       Rations containing fluoride concentrations that exceed the following
       values may result  in clinical fluorosis:
         Class 1  = 30 to 50 ppm
         Class 2  = 70 to 100 ppm
         Class 3  = greater than 100 ppm (poultry 1,200 to 2,400 ppm).
32

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     The principal industries or processes responsible for atmospheric fluoride
emissions are:  (1) aluminum reduction,  (2) smelting of ferrous and nonferrous
ores,  (3) ceramics, and  (4) phosphate reduction and phosphate fertilizers.  In
the aluminum industry the fluorides stem primarily from the molten cryolite bath.
In the others they arise from impurities in the raw materials.

     Exposure to fluorides causes  a characteristic tissue  collapse.  Gaseous fluo-
rides are presumed to enter the plants through openings in the leaves and, once
inside,  to be transported to the edges  of the  leaves along  with the normal flow of
water.  When the accumulation of  fluorides in the tips or  edges of the leaves exceeds
a certain concentration, the tissue collapses, dries out, and usually develops a
reddish tan or deep brown color.  Continued exposure causes the injury to progress
inward from the edges of the leaves.

     Because of the cumulative effect of gaseous fluorides, establishing air quality
goals for these  materials is difficult.  In addition,  the extremely low levels en-
countered in the atmosphere present many analytical  problems.
Fluoride Effects on Farm Animals

     Damage to  farm animals as a result of atmospheric fluoride pollution involves
primarily those animals that graze on contaminated forage.  This contamination
may result from absorption of gaseous fluorides by the forage,  deposition of
particulate fluorides on the leaves, and/or absorption from the  soil.  Fluoride
uptake from  the soil by vegetation, however,  is generally slight even in the pres-
ence of high  concentrations because fluorides are relatively insoluble. '-"

     The effects of fluorides on farm animals are cumulative.  Cattle are the most
susceptible,  with sheep,  swine, horses,  and chickens decreasingly susceptible in
the order named.  In animals with immature teeth dental mottling is an early sign
of fluorosis.   If the fluoride intake is high, an abnormal growth in the bones of
the legs, jaw, and ribs may occur.  Advanced cases of fluorosis are characterized
by lameness, weight loss, lowered fertility, bone lesions, retarded growth, and
reduced milk production. ' '

     Fluorosis may be prevented by reducing the fluoride in the  daily total ration
of cattle to 30 to 50 ppm and that of sheep and swine to 50 to 70  ppm. 96 Since the
quantities of  fluoride present in the rations depend on the ambient air concentra-
tions,  any air quality goals established for fluorides should be low enough to en-
sure the production of acceptable forage crops.
Sulfur Dioxide

     Because of the severe damage it causes in certain areas and its widespread
distribution, sulfur dioxide has been studied more intensively than any other
single pollutant.  Large quantities of this material are released  by the combus-
tion of fossil fuels (especially high-sulfur  coal, and to a lesser but still significant
degree from fuel oils).  The smelting of sulfide ores and the manufacture of sulfuric
acid also produce large quantities of this gas,  which is  emitted to the atmosphere,
unless proper control equipment  are employed.
                                                                               33

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    Sulfur dioxide injury to vegetation can be divided into two distinct types, acute
and chronic.  Acute injuries are characterized by the killing  of sharply defined
marginal  or interveinal areas  of the leaves.  Following exposure,  the leaves take
on a dull water-soaked appearance.  Subsequently, they dry up  and usually bleach
to an  ivory  color; some,  however, turn brown or reddish brown.  Chronic injury
does not produce the leaf collapse observed in connection with acute injury, but
bleaching  occurs; and microscopic examination reveals cellular destruction.
Injured areas of the leaves never recover, but the uninjured areas quickly and
fully regain their functions; and new leaves develop normally.

    Much work has  been  done  on  the effects of sulfur dioxide  on crops  of economic
significance,  and from these investigations formulas have been developed to pre-
dict yield losses  resulting from exposure to this pollutant.  These formulas take
into account both concentration and length of exposure. ''  The  results  of investi-
gations such as these together with the establishment of sulfur  dioxide  threshold
response  levels for  various species  of plants make it possible to establish air
quality goals for  such plants with a reasonable degree of confidence.
Photochemical Smog

    Injury to leafy vegetables and field crops from photochemical smog was first
documented in  1944 in the Dominquez area of Los Angeles.  This injury is now
known to occur throughout the United States in most metropolitan areas. '  Symp-
toms  of this type of plant injury include silvering, glazing, bronzing, and some-
times necrosis of the lower leaf surface.   The under-surface glaze on young
leaves is only one aspect of a complex of  symptoms now recognized to be  associated
with photochemical smog.  Leaf injury has been associated with periods of high air
pollutant concentrations when reduced visibility and human distress are reported' '•
and particularly with elevated oxidant measurements (levels above 0. 05 ppm may
mark tobacco leaves). °° In 1952 it was demonstrated that typical "oxidant" damage
•was produced by complex chemical  compounds resulting from the reactions of
nitrogen dioxide,  olefins, and air in the presence of ultraviolet light. "   Within
the photochemical complex are a number  of known plant toxicants such as ozone
(although ozone injury typically develops on the upper  leaf surface   ),  peroxyacetyl-
nitrate, * and the oxides of nitrogen. "°

    Serious damage occurs to ornamental shrubs and  plants and to leafy vegetable
and forage crops such as alfalfa,  spinach, parsley,  and celery.  Exposure to
photochemical  pollution reduces  tomato yields, retards cereal growth, injures
cotton foliage,  reduces alfalfa hay protein content,  and reduces plant growth rates.
 Ethylene

     Ethylene occurs in the exhaust gases from combustion processes, including
 those of automobiles.  Ethylene damage to a few highly sensitive plants, most
 notably to orchids,  has been observed in many areas of the country.  Exposure to
 concentrations as low as 2 parts per billion for 24 hours results  in premature
 aging of certain portions of the orchid bloom.  Such damage renders these flowers
 almost worthless on the commercial market.
 34

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Miscellaneous Pollutants

     Numerous other pollutants may cause damage to vegetation, but the concentra-
tions of these materials normally found in the atmosphere are generally not suffi-
cient to be of significance.  The rare occasions when they do occur  in significant
amounts are usually the result of a spill of some type - industrial or other.  Among
the contaminants in this category are chlorine,  hydrogen chloride, ammonia,  hydro-
gen sulfide,  and formaldehyde.

VEGETATION DAMAGE IN STUDY AREA

Historical Development

     Among the early published reports concerning the  damaging effect of air pollu-
tion on vegetation in the St.  Louis area were those that appeared in  the Missouri
Botanical Garden  Bulletin  during the  1910's, 20's, and 30's. 10°  These articles
described severe  injury resulting from concentrations  of smoke, soot, and sulfur
dioxide in the atmosphere.  Eighteen varieties of plants were listed as being seri-
ously affected by atmospheric pollution in the November 1917 issue  of the Missouri
Botanical Garden  Bulletin.

     In June  1924, the Garden published a growth zone map, which showed the city
divided into three zones having different levels  of air pollution.   A short list pub-
lished with this map indicated those plant species most  likely to survive in the
general areas  of each of the three zones.     A radial  gradient  of diminishing effect
was easily discernible from the center of the city to the surrounding country.
Kentucky bluegrass, American red cedar, and the lily  were among the plants that
could not survive  in the more highly polluted areas.  Because of this situation the
Garden found it necessary to grow all  of its display plants at Gray Summit growing
station some 30 miles southwest of the city.

     Following the enactment of the smoke control ordinance, conditions improved,
and by 1945 many species  of  vegetation could be grown in the city again.

     Since the end of World War II the metropolitan area has expanded in size and
increased in complexity,  and the variety of products manufactured has also ex-
panded.   This growth has  caused new pollutants to be released to the atmosphere
and has increased the levels  of many of the existing pollutants.  The principal
gaseous pollutants of importance in vegetation damage  are ethylene, fluorides,
sulfur oxides,  hydrogen sulfide, hydrocarbons,  nitrogen oxides,  and photochemical
reaction products  including oxidants such as peroxyacetylnitrate  (PAN).  The in-
creasing  concentrations of these various substances has once again  resulted in in-
creased deleterious effects to vegetation.  As evidence, Dr. Edgar Anderson of  the
Missouri  Botanical Garden has reported that attempts to grow Korean lespedeza
(a plant used for ground cover on right-of-ways) in  and  near the center of the
metropolitan area have been  unsuccessful and attributes the problem to air pollution.

     Over the past several years repeated instances of  orchid damage  have been
observed  by Mr.  Robert J. Gillespie,  Professor of Biology, Meramec Community
College.  Disfigurement of the flower's lower leaf division occurs most frequently
in November and December,  especially during  or immediately after periods of
heavy fog and smoke.  The condition is seldom observed by growers in the rural
areas away from the city.
                                                                               35

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     E.  P. Hume,  a horticulturalist  from Southern Illinois University, reported in
June 1966 that over the past 3 years  he had noted severe damage  from air pollution
to ornamental  plants in the East St.  Louis area.  Plants most affected are the
Chinese elm, tree of heaven, empress  tree, and all the members of the legume
family that were observed.

     The injuries  sustained were identical to injuries caused by certain growth-regu-
lating hormones when used in toxic quantities.  The  causal factor attacks the terminal
growth,  often the tip leaf on a branch, or the top leaflets  of a compound  leaf.  Grow-
ing points may be injured or killed,  and similar damage to side branches, starting from
below,  may also take place.  Repeated  injury usually results in plant death.

     Some sulfur dioxide damage was observed and reported  in the Interstate Air
Pollution Study Phase I Report.  Other  air-pollution vegetation damage was  reported,
but was not verified by the project staff.


Tobacco Plant Ox id ant Study

     A study to define plant injury due to oxidant exposure in the  St.  Louis Metro-
politan  Area was  conducted from April  29 to October 15,  1965.  This study showed
that oxidant, presumably of photochemical origin, occurs in  the St. Louis area in
sufficient concentrations  to produce  markings  on sensitive vegetation (Figure  10).
                     Figure 10.  Markings on sensitive vegetation.
 36

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Observations were made at 14 sites (Figure 11).  Tobacco plant oxidarit damage
occurred most frequently at the  three central metropolitan sites (those within East
St.  Louis and St.  Louis cities),  probably because of the dense traffic in these areas.
Leaf damage was  reported at each  of these three sites on 20 or more occasions.
Since all sites  reported damage  on at least two occasions, damaging oxidant con-
centrations occur throughout the Study area (Figure  11).

    Observed leaf damage is apparently  associated  with sudden increases in oxidant
levels measured by the USPHS Continuous Air Monitoring Program station the day
         400- 410  420  430  T40  450   460   470   480   490   500*"' 510  520  530  540
                                                                      550
 Figure 11.  Locations  of tobacco leaf damage  observations.   Underlined figures
             indicate 4- or  5-month observation period, other figures 2-month
             observation period.  Numbers  report number of times leaf damage
             occurred.
                                                                               37

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before the observable damage occurs.  Table 12 shows that the sum of total hourly
daytime (8 a.m. to 4 p.m. Central Standard Time) averages of oxidant concentra-
tions increased significantly during the day before observed damage.  This sum for


    Table 12.   OBSERVED DAMAGE VERSUS CONTINUOUS AIR MONITORING
       PROGRAM OXIDANT MEASUREMENTS IN MAY AND AUGUST 1965a
Levels of oxidant - sum of
hourly daytime averages, ppm
(1)
Date of
observed
damage
May 2
5
12
14
19
22
25
31

June 3
10
13
18
24
28

July 5
11
18
25
29

Aug 10
16
20
24
30

(2)
2 days
before (1)
b
X
25
30
40
X
X
30
40
May avg 33
20
25
40
45
30
50
June avg 35
35
25
30
40
45
July avg 35
15
35
X
25
20
Aug avg 24
(3)
1 day
before (1)
35
30
55
45
X
40
20
50
39
35
90
50
55
50
25
51
70
30
40
X
25
41
25
55
X
50
25
39
(4)
day
of (1)
X
25
40
X
X
40
15
35
31
55
80
40
50
30
X
51
45
40
50
45
30
42
35
45
X
30
30
35
Change in sum of hourly
daytime averages, ppm
(3) to (2)
X
5
25
5
X
X
-10
10
7
15
65
10
10
20
-25
16
35
5
10
X
-15
9
10
20
X
25
5
15
(4) to (3)
X
-5
-15

X
0
-5
-15
-8
20
-10
-10
-5
-20
X
-5
-25
10
10
X
5
0
10
-10
X
-20
5
-4
   The average of the sums of daily hourly averages (8 a. m.  to 4 p. m.  Central
   Standard Time) was 32 ppm for May, 42 for June, 37 for July, and 32 for August.
   x indicates no data.
  38

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the day before observed damage was. also significantly greater than the.monthly
average in most cases.  Decreases in the sum generally occurred the day of and
the second day before the observed damage,  with the sum of the second day before
usually being considerably lower than the sum of the day of the observed damage.

    Several cooperating growers noted the appearance  of similar injury patterns
on other greenhouse crops simultaneously with the injury of the sensitive  tobacco
plants.  Especially noted as having developed typical oxidant damage  lesions were
geranium,  gloxinia, begonia, and periwinkle plants.


MATERIALS DETERIORATION

    During the Study several activities were conducted to determine the effects of
air pollution on steel plates,  cotton fabrics,  and nylon fabrics.  These studies
generally showed that the severity of effects  coincided with the sulfur oxides and par-
ticulate air pollutant distribution pattern over the  metropolitan area.

Steel Corrosion Study - 3-Month

     Figure 12 shows the geographical distribution of steel panel exposure sites
used for a study from December 1964 through February  1965 and the  resulting
3-month corrosion losses.   Comparison of these losses with high sulfur oxides
and particulate air pollutant levels shows that increased corrosion generally
occurred  in the areas with higher  pollutant levels.  Comparison between the corro-
sion level  at a suburban site  west  of the  metropolitan area and that in the highest
pollutant area showed an increase of approximately 240 percent.  Figures 13 and 14
show that statistical correlations of corrosion with sulfur dioxide levels and sulfa-
tion levels -were quite high.


Steel Corrosion Study - 16-Month

     Figure 15 shows the locations of  33  of the 35  exposure sites used for this study
and their  corresponding 2- and 16-month •weight losses due to corrosion.   For the
16-month period,  above-average corrosion  occurred primarily in south St. Louis
and in Illinois, along the Mississippi  River  from Alton to below East  St. Louis.
Little difference  was noted between St.  Louis County and St. Louis City residential-
commercial areas by the end of the 16-month exposure period.

     A significant  relationship was found between corresponding sulfation  rates and
losses from corrosion (see Figure 16).   Dustfall data compared in  a  similar manner
did not  show a similar correlation.  The conclusion is that gaseous pollutants cause
more damage than particulate pollutants to metals in the Study area.

     Because of the  "protective" nature  of rust coatings,  atmospheric corrosion
rates generally decrease with the  length of exposure time. When plotted  on graph
paper,  these rates assume a form between parabolic and logarithmic functions.
The maximum protection offered by the rust coating  takes several years or more
to develop fully.   During this period,  and especially in the early stages, seasonal,
meteorological, and air pollutant variations  markedly influence corrosion rates.
As exposure time increases, the influence of these environmental factors becomes
less and less, as  demonstrated graphically by Figure 17, which shows the composite
curves  for time versus weight loss for the St.  Louis County residential-commercial
                                                                              39

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    10.040 ppm 24-hr S02 geometric  mean
    12.00 mg 303 100 cm2'day  sulfation geometric mean
sssssSl.40 Cohs 1,000 lineal  ft AISI sampler geometric mean
    '        1
    :150 Mg/mJ High-Volume  sampler geometric mean
        i  /  trmn
                                                                               780

                                                                               770

                                                                               700

                                                                               750

                                                                               740

                                                                               730

                                                                               720

                                                                               710

                                                                               700

                                                                               690

                                                                               680

                                                                               670
                                                      000
440    450     460     470    480   490    500"°   510    520    530    540    550
                                                                              660
  Figure 12.   Three-month mean corrosion losses (Dec.  1964 -  Feb. 1965) and
               high mean pollution levels  (July 1963  - July 1964).
sites (9 sites east of Bypass 66 and 67 Highway) and for the St.  Louis City residential-
commercial sites  (9 sites).  The corrosion rates for the two types of sites are signi-
ficantly different (at the 99 percent confidence level)  during the early stages of corro-
sion, but at the end  of 16 months, the protective coatings provide equal protection
against the pollutants at both types of sites.   This relationship is  not true for sites
in the higher pollution areas.  The composite high-pollution (industrial) curve shows
a higher initial weight loss from corrosion and a consistently greater corrosion rate
than that determined for the residential-commercial  areas.  After 16 months, panels
exposed in the industrial areas had lost  35 percent more weight than those exposed  in
the residential-commercial areas.
 40

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       14.0
       12.0
     in
     E
     o
       10.0
     tf)
     CO
     o
     o
     01
        8.0
        6.0
        2.0
                     I     I    '
	 O   2 - hr MEASUREMENTS
	X   24-hr MEASUREMENTS
0.02
0.04
0.06
0.08
                   0.10
                                                                 0.12
O.I4
                       MEAN  SULFUR DIOXIDE  CONCENTRATION, ppm
          Figure 13.  Relationship between corrosion of mild steel and
                      corresponding mean sulfur dioxide concentration
                      for a 3-month exposure at 1 0 metropolitan St.  Louis
                      sites (Dec.  1964 - Feb. 1965).
Effects on Exposed Nylon Fabric

     As part of the Interstate Air  Pollution Study effects-measurement program,
nylon panels were mounted on small wooden frames and exposed.  The nylon cloth
panels consisted of Dupont* nylon 66, woven into a fine 210-mesh material of a type
ordinarily used as a filter material.  The panels were set out in mid-June of 1963
and were  observed monthly.  After 2 months of exposure, the panels exhibited
varying degrees of dirtiness, a few runners had developed,  and chemical (rust-
like) stains were noted.  After 4 months,  runners had developed on five  of the panels.
At the end of 8 months, fine pinhead-size perforations began to appear in the panel
 :=Mention of company or product names does not constitute endorsement by the Public
  Health Service or the Department of Health, Education,  and Welfare.
                                                                                41

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           14.0
                             2345
                      MEAN  SULFATION RATE , mg S03/I00 cmVday

           Figure 14.  Relationship bet-ween corrosion of mild steel and
                       corresponding monthly mean sulfation rate for a
                       3-month exposure at 10 metropolitan St. Louis
                       sites (Dec.  1964 -  Feb. 1965).

located at site coordinate*   472-680 (see map  Figure 15).  After  9 months, fine
perforations had appeared in the panel at site 499-700, and had extensively covered
the panel at site 472-680.  The latter was  estimated to have approximately five holes
per square inch.  The condition of three of the panels after  11 months is shown in
Figure 18.  During this  exposure period, all the panels developed progressively
dirtier surfaces; those in the East St. Louis and south  St. Louis  City areas became
opaque.  Panels in the Brentwood and Wood River areas remained essentially trans-
parent and relatively clean.

    Observations made  after heavy rainfall during the  fifth month of exposure
indicated that the rain tended to clean the nylon quite well, although in some instances
the panels  remained dark gray and almost  opaque.   The texture of all exposed  panels
changed visibly,  and the exposed fabric lost strength probably because  of chemical
*Site coordinates refer to the cell to the north and east of the designated point.
 42

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      AND 16- MONTH WEIGHT LOSS CORROSION
    VALUES INDICATED BY EACH SITE, grams
    PER 4~ BY 6- INCH PANEL
400°°° 410  420  430  440   450  460  470  480   490 500°°° 510  520   530  540   550
     figure  15.  Corrosion exposure sites  in St. Louis - East St. Louis area.
                 Shaded portion of map indicates area having above-average
                 corrosion of steel panels during 16-month exposure period.
                                                                                    43

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          12
          10
       cc
       iu  c
       Q.  6
       i
                           000
                        I
                                               12-MONTH MEAN SULFATION RATE
            0
                                                                       2.5
                        0.5         1.0          1.5         2.O
                        MEAN SULFATION RATE, mg  S03/IOO cm2/day
          Figure 16.   Relationship between corrosion of mild steel panels
                       and corresponding mean sulfation rate measured at
                       selected sites in St. Lcnus - East  St. Louis Metro-
                       politan Area from December 1964 through February
                       1965.

decomposition caused by ultraviolet radiation  and  air pollution.  Unexposed fabric
could not be torn by hand, but all exposed panels could be easily torn by  hand.   Panels
exposed in  areas of highest air pollution were found to be  the weakest.

     Nylon hose  could have a similar  response to that  observed in these studies.   The
fabric used in the study was much stronger than material  used for hose.

Effects on Exposed Cotton Fabrics

     During the period June 1963 to June  1964,  cotton  fabrics were exposed at seven
different sites in the Study area.  The objectives of the study were to determine
whether various  levels of air pollution significantly damaged outdoor-exposed cotton
44

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      10
E
a
» 6
tff
(f)
O
   I  4
                   INDUSTRIAL AREAS
                   (9 SITES- NO. 498-704 OMITTED)
                                                            COMMERCIAL AREAS
                                                            (9 SITES)
                                                           ST. LOUIS COUNTY
                                                        RESIDENTIAL-COMMERCIAL
                                                          AREAS (9 SITES)
        0
                                                          8
16
                                EXPOSURE,  months
            Figure  17.
                     Mean corrosion rate of mild steel panels versus
                     exposure periods for specified types  of land use
                     from April 1963 through July  1964.
fabrics beyond the damage normally caused by photolysis and biological effects.  Two
fabrics, a print cloth and an army duck cloth, were used.   After exposure periods of
1 to 12. months, chemical and physical  tests were made on samples of the cloths.

     Figure 19 shows the loss in breaking strength with exposure time. Table 13
shows the sulfation,  dustfall, and suspended particulates at the sites  plotted in
Figure 19.  Figure 20  shows that there is a close relationship bet-ween breaking
strength and fluidity  (a chemical  physical test of material degradation   '     ).
(Fluidity  is expressed  in rhes, a unit equal to the reciprocal of 1  poise,  which is a
measure  of viscosity. )  Fabric test results were compared with the air pollution
levels at  the points where these fabrics were exposed.  The rates  of degradation of
the cotton fabrics increased  as air pollution levels  increased for dustfall,  suspended
particulate, and sulfation.

     Of these three, degradation was most directly  related to sulfation levels. Visual
examination,  comparison of breaking strength values for  exposed print cloth and
duck samples, and the correlation of fluidity versus breaking strength (Figure 20)
all indicated that degradation was not caused by  biological factors, but by chemical
action resulting from exposure to ultraviolet radiation and air pollution.
                                                                                45

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                  AERO - CHARTS
                    (472 - 680)
  GRANITE  CITY
    (505- 740)
              MUNICIPAL  COURTHOUSE
                    C49Q- 713 J
UNEXPOSEO FABRIC
                 Figure 18.  Effects on nylon fabric exposed to ambient
                            air (June 1963 - April 1964).

EFFECTS OF AIR  POLLUTION ON PROPERTY VALUES

    Air pollution is generally assumed to depress property values; however,  very
few attempts have been made to measure this relationship quantitatively.  As yet
no commonly accepted hypothesis exists for  the mathematical  form that  this rela-
tionship might take.  Dr. Ronald G.  Ridker of  Washington University started  work
toward defining  this mathematical  relationship in 1963.  Dr. Ridker used Interstate
Air Pollution Study air-quality data and census tracts in which s ingle-family housing
units  comprised at least 60 percent of the total housing and the population  density
\vas at least one person per  acre.  He then applied the following variables  to his
census tract population sample: (1) air pollution as measured by sulfation,  (2) time
46

-------
     100
Q
UJ
Z
UJ
cc
UJ
on
i-
oo
o
z
Ul
CC
CD
      80
   c  60
   o
   H-
   o

   c 40
   0>
      20
       0
                        	PRINT CLOTH
                        	 DUCK CLOTH
         -   \
              \
               \
                 \
                   \
                    \
                                            ^COMPLETE 	
                                     N,   ^ DEGRADATION
                                                              \
        0
                              468
                                EXPOSURE,  months
10
12
          Figure 19.  Percent of fabric breaking strength retained versus
                     exposure time.
                   Table 13.  MEAN POLLUTANT LEVELS
Site grid
coordinates
449-719, residential,
St. Louis County
505-740, industrial,
Illinois
472-680, industrial,
St. Louis
Sulfation, a mg SO^/
100 cm2/day
0. 56

2.9

5. 5

Dustfall, a tons/
mi /mo
14

67

61

Suspended par-
ticulate.b (ig/m^
84

246

303

 Arithmetic mean, March 1963 through February 1964.
^Arithmetic mean, July 1963 through June 1964.
                                                                          47

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          100
         -  80
        i
        LJ
        cr
        in
        2
        cr
        CD
60
           20
              0
             10
 20          30
FLUIDITY, rhes
40
50
               Figure 20.  Loss in breaking strength as a function of
                           fluidity for cotton duck cloth exposed from
                           June 1963 to June 1964 (Results  are plotted
                           for all seven stations).
from the central business district as measured by the average time during rush hours
hours required by an express bus to reach the central business district, (3) accessi-
bility to highways as measured by the census tract touching a highway or a major
thoroughfare,  (4) shopping area accessibility as  measured by a shopping area in the
census  tract,  (5) industrial area accessibility as measured by the inclusion of an
industrial area in the census tract,  (6) school quality,  (7) crime rates, and  (8) state
location - Illinois or Missouri. 1^4 Shopping area location, industrial area location,
and crime rates  proved to be unimportant  in explaining variations in property values.

     The remaining  variables, however, explained practically all the variation in
these property values.  Air pollution as measured by sulfation was iound to be
significant in the overall explanation of property value variation; in fact, it was
shown to be almost  as  important as highways and more important than state
location,  time from the central  business district, or school quality.  Partial  re-
gression coefficients calculated for  sulfation indicated that if sulfation levels  to
which any single-family dwelling unit is exposed were to drop 0. 25 milligram SOj
per  100 square centimeters per day, the value of that property could be expected to
48

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rise by at least $83,  and possibly by as much as $245.   If no off setting'market ad-
justments are assumed to occur, this conclusion can be generalized to include all
house's in the St. Louis Metropolitan Area.  If,  therefore,  sulfation levels -were
reduced by 0. 25 milligram SO^ per 100 square centimeters per day,  but with no
level below 0. 49,  the estimated  property value increase in Dr. Ridker's sample
area \vould range from $24 million to $72 million.  If the sulfation levels were
brought to a uniform 0. 49 milligram per 100 square centimeters  per day over the
sample area,  the estimated property value increase would range  from $74 million
to $219 million.  If this  analysis were applied to the entire St. Louis standard
metropolitan statistical  area,  the increase in value at $83 to $245 per single dwell-
ing unit per 0.25 milligram SO^  per 100 square centimeters per  day reduction -would
range from $28 million to $83  million.  If a uniform sulfation level of 0.49 milli-
gram SOj per 100 square centimeters per day were reached, the change in value
would range from $85 million to  $251  million.  It seems doubtful  that these in-
creases in value  could be obtained because the greater availability of pollution-free
property would more than satisfy the demand.  Although Dr.  Ridker does  not  feel
that his findings report every aspect of  property value change, he does feel that  they
point to air pollution as  an  important contributing factor in depressing property
values.

     An analysis of an air pollution problem area adds further weight to these findings.
In south St. Louis, Dr.  Ridker selected an area in which an air pollution source
caused a major complaint.  This complaint,  in  1962, in a quiet middle-class  neigh-
borhood,  concerned offensive gases and fumes.  It apparently was considered to be
a serious problem because petitions against it were signed by 270 residents.
     To assess the effect that air pollution had on property values in this neighbor-
hood,  apart from the changes in a general market condition,  a study-control area
as similar to the affected area  as possible was selected.  A comparison was made
between recorded sales of property in the two areas  for the years 1957 through
July 1964.  (See  Figure 21).  The control area, over this period,  exhibited a slight
upward trend in property values.  During the period  from 1957 to 1962 the property
values in the  south section of St.  Louis remained stable; however, after 1962, when
this  area was subjected to increase air pollution, the polluted area showed a marked
depression in property values.   By taking the 1964 difference between actual property
values and property values estimated by using control-area property indexes,  an
individual property value loss of  $400  to $1000 each was  estimated by Dr.  Ridker.
For  the area  under study, this  amounts to a total property value  loss of $306, 000
to $765, 000.  The  study is being  continued (June 1966)  to add sales data beyond
July 1964; these  estimates are, therefore,  provisional.
Economic Effects of Open Burning

     A report by the St.  Louis County Health Department in January 1966    in-
dicates the cost of open  burning.  The report results from a questionnaire survey
of 52 fire departments.  In 1965,  10,993 fire calls were  received in the  county.
Of these, 1,203, or 11 percent,  resulted from some type of open burning.  Based
on cost information from 20 percent of the fire departments,  these fires cost the
fire  departments about $83, 000 and the property owners  $473, 000,  a total of
$556,000 in  10 months of 1965.  Regulation of open burning was  reported to be
effective in eliminating fire  calls for this  type of fire.
                                                                               49

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     1957       1956       1959       I960       1961
                                        YEAR
1962
1963
1964
             Figure Zl.  Comparison of property values in control area
                         and area affected by offensive odors in 1962.
PUBLIC OPINION SURVEY  - EFFECTS REPORTED


     The effects of air pollution are  not wholly measured by physical and  bio-
logical means.  The  air  quality,  likewise,  is  only  partly defined by physical
measurements  such as those  reported in Volume in  of  this report.   The
opinion  surveys reported in Volume  VII reflect  total air pollution  effects as
respondents sensed them.  The surveys included responses to some air pollu-
tion effects not measured  by  physical and chemical means  such  as "bother, "
dirtiness,   and odors  and eye, nose,  and throat irritation.  They excluded
some  air  pollution effects  because they are not detected by the  respondents'
sense of smell,  sight, or  touch.   Volume VII reports  both the  magnitude  and
distribution of effects  in the  air  pollution basin.  To  a  considerable extent the
opinion  survey results are used here  to  substantiate air quality goals selected
on the basis of chemical,  physical,  and  biological  measurements.


     The opinion survey revealed that 90 percent of the respondents were satisfied
with air quality, 43 percent reported  some bother with air pollution,  and 35 percent
 50

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reported air pollution existing  in their neighborhood -when the respective pollutants
were at the following levels:

     1.   Suspended particulates (high-volume  sampler)
         -  geometric mean, 78 to 85 ug/m
         -  99th percentile, 240 to 268
         Soiling index (AISI strip filter paper sampler)
         - geometric mean, 0. 37 to 0.45 Coh/1, 000 lineal ft
         - 99th percentile, 2.  8 to 4. 0 Cohs/ 1 , 000 lineal ft

         Sull'ation (lead  peroxide candle method)
         - geometric mean, 0. 42 to 0. 73 mg SOj/100  cm  /day
         - 99th percentile,  1.  9 to 2. 4 mg SC>3/100 cm2/day.
     More people were found to be bothered by air pollution than recognized air
 pollution in their neighborhoods.   This  seems logical in a suburban way of life in
 which many people live away from highly polluted industrial and central city areas,
 but work in or travel through these high-pollution areas and,  consequently, are
 bothered by the high pollutior conceatrations in such areas.

     In general,  there is agreement between goals selected  by means of public
 opinion surveys  and those based on physical,  chemical, and biological measure-
 ments .
 HEALTH EFFECTS - A SUMMARY STATEMENT

     A summary statement comes from an address made in 1965 in Los Angeles by
 E.  T. Blomqmst,  M.D. , Assistant Chief, Public Health Service, Division of Air
 Pollution:

     "The fact that air pollution in high concentration can cause widespread illness
 and death was amply demonstrated by tragic episodes in the Meuse Valley of Belgium,
 in London,  and in Donora, Pennsylvania.  These episodes  were recognized and
 documented at the time they occurred,  but epidemiologic studies revealed that
 similar  episodes could occur and, in fact, had occurred, without being noticed. For
 example, it v/as found, 9 years after the fact,  that some 200 excess  deaths occurred
 in New York City in 1953 during a period of air stagnation.

     "In  the  long run, however, there is even greater  significance in the health haz-
 ards associated with levels of air pollution to which millions of urban dwellers are
 exposed almost  constantly.   Knowledge of this  aspect  of the problem has been
 broadened and amplified through epidemiological and statistical as -well as labora-
 tory and chemical studies.   These investigations have covered a broad area ranging
 from correlations between urban air pollution and the incidence and mortality rates
 for various  respiratory diseases  to the effects produced by exposure of animals and,
 111 some cases, human beings, to controlled  amounts of specific air pollutants.

     "The results of these studies can be summed up by saying that air pollution is
 associated  with  the occurrence and  worsening of many serious respiratory diseases,
 including asthma,  chronic bronchitis,  lung cancer,  and emphysema."
                                                                                51

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     The foregoing remarks by Dr. Blomquist summarize health effects from an
epidemiological point of view.  The following quotation from the February  1966
Scientific American article "The Lung"-'"" summarizes the same subject in this way:

     "Other air pollutants  - irritant gases,  vapors, fumes,  smokes,  aerosols, or
small particles  -  may give rise to a similar bronchial constriction.  It is one of the
ironies of man1 s urban way of life that exposure to the pollutants that produce severe
and repeated bronchial constriction results in excessive secretion of mucus,  a re-
duction in ciliary  activity,  obstruction  of the  fine air paths, and finally cell damage.
These  circumstances enable bacteria to penetrate to the alveoli and remain there
long enough to initiate infectious lung disease.  They are probably a factor in the
development of such  tracheobronchial diseases as chronic bronchitis and lung
cancer.   Thus man's  advances in material culture increasingly threaten the air
pump that helped to make his evolutionary success possible. "
ECONOMIC EFFECTS - A SUMMARY STATEMENT

     A 1958 estimate of economic losses due to air pollution in the United States
was  $65 per capita per year. ^^  Applied to the Nation, this amounted to $11 billion
for 1964, or $130 million  per year for the Interstate Air Pollution Study area.

     A number of economic effects were studied,  observed, or reported in the
Study area.  Visibility was found to be reduced sufficiently by air pollution to
affect airport operation and to obscure  valuable views  in certain parts  of the Study
area.  Vegetation damage of several types was reported or found by observation
and study.  This damage was  of the ozone  or photochemical-smog-associated type,
the sulfur dioxide type, as well as types of damage caused by other pollutants.
Materials deterioration associated with air pollution was found by studies of steel
corrosion, nylon fabric, and cotton fabric.  Soiling effects occur and -were mea-
sured by determining the  soiling characteristics of the air.  Property values were
found to be decreased by $400 to $1, 000 for  each  single residence in an air-pollu-
tion-problem  area.   Single-dwelling residences -were found to have a potential in-
crease  in value of $83  to $245 each for  each 0.25 mg SO, per 100 square centimeters
per day decrease in sulfation.

     The $130 million per  year estimate of the cost of air pollution in the Study area
is  logical when the great variety of effects is considered.  It would also seem that
the air-pollution-related economic effects  are basically matters  of equity.  This
equity involves the importance of the purpose for which the air is being used by
those who claim the air.  This is illustrated by two photographs,  Figures 22 and
23, taken in the central part of the Study area.  Figure 22  shows the air  being used
for dilution of air pollutants from  a number  of sources located near each other.
The  second photograph, of the same area and air mass as  the first,  shows the
St. Louis central city district as it is now being rebuilt.   The new structures,
changing the character of  the area, represent  an  investment of at least $200 mi-
lion.  Possibly  of more importance than the dollar amount of the  change  is the
major change in functions  and purpose of the entire metropolitan  area illustrated
by the central city district photograph.   There  is little doubt that the two photo-
graphs  show the same  air  mass being used for  conflicting  purposes. The back-
                                                 1 08
ground  of this conflict  is amply stated by Bollens,    "Growing up in the age coal
and steam,  the  older portions of St. Louis City reflect the high premium placed
on land near transportation facilities.   Until recently,  the  most important facili-
52

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    Figure 22.  Air pollution in central city area.
Figure 23.  Urban renewal in central city area.
                                                              53

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ties were the river and the railroads.  Location of industry in such sections
brought about the construction nearby of the extensive,  crowded residential districts
to house the labor force.  Another heritage from the age of coal and steam is the
thick film, of grime covering many of the aged buildings in the downtown com-
mercial center.   This  discoloration creates the  impression that the older part
of the City is even older  than it is;  only during the past two decades has the
municipal government  been able to  suppress the use of fuels that once gave down-
town St. Louis a dusky, evening aspect at noontime. "

     Future air use, including resolution of air-use conflicts  typified by the two
photographs,  have not  been decided for the  Study area.  To a  considerable extent
the Interstate Air Pollution Study has been  dedicated to providing background in-
formation that will help others reach decisions concerning this important matter.
In planning  for the solution of air pollution  problems having economic effects
relating to potentially conflicting air uses,  information and data will need to be
obtained and analyzed on a continuing basis.  These program activities must in-
clude urban planning as well as regulatory  activities.  The resulting bases for
decision will need be acted upon through a suitable decision-making and program-
implementation process covering the entire air pollution basin as a unit.
 54

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            U.S.  Environmental  Protection Agency
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