xvEPA
              United States
              Environmental
              Protection
              Agency
              Office of Air Quality
              Planning and Standards
              Technical Support Division
              Research Triangle Park NC 27711
EPA-450/4-91-003
February 1991
              AIR
National Air Quality and
Emissions Trends Report,
1989
  Ozone

  Ozone - Carbon Monoxide
           Carbon Monoxide      |f] PMio

           Ozone - PMio        M Carbon Monoxide -  PMio

           Ozone - Carbon Monoxide - PMio
             Areas Not Meeting Ozone, CO or PM10 NAAQS

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                                   EPA-450/4-91-003
National Air Quality and
Emissions Trends Report,
              1989

       Technical Support Division
 U.S. ENVIRONMENTAL PROTECTION AGENCY
          Office of Air and Radiation
      Office of Air Quality Planning and Standards
     Research Triangle Park, North Carolina 27711
             February 1991

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                                  DISCLAIMER
   This report has been reviewed by the Office of Air Quality Planning and Standards,
U. S. Environmental Protection Agency, and has been approved for publication.
Mention of trade names or commercial products is not intended to constitute
endorsement or recommendation for use.
About the Cover:   The map displays ihose counties within the contiguous U.S. that contain areas not
                meeting ozone, carbon monoxide and/or paniculate matter National Ambient Air
                Quality Standards (NAAQS). See Section 4 for information on these areas.
                                        11

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                                  PREFACE
   This is the seventeenth annual report of air pollution trends issued by the U. S.
Environmental Protection Agency.  The report is prepared by the Technical Support
Division and is directed toward both the technical air pollution audience and the
interested general public.  The Division solicits comments on this report and welcomes
suggestions on our trend techniques, interpretations, conclusions, and methods of
presentation. Please forward any response to Dr. Thomas C. Curran, (MD-14) U. S.
Environmental Protection Agency, Technical Support Division, Research Triangle Park,
North Carolina 27711.
                                      in

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Preceeding Page Blank
                                   CONTENTS

     LIST OF FIGURES	vii

     LIST OF TABLES	xi

     1.    EXECUTIVE SUMMARY	1-1
          1.1  INTRODUCTION	1-1
          1.2  MAJOR FINDINGS  	1-2
              Paniculate Matter	 — 1-2
              Sulfur Dioxide 	1-4
              Carbon Monoxide	1-6
              Nitrogen Dioxide  	1-8
              Ozone	1-10
              Lead	1-12
          1.3  SOME PERSPECTIVE	1-14
          1.4  REFERENCES	1-16

     2.    INTRODUCTION	2-1
          2.1  DATA BASE	2-3
          2.2  TREND STATISTICS	2-4
          2.3  REFERENCES	2-7

     3.    NATIONAL AND REGIONAL TRENDS IN NAAQS POLLUTANTS	3-1
          3.1  TRENDS IN PARTICULATE MATTER	3-2
              3.1.1 Long-term TSP Trends: 1980-89  	3-2
              3.1.2 TSP Emission Trends	3-4
              3.1.3 Recent TSP Trends: 1987-89	3-5
              3.1.4 Recent PM10 Air Quality	3-5
              3.1.5 PM10  Emission Trends	3-8
          3.2  TRENDS IN SULFUR DIOXIDE 	3-10
              3.2.1 Long-term SO2 Trends: 1980-89	3-10
              3.2.2 Recent SO2 Trends: 1987-89 	3-14
          3.3  TRENDS IN CARBON MONOXIDE	3-15
              3.3.1 Long-term CO Trends: 1980-89	3-15
              3.3.2 Recent CO Changes	3-19
          3.4  TRENDS IN NITROGEN DIOXIDE	3-20
              3.4.1 Long-term NO2 Trends: 1980-89	3-20
              3.4.2 Recent NO2 Changes  	3-23
          3.5  TRENDS IN OZONE  	3-24
              3.5.1 Long-term O3 Trends: 1980-89	3-25
              3.5.2 Recent O3 Changes	3-28
              3.5.3 Preview of 1990 Ozone Trends	3-29

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    3.6  TRENDS IN LEAD	3-31
         3.6.1 Long-term Pb Trends; 1980-89  	3-31
         3.6.2 Recent Pb Trends: 1987-89	3-35
    3.7  REFERENCES	3-37

4.   AIR QUALITY STATUS OF METROPOLITAN AREAS, 1989	4-1
    4.1  AREAS NOT MEETING OZONE, CARBON MONOXIDE AND
         PARTICULATE MATTER NAAQS  	4-1
    4.2  POPULATION ESTIMATES FOR COUNTIES NOT MEETING
         NAAQS, 1989  .	 4-5
    4.3  AIR QUALITY LEVELS IN METROPOLITAN STATISTICAL
         AREAS		.		 4-7
         4.3.1 Metropolitan Statistical Area Air Quality Maps, 1989	4-7
         4.3.2 Metropolitan Statistical Area Air Quality Summary, 1989	4-15
    4.4  REFERENCES	 4-15

5.  SELECTED METROPOLITAN AREA TRENDS	 5-1
    5.1  THE POLLUTANT STANDARDS INDEX	5-1
    5.2  SUMMARY OF PSI ANALYSES	5-2
    5.3  DESCRIPTION OF GRAPHICS	5-4
       TRENDS IN METROPOLITAN STATISTICAL AREAS
         Atlanta, GA	 5-6
         Boston, MA	 5-8
         Chicago, IL	5-10
         Dallas, TX		.. 5-12
         Denver, CO			5-14
         Houston, TX	5-16
         Kansas City, MO-KS	5-18
         Los Angeles, CA	5-20
         New York, NY	5-22
         Philadelphia, PA	5-24
         Pittsburgh, PA	5-26
         San Francisco, CA	5-28
         Seattle, WA	5-30
         Washington, DC-MD-VA	5-32
                                 VI

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                              LIST OF FIGURES

2-1.  Sample illustration of use of confidence intervals to determine statistically
     significant change	 2-5
2-2.  Illustration of plotting convention of boxplots	 2-5
2-3.  Ten Regions of the U.S. Environmental Protection Agency.	 2-6
3-1.  Comparison of 1970 and 1989 emissions		3-1
3-2.  National trend in the composite average of the geometric mean total
     suspended particulate at both NAMS and all sites with 95 percent
     confidence intervals, 1980-1989	3-3
3-3.  Boxplot comparisons of trends in annual geometric mean total suspended
     particulate concentrations at 1648 sites, 1980-1989	 3-3
3-4.  National trend in particulate emissions, 1980-1989.	 3-4
3-5.  Regional comparisons of the 1987,1988 and 1989 composite averages of the
     geometric mean total suspended particulate concentrations	3-5
3-6.  Boxplot comparisons of the 2-year change in PM10 concentrations (1988-
     1989) at 357 sites with 1989 PM10 air quality at 763 sites	 3-6
3-7.  Boxplot comparisons of 24-hour PMW peak value statistics for 1989 at 763
     sites			.3-6
3-8.  Regional comparisons of annual mean and 90th per cent ile of 24-hour
     PMM concentrations for 1989	3-7
3-9.  Regional changes in annual  average and 90th percentile of 24-hour PM10
     concentrations, 1988-1989. .	3-7
3-10. National trend in annual average sulfur dioxide concentration at both
     NAMS and all sites with 95  percent confidence intervals, 1980-1989	3-10
3-11. National trend in the second-highest 24-hour sulfur dioxide concentration
     at both NAMS and all sites  with 95 percent confidence intervals,
     1980-1989.		..		3-11
3-12. National trend in the estimated number of exceedances of the 24-hour
     sulfur  dioxide NAAQS at both  NAMS and all sites with 95 percent
     confidence intervals, 1980-1989	3-11
3-13. Boxplot comparisons of trends in annual mean sulfur dioxide
     concentrations at 409 sites, 1980-1989	3-12
3-14. Boxplot comparisons of trends in second highest 24-hour average sulfur
     dioxide concentrations at 405 sites, 1980-1989	 3-12
3-15. National trend in sulfur oxides emissions, 1980-1989	3-13
3-16. Regional comparisons of the 1987,1988,1989 composite averages of the
     annual average sulfur dioxide concentration	3-14
3-17. National trend in the composite average of the second highest
     nonoverlapping 8-hour average carbon monoxide concentration at both
     NAMS and all sites with 95  percent confidence intervals, 1980-1989	3-16
3-18. Boxplot comparisons of trends in second highest nonoverlapping 8-hour
     average carbon monoxide concentrations at 280 sites, 1980-1989.	3-16
                                      Vll

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3-19. National trend in the composite average of the estimated number of
     exceedances of the 8-hour carbon monoxide NAAQS, at both NAMS and
     all sites with 95 percent confidence intervals, 1980-1989	3-16
3-20. National trend in emissions of carbon monoxide, 1980-1989.	3-17
3-21. Comparison of trends in total national vehicle miles traveled and national
     highway vehicle emissions, 1980-1989	3-18
3-22. Decrease in carbon monoxide exceedances in Denver, Colorado	3-18
3-23. Metropolitan area trends in the composite average of the second highest
     non-overlapping 8-hour average carbon monoxide concentration, 1980-
     1989					  3-19
3-24. Regional comparisons of the 1987,1988 and 1989 composite averages of
     the second highest non-overlapping 8-hour average carbon monoxide
     concentration.	3-19
3-25. National trend in the composite annual average nitrogen dioxide
     concentration at both NAMS and all sites with 95 percent confidence
     intervals, 1980-1989	3-20
3-26. Boxplot comparisons of trends in annual mean nitrogen dioxide
     concentrations at 148 sites, 1980-1989	3-21
3-27. Metropolitan area trends in the composite annual average nitrogen
     dioxide concentration, 1980-1989	3-21
3-28. National trend in nitrogen oxides emissions, 1980-1989	3-22
3-29. Regional comparisons of 1987,1988,1989 composite averages of the
     annual mean nitrogen dioxide concentration.	3-23
3-30. National trend in the composite average of the second highest maximum
     1-hour ozone concentration at both NAMS and all sites with 95 percent
     confidence intervals, 1980-1989	3-24
3-31. Boxplot comparisons of trends in annual second highest daily maximum
     1-hour ozone concentration at 431 sites, 1980-1989.	  3-25
3-32. National trend in the estimated number of  daily exceedances of the ozone
     NAAQS in the ozone season at both NAMS and all sites with 95 percent
     confidence intervals, 1980-1989			  3-25
3-33. Metropolitan area trends in the composite average of the second highest
     maximum 1-hour ozone concentration, 1980-1989.	3-26
3-34. National trend in emissions of volatile organic compounds, 1980-1989. ..  3-27
3-35. Boxplot comparison of recent changes in ozone second daily maximum
     1-hour concentrations in metropolitan areas, 1988-1989	  3-28
3-36. Regional comparisons of the 1987,1988,1989 composite averages of the
     second-highest daily 1-hour ozone concentrations	3-28
3-37. Regional comparisons of the number of days greater than 90°F in 1987,
     1988,1989  for selected cities	3-29
3-38. Regional comparisons of the number of days with precipitation in 1987,
     1988,1989  for selected cities.	3-29
3-39. Preliminary estimate of the national trend in the composite average of the
     second highest daily maximum 1-hour ozone concentration, 1980-90	3-30
                                    vm

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3-40. Regional comparisons of the 1987,1988,1989 and preliminary 1990
     composite averages of the second-highest daily 1-hour ozone
     concentrations.	3-30
3-41. National trend in the composite average of the maximum quarterly
     average lead concentration at both NAMS and all sites with 95 percent
     confidence intervals, 1980-1989	3-32
3-42. Comparison of national trend in the composite average of the maximum
     quarterly average lead concentrations at urban and point-source oriented
     sites, 1980-1989	3-32
3-43. Boxplot comparisons of trends in maximum quarterly average lead
     concentrations at 189 sites, 1980-1989.  ....		3-33
3-44. National trend in lead emissions, 1980-1989	3-34
3-45. Regional comparison of the 1987,1988,1989 composite average of the
     maximum quarterly average lead concentration.	 3-35
4-1.  Areas failing to meet the ozone NAAQS, 1987-1989.	4-2
4-2.  Areas failing to meet the carbon monoxide NAAQS, 1988-1989	 4-3
4-3.  Areas not meeting the NAAQS  for particulate matter through 1988.  — .. 4-4
4-4.  Number of persons living in counties with air quality levels above the
     primary national ambient air quality standards in 1989 (based on 1987
     population  data).	 4-5
4-5.  United States map of the highest annual arithmetic mean PM10
     concentration by MSA, 1989.		...	4-8
4-6.  United States map of the highest annual arithmetic mean sulfur dioxide
     concentration by MSA, 1989.	.4-9
4-7,  United States map of the highest second maximum 24-hour average sulfur
     dioxide concentration by MSA, 1989	4-10
4-8.  United States map of the highest second maximum nonoverlapping
     8-hour average carbon monoxide concentration by MSA, 1989.	4-11
4-9.  United States map of the highest annual arithmetic mean nitrogen dioxide
     concentration by MSA, 1989	4-12
4-10. United States map of the highest second daily maximum 1-hour average
     ozone concentration by MSA, 1989	4-13
4-11. United States map of the highest maximum quarterly average lead
     concentration by MSA, 1989.	4-14
5-1.  Shaded wedges identifying pollutants monitored shown on metropolitan
     area maps	5-5
                                     IX

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Preceeding Page Blank
                                      LIST OF TABLES

       2-1.  National Ambient Air Quality Standards (NAAQS) in Effect in 1989	2-2
       2-2.  Number of Air Quality Trend Sites, 1980-89 and 1987-89	2-4
       3-1.  National Total Suspended Particulate Emission Estimates, 1980-1989	3-4
       3-2.  National PM10 Emission Estimates, 1985-1989  	3-8
       3-3.  1989 Fugitive Emissions For PMM	3-9
       3-4.  National Sulfur Oxides Emission Estimates, 1980-1989	3-13
       3-5.  National Carbon Monoxide Emission Estimates, 1980-1989	,	3-17
       3-6.  National Nitrogen Oxides Emission Estimates, 1980-1989	3-22
       3-7.  National Volatile Organic Compound Emission Estimates, 1980-1989  . ..  3-27
       3-8.  National Lead Emission Estimates, 1980-1989	3-34
       4-1.  Selected Air Quality Summary Statistics and Their Associated National
            Ambient Air Quality Standards (NAAQS)  	4-6
       4-2.  Population Distribution of Metropolitan Statistical Areas Based on 1987
            Population Estimates	4-7
       4-3.  1989 Metropolitan Statistical Area (MSA) Air Quality Factbook Peak
            Statistics for Selected Pollutants by MSA	4-16
       5-1.  PSI Categories and Health Effect Descriptor Words	5-1
       5-2.  Number of PSI Days Greater than 100 at Trend Sites, 1980-89, and all Sites
            in 1989	5-3
       5-3.  Number of Trend Monitoring Sites for the  14 Urban Area Analyses	5-4

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Preceeding Page Blank
         NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT. 1989

                            1. EXECUTIVE SUMMARY


  1.1    INTRODUCTION

        This is the seventeenth annual report1"16 documenting air pollution trends in the
  United States for those pollutants that have National Ambient Air Quality Standards
  (NAAQS). These standards have been promulgated by the U. S. Environmental
  Protection Agency (EPA) to protect public health and welfare.  There are two types of
  NAAQS,  primary and secondary. Primary standards are designed to protect public
  health, while secondary standards protect public welfare,  including effects of air pollution
  on vegetation, materials and visibility.  This report focuses on comparisons with the
  primary standards in effect in 1989 to examine changes in air pollution levels over time,
  and to summarize current air pollution status.  There are six pollutants that have
  NAAQS: paniculate matter (formerly as total suspended particulate (TSP) and now as
  PM10 which emphasizes the smaller particles), sulfur dioxide (SO2), carbon monoxide
  (CO), nitrogen dioxide  (N02), ozone (O3) and lead (Pb). It is important to note that the
  discussions of ozone in this report refer to  ground level, or tropospheric, ozone and not
  to stratospheric ozone. Ozone in the stratosphere,  miles above the earth, is a beneficial
  screen from the sun's ultraviolet rays.  Ozone at ground level, in  the air we breathe, is a
  health and environmental concern.
        The trends in ambient air quality that follow are
  presented as boxplots, which display the 5th, 10th,
  25th, 50th (median), 75th, 90th and 95th percentiles of
  the data, as well as the composite average. The 5th,
  10th and 25th percentiles depict the "cleaner" sites,
  while the 75th, 90th and 95th depict the "higher" sites
  and the median and average describe the  "typical"
  sites. For example, the 90th percentile means that  90
  percent of the sites had concentrations less than or
  equal to that value, and only  10 percent of the sites
  had concentrations that were higher. Boxplots
  simultaneously illustrate  trends in the "cleaner",
  "typical" and "higher" sites.
        The ambient air quality trends presented in this report are  based upon actual
  direct measurements.  These air quality trends are supplemented with trends for
  nationwide emissions, which are based upon the best available engineering
  calculations. Chapter 4 of this report includes a detailed listing of selected 1989 air
  quality summary statistics for every metropolitan statistical area (MSA) in the nation and
  maps highlighting the largest MSAs,  Chapter 5 presents 1980-89 trends for 14 cities.


















                                        1-1

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1.2   MAJOR FINDINGS
      AIR QUALITY

      Total Suspended Particulates (TSP)
      1982-89*: geometric mean: 1 percent decrease (1648 sites)
      1988-89: geometric mean: 5 percent decrease (1014 sites)
            * 8-year period (see comments)
         .10
EM
1988-89: arithmetic mean: 3 percent decrease (357 sites)

EMISSIONS

1982-89:1  percent increase (TSP)
      (Note: 10-year 1980-89 change was 15 percent decrease)
1988-89: 4 percent decrease (TSP); 3 percent decrease (PM10)

COMMENTS

The 1980-81 TSP data were affected by a change in sampling filters, therefore,
these years are shaded to indicate the uncertainty in the TSP measurements.
The highest average and peak 24-hour PMto concentrations are seen in Regions
IX and X.  The 1988 TSP and PM10 air quality levels were affected by generally
drier conditions and higher than normal forest fire activity.

PM EFFECTS

Based on studies of human populations exposed to high concentrations of
particles (often in the presence of sulfur dioxide), and laboratory studies of
animals and humans, the major effects of concern for human health  include
effects on breathing and respiratory symptoms, aggravation of existing respiratory
and cardiovascular disease, alterations in the body's defense systems against
foreign materials, damage to lung tissues, carcinogenesis, and premature
mortality. The major subgroups of the population that appear likely to be most
sensitive to the effects of particulate matter include individuals with chronic
obstructive  pulmonary or cardiovascular disease, individuals with influenza,
asthmatics, the elderly, and children.  Particulate matter causes material soiling
and is responsible for substantial visibility impairment in many parts of the U.S.

                                1-2

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           TSP  AIR  QUALITY
      CONCENTRATION UG/M3
ANNUAL GEOMETRIC MEAN
WORTH NOTING

The PM10 NAAQS replaced EPA's earlier TSP standard In 1987,  PM10
focuses on those particles with aerodynamic diameters smaller than 10
micrometers, which are likely to be responsible for adverse health effects
because of their ability to reach the lower regions of the respiratory tract*
PM10 appears to represent essentially all of the partlculate emissions .
from transportation sources and most of the emissions in the other
traditional categories.  However, fugitive PM10 emissions are 8 times
more than the total of all traditional paniculate matter sources categories.
                          1-3

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AIR QUALITY

1980-89: arithmetic mean: 24 percent decrease (409 sites)
         24-hour second high: 26 percent decrease (405 sites)
         24-hour exceedances: 95 percent decrease (405 sites)

1988-89: arithmetic mean: 3 percent decrease (513 sites)

EMISSIONS (SOx)

1980-89:10 percent decrease

1988-89:1  percent increase

COMMENTS

The vast majority of SO2 monitoring sites do not show any exceedances of the
24-hour NAAQS and the exceedance trend is dominated by source oriented
sites.  The decrease in sulfur oxides emissions from 1980 to 1989 reflects
reductions at coal-fired power plants. The increase in sulfur oxides emissions
between 1988 and 1989 is due to increased emissions from fuel combustion.
The difference between the air quality trends and the emission trends result
from the historical ambient monitoring networks being population-oriented while
the major emission sources tend to be in less populated areas.

SO3 EFFECTS

The major health effects of concern associated with high exposures to SO2
include effects on breathing, respiratory Illness and symptoms, alterations in the
lung's defenses, aggravation of existing respiratory and cardiovascular disease,
and mortality. The major subgroups of the population most sensitive to SO2
include asthmatics and individuals with chronic lung disease (such as bronchitis
or emphysema) or cardiovascular disease.  Children and the elderly may also
be sensitive. Sulfur dioxide produces foliar damage  on trees and agriculture
crops  and acts as a precursor to acidic precipitation.
                               1-4

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  0.040
        SO2  AIR QUALITY
      CONCENTRATION, PPM                ANNUAL MEAN
  0.035 -


  0.030


  0.025 -


  0,020 -


  0.015-


  0.010-


  0.005 -


  0.000
                                 409 SITES
NAAOS
'•^^^^^M^^^r^&ii^^i^^m^^t^Mf^^Wi^m^M^^MW^^^^i^^^t^MM
i |if® oiill
                      1-5

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AIR QUALITY

1980-89: 8-hour second high: 25 percent decrease (280 sites)
         8-hour exeeedanees: 80 percent decrease (280 sites)

1988-89: 8-hour second high: 1 percent decrease (355 sites)

EMISSIONS

1980-89: 23 percent decrease

1988-89: 6 percent decrease

COMMENTS

While there is general agreement between the air quality and emission changes
over this 10-year period, it should be recognized that the emission changes
reflect estimated national totals while the ambient CO monitors are frequently
located to identify problems. The mix of vehicles and the change in vehicle
miles  of travel in an area around a typical CO monitoring site may differ from
the national averages.

CO EFFECTS

Carbon  monoxide enters the bloodstream and disrupts the delivery of oxygen to
the body's organs and tissues. The health threat from carbon monoxide is
serious for those who suffer from cardiovascular disease, particularly those with
angina or peripheral vascular disease.  Healthy  individuals also are affected.
Exposure to elevated carbon monoxide levels is associated with impairment of
visual perception, manual dexterity, learning ability and performance of complex
tasks.
                               1-6

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          CO  AIR QUALITY
 20
   CONCENTRATION, PPM
SECOND HIGHEST 8-HOUR AVERAGE
 15-
 10-
  5 -
                                 280 SITES
     QOllJ^^

               J|^
     betwen 1988  riiil
                     ^
      nef:^^
sitf ats tfiifi ;for tHP:i 987-88" tirtte^periocl.
                     1-7

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AIR QUALITY

1980-89: annual mean; 5 percent decrease (148 sites)

1988-89: annual mean: 2 percent decrease (200 sites)

EMISSIONS fNOx)

1980-89: 5 percent decrease

1988-89:1 percent decrease

COMMENTS

The national trend in annual mean NO2 concentrations in the late 1980's
continues to be flat.  The two primary source categories of nitrogen oxide
emissions, and their contribution in 1989, are fuel combustion (56 percent) and
transportation (40 percent).

NO* EFFECTS

Nitrogen oxides can irritate the lungs and lower resistance to respiratory
infections such as  influenza.  The effects of short-term exposures are still under
study, but continued or frequent exposure to concentrations higher than those
normally found in the ambient air can cause pulmonary edema.  Nitrogen
dioxide acts as a precursor to acidic precipitation and plays a key role in
nitrogen loading of forests and ecosystems.
                               1-8

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NO2 AIR QUALITY
CONCENTRATION, PPM ANNUAL MEAN
0.06 -
0.05 -
0.04 ~
0.03 -
0.02 -
0,01 -
"I

	

14
J| )f pS| P Si =ii' pi
si 1 nil
oVj «'i\ ipyL riifA f\Qf **k0iO j-yffjQ *vCCl
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NMQS
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tHIMili)                          1017
•K» S5^f8:¥i¥::i¥ ~tt>	'"•"
         llftiliiNiiiipiiiiiiiiiii
         Sggg gSjSjgSS 5 KfeSpif *KJ:;SiftKffiB5jSg8|;;SS;«:»S:5»:i
                                       iflhiWinM
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                                                         *
                    1-9

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AIR QUALITY

1980-89: second highest daily max 1-hour: 14 percent decrease (431 sites)
         exceedance days: 53 percent decrease
1988-89: second highest daily max 1-hour: 15 percent decrease (581 sites)

EMISSIONS (VOC)

1980-89:19 percent decrease
1988-89: 5 percent decrease

COMMENTS

The volatile organic compound (VOC) emission  estimates represent annual
totals.  While these are the best national numbers now available, ozone is
predominantly a warm weather problem and seasonal  emission trends would be
preferable. Previously, VOC emissions from highway vehicles were estimated
using nationwide annual temperatures and nationwide  average Reid Vapor
Pressure (RVP).  This year's estimates are based on statewide average
monthly temperatures and statewide RVP.  NOX emissions, another factor in
ozone formation, decreased 5 percent between  1980 and 1989.

O3 EFFECTS

The reactivity of ozone causes health problems because it tends to break down
biological tissues and cells. Recent scientific evidence  indicates that high levels
of ozone not only affect people with impaired respiratory systems, such as
asthmatics, but healthy adults and children, as well.  Exposure to ozone for only
several hours at relatively low concentrations has been found to significantly
reduce lung function in normal, healthy people during periods of exercise.  This
decrease in lung function generally is accompanied by symptoms including chest
pain, coughing, sneezing and pulmonary congestion. Though less well
established in humans, animal studies have demonstrated that repeated
exposure to ozone for months to years can produce permanent structural
damage in the lungs and accelerate the rate of lung function loss. Ozone is
responsible each year for agricultural crop yield loss in  the U.S. of several billion
dollars and causes  noticeable foliar damage in many crops and species of trees.
Forest and ecosystem damage may result from high ambient ozone levels.

                               1-10

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0.30
    OZONE AIR QUALITY
   CONCENTRATION, PPM    SECOND HIGH DAILY MAX 1 -HOUR
0.25 -


0.20 -


0.15


0.10


0.05 -H
0.00
                          431 SITES
NAAQS


                 1-11

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AIR QUALITY

1980-89; maximum quarterly average: 87 percent decrease (189 sites)

1988-89; maximum quarterly average: 14 percent decrease (245 sites)

EMISSIONS

1980-89; 90 percent decrease in total lead emissions
        (96 percent decrease in lead emissions from transportation sources)

1988-89: 5 percent decrease in total lead emissions
        (15 percent decrease in lead emissions from transportation sources)

COMMENTS

The ambient lead trends presented here primarily represent general urban
conditions predominantly reflecting automotive sources.  Ambient trends are
also presented for a small  number of lead monitoring sites (19) in the vicinity of
point sources of lead such as primary and secondary lead smelters.

LEAD EFFECTS

Exposure to lead can occur through multiple pathways, including air, diet and
Ingestion of lead in soil and dust. Lead accumulates in the body in blood, bone,
and soft tissue.  Because it is not readily excreted, lead also affects the
kidneys, nervous system, and blood-forming organs.  Excessive exposure to
lead may cause neurological impairments such as seizures, mental retardation,
and/or behavioral disorders. Even at low doses, lead exposure is associated
with changes in fundamental enzymatic, energy transfer and homeostatic
mechanisms in the body.  Infants and children are especially susceptible to low
doses of lead, often suffering central nervous system damage. Recent studies
have also shown that lead  may be a factor in high blood pressure and
subsequent heart disease.
                              1-12

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        LEAD AIR QUALITY
 2.5
    CONCENTRATION UG/M3
MAXIMUM QUARTERLY AVERAGE
  2 -
 1.5
  1 -





 0.5 -




  0
                             189 SITES
                                    NAAQS
                                     Hlfti
                                   HIiMlfl
!6iciiii;

                   1-13

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1.3   SOME PERSPECTIVE

     A 10-year time period is convenient for considering ambient air pollution trends
because monitoring networks underwent many changes around 1980.  However, it is
important not to overlook some of the earlier control efforts in the air pollution field.
Emission estimates are useful in examining longer term trends. Between 1970 and
1989, lead clearly shows the most impressive decrease (-96 percent) but
improvements are also seen for total suspended paniculate (-61 percent), sulfur
oxides (-26 percent), carbon monoxide (-40 percent), and volatile organic compounds
(-31 percent). Only nitrogen oxides did not show improvement with emissions
estimated to have increased 8 percent, due primarily to increased fuel combustion by
stationary sources and motor vehicles.  It is also important to realize that many of
these reductions occurred even in the face of growth of emissions sources. More
detailed information is contained in a companion report.17
   COMPARISON OF 1970 AND 1989 EMISSIONS
    MILLION METRIC TONS/YEAR
   120


   100 h
                                        THOUSAND

                                      METRIC TONS/YEAR
                                   250
          TSP
SOx
NOx
VOC
LEAD
                               1970 \m 1989
                                  1-14

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      While it is important to recognize that progress has been made, it is also
important not to lose sight of the magnitude of the air pollution problem that still
remains.  About 84 million people in the U.S. reside in counties which did not meet at
least one air quality standard during 1989.  The 67 million people living in counties
that exceeded the ozone standard in 1989 is 45 million fewer than in 1988.
Meteorological conditions in 1988 were more conducive to ozone formation than
conditions in 1989. Also, beginning in summer 1989, gasoline evaporative emissions
were reduced as a result of fuel volatility regulations which lowered the Reid vapor
pressure in  gasoline.  These statistics,  and  associated qualifiers and limitations, are
discussed in Chapter 4.
      People in counties with measured 1989 air quality above
           primary National Ambient Air Quality Standards
 pollutant	
                                                                 B4.4
            0
20
                                 40         60
                                millions of people
Note: Based on 1d87 county population data and only 1969 air quality data.
80
100
      Finally, it should be recognized that this report focuses on those pollutants that
have National Ambient Air Quality Standards. With the passage of the Clean Air Act
Amendments of 1990, additional control programs are being put in place to solve the
remaining nonattainment problems for these pollutants.
                                    1-15

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1.4   REFERENCES

      1.  The National Air Monitoring Program: Air Quality and Emissions Trends -
Annual Report. EPA-450/1-73-001 a and b, U. S. Environmental Protection Agency,
Office of Air Quality Planning and Standards, Research Triangle Park, NC 27711, July
1973.

      2.  Monitoring and Air Quality Trends  Report. 1972. EPA-450/1-73-004, U. S.
Environmental Protection Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, NC 27711, December 1973.

      3.  Monitoring and Air Quality Trends  Report. 1973. EPA-450/1-74-007, U. S.
Environmental Protection Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, NC 27711, October 1974.

      4.  Monitoring and Air Quality Trends  Report. 1974. EPA-450/1-76-001, U. S.
Environmental Protection Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, NC 27711, February 1976.

      5.  National Air Quality and Emissions Trends Report. 1975. EPA-450/1-76-002,
U. S. Environmental Protection Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, NC 27711, November 1976.

      6.  National Air Quality and Emissions Trends Report. 1976.
EPA-450/1-77-002, U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research  Triangle  Park, NC 27711, December 1977.

      7.  National Air Quality and Emissions Trends Report. 1977.
EPA-450/2-78-052, U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research  Triangle  Park, NC 27711, December 1978.

      8.  1980 Ambient Assessment - Air Portion. EPA-450/4-81-014,
U. S. Environmental Protection Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, NC 27711, February 1981.

      9.  National Air Quality and Emissions Trends Report. 1981.
EPA-450/4-83-011, U, S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research  Triangle  Park, NC 27711, April 1983.

      10.  National Air Quality and Emissions Trends Report. 1982.
EPA-450/4-84-002, U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research  Triangle  Park, NC 27711, March 1984.
                                     1-16

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      11. National Air Quality and Emissions Trends Report. 1983.
EPA-450/4-84-029, U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, NC 27711, April 1985.

      12. National Air Quality and Emissions Trends Report. 1984.
EPA-450/4-86-001, U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, NC 27711, April 1986.

      13. National Air Quality and Emissions Trends Report. 1985.
EPA-450/4-87-001, U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, NC 27711, February 1987.

      14. National Air Quality and Emissions Trends Report. 1986.
EPA-450/4-88-001, U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, NC 27711, February 1988.

      15. National Air Quality and Emissions Trends Report. 1987.
EPA-450/4-89-001, U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, NC 27711, March  1989.

      16. National Air Quality and Emissions Trends Report. 1988.
EPA-450/4-90-002, U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, NC 27711, March  1990.

      17. National Air Pollutant Emission Estimates. 1940-1989.
EPA-450/4-91-004, U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, NC 27711, February 1991.
                                     1-17

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2. INTRODUCTION
   This  report focuses  on  10-year (1980-89)
national air quality trends for each of the major
pollutants for which National Ambient Air Quality
Standards (NAAQS) have been established. This
Section presents  many of the technical details
involved  in these  analyses; readers familiar with
prevbus  reports may prefer  initially  to  proceed
directly to the remaining Sections. The national
analyses are complemented in Section 5 with air
quality trends in  14 metropolitan areas for the
period 1980 through 1989.  The areas examined
are Atlanta, GA; Boston, MA; Chicago, IL; Dallas,
TX; Denver, CO; Houston, TX; Kansas City, MO-
KS; Los Angeles, CA; New York, NY; Philadelphia,
PA; Pittsburgh, PA; San  Francisco, CA; Seattle,
WA; and Washington, DC-MD-VA.

   The national air quality trends are based on the
results of direct air pollution measurements at air
monitoring sites located throughout the U.S. The
National Air Monitoring Station (NAMS) sites were
established   through   monitoring   regulations
promulgated in May 19791 to provide accurate and
timely data to the U.S. Environmental Protection
Agency  (EPA) from  a national  air monitoring
network.   The  NAMS are located in areas with
higher pollutant concentrations and high population
exposure. These stations meet uniform criteria for
siting, quality  assurance,  equivalent analytical
methodology, sampling intervals, and instrument
selection to  assure  consistent  data  reporting
among the States.  Other sites operated by the
State  and local air pollution control agencies, such
as the State and  Local Air Monitoring  Stations
(SLAMS) and Special Purpose Monitors (SPM), in
general, also meet the same rigid criteria, except
that in addition to being located  in the area of
highest  concentration   and   high  population
exposure, they are located in other areas as well.
   Air quality  status  may be  determined  by
comparing the ambient air pollution levels with Ihe
appropriate  primary  and  secondary   National
Ambient Air Quality Standards (NAAQS)  for each
of the pollutants (Table 2-1).  Primary standards
protect the public health;  secondary standards
protect the public welfare as measured by effects
of pollution on vegetation, materials, and visibility.
The standards are further categorized for different
averaging times. Long-term standards specify an
annual  or  quarterly  mean  that  may not  be
exceeded; short-term standards specify upper limit
values for 1 -, 3-, 8-, or 24-hour averages. With the
exception of the pollutants ozone and  PM10, the
short-term standards are not to be exceeded more
than once per year.  The ozone standard requires
that the expected number of days per calendar
year with daily maximum hourly concentrations
exceeding 0.12 parts per million (ppm) be less than
or equal to one.  The 24-hour PM10 standard also
allows one expected exceedance per year.

    Trends   are  also  presented  for  annual
nationwide emissions.  These are estimates of the
amount and kinds of  pollution being emitted  by
automobiles, factories, and other sources, based
upon the best available engineering calculations for
a  given time period.  The emission trends are
taken from the  EPA  publication,  National   Air
Pollutant Emission Estimates. 1940-19S92 and the
reader is referred  to this publication  for more
detailed information.  For particulates. emission
estimates are presented for both total paniculate
emissions, without any distinction of particle sizes,
as well  as for PM10, which refers to "inhalable"
particles with aerodynamic diameter less that  10
microns.   Area  source fugitive  dust emissions
(unpaved roads, construction activities, etc.)  for
PM10  are included  for the year 1985.  Similarly,
natural sources of PM10, such as wind erosion or
dust, are also shown. (Forest fires, some of which
result from natural causes are included, however,
for both total  particulates and PM10).  As shown,
these fugitive emissions are estimated to amount
to a considerable portion of paniculate emissions.
For CO,  VOC and  NOX, emission estimates  for
gasoline-and diesel-powered motor vehicles were
based upon vehicle-mile tabulations and emission
factors from the MOBILE 4.0 model.

    Section 4 of this report, "Air Quality Levels in
Metropolitan Statistical Areas"  provides greatly
simplified  air pollution information.  Air quality
statistics are presented for each of the  pollutants
for all MSAs reporting  monitoring data to EPA  for
1989.
                                             2-1

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   TABLE 2-1.  National Ambient Air Quality Standards (NAAQS) in Effect in 1989.
POLLUTANT   PRIMARY (HEALTH RELATED)    SECONDARY (WELFARE RELATED)
                          Standard Level *
            Averaging Time  Concentration*
                                               Standard Level
                                 Averaging Time   Concentration
PM,
 Annual
Arithmetic
  Mean"
             24-hour15
 50 jig/m*
                 150
           Same as Primary
                             Same as Primary
SO,
 Annual
Arithmetic
  Mean
(0.03 ppm)
 80
3-hour"
1300 jig/m3
(0.50 ppm)
             24-hour"
                 (0.14 ppm)
                 365 ug/m3
CO
 S-hour6
 9 ppm
                             (10mg/rn3)
         No Secondary Standard
              1-hour0
                 35 ppm
                 (40 mg/m3)
                           No Secondary Standard
NO,
    Annual
  Arithmetic
    Mean
 0.053 ppm
(1QOng/m3)
           Same as Primary
O,
Maximum Daily
    1-hour
   Average"
 0.12 ppm
(235 ug/ma)
           Same as Primary
Pb
  Maximum
  Quarterly
   Average
 1.5
           Same as Primary
       Parenthetical value is an approximately equivalent concentration.

       TSP was the indicator pollutant for the original particulate matter (PM) standards.  This
       standard has been replaced with the new PM10 standard and it is no longer in effect.  New PM
       standards were promulgated in 1987, using PM10 (particles less than 1Qu in diameter) as the
       new indicator pollutant.  The annual standard is attained when the expected annual arithmetic
       mean concentration is less than or equal to 50 ng/ma; the 24-hour standard is attained when
       the expected number of days per calendar year above 150 jig/m3 is equal to or less than 1; as
       determined in accordance with Appendix K of the PM NAAQS.

       Not to be exceeded more than once  per year.

       The standard is attained when the expected number of days per calendar year with maximum
       hourly average concentrations above 0.12 ppm is equal to or less than 1, as determined in
       accordance with Appendix H of the Ozone NAAQS.
                                          2-2

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Zl  DATABASE
   The ambient air quality data used in this report
were obtained from EPA's Aerometric Information
and Retrieval System (AIRS). Air quality data are
submitted to AIRS  by both State  and local
governments, as well as federal agencies. At the
present time, there  are  about  500  million air
pollution  measurements  on  AIRS, the  vast
majority  of which represent  the  more heavily
populated urban areas of the nation.

   In order for a monitoring site to have been
included in the national 10-year trend analysis, the
site had to contain complete data for at least 8 of
the 10 years 1980  to  1989.  For the regional
comparisons, the site had to report data in each
of the last three years to be included  in  the
analysis. Table 2-2 displays the number of sites
meeting the completeness criteria for both data
bases. For PM10, whose monitoring network has
just  been  initiated  over  the last  few  years,
analyses are based on 357 sites with data in 1988
and  1989.   Data for each year  had to  satisfy
annual data completeness criteria appropriate to
pollutant and measurement methodology. The air
quality data are divided into two major groupings -
- 24-hour measurements and continuous  1 -hour
measurements.  The 24-hour measurements are
obtained from monitoring instruments that produce
one  measurement per 24-hour period and  are
typically  operated  on  a  systematic sampling
schedule of once every 6 days, or 61 samples per
year.   Such instruments  are  used to measure
TSP,  PM10l SOZ, N02 and Pb. For  PM,0, more
frequent sampling of every other day or everyday
is now also common. Data collected only as 24-
hour measurements were not used in the SO2 and
N02 trends  analyses because these methods
have  essentially been  phased  out  of  the
monitoring network.  Total suspended paniculate
and PM10 data were judged adequate for trends if
there were at least 48 samples for the year. Both
24-hour and composite data were used in the Pb
trends analyses.  The  24-hour Pb data  had to
have at least six samples per quarter in at least 3
of the 4 calendar quarters. Monthly composite Pb
data were used if at least two monthly samples
were  available for at least 3  of the 4 calendar
quarters.
   The 1-hour data are obtained from monitoring
instruments that operate continuously, producing
a measurement every hour for a possible total of
8760 hourly  measurements  in  a year.    For
continuous hourly data, a valid annual  mean for
SO2 and NO2 trends requires at least 4380 hourly
observations.      This   same  annual   data
completeness, of at least 4380 hourly values, was
required for the CO standard related statistics -
the  second  maximum nonoverlapping  8-hour
average  and   the  estimated   number  of
exceedances of the 8-hour average CO standard,
A slightly different criterion was used for the SO2
standard related daily statistics - the second daily
maximum  24-hour average  and the estimated
number of daily exceedances of the SO2 standard.
Instead of requiring 4380 or more hourly values,
183 or more daily values were required. A valid
day is defined as one consisting of at least 18
hourly observations.   This  produces  a slightly
different data  base of sites used in the national
analysis for the daily SO2 statistics.

   Finally, because of the seasonal  nature of
ozone, both the  second daily  maximum 1-hour
value and the estimated number of exceedances
of the Og NAAQS were calculated for the ozone
season, which typically varies by  State.3   For
example,  in  California,  the ozone season is
defined  as   12  months,  January   through
December, while in New Jersey it is defined as 7
months, April through October.  In order for a site
to be included, at least 50 percent of its daily data
had to be available for the ozone season.

   The use of  a moving 10-year window for
trends yields a data base that is more consistent
with  the current monitoring network and reflects
the  period following  promulgation  of uniform
monitoring  requirements.    In  addition,   this
procedure increased the  total number of trend
sites by 3  percent for the 10-year period relative
to the data bases used in the last annual report.4
However, the reader should note that the size of
the TSP monitoring network has been declining,
especially  since  promulgation  of the  PM10
standard.
                                           2-3

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           TABLE 2-2. Number of Air Quality Trend Sites, 1980-89 and 1987-89.

POLLUTANT
Total Suspended
Paniculate (TSP)*
Sulfur Dioxide (SO2)
Carbon Monoxide (CO)
Nitrogen Dioxide (NO.,)
Ozone (O3)
Lead (Pb)
TOTAL
NUMBER
1980-89
1648
409
280
178
431
189
3105
OF SITES
1987-89
1014
513
355
200
581
245
2908
          ' Changes in PM10 air quality are based on 357 sites with data in 1988 and 1989.

12.  TREND STATISTICS
   The air quality analyses presented in this report
comply   with   the   recommendations  of  the
Intra-Agency Task Force on Air Quality Indicators.5
The   air   quality   statistics  used   in   these
pollutant-specific trend  analyses relate  to  the
appropriate   NAAQSs.     Two   types   of
standard-related statistics are used - peak statistics
(the second maximum 24-hour SO2 average, the
second  maximum  nonoveriapping  8-hour  CO
average, and the second daily maximum 1-hour O3
average)  and   long-term averages  (the  annual
geometric mean for  TSP, the annual  arithmetic
means tor PM10, SO2 and N02, and the quarterly
arithmetic mean for Pb).  In the case of the peak
statistics,  the  second maximum value is used,
because this is the  value which  traditionally  has
been used to determine whether or not a site has
or has  not met an  air quality standard  in  a
particular year.  For PM10, with its variable sampling
frequency,  the  90th  percentile   of  24-hour
concentrations is used to examine changes in peak
values.  A composite average of each of these
statistics is  used in  the  graphical  presentations
which follow.  All sites were weighted equally in
calculating the composite average trend statistic.
Missing annual summary statistics for the second
through ninth years for a site are estimated by
linear interpolation from the  surrounding  years.
Missing end points are replaced with the nearest
valid year of data.  This procedure results  in a
statistically balanced  data  set to  which simple
statistical  procedures  can  be  applied.    The
procedure is also conservative, because end-point
rates of change are dampened by the interpolated
estimates.

   This  report  presents   statistical confidence
intervals to  facilitate  a better understanding of
measured changes in  air  quality.   Confidence
intervals are placed around composite averages,
which are based on sites that satisfy annual data
completeness  requirements.    The confidence
intervals can  be  used to make  comparisons
between years; if the confidence intervals for any 2
years do not overlap, then the composite averages
of the 2 years are significantly different (Figure 2-1).
                                             2-4

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Ninety-five  percent  confidence  intervals  for
composite averages of annual means (arithmetic
and   geometric)   and  second   maxima  were
calculated from  a two-way  analysis of variance
followed by an application of the Tukey Studentized
Range.6  The confidence intervals for composite
averages  of  estimated   exceedances  were
calculated by fitting Poisson distributions7 to the
exceedances each year and then applying the
Bonferroni multiple comparisons procedure.8 The
utilization of these procedures  is explained in
publications  by  Pollack,  Hunt and Outran9 and
Pollack and  Hunt.10

   Boxplots11 are used to present air quality trends
because  they have the advantage of displaying,
simultaneously,  several  features  of the  data.
Figure 2-2 illustrates the use of this technique in
presenting the 5th, 10th, 25th, 50th (median), 75th,
90th and 95th percenliles of the  data, as well as
the composite average. The 5th,  10th and 25th
percentiles depict the "cleaner" sites.  The 75th,
90th and 95th depict the "higher" sites, and the
median and average describe the "typical" sites.
For example, 90 percent of the sites would have
concentrations equal to or  lower  than the 90th
percentile. Although the average and median both
characterize typical behavior, the median has the
                     -95th PERCENTILE
                   — 90th PERCENTILE


V




	 	 Rth pprorPKmi r
Figure 2-2. Illustration of plotting
convention of boxplots.
                                        COMPOSITE MEAN
           Figure 2-1. Sample illustration of use of confidence intervals to
           determine statistically significant change.
                                             2-5

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advantage of not being affected by a few extremely
high observations. The use of the boxplots allows
us  simultaneously  to  compare trends in  the
"cleaner", "typical" and "higher" sites.

    Bar  graphs are  introduced  for the  Regional
comparisons  with the  3-year trend  data  base,
These comparisons  are based  on the  ten  EPA
Regions (Figure 2-3). The composite averages of
the appropriate air  quality statistic of the  years
1987, 1988  and  1989  are presented.   The
approach is simple,  and it allows the  reader at a
glance to compare the short-term changes in all ten
EPA Regions.

    In addition to  concentration  related  statistics,
other statistics are  used, when appropriate, to
clarify further the observed air quality trends.
Particular  attention  is given to  the estimated
number of exceedances of the short-term NAAQSs.
The estimated number of  exceedances is  the
measured  number of exceedances adjusted to
account  for incomplete sampling. Trends in
exceedances tend to be more variable than in the
other concentration related statistics, particularly on
a percentage basis.  For example, a site may show
a 50 percent decrease in annual exceedances,
from 2 to 1 per year, and yet record less than a 5
percent decrease in average concentration levels.
The  change in concentration levels is likely to be
more indicative of changes in emission levels.

   Trends  are  also  presented  for  annual
nationwide emissions. These  emissions data are
estimated using the best available  engineering
calculations. The emissions data are reported as
teragrams (one  million metric tons) emitted to the
atmosphere per year, with the exception  of lead
emissions, which are reported as gigagrams (one
thousand metric tons).2  These are estimates of the
amount and kinds of pollution being generated by
automobiles,   factories  and  other  sources.
Estimates for earlier years are recomputed using
current methodology so that these estimates are
comparable over time.
      9  0
           Figure 2-3.  Ten Regions of the U.S. Environmental Protection Agency.

                                             2-6

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2,3  REFERENCES
    1.  Ambient  Air Quality  Surveillance. 44 FR
27558, May 10, 1979.

    2.  National Air Pollutant Emission Estimates.
1940-1989. EPA-450/4-91 -004, U. S. Environmental
Protection Agency, Office of Air Quality Planning
and Standards,  Research  Triangle  Park,  NC,
February 1991.

    3.  Ambient  Air Quality  Surveillance. 51 FR
9597, March 19,1986.

    4.  National Air Quality and Emissions Trends
Report. 1988.
EPA-450/4-89-002, U. S. Environmental Protection
Agency,  Office-  of  Air  Quality  Planning  and
Standards,  Research Triangle Park, NC,  March
1990.

    5. U.S. Environmental Protection Agency Intra-
Agency  Task  Force  Report  on  Air  Quality
Indicators, EPA-450/4-81-015, U. S. Environmental
Protection Agency, Office of Air Quality Planning
and Standards,  Research  Triangle  Park,  NC,
February 1981.

    6.    B. J.  Winer,  Statistical Principles in
Experimental Design, McGraw-Hill, NY, 1971.
   7.   N. L. Johnson  and S.  Kotz,  Discrete
Distributions. Wiley, NY, 1969.

   8.  R. G. Miller, Jr.,  Simultaneous Statistical
Inference, Springer-Verlag, NY, 1981.

   9.  A.  Pollack, W. F.  Hunt,  Jr., and T. C.
Curran, "Analysis of Variance Applied to National
Ozone Air Quality Trends",  presented at  the 77th
Annual  Meeting  of  the  Air  Pollution  Control
Association, San Francisco, CA, June 1984.

   10.  A. Pollack and W. Hunt, "Analysis of Trends
and  Variability in Extreme  and Annual  Average
Sulfur Dioxide Concentrations", presented at the Air
Pollution Control Association, American Society for
Quality Control Specialty  Conference on Quality
Assurance in Air Pollution Measurement,  Boulder,
CO,  1985.

   11.  J. W.  Tukey,  Exploratory Data Analysis.
Addison-Wesley  Publishing  Company,  Reading,
MA,  1977.
                                             2-7

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3. NATIONAL AND REGIONAL TRENDS IN NAAQS POLLUTANTS
   EPA  has set National Ambient  Air  Quality
Standards (NAAQS) for six pollutants considered
harmful to public health: paniculate matter [formerly
as total  suspended particulates  (TSP), now as
particulates  less  than 10  microns  in  diameter
(PMio)]> sulfur dioxide (SCy,  carbon monoxide
(CO), nitrogen dioxide  (NO2), ozone (Cy and lead
(Pb).  This chapter focuses on both 10-year (1980-
89) trends and recent changes In air quality and
emissions for these six pollutants.  Changes since
1987, and comparisons between all the trend sites
and the subset of National Air Monitoring Stations
(NAMS) are  highlighted.  Trends are examined for
both the nation and the ten EPA Regions.

   As in previous reports, the air quality trends are
presented using trend lines, confidence intervals,
boxplots and bar graphs. The reader is referred to
Section  2.2  for  a  detailed description  of the
confidence interval and boxplot procedures.  The
plotting conventions for  the  confidence intervals
and  boxplots are shown  in Figures 2-1  and 2-2
respectively.   Boxplots  of  all trend  sites are
presented for each year in the  10-year trend.
Recent changes are presented using the 3-year
data base, 1987 through 1989,  and using a 1988-
89 data base for PM,Q. The recent 3-year period is
presented to take advantage of the larger number
of sites for all but particulates, and of  sites that
have  operated continuously during the last three
years.
         paniculate matter trends relating to PM10 air quality
         and emissions data.

            While the ambient data trends and the emission
         trends can be viewed as independent assessments
         that  lend added  credence to the  results, the
         emission estimates  can  be   used to  provide
         information  on trends  over longer time periods.
         Because of changes that have occurred in ambient
         monitoring  measurement methodology and the
         change over time in the geographical distribution of
         monitors, it is difficult  to provide  ambient trends
         going back to 1970, other than for TSP, and yet it
         is important not to  lose sight of some of the earlier
         progress that was made in air pollution  control.
         Emission estimates can provide some insight in this
         area.   Figure  3-1 depicts long-term change  In
         emission estimates.  Lead clearly shows the most
         impressive   decrease   of  96   percent   but
         improvements are also seen for TSP (-61 percent),
         SOx (-26 percent),  CO (-40 percent), and VOC (-31
         percent). Only NOx has not shown improvement
         with  emissions  estimated  to  have increased 8
         percent, due primarily to increased fuel combustion
         by stationary sources.  Because all areas except
         Los Angeles, CA meet the current NAAQS for NO2,
         it is probably not surprising that the other pollutants
         are where the emission reductions have occurred.
    Trends are also presented for annual
nationwide  emissions  of   paniculate
matter,  sulfur  oxides (SOx),  carbon
monoxide (CO), nitrogen oxides (NOx),
volatile organic compounds (VOC)  and
lead (Pb).   These emissions data are
estimated  using   best   available
engineering  calculations.  The reader is
referred to  a  companion  report for a
detailed description of emission trends,
source   categories   and   estimation
procedures.1  For particulates, emission
estimates are presented both in terms of
total particulate matter, which includes all
particles regardless of size, and for PM10.
This   report   introduces   short-term
    MILLION METRIC TONS/YEAR
    120
                                                                                     tMQUSANO

                                                                                    MEtlBC TQNSffEAR
                                              LEAD
Figure 3-1.  Comparison of 1970 and 1989 emissions.
                                             3-1

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3.1  TRENDS IN PARTICULATE MATTER
   Air pollutants called participate matter include
dust, dirt, soot, smoke and liquid droplets directly
emitted into the air by sources such as factories,
power plants, cars, construction activity, fires and
natural windblown dust as well as particles formed
in  the   atmosphere  by  condensation  or
transformation of emitted  gases  such as  sulfur
dioxide and volatile organic compounds.

   Annual   and 24-hour  National  Ambient  Air
Quality Standards  (NAAQS) for particulate matter
were first set in 1971. Total suspended particulate
(TSP)  was  the  indicator  used to  represent
suspended particles in the ambient air.  TSP is
measured  using a high volume sampler  (Hi-Vol)
which  collects suspended  particles ranging up to
approximately 45 micrometers in diameter.

   On July 1, 1987 EPA promulgated new annual
and 24-hour standards for particulate matter, using
a  new indicator,  PM,0, that includes  only  those
particles with aerodynamic diameter smaller than 10
micrometers.  These  smaller particles are likely
responsible for  most adverse  health effects  of
particulate  because of their ability to reach  the
thoracic  or lower regions of the respiratory tract.
The  original (TSP) standards  were  an  annual
geometric mean of 75 ng/m3, not to be exceeded,
and a 24-hour concentration of 260 ng/nf, not to be
exceeded more than  once  per year.  The new
(PM10)  standards  specify  an  expected   annual
arithmetic mean not to exceed  50 jig/m3 and an
expected number of 24-hour concentrations greater
than 150 u,g/m3 per year not to exceed one.

   Now that the standards have been revised, PM,0
monitoring  networks are being deployed nationally.
There  are  basically  Iwo  types of  reference
instruments currently used  to sample  PM,0.  The
first is essentially a Hi-Vol, like the one used for
TSP,  but with a different size selective inlet (SSI).
This sampler uses an inert quartz filter.  The other
type of instrument is a "dichotomous" sampler. It
uses a different PM10 inlet, operates at a slower flow
rate, and produces two separate samples: 2.5 to 10
microns and less than 2.5  microns, each collected
on a teflon filter.

   With the new PM10 standards, more emphasis is
being  placed  on detection  of   peak  24-hour
concentrations.  Unlike monitoring regulations for
TSP which only required once in 6 day sampling,
new specifications for PM,0 now dictate  more,
frequent sampling.  Approximately 15 percent of all
PM10 sampling sites operate either every other day
or everyday. In contrast, only 5 percent of TSP Hi-
Vols operate more frequently than once in 6 days.

    Although some monitoring for PM10 was initiated
prior to promulgation of the new standards, most
networks  did  not  produce data with  approved
reference samplers until mid-1987 or 1988.  Thus,
only a limited data base  is currently available to
examine trends in  PM10 air quality.  Accordingly,
longer-term trends in particulate matter are based
primarily on TSP.  Both 10-year  trends and recent
3-year changes in TSP are presented in terms of
average air quality (annual geometric mean).  In
addition, available information on PM,0 air quality
will  be used to report the 1988-1989 change in PM10
concentration levels.   Two PM1B statistics  are
presented.     The   annual   arithmetic  mean
concentration is used to reflect average air quality,
and the 90th percentile of 24-hour concentrations is
used   to   represent   the  behavior   of   peak
concentrations.  Because PM10 sampling frequency
varies among sites and may have changed during
the  2-year period, the 90th percentile is used. This
statistic is less sensitive  to changes in  sampling
frequency than the peak  values.  Finally, cross
sectional  PM10  data are  included for  the  more
comprehensive  data  available  for calendar year
1989.

3.1.1  Long-term TSP Trends: 1980-89

    The 10-year trend in average TSP levels, 1980
through 1989, is shown in Figure 3-2 for 1648 sites
geographically distributed  throughout the Nation.
Trends  are also  shown  for the subset of 219
National Air Monitoring Stations (NAMS) which are
located  in  areas  of  greater  than  50,000 in
population. The TSP levels are expressed in terms
of the composite average  annual geometric mean.

    The curves in  Figure 3-2  show  very  similar
trends for both the NAMS and the larger group of
sites, although composite particulate concentrations
are  higher for the  NAMS.   For  both curves,
                                              3-2

-------
measured TSP concentrations appear to
have declined during the first 2 years of
the 10-year period and are relatively
stable in the later years.  However, the
data collected during 1979 to 1981  may
have been affected by the type of filters
used  to collect  the TSP."   For this
reason,   the  portion  of  Figure  3-2
corresponding to the  years 1980-1981
are shaded, to indicate the uncertainty in
the TSP measurements collected during
this period. Nevertheless, a 20 percent
decrease between 1978  and 1982 has
been well documented. Since the exact
year-to-year changes during the 1980 to
1982  period are uncertain, the longer-
term  change   in  total   particulate
concentrations is described in terms  of
the 8-year period 1982-1989.

    Figure 3-2 also  includes 95 percent
confidence intervals developed for the
composite annual estimates.  It can be
seen that the estimates for  1982 -1989
are  relatively   stable   and  are  all
significantly lower than those of 1980 -
1981. Nationally, the composite average
TSP levels declined 1 percent from 1982
to 1989.  Upon close inspection, some
slight changes since 1982  are  evident.
First, the minimum composite TSP levels
occurred  during the  years  1985  and
1986.   Second, statistically  significant
changes were detected during the last 4
years, with the 1989 concentration levels
returning  to  the lower  concentrations
observed in  the  mid-1980's.    No
statistically significant  differences are
noted for the smaller group of TSP NAMS
trend  sites.   These recent changes  in
total suspended particulate matter will be
discussed in more detail in Section 3.1.3.

    The long-term trends in TSP are also
illustrated in Figure 3-3.  Using the same
national  data base of 1648 TSP sites,
Figure 3-3 shows the yearly change  in
the   entire  national   concentration
distribution using boxplot displays.  The
large difference between 1980-1981 and
the subsequent years is  evident for the
entire concentration distribution.  During
 80
    CONCENTRATION, UG/M'
 70 -

 60 -

 SO -

 40

 30 -

 20

 10

  0
                       • FORMER NAAQS
NAMS SITES (219)    ALL SITES (1648)
         I    i    i     i    I     i    i    i     i    i
      1980 1981 1982  1983 1984 1985 1986 1987  1988 198§
Figure 3-2. National trend in the composite average
of the geometric mean total suspended particulate at
both NAMS and all sites with 95 percent confidence
intervals, 1980-1989.
110
    CONCENTRATION, UG/MJ
100 -

 90 -

 80

 70 -

 60 -

 50 -

 40 -

 30 -

 20 -

 10 -

  0
                                       1848 SITES
         I    I    I     i    I    I     I    I     i    I
       1980 1981  1982 1983 1984 1985 1986 1987 1988 1989
Figure 3-3. Boxplot comparisons of trends in. annual
geometric mean total suspended particulate
concentrations at 1648 sites, 1980-1989.
                                              3-3

-------
the last 8  years,  the  national  TSP
distribution shows little change, although
more improvement is apparent among the
cleanest 10 percent of the sites.

3.1J2  TSP Emission Trends
    Nationwide  TSP  emission  trends
show an overall decrease of 15 percent
from 1980 to 1989.  Over the 8 years,
1982-1989,   these  total   particulate
emissions remained relatively constant.
(See  Table 3-1 and Figure  3-4).  The
trend in PM emissions is normally not
expected to  agree precisely with the
trend in ambient TSP levels, however,
due to unaccounted for natural  PM
background and uninventoried emission
sources such  as,  unpaved  roads  and
construction  activity.    Such  fugitive
emissions are not considered in  estimates of the
annual nationwide total and could be significant in
populated areas. Information on these sources is
presented in terms of the PM10 portion of particulate
matter in Section 3,1.5. The  10-year reductions in
inventoried particulate emissions occurred primarily
in the fuel combustion and  industrial processes
categories.
      TSP EMISSIONS, 10° METRIC TONS/YEAR
    1980  1981   1982  1983  1984  1985  1986  1987  1988  1889
Figure 3-4. National trend in particulate emissions,
            1980-1989.
         This is attributed to installation of control equipment
         by  electric utilities,  despite an increase  in  fuel
         comsumed and also to reduced activity in some
         industries, such as iron and steel.1 A large increase
         in the miscellaneous category for 1988 is attributed
         to the forest fires which occurred that year. Total
         particulate  emissions  are  estimated  to have
         decreased 4 percent from  1988 to 1989.
   TABLE 3-1.  NATIONAL TOTAL SUSPENDED PARTICULATE EMISSION ESTIMATES, 1980-1989
(mill
SOURCE
CATEGORY
Transportation
Fuel
Combustion
Industrial
Processes
Solid Waste
Miscellaneous
TOTAL
1980
1.3
2.4
3.3
0.4
1.1
8.5
1981
1.3
2.3
3.0
0.4
0.9 '
8.0
1982
1.3
2.2
2.6
0.3
0.7
7.1
on metric tons/year)
1983
1,3
2.0
2.4
0.3
1.1
7.1
1984
1.3
2.1
2.8
0.3
0.9
7.4
1985
1.4
1.8
2.8
0.3
1.1
7.3
1986
1.4
1.8
2.5
0.3
0.9
6.8
1987
1.4
1.8
2.5
0.3
1.0
7.0
1988
1.5
1.7
2.7
0.3
1.3
7.5
1989
1.5
1.8
2.7
0.3
1.0
7.2
*> ">

                                             3-4

-------
3.13 Recent TSP Trends 1987-89
   The TSP trends for the 3-year period
1987-1989  are presented in terms of
1014 sites which produced data in each
of the last 3 years.  The group of sites
qualifying for this analysis is smaller than
the group  used to analyze long-term
trends, reflecting the revisions to TSP
SLAMS  networks   and  the  shift  of
paniculate  monitoring   to   PM,0.
Nationally,   little   change   occurred
between 1987 and 1969, although 1988
produced  statistically   higher
concentrations. On the basis of the 1014
sites with data in 1987,1988 and 1989,
average   TSP  concentrations   were
highest in 1988 and were lowest in 1989.
Nationally,  average  concentrations
decreased  5  percent between these 2
years.   This  3-year  pattern was not
consistent,  however, among geographic
Regions of the country.
  80
                                            CONCENTRATION, UG/M
70 -

60-

50 -

40 -

30 -

20 -

10 -
                    COMPOSITE AVERAGE
                      mi  M IBM   DIM
 REGION  I
 # SITES 79
           II   III   IV   V   VI  VII  VIII  IX   X
           69  89   315  159   54   90   50  72  27
Figure 3-5.  Regional comparisons of the 1987,1988
and 1989 composite averages of the geometric mean
total suspended participate concentrations.
    Figure 3-5 focuses on the last 3 years with a
bar chart of Regional average TSP. Overall there
were relatively small changes in  most Regions.
The  most  notable difference  occurred  in  the
western most Regions. For Region IX (AZ, CA, HI,
NV),  total  paniculate concentrations  showed  a
slight but steady increase. This is attributed to the
extended drought in this Region. In Region X (AK,
ID,  OR, WA),  total  paniculate  levels  sharply
declined, and then showed no change between the
last  2 years.   This change is due to abnormally
high  1987  paniculate levels associated with an
unusual  number  of wildfires  in  the  Pacific
Northwest.6

    The  observed  year-to-year  variations  in
paniculate  levels may  in part be attributable to
meteorology.      Among   all   meteorological
parameters, precipitation has been shown to have
had the greatest influence on paniculate air quality.
Rainfall has the effect of reducing reenlrainment of
particles and of washing particles out of the air.
Generally drier conditions are also associated  with
an increase in forest fires.

    During 1988, most of the nation experienced an
extreme  drought.  Nationally, this year was the
         driest since 1956 and the second driest in the last
         50 years.   Most of the Nation returned to more
         normal annual  rainfall  in  1989.   The  drought
         worsened,  however,  in  EPA Region  IX where
         annual rainfall declined 18 percent.7

         3.1.4 Recent  PMJO Air Quality

            The 1988-1989 change in the PM10 portion of
         total paniculate concentrations is examined at 357
         monitoring locations which produced data in both
         years. A more comprehensive national sample of
         763 sites  is also presented to provide  a more
         representative   indication  of  PM10 air  quality
         produced by reference PM10 samplers.

            The sample of 357 "trend" sites reveals a small
         but statistically significant 3 percent decrease in
         average PM10 concentrations. This is  consistent
         with the 5  percent decrease in total particulates
         described  earlier.      Peak  24-hour  PM10
         concentrations decreased 3  percent.   This was
         examined  in terms of the average of the  90th
         percentiles  of  24-hour concentrations  among
         sampling locations.
                                             3-5

-------
          110
                CONCENTRATION, UG/M'
                        357
                    Trend Sites
                    1988 & 1989
                                                     90th %-tile
                                                  of 24-hr concentrations
                      1   I
                    1988 1989
1989
   I   I
1988 1989
1989
         Figure 3-6.  Boxplot comparisons of the 2-year change in PM10
         concentrations (1988-1989) at 357 sites with 1989 PM10 air quality at 763
         sites.
   Figure 3-6 displays boxplots of the concentration
distribution for the two PM10 trend statistics - annual
arithmetic mean and 90th  percentile  of 24-hour
concentrations.   The  1988  and  1989 national
distributions are very similar for both annual average
and 90th percentile of 24-hour PM10 concentrations.
Figure   3-6   also   displays  the  concentration
distributions  for the larger  sample of 763  sites.
While the larger group of sites is 2 percent lower in
the composite average  annual arithmetic mean, it
also has a  slightly  higher percentage of  high
concentrations sites.

   The more representative  1989 concentration
distribution of annual arithmetic means also provides
a basis for direct comparison to the annual standard
of 50 pg/m3.  Approximately 7 percent of monitoring
stations  reported  averages  above  the  annual
standard.

   Although the 90th percentile  is a  reasonable
peak   concentration   indicator   for  temporal
comparisons, it does not directly relate to the 150
ng/m3 level of the 24-hour PM10 standard. Since this
standard permits  one expected  exceedance  per
                         CONCENTRATION, UG/M3
180 -
120 -

90 -


60 -

30 -
n -
, 1

1 1 "
1 *
1 x

•• ^.

3V"
T
                               90TH     2ND     MAX
                              %-TILE    MAX
                    Figure 3-7.  Boxplot comparisons of 24-
                    hour PM10 peak value statistics for 1989
                    at 763 sites.
                                             3-6

-------
year, the maximum and second maximum
24-hour concentrations  provide  a more
direct indication of attainment status.  A
comparison of the 90th percentile of 24-
hour  concentrations  to  these  other
indicators  of  peak  concentrations  is
presented in Figure 3-7  using boxplots of
the   1989   national   concentration
distribution.  Although the 90th percentile
concentrations are well below 150 WJ/m3,
maximum  concentrations  exceed  tie
standard at  11 percent of the  reporting
locations while  the  second  maximum
concentrations exceed at 7 percent.

   Figure 3-8 presents  the  Regional
distribution of PM10 concentrations for both
average   and   90th  percentile
concentrations among the 763  stations
producing  reference  measurements  in
1989. The highest average and peak 24-
hour concentrations are seen in  Regions
IX and X.

   The  90th  percentile   of   24-hour
concentrations has  been  used as  the
indicator of peak concentrations because
of differences  in sampling  frequency
among PM10 sampling locations.  Note that
average sampling frequency varies among
Regions, with  samplers in Regions  VIII
and X operating at more than twice the
frequency of samples in Region II and
Region  IX.  The  monitoring regulations
permit  such  differences  in  sampling
frequency.  The  regulations specify that
only areas that are close to the 24-hour
standard must sample more frequently.

   Rgure 3-9 presents the 2-year change
in annual average and 90th percentile
PM10 concentrations by EPA Region. The
slight  national decrease is evident in most
Regions.  The PM10 increase  seen in
Region IX is consistent with the change in
total  participates reported  earlier, but is
not statistically significant.  Due to the
drought  in  the  Southwestern  United
States, particulate levels may be higher
than  normal.  Region IX's 1989 rainfall
was 31 percent below normal.
     CONCENTRATION, UG/M
                  78       96   „.  84  151
                REGIONAL AVERAGE
                   ARITHMETIC    • 90TH
                   MiAN           PERCiNTlLE
  REGION I    II
  # SITES 95   39
111   IV   V   VI
69  68  158  52
VII  VIII  IX   X
39   70 120  61
Figure 3-8. Regional comparisons of annual mean
and 90th percentile of 24-hour PM10 concentrations
for 1989,
  150
     CONCENTRATION, UG/M"5
  100-
            1988-09
        • •MEANS
            1988-89
        DD 90TH-%TILES
       Jl
  REGION   I    I!   Ill   IV  V   VI   VII  VIII  IX  X
  # SITES   32  18  25  43  81   26   29  45  22  36
Figure 3-9. Regional changes in annual average and
90th percentile of 24-hour PM10 concentrations,
1988-1989.
                                              3-7

-------
3.1.5  PMin Emission Trends
    Trends in the PM10 portion of paniculate matter
emissions are presented for the five-year period,
1985-1989 in Table 3-2. These estimates indicate
that  virtually no  change  had occurred  in the
"traditional" source categories during this five year
period.  Furthermore, PM1? appears to  represent
essentially all of  the paniculate  emissions from
transportation sources and most of the emissions
in the other traditional source categories.  As was
the case for TSP, higher emissions  occurred in
1988 due to forest fires.  National estimates are
also provided for PM10 fugitive emissions for the
single year, 1985, in Table 3-3. The 1985 data was
selected because it represents tile best available
inventory of fugitive  emissions,   in  total, these
fugitive  emissions are 8  times more  than the
traditional paniculate matter sources categories.
Regional  breakdowns  reveal  that  particulates
attributed  to wind  erosion  are highest in the
Southwest  (Region VI) and the Rocky Mountain
States (Region VIII), while emissions from unpaved
roads are  high in all  Regions  covering  large
geographic areas.1
                 TABLE 3-2. NATIONAL PM10 EMISSION ESTIMATES, 1985-1989
(million metric tons/year)
SOURCE
CATEGORY
Transportation
Fuel
Combustion
Industrial
Processes
Solid Waste
Miscellaneous
TOTAL
1985
1.3
1.2
2.4
0.2
0.8
5.9
1986
1.3
1.2
2.1
0.2
0.6
5.5
1987
1.3
1.2
2.1
0.2
0.7
5.6
1988
1.4
1,2
2.3
0.2
1.0
6.1
1989
1.5
1.3
2.3
0.2
0.7
5.9

I 11
11
                                             3-8

-------
TABLE 3-3. 1985 FUGITIVE EMISSIONS FOR PM
                                      10
SOURCE CATEGORY
Agricultural Tilling
Burning
Construction
Mining and Quarrying
Paved Roads
Unpaved Roads
Wind Erosion
TOTAL
MILLION METRIC TONS/YR
7.4
0.7
12.2
0.4
5.9
17.3
3.8
47.7
                   3-9

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3.2 TRENDS IN SULFUR DIOXIDE
   Ambient sulfur dioxide  (SO2) results largely
from stationary source coal and oil combustion,
refineries,  pulp  and  paper  mills  and  from
nonferrous smelters. There are three NAAQS for
SOZ: an annual arithmetic mean of 0.03 ppm (80
u.g/m3}, a 24-hour level of 0.14 ppm {365 ug/m3)
and a 3-hour level of 0.50 ppm (1300 u.g/nf). The
first two standards are primary (health-related)
standards,  while  the  3-hour NAAQS  is  a
secondary (welfare-related) standard. The annual
mean standard is not to be exceeded, while the
short-term standards are not to be exceeded more
than once per year.  The trend analyses which
follow are for the primary standards.  It should be
noted that EPA is currently evaluating the need
for a new shorter-term 1-hour standard,8

   Although this report does not directly address
trends in acid deposition, of which SO2 is a major
contributor,  it does include information on total
nationwide emissions which is a measure relating
to total atmospheric loadings.

   The trends in  ambient concentrations  are
derived from continuous monitoring instruments
which can  measure as  many  as 8760 hourly
values per year. The SO,, measurements reported
in this section are summarized  into a variety of
summary  statistics  which relate  to the  SO2
NAAQS.  The statistics on which ambient trends
will  be reported are the annual  arithmetic mean
concentration, the second highest annual 24-hour
average (summarized midnight to midnight), and
the   expected  annual  number  of  24-hour
exceedances of the 24-hour standard of 0.14 ppm.

3.2.1 Long-term SO2 Trends: 1980-89

    The  long-term trend  in ambient  SO2,  1980
through 1989, is graphically presented in Figures
3-10 through 3-12. In each figure, the trend at the
NAMS is contrasted with the trend at all sites. For
each  of  the statistics presented,  a  10-year
downward trend is evident, although the rate of
decline  has slowed over  the  last 3 years.
Nationally, the annual mean SO2, examined at 409
sites, decreased at a median rate of approximately
3 percent per year; this resulted in an overall
change of about 24 percent (Figure 3-10).  The
subset of 133 NAMS recorded higher average
                CONCENTRATION, PPM
U.UO3
OnQn _
,uou
0.025 -
0.020 -
0.015 -
OA-1 f\
,UiU

0.005 -
n nnn -

NAAQ^


*-— - *-_.
1 	 * ~ 	 T T T
n 	 x 	 s. 	 _ I -1- -I

• NAMS SITES {1 33) - ALL SITES 1409^

                   1980  1981  1982 1983 1984 1985 1986 1987  1988 1989
          Figure 3-10. National trend in annual average sulfur dioxide
          concentration at both NAMS and all sites with 95 percent confidence
          intervals, 1980-1989.

                                           3-10

-------
concentrations and also declined at the
same median rate, with a net change of
28 percent for the 10-year period.

   The annual second highest 24-hour
values displayed a similar improvement
between  1980 and 1989.   Nationally,
among 405 stations with adequate trend
data, the median rate of change was 3
percent per year, with an overall decline
of 26 percent (Figure 3-11). The 135
NAMS exhibited an overall decrease of
30 percent.  The estimated number of
exceedances also showed declines for
the NAMS as well as for the composite
of all sites (Figure 3-12).  The national
composite   estimated   number  of
exceedances decreased 95 percent
from 1980 to 1989.  However, the vast
majority of SO2 sites do not show any
exceedances of the 24-hour NAAQS.
Most of the exceedances, as well as the
bulk of the improvements, occurred at
source-oriented sites.

   The statistical significance of these
long-term trends is graphically illustrated
in Figures 3-10 to 3-12 with  the 95
percent confidence intervals.  These
figures show that  the SOZ  levels are
statistically indistinguishable among the
last 3 years.   For both annual averages
and  peak 24-hour values, the  1989
composite average is significantly lower
than levels recorded before 1986.  For
expected exceedances of the 24-hour
standard, which experienced a more
rapid decline, the 1989 values are only
statistically different than the levels for
1984 and 1980 to 1982.
0,16
     CONCENTRATION, PPM
0.14

0.12 -

0.10 -

0,08 -

0.06 -

0.04 -

0.02

0.00
                       -NAAQS•
         NAMS SITES (135)
       1980 1981 1982  1983 1984 1985 1986 1987  1988 1989
Figure 3-11.  National trend in the second-highest
24-hour sulfur dioxide concentration at both NAMS
and all sites with 95 percent confidence intervals,
1980-1989.
 1.0
     ESTIMATED EXCEEDANCES
 0.5 -
         NAMS SITES.(135)
                             n ALL SIT£SJ40_5)_
                                             1980 1981  1962 1983 1984 1985 1986  1987 1988 1989
                                       Figure 3-12. National trend in the estimated
                                       number of exceedances of the 24-hour sulfur
                                       dioxide NAAQS at both NAMS and all sites with 95
                                       percent confidence intervals, 1980-1989.

                                           3-11

-------
   The inter-site variability for annual
mean  and  annual  second  highest
24-hour  SO2   concentrations   is
graphically displayed  in  Figures 3-13
and  3-14.   These  figures show that
higher concentrations decreased more
rapidly and that the concentration range
among sites has also diminished during
the 1980's,

   Nationally,  sulfur  oxides  (SOx)
emissions decreased 10 percent from
1980 to 1989 (Figure 3-15 and Table
3-4).  This decrease is attributable to
three general changes.1    First,  the
decrease   is   attributable   to   the
installation of  flue gas desulfurization
controls  at  new  coal-fired  electric
generating stations and a reduction in
the  average sulfur content of fuels
consumed  over  the  10-year period.
Second,   emissions  from   industrial
processes have  declined, primarily as
the result of controls  implemented to
reduce  emissions  from  nonferrous
smelters and sulfuricacid manufacturing
plants, as well as shutdowns of some
large smelters.  Finally, emissions from
other stationary source fuel combustion
sectors also declined, mainly due to
decreased combustion of coal by these
consumers.

   A small  (1  percent)  increase  in
sulfur oxides emissions between 1988
and 1989 can be attributed to increased
electric generation.

   The  disparity  between  the  24
percent improvement in SO2 air quality
and  the 10 percent decrease in SOx
emissions can be attributed  to several
factors.  SO2  monitors with  sufficient
historical data for trends are  mostly
urban population-oriented. They do not
monitor many of the  major emitters
which tend to be located in more rural
areas (e.g. large power plants).
 0.040
      CONCENTRATION, PPM
 0.035 -

 0.030

 0.025 -

 o.oao -

 0.015 -

 0.010 -

 0.005 -

 0.000
                                        409 SITES
-NAAQS
          I     I    I    I    I    I    I    I     I    I

         1980 1981 1982 1983  1984 1985 1986 1987 1S88 1989
Figure 3-13. Boxplot comparisons of trends in
annual mean sulfur dioxide concentrations at 409
sites, 1980-1989.
 0.20
      CONCENTRATION, PPM
 0.15 -
 0.10 -
 0.05
 0.00
                                        405 SITES
                                                -•NAAQS
          I     I    I    i    I     I    I    I     I    I

         1980 1981 1982 1983 1984 1985 1986 1987 1888 1989
                                       Figure 3-14.  Boxplot comparisons of trends in
                                       second highest 24-hour average sulfur dioxide
                                       concentrations at 405 sites, 1980-1989.
                                            3-12

-------
   Although most of the trend sites are
categorized as population-oriented, the
majority   of   SOx   emissions   are
dominated  by  large  point sources.
Two-thirds of all national SOx
emissions are  generated by  electric
utilities (95 percent of which come from
coal fired power plants). The majority of
these emissions, however, are produced
by a small  number  of facilities. Fifty
individual plants in 15 states account for
one-half  of all power plant emissions.
In addition,,  the  200  highest  SOx
emitters  account  for  more than  85
percent  of   atl  SOx  power  plant
emissions.  These 200 plants account
for 59 percent of all  SOx  emissions
nationally.0

   Another factor which  may account
for differences in SOx emissions and
ambient air quality is stack height.  At
large utilities  and  smelters,  SO2  is
generally released into the atmosphere
through tall stacks.  Although sources
are not permitted to increase emissions
through increased dispersion from tall
stacks, measured ground level
    SCL EMISSIONS, 10* METRIC TONS/YEAR
 10
  1i80  1981   1982  1983  1984  1985  1986   1987  1988  1989
Figure 3-15.  National trend in sulfur oxides
emissions, 1980-1989.
           TABLE 3-4.  NATIONAL SULFUR OXIDES EMISSION ESTIMATES, 1980-1989
(million metric tons/year)
SOURCE
CATEGORY
Transportation
Fuel
Combustion
Industrial
Processes
Solid Waste
Miscellaneous
TOTAL
1980
0.9
18.7
3.8
0.0
0.0
23.4
1981
0.9
17.8
3.9
0.0
0.0
22.6
1982
0.8
17.3
3.3
0.0
0.0
21.4
1983
0.8
16.7
3.3
0.0
0.0
20.7
1984
0.8
17.4
3.3
0.0
0.0
21.5
1985
0.9
17.0
3.2
0.0
0.0
21.1
1986
0.9
16.9
3.2
0.0
0.0
20.9
1987
0.9
16.6
3.2
0.0
0.0
20.7
1988
0.9
16.6
3.4
0.0
0.0
20.9
1989
1.0
16.8
3.3
0.0
0.0
21.1

NOTE: The sums of sub-categories may not equal total due to rounding.
                                            3-13

-------
concentrations  in the vicinity of these
exixting  sources  may not reflect local
emissions.  Total atmospheric  loading
impacts   also  arise, in  part,  as  a
consequence of tail stacks.

3.2J2 Recent SO2 Trends: 1987-89

   Nationally.   SO2 showed   minor
changes over the  last three  years.
Composite   average   concentrations
increased 3 percent between 1987 and
1988 and then decreased a little over 3
percent   between   1988 and  1989.
Regional changes in composite annual
average SO2 concentrations for the last
3  years,  1i87-1989,  are  shown in
Figure 3-16.  Most Regions show little
change among the last 3 years, with the
exception of Region X, which shows a
large decrease since 1987. This was
the   result  of   tower   monitored
concentrations in the vicinity of State of
Washington pulp mills.
0,016
     CONCENTRATION, PPM
0.014 -

0.012 -

0.010 -

0.008-

0.006-

0.004-

0.002 -
         COMPOSITE AVERAGE
           1987 • 1968 01989
                        1
It
 REGION I
 # SITES 46
II   III   IV   V   VI   VII   VIII  IX   X
43  67  78  147   38  25   16  43  10
Figure 3-16.  Regional comparisons of the 1987,1988,
1989 composite averages of the annual average
sulfur dioxide concentration.
                                           3-14

-------
33 TRENDS IN CARBON MONOXIDE
   Carbon  monoxide  (CO)  is  a  colorless,
odorless  and poisonous  gas  produced  by
incomplete   burning  of  carbon  in   fuels.
Two-thirds of the nationwide CO emissions are
from transportation  sources, with the largest
contribution coming from highway motor vehicles.
The NAAQS for ambient CO specify upper limits
for both 1-hour and 8-hour averages that are not
to be exceeded more than once per year.  The
1-hour level is 35 ppm, and the 8-hour level is 9
ppm. This trends analysis focuses on the 8-hour
average results because the 8-hour standard is
generally the more restrictive limit.  Nationally,
during  1989, only three  exceedances of the CO
1 -hour NAAQS were recorded at two sites which
are impacted by localized,  non-mobile sources,
and in each case the 8-hour NAAQS was still the
controlling standard.

   Carbon monoxide  enters the bloodstream
and disrupts the delivery of oxygen to the body's
organs and tissues.  The health threat is serious
for those who suffer from cardiovascular disease,
particularly  those with  angina or peripheral
vascular disease.  Exposure to elevated carbon
monoxide levels is associated with impairment of
visual  perception,  manual  dexterity,  learning
ability and performance of complex tasks.

   Trends   sites were  selected  using the
procedures  presented  in  Section  2.1 which
yielded a data base of 280 sites for the 10-year
period  1980-89 and a data base of 355 sites for
the 3-year  1987-89 period.   There  were 87
NAMS sites included in the 10-year data base
and 103 NAMS sites in  the 3-year data base.
3.3.1 Long-tern CO Trends: 1980-89

    The 1980-89  composite national average
trend is shown in  Figure 3-17 for the second
highest non-overlapping 8-hour CO concentration
for the 280 long-term trend sites and the subset
of 87 NAMS sites.  During this 10-year period,
the national composite average decreased by 25
percent and the subset of NAMS decreased by
28 percent. The median rate of improvement for
this time period is slightly more than 3 percent
per  year.  After leveling off to no  significant
change from 1985 to 1986,  the trend resumed
downward in 1987 and tater years.   Long-term
improvement was seen in each EPA Region with
median rates of improvement varying from 2 to 5
percent per year. The  1989  composite average
is significantly lower than the composite means
for 1986 and earlier years.  This same trend is
shown in Figure 3-18 by a boxpiot presentation
which provides more information on the year-to-
year distribution of ambient CO levels at the 280
long-term trend sites.  While  there is some year
to year  fluctuation in  certain percentiles, the
general long-term improvement in ambient CO
levels is clear.

   Figure 3-19 displays the 10-year trend in the
composite average of the estimated number of
exceedances of the 8-hour  CO NAAQS.  This
exceedance  rate was  adjusted to account for
incomplete sampling. The trend in exceedances
shows long-term improvement but the rates are
much  higher  than  those   for  the  second
maximums. The composite average of estimated
exceedances  decreased  80 percent between
1980 and 1989 for the 280 long-term trend sites,
while the subset of 87  NAMS  showed a 77
percent decrease.  These percentage changes
for exceedances are typically much  larger than
those found for peak concentrations, such as the
annual second maximum 8-hour value, which is
more likely to reflect  the change in emission
levels. The upturns in the composite average of
the  estimated exceedances  between 1987 and
1988, and between 1988  and  1989  are not
statistically significant, and are  not evident in the
larger 3-year data base.
                                          3-15

-------
Figure 3-17. National trend in the
composite average of the second
highest  nonoverlapping  8-hour
average   carbon   monoxide
concentration at both MAMS and
all  sites   with  95   percent
confidence intervals, 1980-1989.
 12 •
   CONCENTRATION, PPM
 10 -


 8 -


 6 -


 4 -
	NAAQS 	
• NAMS SITES (87)
• ALL SITES [280J
                                              I    I    I    1    I    I    I    I    I     I
                                            1880 1981 1982 1983  1984 1985 1986 1987 1988 1989
Figure 3-18. Boxplot comparisons
of  trends  in  second  highest
nonoverlapping 8-hour  average
carbon monoxide  concentrations
at 280 sites, 1980-1989.
20
   CONCENTRATION, PPM
•15 -
                                       10 -
                                     280 SiTES
                                              I    i    I     I    r    i    I    l    l     I
                                            1980 1981  1982 1983 1984 1985 1986 1987  1988 1989
Figure 3-19. National trend in the
composite   average   of   the
estimated number of exceedances
of the 8-hour  carbon  monoxide
NAAQS, at both NAMS and all
sites with 95 percent confidence
intervals, 1980-1989.
    EST. 8-HR EXCEEDANCES
 10 -
         NAMS SITES (87)
      ALLSlT|S_(2BO)_
                                              1    I    1     !    I    i    I    i    I     I
                                            1980 1981 1982  1983  1984 1985 1986 1987 1988 1989
                                           3-16

-------
                              120
                                  CO EMISSIONS, 106 METRIC TONS/YEAR
                              100 -
                               80 -
                               60 -
                               40 -
SOURCE CATEGORY

  TRANSPORTATION

• FUEL
  COMBUSTION
                                                               INDUSTRIAL PROCESSES

                                                               SOLID WASTE S M ISC
   The  10-year 1980-89  trend  in
national  carbon monoxide  emission
estimates is shown in Figure 3-20 and
in Table 3-5.  These estimates show a
23 percent decrease between 1980
and  1989.   Transportation  sources
accounted for approximately 70 percent
of the total in 1980 and decreased to
66 percent of total emissions in 1989.
Emissions  from highway   vehicles
decreased  33   percent during  the
1980-89  period, despite a 39 percent
increase in vehicle miles of travel.1
Figure 3-21  contrasts  the  10  year
increasing  trend  in   vehicle  miles
travelled (VMT) with the declining trend
in  carbon monoxide emissions  from
highway  vehicles. This  indicates that
the  Federal  Motor  Vehicle Control
Program (FMVCP) has been effective
on the  national scale,  with controls
more than offsetting growth during this
period.     While there  is  general
agreement between  changes  in  air
quality and emissions over this 10-year
period,  it  is worth  noting  that  the
emission changes reflect estimated
TABLE 3-5. NATIONAL CARBON MONOXIDE EMISSION ESTIMATES, 1980-1989
                                1980  1981  1982  1983  1984  1985  1986  1987  1988  1989
                             Figure 3-20.  National trend in emissions of carbon
                             monoxide, 1980-1989.
(million metric tons/year)
SOURCE
CATEGORY
Transportation
Fuel
Combustion
Industrial
Processes
Solid Waste
Miscellaneous
TOTAL
1980
56.1
7.4
6.3
2.2
7.6
79.6
1981
55.4
7.7
5.9
2.1
6.4
77.4
1982
52.9
8.2
4.3
2,0
4.9
72.4
1983
52.4
8.2
4.3
1.9
7.7
74.5
1984
50.6
8.3
4.7
1.9
6.3
71.8
1985
47.9
7.5
4.4
1.9
X /
7.9
69.6
1986
44.6
7.5
4.2
1.8
5.9
64.0
1987
43.3
7.6
4.3
1.8
7.2
642
1988
41.2
7.6
4.6
1.7
9.9
65.0
1989
40.0
7.8
4.6
1.7
6.7
60.9

NOTE: The sums of sub-categories may not equal total due to rounding.
                                  3-17

-------
national  totals,   while   ambient  CO
monitors are frequently located to identify
problems. The mix of vehicles and the
change in vehicle miles of travel in the
area around  a specific CO  monitoring
site  may  differ  from  the  national
averages.
    Figure  3-23 displays  the 10-year
trend among MSAs of varying population
size.  Only those sites meeting the ten-
year  trends  data  completeness and
continuity  criteria were included  in the
analysis.   Three  size categories are
shown:  27 moderate-sized MSAs with
populations of 250  to 500 thousand; 35
large MSAs with populations between
500 thousand and one million; and  43
very-large MSAs with populations greater
than one million. The composite means
are generally  higher in the very-large
MSAs, although the patterns are  mixed
for some years. The moderate and large
MSAs  had  1989  composite  average
second  highest nonoverlapping 8-hour
concentrations  22  percent lower than
1980 levels.    The  43  MSAs  with
populations  greater  than  one  million
recorded a 25 percent decrease during
                                      140
                                           % of 1980 towel
                                      120 -
                                       80 -
                                       60 -
                                       40
   Despite the progress that has been  100 -
made,  CO remains  a concern  in many
urban areas. The characterization of the
CO problem is  complicated because of
the growth  and possible changes in
traffic  patterns  that  have occurred in
many major urban areas.  There are a
variety of possible factors to consider,
such as  topography, meteorology, and
localized traffic flow.   The  goal  Is to
ensure  that the  monitoring networks
continue to characterize the ambient CO
problem  adequately.  However, these
concerns  should  not overshadow the
genuine progress documented over time
in areas that have traditionally been the
focus of the CO problem. Figure 3-22
demonstrates the progress that has been
made  in  reducing   carbon  monoxide
levels in Denver following implementation
of local and Federal  control measures.
Highway Vehicles
  I CO Emissions
                                             1980 1981  1982 1983 1984 1985 1986 1987 1988 1989
                                       Figure 3*21.  Comparison of trends in total national
                                       vehicle miles traveled and national highway vehicle
                                       emissions, 1980-1989.
                                        35

                                        30

                                        25

                                        20

                                        15

                                        10

                                         5

                                         0
                                           18-hr CO Exceedances
       Enhanced I/M
                   1.5% by wgt
                   Jan 1, 1988
                             Qxy-fucls
                             z.oKbx.wgt.
                          9  Nov 1,1988
                                             1986-87      1987-88      1988-89
                                                            Winter Seasons
                                 1989-9D
                                        Implementation of Local and Federal Control
                                        Measures - I/M, Oxy-Fuel, FMVCP
                                       Figure 3-22. Decrease in carbon monoxide
                                       exceedances in Denver, Colorado.
                                            3-18

-------
this 10-year period.  Between 1988 and
1989, the composite average decreased
3 percent for the moderate-sized MSAs,
2 percent for the large MSAs and less
than 1  percent for  the  very  large
metropolitan complexes.
3.3.2 Recent CO Changes

     This  section examines ambient
CO changes during the last 3 years,
1987-89. As discussed in Section 2.1,
this  allows the  use of a larger data
base, 355 versus 280 sites.  Between
1988 and 1989, the composite average
of the second highest non-overlapping
8-hour average concentration at 355
sites decreased by 1 percent and by
less  than 1 percent at the 103 NAMS
sites. The composite average of the
estimated  number of exceedances of
the 8-hour CO NAAQS at the 355 sites
decreased  by less than  1 percent
between 1988 and 1989.   Estimated
nationwide CO emissions decreased 6
percent between  1988 and 1989. Part
of this decrease is  attributed to a 4
percent reduction  in  CO   emissions
from highway vehicles.  A larger part,
however, is due to higher than normal
forest fire activity in 1988.

   Figure 3-24  shows  the composite
Regional averages for the 1987-89 time
period.  Five of the  10 Regions have
1989 composite mean levels lower
than their 1988  values and five are
higher in 1989.  Every Region, except
Region IX, have 1989 composite mean
levels  less than the  corresponding
1987 value. These Regional graphs
are primarily intended to depict relative
change.     Because   the   mix  of
monitoring  sites  may  vary  from  one
area  to another, this  graph is not
intended   to    indicate   Regional
differences in absolute concentration
levels.
     10
       CONCENTRATION, PPM
                         MSA Size
                > 1,OOQ,OQO > '508,000 > 2SO,000
                 I
      1980  1981  1982 1983  1984  1985 1986 1987  1988  1989

     No to: WB7 MSA population astliwlas
Figure 3-23. Metropolitan area trends in the
composite average of the second highest non-
overlapping 8-hour average carbon monoxide
concentration, 1980-1989.
    14
       CONCENTRATION, PPM
    12 -
                    COMPOSITE AVERAGE
                      19S7  • 1988  Q 1989
   REGION I    II   III  IV   V   VI  VII  VIII  IX   X
   # SITES 13   27  44  55  50   29  22   18   75   22
Figure 3-24. Regional comparisons of the 1987,1988
and 1989 composite averages of the second highest non-
overlapping 8-hour average carbon monoxide
concentration.
                                          3-19

-------
3.4  TRENDS IN NITROGEN DIOXIDE
   Nitrogen dioxide (MCy  is a yellowish brown,
highly  reactive  gas which is present in  urban
atmospheres.   The  major mechanism for the
formation of NO2 in the atmosphere is the oxidation
of the primary  air pollutant,  nitric oxide  (NO).
Nitrogen  oxides play  a major role, together with
volatile organic  compounds,  in the atmospheric
reactions that produce ozone.  Nitrogen oxides
form when fuel  is burned  at high temperatures.
The two major emissions sources are transportation
and stationary fuel combustion sources  such as
electric utility and industrial  boilers.

   Nitrogen oxides can irritate the tungs,  cause
bronchitis and pneumonia, and lower resistance to
respiratory infections.  Los Angeles, CA is the only
urban area  that has recorded violations of the
annual NO2 standard of 0.053 ppm during the past
10 years.

   NO2 is measured using a continuous monitoring
instrument which can collect  as many as  8760
hourly observations per year.  Only annual means
based on at  least 4380 hourly observations were
 considered in the trends analyses which follow. A
 total of 148  sites were selected for the 10-year
 period and 200 sites were selected for the 3-year
 data base.

 3.4.1 Long-term NO2 Trends: 1980-89

    The composite average long-term trend for the
 nitrogen dioxide mean concentrations at the 148
 trend sites and the 36  NAMS sites, is shown in
 Figure 3-25.  The 95 percent confidence intervals
 about the composite means allow for comparisons
 among the years.  Nationally, composite annual
 average NO2 levels decreased from 1980 to 1983,
 and remained essentially constant since 1984, The
 1989 composite average NO2 level is 5 percent
 lower than the 1980 level,  indicating  an overall
 downward trend during this period. A similar trend
 is seen for the NAMS sites which, for NO2, are
 located only in urban  areas with populations of
 1,000,000 or greater. As expected, the composite
 averages of the NAMS are higher than those of all
 sites, however, they also recorded a 5 percent
 decrease in composite mean levels during this
         0.06
               CONCENTRATION, PPM
0.05  -


0.04  -


0,03


0.02  -


0.01
               	NAAQS
         0.00
                     NAMS SITES (36)
n AJikSITES_(1_4_8)_
                    I     I      [     I     I     I      I     I     i      I
                 1980  1981  1982 1983  1984  1985 1986 1987  1988 1989
           Figure 3-25.  National trend in the composite annual average nitrogen
           dioxide concentration at both NAMS and all sites with 95 percent
           confidence intervals, 1980-1989.

                                           3-20

-------
period.  Although the 1989 composite
mean levels are 5 percent lower than the
1980  means,  an  examination  of  the
confidence intervals reveals that there
are no significant differences among all
years, for all sites and for the subset of
NAMS.

    Long-term  trends  in  NO2  annual
average  concentrations    are   also
displayed in Figure 3-26 with the use of
boxptots.   The improvement  in  the
composite average between 1980 and
1989 can generally be seen in the upper
pencentiles until 1984, with mixed results
in the  following years.   The  lower
pencentiles show little change, however.

    Figure  3-27 displays  the 10-year
trend among MSAs of varying population
size.  Only those sites meeting the ten-
year  trends  data  completeness and
continuity criteria were included in the
analysis. As expected, there are fewer
MSAs for NO2 in each size category than
for carbon  monoxide,  because  NO2
monitoring is only required in large cities.
Three size categories are shown:   16
moderate-sized MSAs with populations of
250 to  500 thousand;  14  large MSAs
with populations between 500 thousand
and one million; and 30 very-large MSAs
with populations greater than one million.
Unlike carbon monoxide, the level of the
NO2 composite means varies directly with
MSA size, the larger the population the
higher the concentration level. Although
the pattern of the year-to-year changes
differs somewhat among MSA size, the
long-term trend is consistent across MSA
size category with 1989 composite mean
levels 6 percent lower than  1980 levels.
 0.07
     CONCENTRATION, PPM
 0.06 -


 0.05


 0.04 -


 0.03 -


 0.02 -


 0.01 -


 0.00
                                        148 SITES

             I
                                  n
                                               -NMQS
I  I
          I    I    I     I    I    I     I    I    I     I

        1980 1981  1982 1983 1984 1985 1986 1987 1988 1989
Figure 3-26.  Boxplot comparisons of trends in
annual mean nitrogen dioxide concentrations at 148
sites, 1980-1989.
 0.03


0.025


 0.02


0.015


 0.01


0.005




 ttota:
      CONCENTRATION, PPM

                                „	O	•©	8	€
                                          — ^^^
                         MSA Size
                > 1,000,000 > 500,000  >  250,000
                                            1980  1981  1982  1983  1984  1985  1986  1987  1988  1989
                                       Figure 3-27. Metropolitan area trends in the
                                       composite annual average nitrogen dioxide
                                       concentration, 1980-1989.
                                            3-21

-------
   Table  3-6 presents  the  trend  in
estimated   nationwide   emissions   of
nitrogen oxides (NOx).  The decreasing
trend in  NOx  emissions from  1980
through 1983 was reversed in 1984. The
decline  in  NOx  nationwide  emissions
between  1985 and  1986  has  been
followed by increased NOx emissions in
1987 and 1988.   However, total 1989
nitrogen oxides emissions are 5 percent
less  than 1980  emissions.   Highway
vehicle  emissions decreased by  25
percent during this period, while fuel
combustion  emissions  have increased
during the last 3 years.  Figure 3-28
shows that the  two  primary source
categories of nitrogen oxides emissions
are fuel combustion and transportation,
composing 56 percent and 40 percent,
respectively,  of   total  1989  nitrogen
oxides emissions.
30
25 -
20 -
15
      y EMISSIONS, 10s METRIC TONS/fEAR
SOURCE CATEGORY

  THANSPOHTAT1ON

• FUELCOMBUSDON
                               SS INDUSTRIAL PROCESSES

                               • SOUD WASTE & MISC.
  1980  1B81  1982  1983  1984  1985  1986  1987  1988  1989
                                       Figure 3-28.  National trend in nitrogen oxides
                                       emissions, 1980-1989.
          TABLE 3-6.  NATIONAL NITROGEN OXIDES EMISSION ESTIMATES, 1980-1989
(million metric tons/year)
SOURCE
CATEGORY
Transportation
Fuel
Combustion
Industrial
Processes
Solid Waste
Miscellaneous
TOTAL
1980
9.8
10.1
0.7
0.1
0.2
20.9
1981
10.0
10.0
0.6
0.1
0.2
20.9
1982
9.4
9,8
0.5
0.1
0.1
20.0
1983
8.9
9.6
0.5
0.1
0.2
19.3
1984
8.8
10.2
0.6
0.1
0.2
19.8
1985
8.9
10.2
0.6
0.1
0.2
19.9
1986
8.3
10.0
0.6
0.1
0.2
19.1
1987
8.1
10.5
0.6
0.1
0.2
19.4
1988
8.1
10.9
0.6
0.1
0.3
20.0
1989
7.9
11.1
0.6
0.1
0.2
19.9

^^^^^^^^^^^^^^^ffi^^^^^K^^H^^^^i^S
                                            3-22

-------
3.4J2 Recent NO2 Changes
   Between  1988   and  1989,  the
composite  annual   mean   NO2
concentration at 200 sites, with complete
data  during  the  last  three   years,
decreased by 2 percent.  At the subset
of 47 NAMS,  the   composite  mean
concentration  decreased  1  percent
between  1988 and 1989,  Nationwide
emissions of nitrogen oxides decreased
1 percent between 1988 and 1989.

   Regional trends  in  the composite
average NO2 concentrations for the years
1987-89 are displayed  in  Figure 3-29
with bar graphs. Region X, which did not
have any NO2 sites which met the 3-year
data completeness and continuity criteria,
is not shown.  Since  the national trend
shows no significant change during this
period, the mixed pattern of the Regional
year-to-year changes is not surprising.
Between 1987 and 1988, three Regions
had increased  levels, three decreased,
and three remained  unchanged.   The
downturn seen in the  long-term data
base  in also found in the larger 3-year
data base.  Seven of the  nine Regions
have   1989  composite  mean
concentrations which are lower than the
corresponding  1988  levels.   Region  V
and Region VII recorded increases of 2
percent and 1 percent, respectively.
0.040
     CONCENTRATION, PPM
0.035 -

0.030

0.025 -

0.020 -

0.015 -

0.010 -

0.005 -
COMPOSITE AVERAGE
  1987  • 1988  Q19B9
 REGION  I    II   III   IV   V   VI   VII  VUI   IX
 # SITES  9    12  37   17   25   22    10   10   58
Figure 3-29.  Regional comparisons of 1987,1988,
1989 composite averages of the annual mean
nitrogen dioxide concentration.
                                           3-23

-------
3.5  TRENDS IN OZONE
   Ozone (O3) is a photochemical oxidant and the
major component of smog.  While ozone in the
upper atmosphere is beneficial to life by shielding
the earth from harmful ultraviolet radiation from the
sun,  high concentrations of ozone at ground level
are a major health  and environmental concern.
Ozone is not emitted directly into the air but  is
formed  through  complex   chemical   reactions
between precursor emissions of volatile organic
compounds and nitrogen oxides in the presence of
sunlight.    These reactions are  stimulated  by
sunlight and temperature so that peak ozone levels
occur typically during the warmer times of the year.
Both volatile organic  compounds  and nitrogen
oxides are emitted by transportation and industrial
sources. Volatile organic compounds are emitted
from sources  as  diverse  as  autos,  chemical
manufacturing, and dry cleaners, paint shops and
other sources  using solvents.   Nitrogen  oxides
emissions were discussed in Section 3.4.

   The reactivity of ozone causes health problems
because it tends to break down biological tissues
and cells. Recent scientific evidence indicates that
high  levels of ozone not only affect people with
impaired respiratory systems, such as asthmatics,
but healthy adults and children, as well. Exposure
to ozone for only several hours at relatively low
concentrations  has been  found to significantly
reduce  lung function in normal, healthy  people
during exercise. This decrease in lung function
generally is accompanied by symptoms including
chest pain, coughing, sneezing  and pulmonary
congestion.

    The O3 NAAQS is defined in terms of the daily
maximum, that  is, the highest hourly average for
the day, and it specifies that the expected number
of days per year with values greater than 0.12 ppm
should not be greater than one.  Both the annual
second highest  daily maximum and the number of
daily exceedances during the ozone season are
considered in this analysts.  The strong seasonality
of ozone levels  makes it possible for areas to limit
their ozone monitoring to a certain portion of the
year, termed the ozone season. The length of the
ozone season varies from one area of the country
to another.  May through  October  is typical but
states in the south and southwest may monitor the
entire year.  Northern States would have  shorter
ozone seasons such as May through September for
        0.18
              CONCENTRATION, PPM
0.16  -

0.14  -

0.12  -

0.10  -

0.08

0.06  -

0.04  -

0.02  -

0.00
                   NAMS SITES (1 86)
ALL SITES (431J
                   i      i     I     I      i     I     i      i     i      i
                 1980  1981 1982  1983  1984 1985  1986 1987 1988  1989
           Figure 3-30.  National trend in the composite average of the second
           highest maximum 1-hour ozone concentration at both NAMS and all
           sites with 95 percent confidence intervals, 1980-1989.
                                            3-24

-------
North Dakota. This analysis uses these
ozone seasons to ensure that the data
completeness requirements apply to the
relevant portions of the year.

   The trends site selection process,
discussed in Section 2.1,  resulted in 431
sites being selected for the 1980-89
period, an increase of 43 sites (or 11%)
from the 1979-88  trends data base.  A
total of 581 sites  are included in the
1987-89  data  base.    The  NAMS
compose 186 of  the long-term trends
sites and 208 of the sites in the 3-year
data base.
3.5.1 Long-term   O3
      1980-89
Trends;
             0.30
                 CONCENTRATION, PPM
0.25 -


0.20 -


0.15 -


0.10 -


0.05 -


0.00
                                                   431 SITES
                      I    T    I    I     I    1    I    I     I    I
                    1980 1981 1982 1983 1984 1985 1986  1987 1988 1989
   Figure 3-30  displays the  10-year
composite average trend for the second
highest day during the ozone season for
the 431  trends sites and the subset of
186 NAMS sites.  The 1989 composite
average lor the  431  trend  sites  is 14
percent  lower than the  1980  average,
yielding the lowest composite average of
the past ten years. The 1989 composite
average is significantly  less  than  the
1988  composite  mean, which  is  the
second highest average  (1983 was the
highest) during this ten year period. The
relatively high ozone concentrations in
both 1983 and 1988 are  likely  attributed
in part to hot, dry, stagnant conditions in
some areas of  the country that were
more conducive to ozone formation than
other years. Meteorological conditions in
the summer of 1989 were less conducive
to ozone formation than 1983 and 1988.
In the East, the  period from January
through  July 1989  was  among  the
wettest on record in nine states.10

   The inter-site variability of the annual
second   highest  daily   maximum
concentrations for the 431 site data base
is displayed in Figure 3-31.  The years
1980,1983 and 1988 values are similarly
high, while the remaining years in the
1980-89 period are generally lower, with
            Figure 3-31.  Boxplot comparisons of trends in
            annual second highest daily maximum 1-hour ozone
            concentration at 431 sites, 1980-1989.
              15
                 NO. OF EXCEEDANCES
              10  -
               5 -
                     NAMS SITES (186)
                              aALLSJTES|431i_
                      i    i    i    i     I    i    I    i     I    i
                    1980 1981 1982 1983 1984 1985 1986 1987  1988 1989
            Figure 3-32. National trend in the estimated
            number of daily exceedances of the ozone NAAQS
            in the ozone season at both NAMS and all sites
            with 95 percent confidence intervals, 1980-1989.
                                            3-25

-------
1989  being  the  lowest,  on  average.   The
distribution  of second daily  maximum 1-hour
concentrations in 1989 is similar to that recorded in
1986. The 1987 ozone concentration distribution is
comparable to 1984 and 1985 except  for the peak
sites,  which were  considerably tower than these
earlier years.   Figure 3-32  depicts the 1980-89
trend for the composite  average number of ozone
exceedanees. This statistic is adjusted for missing
data,  and ft reflects the number of days that the
ozone standard is exceeded  during the ozone
season.  Since 1980,  the expected number of
exceedances  decreased 53 percent  for the 431
sites and 60 percent for the  186 NAMS. As with
the second maximum, the 1980, 1983  and  1988
values are  higher than the other years in the
1980-89 period.  The endpoints of this ten year
period represent the two extremes, with the  1980
composite average of the number of  estimated
exceedances being the highest level during the last
ten years, and 1989 the lowest.
                   Figure 3-33 displays the 10-year trend in the
                composite average of the second daily maximum 1-
                hour concentrations  among MSAs  of  varying
                population size.  Only those sites meeting the ten-
                year trends  data completeness and  continuity
                criteria were  included in the analysis.  Three size
                categories are shown: 40 moderate-sized MS As
                with populations of 250 to 500 thousand; 34 large
                MSAs with populations between 500 thousand and
                one  million;  and   37  very-large MSAs with
                populations   greater  than  one  million.    The
                magnitude of the ozone composite averages of the
                second daily maximum 1-hour concentrations varies
                directly with MSA size, the larger the population the
                higher the concentration level.  Although the pattern
                of the year-to-year changes is similar among MSA
                size, the  long-term trend varies across  MSA size
                category. The 1989 composite mean in the very-
                large MSAs is 16 percent lower than 1980 level, 13
                percent lower for the large MSAs and  8 percent
                lower for the  medium-sized MSAs.
        0.16

        0.14

        0.12

         0.1

        0.08

        0.06

        0,04

        0.02
             CONCENTRATION, PPM
              j_
            MSA Size
> 1,000,000 >  500,000  > 250,000
                                    L
                                                                                I
             1980    1981    1982   1983    1984   1985   1986    1987    1988   1989

         Note.- 1S87MSA population estimates
           Figure 3-33, Metropolitan area trends in the composite average of the
           second highest maximum 1-hour ozone concentration, 1980-1989.
                                           3-26

-------
   Table 3-7 and Figure 3-34 display the
1980-89  emission trends  for volatile
organic compounds (VOC) which, along
with nitrogen oxides, are involved in the
atmospheric  chemical  and  physical
processes that result in the formation of
O3. Total VOC emissions are estimated
to have decreased 19 percent between
1980  and 1989.   Between 1980 and
1989,  VOC emissions  from highway
vehicles   are  estimated   to   have
decreased  34 percent,  despite  a 39
percent increase in vehicle miles of travel
during this time period (see Figure 3-21).
Previously, VOC emissions from highway
vehicles were estimated using nationwide
annual temperatures  and  nationwide
average  Reid  Vapor  Pressure  (RVP).
The   new  estimates  are  based  on
statewide average monthly temperatures
and  statewide RVP.   Emissions from
forest fires have also been revised. The
net result is that  the new estimate for
1988  is  5  percent  higher than  the
estimate presented in last year's report.
  35
  30
  25 -
  20 -
  15 -
     VOC EMISSIONS, 106 METRIC TONS/YEAR
SOURCE CATEGORY

  TRANSPORTATION

• FUilCOMBUSnON
                                 S8S INDUSTRIAL PROCESSES

                                 •i SOLID WASTE S M1SG
   1980  1981   1982  1983  1984  1985  1986  1987  1988  1989
Figure 3-34.  National trend in emissions of volatile
organic compounds, 1980-1989.
    TABLE 3-7. NATIONAL VOLATILE ORGANIC COMPOUND EMISSION ESTIMATES, 1980-1989
(million metric tons/year)
SOURCE
CATEGORY
Transportation
Fuel
Combustion
Industrial
Processes
Solid Waste
Miscellaneous
TOTAL
1980
9.0
0.9
9.2
0.6
2.9
22.7
1981
8.9
0.9
8.3
0.6
2.5
21.3
1982
-8.3
1.0
7.5
0.6
2.2
19.5
1983
8.2
1.0
7.9
0.6
2.7
20.3
1984
8.1
1.0
8.8
0.6
2.7
21.1
1985
7.6
0.9
8.5
0.6
2.6
20.2
1986
7.2
0.9
8.1
0.6
2.3
19.1
1987
7.1
0.9
8.3
0.6
2.5
19.4
1988
6.9
0.9
8.1
0.6
2.9
19.5
1989
6.4
0.9
8.1
0.6
2.5
18.5

.NOTE: ' Tte^um¥bt;sui:^^
........ -• '.'. - ,- - -•---, _: •::-.::: :...-. >,.,:-:--f-^-^:;::^_ ::y. ^f^f.^^f.:-^:-^ x-^^::_-t.::.>.iff,::.:jA.i;; ^KK^sfs^y^^S^j^^S^f^K^f^^^^^f^y^S
                                            3-27

-------
3.5.2 Recent O3 Changes
   This section discusses ambient O3
changes during the  3-year time period
1987-89.    Using  this  3-year  period
permits the use of a larger data base of
581  sites,  compared  to 431  for  the
10-year period.  The composite average
at these 581 sites increased 8 percent
from 1987 to 1988, likely due to the hot,
dry   meteorological  conditions
experienced in much of the Eastern U.S.
during Summer 1988.  Nationally, 1988
was  the  third  hottest  summer  since
1931.11    Between  1988 and  1989,
composite mean ozone concentrations
decreased 15 percent at the 581 sites
and  16 percent at  the  subset of 208
NAMS.   The  interpretation  of  recent
trends is difficult due to the confounding
factors of  meteorology  and emission
changes.  Just as the increase in 1988 is
attributed  in   part  to   meteorological
conditions, the 1989 decrease  is likely
due, in part, to meteorological conditions
being less favorable  for ozone formation
in 1989  than   in  1988,   Also,  new
regulations  lowered  national  average
summertime RVP  in regular unleaded
gasoline from 10.0 to 8.9 psi between
1988 and 1989.12'13'14 Between 1988 and
1989, the  composite  average of  the
number of estimated  exceedances of the
ozone standard decreased by 49 percent
at the 581 sites, and 53 percent at the
208 NAMS. Nationwide VOC emissions
decreased 5 percent between 1988 and
1989.

   Figure 3-35 uses boxplots to illustrate
that  the  decrease   in  second  daily
maximum  1-hour ozone concentrations
can be found across metropolitan areas
of varying size.  Between 1988 and 1989,
the composite average decreased by 12
percent at 62 sites in 40 moderate-sized
MSAs.  A  decrease of 16  percent in
composite  mean  concentrations  was
recorded for both the large and very-large
MSAs.   Decreases in  concentration
levels can be found across all percentiles
as well.
     CONCENTRATION, PPM
0.24 -
o.ao -
0.16 -
0,12 -
0.08 -
0.04 -
0.00 -



_
City Size is
250,000 to
500,000
(62 sites)
I [
1988 1989

I
A * HI
	 H---|~NAAQS-U-|-.-
• r*1 T IM!
I ¥ T
City Si/0 is City Size is
500,000 to > 1,000,000
1,000,000
(75 Silts) (245 sites)
II II
1988 1989 1988 1989
Figure 3-35.  Boxplot comparison of recent changes
in ozone second daily maximum 1-hour
concentrations in metropolitan areas, 1988-1989.
 0.20
     CONCENTRATION, PPM
 0.16 -
 0.12
 0.08
 0.04
                    COMPOSITE AVERAGE

                      19B7 • 1988  01989
  REGION  !    II   III  IV  V  VI  VII   VIII  IX   X
  # SITES 36   34  73  84  131   59  28   15   113   8
Figure 3-36.  Regional comparisons of the 1987,1988,
1989 composite averages of the second-highest daily
1-hour ozone concentrations.
                                           3-28

-------
    The  composite  average  of  the
second  daily maximum concentrations
increased in every region of the nation
between 1987 and 1988. As Figure 3-36
indicates,  the  largest  increases were
recorded in  the  northeastern  states,
composing  EPA Regions I through III.
This pattern was reversed in  1989  with
every Region recording  lower composite
average concentrations in 1989 than  in
1988. The largest decreases  are found
in the Northeast.

    Peak ozone concentrations typically
occur   during   hot,   dry,   stagnant
summertime conditions (high temperature
and strong  solar insolation).15   Thus,
studies have compared the variability in
meteorological   parameters   such   as
maximum   daily   temperature,  solar
radiation, average daily wind speed  and
precipitation with the variability in peak
ozone concentrations.18  Figures 3-37
and 3*38, respectively,  present summer
1987-89 data  on the number of days
greater than 90° F {directly related) and
the number of days with precipitation
(inversely related) for selected cities  in
each  EPA Region.17  Although the year-
to-year  changes in the meteorological
parameters are similar to the changes in
regional air quality  (Figure  3-36), as
shown later in Section  5, these simple
indicators   may  not be  sufficient  to
describe long-term trends in some cities.
3.53 Preview
      Trends
of   1990   Ozone
      In response to public concern and
media attention  during the summer  of
1988,  EPA   initiated   a  cooperative
program  with  the state  and  local air
pollution  control  agencies for the early
reporting  of  ozone  summary  data."
Preliminary,  unvalidated   data  were
reported  to EPA approximately 3  to 4
months ahead of the schedule typically
required for quality assurance and  data
submittal.  Preliminary,  unvalidated  data
and  normally reported  1990 data have
                             Days > JO deg F
                         90

                         80

                         70

                         60

                         50

                         40

                         30

                         20

                         10
                        Cfty
                      (Region)
                                JUNE - AUGUST
                                  1987  • 1988 ' n 1989
                      Figure 3-37. Regional comparisons of the number of
                      days greater than 90°F in 1987,1988,1989 for
                      selected cities.
                         BO
                             Days with Precip
70 -

60 -

50 -

40 -

30 -

20 -

10
                                            JUNE - AUGUST
                                              1887  • 1988 01989
                      (Region)
                      Figure 3-38. Regional comparisons of the number of
                      days with precipitation in 1987,1988,1989 for
                      selected cities.
                                             3-29

-------
been used here to provide a preliminary
estimate of future ozone trends.

   Summer 1990 temperature averaged
across the nation was above the long-
term  mean and  ranks  as  the 15th
warmest summer on record since 1895."
Areally averaged precipitation was below
the long-term mean and ranks as the 29th
driest summer.  Regionally, the  Central
and  East North  Central had  average
temperatures,  with  warmer rankings
elsewhere.   The  South  and Southeast
were unusually dry, the Northeast, East,
North Central  and  Northwest  Regions
were in the  dry third of the distribution,
and the rest of the  nation  was  in the
middle third of the distribution of yearly
rankings.18   Also,  1990  average RVP
decreased 3 percent from summer 1989
levels.19

   Figure 3-39 presents a  preliminary
estimate of  the trend in the composite
average of the annual daily maximum 1 *
hour concentration for the period 1980
through 1990.   The 1990 composite
average estimate is 1 percent lower than
the 1989 level and is 16 percent  lower
than the 1988 level.  This  estimate is
based on a subset of 337 of the 431 long-
term trend sites and was adjusted for the
mix of  sites in  the  trends database.
Although based on a larger number of
sites than last year's preliminary  1989
estimate, this 1990 estimate should be
viewed as preliminary, because summer
1990 data have not yet been  subjected to
the complete quality assurance process.

   A preliminary estimate of the year-to-
year changes  among the  Regions is
shown in Figure 3-40. The preliminary
1990 composite mean concentrations are
lower than the previous three  years in 5 of
the 10 Regions.  Regions II through IV,
and  VI  (the  East,  Southeast and
Southwest)  recorded  similar, or  slightly
higher, levels than 1989, while Region X
(the  Northwest)  recorded  its highest
composite mean concentration during the
past 4 years.
       CONCENTRATION, PPM
  0.20

  0.18

  0.16

  0.14

  0.12 +- NAAQS

  0.10

  0.08

  0.06

  0.04

  0.02

  0.00
• TREND SITES
 (431 SITES)
o 1990 SURVEY
  (337jSiTES).	
         1980 1981 1982 1983 19B4 1985 1986 1987 1980 1i89 1990
Figure 3-39. Preliminary estimate of the national
trend in the composite average of the second
highest daily maximum 1-hour ozone concentration,
1980-90.
       CONCENTRATION, PPM
O.HU -
0.16 -
0.12 -
0.08 -
0.04 -





REGION
# SITES 1E









GOf
• 1
H 1





JlPOSlTEAVERAG
9B7 a 19S9
988 B1990






























II HI IV V VI VII Vlil IX X
! 24 58 58 77 32 11 4 51 4
Figure 3-40. Regional comparisons of the 1987,1988,
1989 and preliminary 1990 composite averages of the
second-highest daily 1-hour ozone concentrations.
                                            3-30

-------
3.6  TRENDS IN LEAD
    Lead  (Pb)  gasoline  additives,  nonferrous
smelters  and  battery  plants  are  the  most
significant   contributors   to  atmospheric   Pb
emissions.   Transportation  sources  in  1989
contributed 31 percent of  the annual emissions,
down substantially from 73 percent in 1985. Total
lead emissions from all sources dropped from 21.1
x 103 metric tons in 1985  to 7.6 x 103 and 7.2 x
103 metric tons, respectively in  1988 and 1989.
The decrease in lead emissions from highway
vehicles accounts for essentially all of this drop.
The reasons for this drop are noted below.

    Two  air   pollution  control  programs
implemented by EPA before promulgation of the
Pb standard in October 197820  have resulted in
lower ambient Pb levels. First, regulations issued
in the early  1970s required gradual reduction of
the Pb  content of all gasoline over a period of
many years.  More recently, the Pb content of the
leaded  gasoline  pool  was  reduced  from  an
average of 1.0  grams/gallon to 0.5 grams/gallon
on  July  1,  1985  and  still  further  to  0.1
grams/gallon on January  1, 1986.  Second, as
part of EPA's overall automotive emission control
program,  unleaded gasoline was introduced in
1975 for use  in  automobiles  equipped  with
catalytic control devices.  These devices reduce
emissions of carbon monoxide, volatile organics
and nitrogen oxides. In 1989, unleaded gasoline
sales accounted  for 89  percent of the  total
gasoline, market - up from 82% in 1988.  These
programs have essentially eliminated violations of
the lead standard in urban areas, except in those
areas with lead point sources. Programs are also
in place to control Pb emissions from stationary
point sources.   Pb emissions from stationary
sources have  been substantially  reduced by
control programs oriented toward attainment of the
paniculate  matter and  Pb  ambient standards,
however, significant ambient problems still remain
around  some lead point sources.  Lead emissions
in 1989 from industrial sources, e.g. primary and
secondary lead smelters,  dropped by more than
one-half from levels reported in the  late  70s.
Emissions of lead from solid waste disposal are
down 43  percent since the late 70s.  In 1989,
emissions from solid waste disposal and industrial
processes (2.3 x 103 metric tons) represent the
largest category of lead emissions just ahead of
the 2.2 x 103 metric tons from transportation. The
overall effect of these three control programs has
been a major reduction in the amount of Pb in the
ambient air.

3.6.1  Long-term  Pb Trends: 1980^9

    Early trend analyses of ambient Pb  data21-22
were  based almost exclusively on  National Air
Surveillance Network (NASN) sites.  These sites
were established in the 1960's to monitor ambient
air quality levels of TSP  and associated trace
metals,  including   Pb.     The   sites  were
predominantly  located  in  the central business
districts of larger American cities.  In September
1981,  ambient Pb  monitoring regulations were
promulgated,23    The  siting  criteria  in  the
regulations resulted in finding many of the old
historic TSP monitoring sites unsuitable for the
measurement  of ambient Pb concentrations and
many  of the  earlier  sites  were  moved  or
discontinued.

   As with the other pollutants, the sites  selected
for the long-term trend analysis had  to satisfy
annual data completeness criteria of at least 8 out
of 10 years of data in the 1980 to 1989 period. A
year was included as "valid" if at least 3 of the 4
quarterly averages were  available. As in  last
year's report, composite lead data, i.e., individual
24-hour observations are composited together by
month or quarter and a single analysis  made, are
being used in the trend analysis. Seventeen sites
qualified for the 10-year  trend because of the
addition of composite data. A total of 189 urban-
oriented sites, from 41 States,  met the  data
completeness  criteria.   Forty-six of these  sites
were NAMS, the largest number of lead NAMS
sites to qualify for the 10-year trends. Thirty-three
(17 percent) of the 189 trend sites were located in
the State of California,  thus  this State  is over-
represented in the sample of sites satisfying the
long-term trend criteria.  However, the  lead trend
at the California sites was almost identical to the
trend at the non-California sites; so that these
sites did not distort  the overall trends.  Sites that
                                            3-31

-------
were  located near lead point sources
such  as primary  and secondary  lead
smelters were excluded from the urban
trend  analysis, because the magnitude
of the levels at these sources could
mask  the  underlying  urban  trends.
Trends  at lead point source oriented
sites will be discussed separately in the
next section.

    The  means  of  the  composite
maximum quarterly averages and  their
respective   95   percent   confidence
intervals are  shown in  Rgure 3-41 for
both the 189 urban sites and 46 NAMS
sites  (1980-1989).  There was an 87
percent  (1980-89)  decrease  in  the
average for the 189 urban sites.  Lead
emissions over this 10-year period also
decreased.  There was a  90  percent
decrease in total lead emissions and a
96 percent decrease in lead emissions
from  transportation  sources.     The
confidence   intervals for  these   sites
indicate that the 1985-89  averages are
significantly less than all averages  from
preceding years.    Because  of the
smaller number (46) of NAMS sites with
at least 8 years of data, the confidence
intervals are wider. However, the 1985-
89 NAMS averages are stilf significantly
different from all averages before 1985.
It is interesting to note that the average
lead concentrations  at the NAMS  sites
in 1989 is essentially the same (0.073
jig/rn3)  as  the  "all  sites" average;
whereas in  the  early   1980's  the
averages  of the  NAMS sites  were
significantly higher.  Figure 3-42 shows
the trend in average lead concentrations
for the urban-oriented sites and for 19
point-source oriented sites which met
the 10-year data completeness criteria.
The improvement in average ambient
lead concentrations at the point-source
oriented sites, which are near industrial
sources of lead, e.g. smelters, battery
plants,  is   about the  same  on  a
percentage basis as the urban oriented
sites.   However,  the average at the
point-source oriented sites  dropped  in
  1.6

  1.4

  1.2

  1.0

  0.8

  0.6

  0.4

  0.2

   0
     CONCENTRATION, UG/M3
                  -NAAQS
NAMS SITES (46)
       1980 1§81 1982 1983 1984 1985 1i86 1987 1:988 1989
Figure 3-41.  National trend in the composite
average of the maximum quarterly average lead
concentration at both NAMS and all sites with 95
percent confidence intervals, 1980-1989.
  2.5
     CONCENTRATION, UG/M3
  2.0 -
  1.0 -
  0.5 -
         POINT SOURCE SITES (19)  o URBAN SITES J18_9}_
                                      -O-	B	
          I    I    I    I     I    I    I    I    1     I
       1980 1981 1982 1983 1884 1985 1986 1987 1988 1888
Figure 3-42.  Comparison of national trend in the
composite average of the maximum quarterly
average lead concentrations at urban and point-
source oriented sites, 1980-1989.
                                            3-32

-------
magnitude from 1.8 to 0.4  ug/m3, a 1.4 pglm3
difference; whereas, the average at the urban site
dropped only from 0.6 to 0.1 ug/m3.  A site in
Idaho,  located near  a shutdown smeRer,  with
extremely  high 1980-81 lead concentrations did
not qualify for inclusion in this years 10-year data
base but was in last years report.  The result is
that the 1980-89 change is now less pronounced
than that  shown last  year for the point-source
oriented sites.  This  improvement at the point-
source oriented sites reflects both industrial and
automotive lead emission controls, but in some
cases,  the  industrial  source  reductions   are
because of plant shutdowns. The 4 MSA's shown
in Table 4-3 that are above the lead NAAQS in
1989 are all caused by lead point sources. These
MSA's are Birmingham Al, Dallas TX, Omaha NE-
IA, and St  Louis  MOIL.   Figure 3-43 shows
boxplot comparisons of the maximum quarterly
average Pb concentrations at the 189 urban-
oriented Pb trend sites (1980-89). This figure
                   shows the dramatic improvement in ambient Pb
                   concentrations for the entire distribution of trend
                   sites.     As  with  the  composite   average
                   concentration since 1980, most of the percentiles
                   also show a monotonically decreasing pattern.
                   The 189 urban-oriented sites that qualified for the
                   1980-89 period, when compared to the 139 sites
                   for 1979-88 and the 97 sites for 1978-87 period,11
                   indicate a substantial expansion of the 10 year
                   trends data base,

                       The trend in total lead emissions is shown in
                   Rgure  3-44.  Table 3-8 summarizes the Pb
                   emissions data as well. The 1980-89 drop in total
                   Pb emissions was 90 percent.  This compares
                   with the 87 percent decrease (1980-89} in ambient
                   lead concentrations. The drop in Pb consumption
                   and subsequent Pb  emissions since 1980 was
                   brought about by the increased use of unleaded
                   gasoline  in  catalyst-equipped  cars  and  the
                   reduced Pb content in leaded gasoline.
      2.5
          CONCENTRATION, UG/M3
      2.0  -
      1.5
      1.0  -
      0.5  -
                                                     189 SITES
	 NAAQS 	
                I     I     I      I     I     I     I     I     1     I
              1980 1981  1982 1983  1984 1985 1986 1987  1988  1989
           Figure 3-43.  Boxplot comparisons of trends in maximum quarterly
           average lead concentrations at 189 sites, 1980-1989.
                                           3-33

-------
The  results  of these  actions in  1989
amounted to a  66 percent reduction
nationwide in total Pb emissions from
1985 levels.    As  noted  reviously,
unleaded  gasoline  represented  89
percent  of 1989 total gasoline sales.
Although the good agreement among
the  trend   in   lead  consumption,
emissions and ambient levels is based
upon a  limited geographical sample, it
does show that ambient urban Pb levels
are  responding  to  the drop  in lead
emissions.  In Canada a  very similar
trend in ambient lead concentrations
has  been observed.   In a soon to be
released  report, declines  in average
lead concentrations of 86 percent were
found for the 1980-89 time period.24
100
    LEAD EMISSIONS, 1Q3 METRIC TONS/lfEAR
             SOURCE CATEGORY

              TRANSPORTATION
                                 INDUSTRIAL PROCESSES

                                 SCUD WASTE
  1980  1981   1982  1983  1984  1985  1986  1B87  1988  1989
                                       Figure 3-44.   National trend in lead emissions, 1980-
                                                     1989.
                TABLE 3-8. NATIONAL LEAD EMISSION ESTIMATES, 1980-1989
(million metric tons/year)
SOURCE
CATEGORY
Transportation
Fuel
Combustion
Industrial
Processes
Solid Waste
Miscellaneous
TOTAL
1980
59.4
3.9
3.6
3.7
0.0
70.6
1981
46.9
2.8
3.0
3.7
0.0
56.4
1982
46.9
1.7
2.7
3.1
0.0
54.4
1983
40.8
0.6
2.4
2.6
0.0
46.4
1984
34.7
0.5
2,3
2.6
0.0
40.1
1985
15.5
0.5
2.3
2.6
0.0
20.9
1986
3.5
0.5
1.9
2.6
0.0
8.4
1987
3.0
0.5
1.9
2.6
0.0
8.0
1988
2.6
0.5
2.0
2.5
0.0
7.6
1989
2.2
0.5
2.3
2.3
0.0
7.2


                                            3-34

-------
      Recent Pb Trends 1987-89
   Ambient Pb trends were also studied
over the shorter period 1987-89. A total
of 245 urban sites in 39 States met the
data requirement that a site have all 3
years with  data.   In recent years, the
number of  lead  sites  has  dropped
because of the elimination of some TSP
monitors  from  State  and  local  air
monitoring  programs.  Some  monitors
were  eliminated due to the change  in
the particulate  matter standard  from
TSP  to  PM,0  while  others  were
discontinued because  of  the  very low
lead concentrations measured in many
urban locations. Although some further
attrition may occur, the core network of
NAMS  lead   sites  together  with
supplementary State  and local  sites
should be sufficient to access national
ambient lead trends. This larger 3-year
data base showed an improvement  of
29  percent  in  average  urban  Pb
concentrations. The 1987 and 1989 lead
averages respectively  were 0.099 and
0.070 ug/mS, a difference of only 0.029
ug/m3.  This corresponds to reductions
in total Pb emissions  of 10 percent  and  a
reduction of 27 percent  in lead emissions from
transportation sources.  Most of this  decrease in
total nationwide Pb emissions was due once again
to the decrease  in automotive  Pb emissions.
Even  this  larger   group   of   sites  was
disproportionately weighted by sites in California,
Illinois, Kansas, Texas and West Virginia.  These
States had about  37  percent of the 245 sites
represented.  However, the percent changes in
1987-89 average Pb concentrations for these five
States were very similar to the  percent change for
the remaining sites, thus the contributions of these
sites did not distort the national trends.  Although
urban  lead concentrations continue to  decline
consistently, there are indications that the rate of
the decline has slowed down. Clearly in some
areas, urban lead levels are so low, that further
improvements have become difficult.

    Indeed, as will be shown later, all sections of
the country are showing declines in average lead
     CONCENTRATION, UG/M"
1.4 -
1.2 -
1.0 -
0.8 -
0.6 -
0.4 -
0.2 -




	 COM
• 1<
posrre AVERAGE
B7 • 1S88 Q 1989







hi hi hi It
REGION [ II III IV
# SITES 18 20 33 40
Iti h m, tl h hi
V VI VII VIII IX X
42 32 23 4 26 7
Figure 3-45.  Regional comparison of the 1987,1988,
1989 composite average of the maximum quarterly
average lead concentration.
         concentrations.    Sixty-two (62)  point  source
         oriented sites showed an average drop of 37
         percent over the 1987-89 time period. Thus, the
         decrease in ambient lead concentrations near lead
         point sources has been slightly more pronounced
         than in urban areas.  The average lead levels at
         these sites are much higher here than at  the
         urban sites.  The 1987 and 1989 lead averages
         were 1.24 and 0.78 u.g/ma respectively. It is worth
         noting that the sites in the 10-year data base also
         showed a 27 percent decrease during this 3-year
         period, suggesting that, despite the geographical
         imbalance, their patterns may adequately depict
         national trends.

            The larger sample of sites  represented in the
         3-year trends (1987-89) will be used  to compare
         the  most  recent individual  yearly  averages.
         However, for the 10  year time period  the largest
         single year drop in average lead concentrations,
         42 percent, occurs as expected between 1985 and
         1986, because of the shift  of the lead content in
                                            3-35

-------
leaded  gasoline.   The  1989  average  lead
concentrations show the more modest decline of
14 percent from 1988 levels.  The  10-year data
base showed a 11 percent decrease in average
lead concentrations from 1988 to  1989.  Lead
emissions between 1988 and 1989 decreased
both for the total (5  percent)  and  from only
transportation sources (15 percent),  this trend is
expected to continue primarily because the leaded
gasoline market will continue to  shrink.  Some
major petroleum  companies have  discontinued
refining  leaded gasoline because of the dwindling
market,  so that in the future the consumer will find
it  more difficult  to  purchase  regular  leaded
gasoline.
   Figure 3-45  shows  1987, 1988  and  1989
composite average Pb  concentrations, by EPA
Region.     Once  again   the   larger   more
representative 3-year data base of 245 sites was
used for this comparison. The number of sites
varies dramatically by Region from 4 in  Region
VIII to 42 in  Region V.  In all Regions, there is a
decrease in  average Pb urban concentrations
between 1987 and 1989. These results confirm
that average Pb concentrations in urban areas are
continuing to  decrease  in all sections  of the
country, which is exactly what is to be expected
because of  the  national air pollution  control
program in place for Pb.
                                            3-36

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3.7 REFERENCES
   1.  National Air Pollutant Emission Estimates.
1940-1989. EPA-450/4-90-004,
U. S. Environmental Protection Agency.  Office ol
Air Quality  Planning  and Standards,  Research
Triangle Park, NC, March 1991.

   2.  National Air Quality and Emissions Trends
Report. 1983. EPA-450/4-84-029,
U. S. Environmental Protection Agency, Office ol
Air Quality  Planning  and Standards,  Research
Triangle Park, NC, April 1985.

   3.  National Air Quality_and Emissions Trends
Report. 1985. EPA-450/4-87-001,
U. S. Environmental Protection Agency, Office of
Air Quality  Planning  and Standards,  Research
Triangle Park, NC, February 1987.

   4.  N.  H. Frank, "Nationwide Trends in Total
Suspended Paniculate  Matter  and Associated
Changes in the Measurement Process",  presented
at the Air Pollution Control Association, American
Society for Quality Control Specialty Conference
on  Quality   Assurance   in   Air  Pollution
Measurement, Boulder, CO, October 1984.

   5.   Written communication from Thomas R,
Hauser,   Environmental    Monitoring   Systems
Laboratory, U. S. Environmental Protection Agency,
Research   Triangle  Park,  NC,  to  Richard  G,
Rhoads, Monitoring and Data Analysis Division, U,
S.  Environmental Protection Agency,  Research
Triangle  Park, NC, January 11,1984.

   6.   1987 Annual Air Quality Report, Oregon
Department of  Environmental Quality,  Portland,
Oregon, July, 1988.

   7.  J.  Steigerwald,  "Update of  Meteorological
Data Compilation for the Contiguous United States:
1989  Update of Total Precipitation Data", EPA
Contract  No.  68-02-4390,  PEI Associates, Inc.,
Durham, NC, August 1990.

   8.   Proposed  Decision Not  to Revise  the
National ^Ambient Air Quality Standards for Sulfur
Oxides (Sulfur Dioxide). 53 FR  14926, April  26,
1988.
  9.  1986 NEDS Data Base, U. S. Environmental
Protection Agency, Research Triangle Park, NC,
September 1988.

  10. R. H. Heim, Jr., "United States July Climate
in Historical Perspective", National Climatic Data
Center, NOAA, Ashvilfe, NC, August 1989.

  11. National Air Quality and Emissions Trends
Report.    1987.    EPA-450/4-89-001,  U.  S.
Environmental  Protection Agency, Office  of  Air
Quality Planning and Standards, Research Triangle
Park, NC, March 1989.

  12.   Volatility   Regulations  for Gasoline and
Alcohol Blends Sold in Calendar Years 1989 and
Beyond. 54 FR 11868, March 22, 1989.

  13.  National Fuel  Survey: Motor Gasoline -
Summer  1988.   Motor  Vehicle  Manufacturers
Association, Washington, D.C., 1988.

  14. National Fuel Survey: Gasoline and Diesel
Fuel - Summer 1989, Motor Vehicle Manufacturers
Association, Washington, D.C., 1989.

  15. Use oLMeteoroloqical Data tn_A'ir Quality
Trend   Analysis.  EPA-450/3-78-024,   U.S.
Environmental  Protection Agency, Office  of  Air
Quality Planning and Standards, Research Triangle
Park, NC, May 1978.

  16.  D.J. Kolaz and  R.L. Swinford,  "How to
Remove  the influence of meteorology from the
Chicago Areas Ozone Trend,"  presented  at the
83rd Annual AWMA Meeting, Pittsburgh, PA, June
1990.

  17. J. Steigerwald, "Report on Compilation of
Historical Meteorological Data for  Fifteen Cities",
EPA Contract No. 68-02-4390, PEI Associates, Inc.,
Durham, NC, August 1990.

  18.  R. H.  Heim, Jr., "United States Summer
Climate in Historical Perspective", National Climatic
Data Center, NOAA. Ashville, NC, August 1990.
                                            3-37

-------
  19.   National Fuel Survey: Motor Gasoline  -
Summer  1990.  Motor  Vehicle  Manufacturers
Association, Washington, D.C., 1990.

  20.  National Primary and Secondary Ambient Air
Quality Standards for Lead. 43 FR 46246, October
5,1978.

  21.   R. 8. Faoro and T. 8. McMuIlen, National
Trends In Trace Metals Ambient Air. 1965-1974,
EPA-450/1-77-003, U. S. Environmental Protection
Agency,  Office of  Air Quality  Planning   and
Standards, Research Triangle Park, NC, February
1977.

  22.  W. Hunt, "Experimental Design in Air Quality
Management,"  Andrews  Memorial   Technical
Supplement, American Society for Quality Control,
Milwaukee, WI, 1984.

  23.   Ambient Air Quality  Surveillance. 46 FR
44159, Septembers, 1981.

  24.    T.  Furmanczyk,  Environment Canada,
personal  communication to R.  Faoro,  U.S.
Environmental Protection Agency, Nov. 6,1990.
                                           3-38

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4L AIR QUALITY STATUS OF METROPOLITAN AREAS, 1989

    This chapter  provides general  information  on the current air quality  status  of
metropolitan areas1 within the United States. Four different summaries are presented in
the following sections.   First, maps  depicting the areaS failing to  meet  the National
Ambient Air Quality Standards  (NAAQS) for ozone, carbon  monoxide and particulate
matter are presented.  Next, an estimate is provided of the number of people living in
counties which did not meet the NAAQS based on 1989 air quality data.  Third, pollutant-
specific maps are presented to provide the reader with a geographical view of  how peak
1989 air quality levels varied throughout the 90  largest Metropolitan Statistical Areas
(MSAs) in the continental United States.  Finally, the peak pollutant-specific statistics are
listed for each MSA with 1989 air quality monitoring, data.
4.1    Areas Not Meeting Ozone, Carbon Monoxide and Particulate Matter NAAQS
       On   August  16,  1990   the   U.S.
Environmental Protection Agency listed2 those
metropolitan  areas  which failed  to  meet the
ozone and carbon monoxide NAAQS based on
ambient monitoring data for 1987 through 1989.
The  areas  include  Consolidated Metropolitan
Statistical Areas (CMS A), which are composed of
groups of MSAs, and Individual MSAs and non-
metropolitan counties.

       Attainment of the ozone  standard is
determined using the three most recent years of
air quality ^monitoring data. These data showed
that 96 areas, mostly major metropolitan areas,
failed to meet the ozone standard for the years
1987-89, a decrease of 5 areas as compared to
the 1986-88 period.  Figure 4-1, "Areas Failing to
Meet the Ozone NAAQS Based  on 1987-89
Data,"  displays the  96 areas failing to meet the
ozone standard  based on 1987-89 monitoring
data.   The  areas  on  the map  are shaded
according to the area classifications in the Clean
Air  Act Amendments of  1990.   These  area
classes are based on the ozone design value for
that area. The ozone design value serves as an
indicator of the  magnitude of  the problem in
terms of peak concentrations.  Typically, the
ozone design value  would be the fourth highest
daily maximum  value  during  the three  year
period.
   For carbon  monoxide,  attainment of the
standard is determined using the two most recent
years  of  monitoring'  data.     The   area
classifications are based on the CO design value
which is  evaluated by  computing the second
maximum 8-hour concentration for each year and
then  using the  higher of  these two values.
Figure 4-2, "Areas Failing  to Meet the Carbon
Monoxide  NAAQS  Based  on  1988-89 Data,"
shows the  41  areas that failed to  meet the
carbon monoxide standard for the years 1988-89.
Seven areas from last year's list now  meet the
carbon monoxide NAAQS, while four new areas
failed to meet the standard In 1989.

   With passage of the 1990 Amendments to
the Clean Air Act,  73 areas failed to  meet the
NAAQS  for particulate matter.   Sixty of these
areas were previously classified as "Group I,"
meaning that the area had a high probability of
not  attaining the  NAAQS and that  State
Implementation Plans were required to attain the
NAAQS.  An additional 13 areas with measured
violations of the  PM10 NAAQS through calendar
year  1988 have been identified, as specified by
the act.  Figure 4-3 displays the counties within
the contiguous U.S. that contain these 73 areas.
The map displays counties which are completely
non-attainment or counties only parts of which
are non-attainment. A total of 81   separate
counties are involved for PM10~

-------
     AREAS  NOT   MEETING  THE  OZONE  NAAQS
                  Based  on  1987-89 Data
*0 ^J^ 5.J
'A.
OFFICE OF AR QUALITY PLANNING AND STANDARDS
   TECHNICAL SUPPORT DIVISION
   Monitoring and Reports Branch

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AREAS   NOT
EETING  THE   CARBON  MONO X IDE   NAAQS
  Based  on  1988-89  Data
      OFFICE OF AR QUALITY PLANNNG AND STAfCARDS
           TECHNICAL SUPPORT DIVISION
           Monitoring end Reports Branch
                                                                      Serious

                                                                      Moderate

-------
AREAS   NOT
EETING  THE   PARTICULATE   MATTER  NAAQS
   Based  on   Da t.a   through  1988
    *«>..
                                                                     Full County

                                                                     Partial County
       OFFICE OF AR QUALITY PLANNNG AND STANDARDS
             TECHNICAL SUPPORT DIVISION
             Monitoring and Reports Branch

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4J2  Population Estimates For Counties Not Meeting NAAQS, 1989
    Figure 4-4 provides an estimate of the number of
people living  in counties in which the levels of the
pollutant-specific primary health NAAQS were not
met by measured  air quality  in  1989,   These
estimates  use a  single-year interpretation  of the
NAAQS to indicate the current extent of the problem
for each pollutant. Table 4-1 lists the selected air
quality  statistics  and  their  associated  NAAQS.
Figure 4-4 clearly demonstrates that  O3 was the
most pervasive air pollution problem  in 1989 for the
United States with an estimated 66.7 million people
living in counties which  did not  meet the O3
standard.   However, this estimate is substantially
lower than last year's  1988 estimate of 112 million
people. This large decrease is likely dye in  part to
meteorological  conditions  in 1989  being  less
conducive to  ozone formation than 1988 (recall the
hot,  dry summer in the eastern U.S.), and to  new
and  ongoing  emission control programs. Between
1988 and 1989, implementation of gasoline volatility
regulations  lowered  the  average  Reid  Vapor
Pressure (RVP) of regular unleaded gasoline from
10.0 to 8.9 pounds per square inch  (psi). Carbon
monoxide follows, with 33.6 million people; PM,0 with
27.4 million people; NO2 with 8.5 million people; Pb
with 1.6 million people  and SQZ with  0.9  million
people.  A total of 84 million persons resided in
counties not meeting at least one air quality standard
during 1989 (out of a total 1987 population of 243
million).  In contrast to the last annual report which
used  1986 county population data, these estimates
are based on more current 1987 estimates. Thus,
the 1  percent growth in total U.S. population since
1986  is  reflected  in  these estimates.   Also, the
estimate for  PM10 is considered  a lower bound
estimate, because the PM10 monitoring network is
still evolving.

    These population estimates  are intended  to
provide a relative measure of the  extent of the
problem for each  pollutant.  The limitations of this
indicator should be recognized. An individual living
in a county that violates an air quality standard may
not actually be  exposed  to  unhealthy  air.  For
example, if CO violations were confined to a traffic-
congested center  city location during evening rush
hours in the winter, it is possible that an individual
may never be in that area, or may be there only at
other  times of the day or during other seasons.
However, it is worth noting that ozone, which
appears to be the most pervasive pollution problem
by this measure, is also the pollutant most likely to
have  fairly uniform concentrations throughout an
area.
                                       40         60
                                       millions of people
           Note; Based on 1987 county population data and only 19S9 oir quality flala.
           80
                      100
           Figure 4-4.  Number of persons living in counties with, air quality
           levels above the primary national ambient air quality standards in
           1989 (based on 1987 population data).

                                              4-5

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Table 4-1.   Selected Air Quality Summary Statistics and Their Associated National
            Ambient Air Quality Standards (MAAQS)*
POLLUTANT
Participate Matter (PM,0)
Sulfur Dioxide (SO2)

Carbon Monoxide (CO)
Nitrogen Dioxide (NO2)
Ozone (O3)
Lead (Pb)
STATISTIC
annual arithmetic mean
annual arithmetic mean
second highest 24-hour
average
second highest
nonoverlapping
8- hour average
annual arithmetic mean
second highest daily
maximum 1 -hour average
maximum quarterly
average
PRIMARY NAAQS
50 ug/m3
0.03 ppm
0.1 4 ppm
9 ppm
0.053 ppm
0.12 ppm
1 .5 ug/m3
u.g/m3 = micrograms per cubic meter ppm = parts per million
*Single year interpretation. For a detailed listing of the NAAQS see Table 2-1.
                                     4r6

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4.3    Aii Quality Levels in Metropolitan Statistical Areas
   This section provides information for general air
pollution audiences on  1989 air quality levels in
each  Metropolitan Statistical Area (MSA) in  the
United States.    For those  large  MS As  with
populations greater than 500,000, the 1989 annual
air   quality  statistics   are  also   displayed
geographically on three-dimensional maps.

   The general concept of a metropolitan area is
one of a  large population center, with adjacent
communities  which  have  a  high degree  of
economic  and social integration  with the urban
center.  Metropolitan Statistical Areas  contain a
central county(ies), and any adjacent counties with
at least 50 percent of their population in  the
urbanized  area.1 Although MSAs compose only 16
percent of the land area  in the U.S., they account
for  77 percent of the  population.   Table  4-2
displays the  population distribution of the 340
MSAs, based on 1987 population estimates.1  The
New  York,  NY  MSA   is the  nation's largest
metropolitan area with a 1987 population in excess
of 8 million.  The smallest MSA is Enid, OK with a
population of 60,000.
4.3,1  Metropolitan  Statistical  Area Air
       Quality Maps, 1989

   Figures 4-4 through 4-10 introduce air quality
maps of the United States that show at a glance
how  air quality varies among the largest MSAs
within the contiguous United States. To enable the
reader to distinguish individual urban  areas, only
the 90 MSAs within the continental  U.S. having
populations greater than 500,000 are shown.  Two
large MSAs, Honolulu, HI and San Juan, PR are
not shown. However, neither area has exceeded
any of the NAAQS during 1989.  In each map, a
spike is plotted at the city location on the  map
surface.  This represents   the  highest pollutant
concentration recorded in 1989,  corresponding to
the appropriate air quality standard.  Each spike is
projected onto a back-drop for comparison with the
level of the standard.  The backdrop also provides
an east-west profile  of  concentration variability
throughout the country.
TABLE 4-2.  Population Distribution of Metropolitan Statistical Areas Based on 1987
              Population Estimates
POPULATION RANGE
< 100,000
100,000 < population < 250,000
250,000 < population < 500,000
500,000 < population < 1,000,000
1 ,000,000 < population < 2,000,000
population > 2,000,000
NUMBER OF
MSA'S
27
148
73
48
26
18
TOTAL POPULATION
2,274,000
23,513,000
25,218,000
34,367,000
38,685,000
65,747,000
TOTAL 340 189,804.000
                                             4-7

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PM10

ANNUAL ARITHMETIC MEAN
    Figure 4-5,   United States map of the highest annual arithmetic mean PM10
                concentration by MSA, 1989.
    The map for PM10 shows the 1989 maximum  annual arithmetic means in
    metropolitan areas greater than 500,000 population.  Concentrations above the
    level of the annual mean PMIO standard of 50 ug/m3 are found in 13 of these
    metropolitan areas.
                                    4-8

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SULFUR DIOXIDE
ANNUAL ARITHMETIC MEAN
     Figure 4-6.   United States map of the highest annual arithmetic mean sulfur
                 dioxide concentration by MSA, 1989.
     The map for sulfur dioxide shows maximum annual mean concentrations in
     1989.  Among these large metropolitan areas, the higher concentrations are
     found in the heavily populated Midwest and Northeast and near point sources
     in the west. All these large urban areas have ambient air quality concentrations
     lower than the current annual standard of 80 ug/m3 (0.03 ppm).  Because this
     map  only represents areas with population greater than one half million, it
     does not reflect air quality in the vicinity of smelters  or large power plants in
     rural areas.
                                      4-9

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                                                                             •so
SULFUR DIOXIDE
2ND MAX 24-HR AVG
 Figure 4-7,    United  States map  of the highest  second  maximum 24-hour
              average sulfur dioxide concentration by MSA, 1989.
 The map for sulfur dioxide shows the highest second highest 24-hour average
 sulfur dioxide concentration by MSA in 1989.  All of these large urban areas
 have ambient concentrations below the 24-hour NAAQS of 365 ug/m3 (0.14
 ppm).
                                 4-10

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CARBON MONOXIDE

2ND MAX 8-HR AVG
     Figure 4-8.   United  States  map  of  the   highest  second  maximum
                 nonoverlapping 8-hour average carbon monoxide concentration
                 by MSA, 1989.
     The map lor carbon monoxide shows the highest second highest 8-hour value
     recorded in 1989.  Twenty of these urban areas in all geographic regions have
     air  quality exceeding  the  9 ppm level  of the standard.   The highest
     concentration recorded in 1989 is found in Los Angeles, CA.

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NITROGEN DIOXIDE
ANNUAL ARITHMETIC MEAN
     Figure 4-9.   United States map of the highest  annual arithmetic mean
                 nitrogen dioxide concentration by MSA, 1989.
     The map for nitrogen dioxide displays the maximum annual mean measured
     in the nation's largest metropolitan areas during 1989. Los Angeles, California,
     with an annual NO2 mean  of 0.057 ppm  is the only area in the country
     exceeding the  MO2 air quality standard of 0.053 ppm.
                                     4-12

-------
OZONE
2ND DAILY MAX 1-HR AVG
     Figure 4-10.  United States map of the highest second daily maximum 1-hour
                 average ozone concentration by MSA, 1989.
     The ozone map shows the second highest daily maximum 1-hour concentration
     in the 90 largest metropolitan areas in the Continental U.S. As shown, 38 of
     these  areas did not  meet the 0.12  ppm  standard  in 1989.  The highest
     concentrations are observed in Southern California, but high levels also persist
     in the Texas Gulf Coast, Northeast  Corridor, and other heavily populated
     regions.
                                     4-13

-------
LEAD
MAX QUARTERLY MEAN
      Figure 4-11.  United States map of the highest maximum quarterly average
                  lead concentration by MSA, 1989.
      The map for Pb displays maximum quarterly average concentrations in the
      nation's largest metropolitan areas. Exceedances of the Pb NAAQS are found
      in four areas in the vicinity of nonferrous smelters or other point sources of
      lead. The two highest concentrations are found at a site near a primary lead
      smelter  in Herculaneum, MO (St. Louis MSA) and at a site in Leeds, AL
      (Birmingham  MSA).   Because of the switch  to  unleaded gasoline, areas
      primarily affected by automotive lead emissions show levels below the current
      standard of 1.5 ug/m3.
                                      4-14

-------
4.3.2  Metropolitan Statistical Area Air Qualify Summary, 1989
   Table 4-3 presents a summary of 1989 air quality
for each Metropolitan Statistical Area (MSA) in the
United States.  The air quality levels reported for
each  metropolitan  area  are  the highest levels
measured from  all available sites within the MSA.
The MSAs are listed alphabetically, with the 1987
population estimate and air quality statistics for each
pollutant.  Concentrations above  the level of the
respective NAAQS are shown in bold type.

       In the case of O3, the problem is pervasive,
and the high values associated with the pollutant can
reflect a large part of the MSA. However in many
cases, peak ozone concentrations occur downwind
of major  urban  areas, e.g.,  peak  ozone levels
attributed  to the Chicago metropolitan area are
recorded in  and  near Racine,   Wisconsin.    In
contrast,  high CO  values  generally  are highly
localized  and  reflect areas with heavy traffic.  The
scale  of measurement for the pollutants - PM10, SO2
and NO2 - falls somewhere in between.  Finally,
while   Pb measurements generally  reflect  Pb
concentrations near roadways in  the  MSA,  if a
monitor is located near  a  point source  of lead
emissions it can produce readings substantially
higher.  Such is the case in  several MSAs.   Pb
monitors located near a point source are footnoted
accordingly in Table 4-3.

   The pollutant-specific statistics reported in this
Section are summarized  in Table 4-1, with their
associated primary  NAAQS concentrations for a
single year of data.  For example, if an MSA has
three  ozone monitors in 1989  with second highest
daily hourly maxima of 0.15 ppm, 0.14 ppm and 0.12
ppm,  the  highest of these, 0.15 ppm, would be
reported for that MSA for 1989.

   The same annual data completeness criteria
used  in  the  air quality trends  data base  for
continuous data was  used here for the calculation of
annual means,   (i.e.,  50  percent of the required
samples for SOZ and NO.,).  If some data have been
collected at one or more  sites, but none of these
sites  meet the annual data completeness  criteria,
then  the  reader will be  advised that there are
insufficient data to calculate the annual mean. With
respect to the summary statistics on air quality levels
with averaging times  less than or equal to 24-hours,
all sites are included, even if they do not meet the
annual data completeness requirement.

   For PM,0 and Pb, the arithmetic mean statistics
are based on 24-hour measurements, which  are
typically  obtained  from  a  systematic  sampling
schedule.   In  contrast to  the trends analyses in
Section 3 which used a more relaxed indicator, only
maximum quarterly average Pb concentrations and
weighted PMto annual means meeting the  AIRS
validity criteria are displayed in Table 4-3.

       This  summary provides  the  reader with
information  on how air quality varied  among  the
nation's metropolitan areas in 1989. The highest air
quality  levels  measured  in   each  MSA  are
summarized for each pollutant monitored in  1989.
Individual MSAs are listed to provide more extensive
spatial coverage for large metropolitan complexes.

    Hrl'l
lirlplJHiifll!!
     pbllutibn severity among different M
    ^Ifl^llllllltll^^l^^lii^llllpl
     	l|.r|ip||1||^ar|f ;||ip||||IJpi
     l^p^^^^^^^^^l^l^S^^II
     ;;i|^I;W)u1tliIi!f iliilelH:
4,4    REFERENCES

       1. Statistical Abstract of the United States.
1989. U. S.  Department  of  Commerce,  U. S.
Bureau of the Census, Appendix II.

       2.  "EPA Lists  Places Failing To  Meet
Ozone or Carbon  Monoxide  Standards",  Press
Release, U.S. Environmental  Protection Agency,
Washington, D.C.. August 16,1990.
                                             4-15

-------
                   TABLE 4-3,   1989 METROPOLITAN  STATISTICAL  AREA  (MSA) AIR QUALITY FACTBOOK
                                    PEAK STATISTICS  FOR  SELECTED POLLUTA*. .3 BY  MSA
METROPOLITAN STATISTICAL AREA
ABILENE, TX
AGOADILLA, PR
AKRON, OH
ALBANY, GA
ALBANY-SCHENECTADY-TROY, NY
ALBUQUERQUE, NM
ALEXANDRIA, LA
ALLENTOWN-BETHLEHEM, PA-NJ
ALTOONA, PA
AMARILLO, TX
ANAHEIM-SANTA ANA, CA
ANCHORAGE, AK
ANDERSON, IN
ANDERSON, SC
ANN ARBOR, MI
ANNISTON, AL
APPLETON-OSHKOSH-NEENAH, WI
ARECIBO, PR
ASHEVILLE, NC
ATHENS, GA
ATLANTA, GA
ATLANTIC CITY, NJ
AUGUSTA, GA-SC
AURORA-ELGIN, IL-
AUSTIN, TX
BAKERSFIELD, CA
BALTIMORE, MD
BANGOR, ME
BATON ROUGE, LA
BATTLE CREEK, MI
BEAUMONT-PORT ARTHUR, TX
BEAVER COUNTY, PA
BELLINGHAM, WA
BENTON HARBOR, MI
BERGEN-PASSAIG, NJ
BILLINGS, MT
BILOXI-GULPPORT, MS
BINGHAMTON, NY
BIRMINGHAM, AL
BISMARK, ND
1987
POPULATION










2,









2,





2,







1,





123,
156,
647,
117,
846,
486,
140,
666,
132,
197,
219,
223,
133,
141,
268,
122,
309,
170,
171,
142,
657,
303,
392,
352,
738,
505,
303,
84,
538,
138,
371,
191,
115,
165,
294,
118,
206,
260,
917,
86,
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
PM10
AM
(UGM) .
ND
ND
IN
ND
IN
37
ND
IN
25
ND
47
31
IN
ND
ND
ND
ND
ND
29
ND
34
IN
IN
ND
23
79
44
27
28
IN
IN
34
IN
ND
40
IN
ND
ND
44
21
S02
AM
JPPM)


0
0
0


0
0

0









0
0


0
0
0

0

0
0
0

0
0
0



ND
ND
.015
,003
.011
ND
ND
.010
.011
ND
.004
ND
ND
ND
ND
ND
ND
ND
ND
ND
.008
.005
ND
ND
.001
.007
.013
ND
.007
ND
.008
.023
.006
ND
,012
.022
.006
ND
ND
ND
S02
24-HR
(PPM)


0
0
0


0
0

0









0
0


0
0
0

0

0
0
0

0
0
0



ND
ND
.054
.016
.040
ND
ND
.047
.059
ND
.013
ND
ND
ND
ND
ND
ND
ND
ND
ND
.046
.029
ND
ND
.004
.022
.044
ND
.056
ND
.124
.128
.018
ND
.045
.121
.029
ND
ND
ND
CO
8HR
JPPM)
ND
ND
7
ND
6
11
ND
5
ND
ND
11
13
ND
ND
ND
ND
16
ND
ND
ND
8 .
ND
ND
ND
4
9
9
ND
4
ND
2
4
7
ND
a
6
ND
ND
9
ND
N02
AM
(PPM)
ND
ND
ND
ND
ND
0.019
ND
0.020
ND
ND
0.047
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.029
ND
ND
ND
0.017
0.033
0.035
ND
0.019
ND
0,007
0.020
ND
ND
0.035
ND
ND
ND
ND
ND
OZONE
2ND DMX
(PPM)
ND
ND
0.14
ND
0.10
0.10
ND
0.10
0.10
ND
0.24
ND
0,10
ND
0.10
ND
0.10
ND
0.08
ND
0.12
0.12
0.10
0.11
0,11
0.16
0.13
ND
0.16
ND
0.15
0.10
0.05
ND
0.12
0.08
ND
ND
0.12
ND
PB
QMAX
(UGM)
ND
ND
0,10
ND
0.03
0.05
ND
0.76
ND
ND
0.08
ND
ND
0,02
0.02
ND
ND
ND
ND
ND
0.04
0.07
0.03
ND
ND
0.06
0.11
0.04
0.09
ND
0,02
0.27
ND
ND
0.05
KO
ND
KD
2.32*
KD

-------
BLOOMINGTON,  IN
BLOOMINGTON-NORMAL,  IL
BOISE CITY,  ID
BOSTON, MA
BOULDER-LONGMONT, CO
BRADENTON, FL
BRAZORIA, TX
BREMERTON, WA
BRIDGEPORT-MILFORD, Cf
BRISTOL, CT
BROCKTON, MA
BROWNSVILLE-HARLINGEN, TX
BRYAN-COLLEGE STATION, TX
BUFFALO, NY
BURLINGTON, NC
BURLINGTON, VT
CAGUAS, PR
CANTON, OH
CASPER, WY
CEDAR RAPIDS, IA
CHAMPAIGN-URBANA-RANTOOL, IL
CHARLESTON, SC
CHARLESTON, WV
CHARLOTTE-GASTONIA-ROCK HILL, NC-SC
CHARLOTTESVILLE, VA
CHATTANOOGA, TN-GA
CHEYENNE, WY
10<3,
124,
196,
2,842,
217,
184,
181,
114,
444,
78,
185,
264,
118,
958,
105,
127,
275,
397,
67,
170,
173,
502,
261,
1,091,
123,
432,
76,
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
ND
ND
IN
36
IN
ND
ND
ND
36
23
ND
IN
ND
29
ND
IN
ND
37
ND
34
IN
IN
35
34
30
35
ND



0




0




0

0

0

0
0
0
0




ND
ND
ND
.014
ND
ND
ND
ND
.014
ND
ND
ND
ND
.014
ND
.007
ND
.012
ND
.009
.005
.005
.015
ND
ND
ND
ND



0




0




0

0

0

0
0
0
0




ND
ND
ND
.058
ND
'ND
ND
ND
.051
ND
ND
ND
ND
.068
ND
,031
ND
.041
ND
.078
.025
.045
.076
ND
ND
ND
ND
ND
ND
5
6
7
ND
ND
6
5
ND
ND
ND
ND
5
ND
4
ND
5
ND
3
ND
6
3
8
ND
ND
ND
ND
ND
ND
0.032
ND
ND
ND
ND
0.026
ND
ND
ND
ND
0.024
ND
0.019
ND
ND
ND
ND
ND
ND
0.021
IN
ND
ND
ND



0
0
0


0

0


0



0

0
0
0
0
0

0

ND
ND
ND
.12
.11
.10
ND
ND
.18
ND
.13
ND
ND
.11
ND
ND
ND
.12
ND
.08
.09
.09
.10
.13
ND
.11
ND
ND
ND
0.06
0.08
ND
ND
ND
ND
0.07
ND
ND
ND
ND
0.04
ND
0.02
ND
ND
ND
ND
ND
0.04
0.04
0.03
ND
ND
ND
PM10
S02

CO
N02
03
PB
HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 50 ug/m3)
HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 0.03 ppm)
HIGHEST SECOND MAXIMUM 24-HOUR CONCENTRATION   '  (Applicable NAAQS is 0.14 ppm)
HIGHEST SECOND MAXIMUM NONOVERLAPPING 8-HOUR CONCENTRATION    (Applicable NAAQS is 9 ppm)
HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 0,053 ppnij
HIGHEST SECOND DAILY MAXIMUM 1-HOUR CONCENTRATION    (Applicable NAAQS is 0.12 ppm}
HIGHEST QUARTERLY MAXIMUM CONCENTRATION     (Applicable NAAQS is 1.15 ug/mj)
ND   = INDICATES DATA NOT AVAILABLE
IN   = INDICATES INSUFFICIENT DATA TO CALCULATE SUMMARY STATISTIC
                                                                     UGM = UNITS ARE MICROGRAMS PER CUBIC METER
                                                                     PPM = UNITS ARE PARTS PER MILLION
    Impact from an industrial source in Leeds, Al.  Highest site in Birmingham, AL is 0.20 ug/m3.

-------
                   TABLE 4-3.  1989 METROPOLITAN STATISTICAL AREA  (MSA) AIR QUALITY FACTBOOK
                                    PEAK STATISTICS FOR SELECTED POLLUTANTS BY MSA
METROPOLITAN STATISTICAL AREA
CHICAGO, IL
CHICO, CA
CINCINNATI, OH-KY-IN
CLARKSVILLE-HOPKINSVILLE, TN-KY
CLEVELAND, OH
COLORADO SPRINGS, CO
COLUMBIA, MO
COLUMBIA, SC
COLUMBUS, GA-AL
COLUMBUS, OH •
CORPUS CHRISTI, TX
CUMBERLAND, MD-WV
DALLAS, TX
DANBURY, CT
DANVILLE, VA
DAVENPORT-ROCK ISLAND-MOLINE, IA-IL
DAYTON-SPRINGFIELD, OH
DAYTONA BEACH,  FL
DECATUR, AL
DECATUR, IL
DENVER, CO
DBS MOINES, IA
DETROIT, MI
DOTHAN, AL
DUBUQOE, IA
DULUTH, MN-WI
EAU CLAIRE, WI
EL PASO, TX
ELKHART-GOSHEN, IN
ELMIRA, NY
ENID, OK
ERIE, PA
EUGENE-SPRINGFIELD, OR
EVANSVILLE, IN-KY
FALL RIVER, MA-RI
FARGO-MOORHEAD, ND-MN
FAYETTEVILLE, NC
FAYETTEVILLE-SPRINGDALE, AR
FITCHBURG-LEOMINSTSR, MA
FLINT, MI
1987
POPULATION

6,199,000
169,000
1,438,000
157,000
1,851,000
390,000
107,000
451,000
2-96,000
1,320,000
360,000
102,000
2,456,000
189,000
109,000
367,000
939,000
332,000
131,000
125,000
1,645,000
385,000
4,362,000
130,000
91,000
242,000
137,000
573,000
150,000
90,000
60,000
279,000
265,000
281,000
153,000
147,000
259,000
110,000
96,000
435,000
PM10
AM
JOGM)
48
35
45
IN
52
34
28
IN
IN
40
33
ND
36
25
ND
29'
35
ND
IN
40
35
37
52
IN
ND
25
ND
69
ND
ND
ND
IN
38
39
22
21
29
IN
ND
26
S02
AM
(PPM)
0,011
ND
0.016
0.007
0.018
ND
0,008
0.003
ND
0.010
0.003
0.011
0.005
0.008
ND
0.006
0.007
IN
ND
0.012
0.007
ND
0.015
ND
0.005
0.005
ND
0.015
ND
0.005
ND
0.014
ND
0.020
0.009
ND
ND
ND
ND
0.004
S02
24-HR
(PPM)
0.037
ND
0,084
0.042
0.061
ND
0,037
0.017
ND
0.041
0.021
0.049
0.018
0.035
ND
0.031
0.035
0.003
ND
0.108
0.033
ND
0.058
ND
0.030
0.086
ND
0.059
ND
0.026
ND
0.074
ND
0.110
0.063
ND
ND
ND
ND
0.026
CO
8HR
{PPM)
7
9
5
2
8
8
ND
7
ND
7
ND
4
5
ND
ND
4
6
ND
ND
ND
11
5
8
ND
ND
10
ND
13
ND
ND
ND
4
6
4
ND
ND
8
ND
ND
ND
N02
AM
(PPM)
0.034
0.016
0.030
ND
0.034
ND
ND
ND
ND
ND
ND
ND
0.021
ND
ND
ND
ND
ND
ND
ND
0.040
ND
0.026
ND
ND
ND
ND
0.022
ND
ND
ND
0.015
ND
0.020
ND
ND
ND
ND
ND
ND
OZONE
2ND DMX
(PPM)
0.12
0.10
0.12
ND
0.12
0,09
ND
0.10
0.09
0.11
0.10
ND
0.13
0.13
ND
0.11
0.15
ND
ND
0.09
0.11
O.OB
0.14
ND
ND
0.06
ND
0.14
ND
0.09
ND
0.12
0,08
0.12
ND
ND
0.11
ND
ND
0.10
PB
QMAX
(UGH)
0.16
ND
0,11
ND
0.17
ND
ND
0.04
ND
0.08
ND
ND
1.76*
ND
ND
0.02
0.06
ND
ND
0.07
0.02
ND
0.09
ND
ND
ND
ND
0.42
ND
ND
ND
ND
0.02
ND
ND
ND
ND
ND
ND
0.32

-------
FLORENCE, AL
FLORENCE, SC
FORT COLLINS, CO
FORT LAUDERDALE-HOLLYWOOD-POMPANO BE
FORT MYERS-CAPE CORAL, FL
FORT PIERCE, FL
FORT SMITH, AR-OK
FORT WALTON BEACH, FL
FORT WAYNE, IN
FORT WORTH-ARLINGTON, TX
FRESNO, CA
GADSDEN, AL
GAINESVILLE, FL
GALVESTON-TEXAS CITY, TX
GARY-HAMMOND, IN
GLENS FALLS, NY
GRAND FORKS, ND
GRAND RAPIDS, MI
GREAT FALLS, MT
GREELEY, CO
GREEN BAY, WI   ,
GREENSBORO-WINSTON SALEM-HIGH POINT,
GREENVILLE-SPARTANBURG, SC
HAGERSTOWN, MD
HAMILTON-MIDDLETOWN, OH
HARRISBURG-LEBANON-CARLISLE, PA
HARTFORD, CT
HICKORY, NC
136,000
117,000
180,000
1,163,000
295,000
215,000
178,000
145,000
364,000
1,269,000
597,000
103,000
205,000
211,000
604,000
112,000
70,000
657,000
78,000
135,000
188,000
916,000
612,000
116,000
276,000
584,000
748,000
219,000
ND
ND
IN
25
ND
ND
IN
ND
29
25
76
31
ND
IN
47
ND
IN
27
20
30
IN
33
IN
ND
IN
21
30
ND
0,006
ND
ND
ND
ND
ND
ND
ND
0,005
0.001
0.004
ND
IN
0.008
0.016
0.004
ND
0.004
ND
ND
0.008
0.007
IN
ND
0.011
0.009
0.011
ND
0.060
ND
ND
ND
• ND
ND
ND
ND
0.026
0.007
0.013
ND
0.008
0.045
0.072
0.023
- ND
0.016
ND
ND
0.030
0.024
0.014
ND
0.046
0.037
0.046
ND
ND
ND
8
7
ND
ND
ND
ND
6
6
12
ND
ND
ND
4
ND
ND
5
8
7
ND
10
ND
ND
ND
6
9
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.011
0.013
0.032
ND
ND
ND
•IN
ND
ND
IN
ND
ND
ND
0.016
ND
ND
ND
0.022
0.020
ND
ND
ND
0.09
0.12
0.10
ND
ND
ND
0.12
0.13
0.15
ND
ND
0.14
0.11
ND
ND
0.13
ND
0.10
0.09
0.10
0.10
ND
0.11
0.11
0.14
ND
ND
ND
ND
0.05
ND
ND
ND
ND
ND
0.04
0.07
ND
ND
0.03
0.42
ND
ND
0.04
ND
ND
ND
ND
0,05
ND
ND
ND
0.09
ND
PM10 = HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 50 ug/m3)
S02  = HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 0.03 ppm)
       HIGHEST SECOND MAXIMUM 24-HOOR CONCENTRATION     (Applicable NAAQS is 0,14 ppm)
CO   = HIGHEST SECOND MAXIMUM NONOVERLAPPING 8-HOUR CONCENTRATION     (Applicable NAAQS is 9 ppm)
N02  = HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 0.053 ppm>
03   = HIGHEST SECOND DAILY MAXIMUM 1-HOUR CONCENTRATION     (Applicable NAAQS is 0.12 ppmj
PB   = HIGHEST QUARTERLY MAXIMUM CONCENTRATION     (Applicable NAAQS is 1.15 uy/ra3)
ND   = INDICATES DATA NOT AVAILABLE .
IN   = INDICATES INSUFFICIENT DATA TO CALCULATE SUMMARY STATISTIC
OGM = UNITS ARE MICROGRAMS PER CUBIC METER
PPM = UNITS ARE PARTS PER MILLION
    Impact from an industrial source in Collin County, TX.  Highest site in Dallas, TX is 0.42 ug/m3.

-------
                   TABLE 4-3.
1989 METROPOLITAN STATISTICAL AREA (MSA)  AIR QUALITY FACTBOOK
     PEAK STATISTICS FOR SELECTED POLLUTANTS BY MSA
METROPOLITAN STATISTICAL AREA
HONOLULU, HI
HOUMA-THIBODAUX, LA
HOUSTON, TX
HUNTINGTON-ASHLAND, WV-KY-OH
HUNTSVILLE, AL
INDIANAPOLIS, IN
IOWA CITY, IA
JACKSON, MI
JACKSON, MS
JACKSON, TN
JACKSONVILLE, FL
JACKSONVILLE, NC
JANESVILLE-BELOIf, WI
JERSEY CITY, NJ
JOHNSON CITY-KINGSPORT-BRISTOL, TN-V
JOHNSTOWN, PA
JOLIET, IL
JOPLIN, MO
KALAMAZOO, MI
KANKAKEE, IL
KANSAS CITY, MO-KS
KENOSHA, WI
KILLEN-TEMPLS, TX
KNOXVILLE, TN
KOKOMO, IN
LA CROSSE, WI
LAFAYETTE, LA
LAFAYETTE, IN
LAKE CHARLES, LA
LAKE COONTY, IL
LAKELAND-WINTER HAVEN, FL
LANCASTER, PA
LANSING-EAST LANSING, MI
LAREDO, TX
LAS CRUCES, NM
LAS VEGAS, NV
LAWRENCE, KS
LAWRENCE-HAVERHILL, MA-NH
LAWTON, OK
LEW-ISTON-AUBURN, ME

1987

POPULATION



3


1














1




















831,
185,
,228,
323,
231,
,229,
86,
147,
396,
78,
878,
126,
135,
547,
443,
252,
377,
134,
219,
98,
,546,
120,
234,
594,
101,
95,
212,
125,
172,
494,
387,
404,
428,
124,
129,
600,
75,
375,
119,
85,

000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
PM10
AM
(UGM)
IN
ND
30
42
31
43
ND
ND
26
30
37
ND
ND
37
32
33
33
ND
ND
ND
47
ND
ND
35
ND
ND
ND
37
IN
ND
ND
29
IN
IN
68
69
ND
ND
IN
ND


I
0

0
0

0




0


0
0
0
0



0
0

0



0
0

0
0


0


0
0
0
S02
AM
PPM)
.001
ND
.009
.017
ND
.014
ND
ND
ND
ND
.006
ND
ND
.016
.014
.016
.007
ND
ND
ND
.006
.003
ND
.013
ND
ND
ND
.006
.002
ND
.004
.007
ND
ND
.016
ND
ND
.010
.010
.008

502
24-HR
1
0

0
0

0




0


0
0
0
0



0
0

0



0
0

0
0


0


0
0
0
PPM).
.003
ND
.055
.085
ND
.056
ND
ND
ND
ND
.060
ND
ND
.052
.072
.089
.031
ND
ND
ND
.020
.013
ND
.051
ND
ND
ND
.025
.011
ND
.016
.037
ND
ND
.105
ND
ND
.041
.039
.035
CO
8HR
JPPM)
4
ND
8
6
5
5
ND
ND
6
ND
7
ND
ND
7
4
4
ND
ND
ND
ND
7
ND
ND
7
ND
ND
ND
1
ND
ND
ND
4
ND
ND
6
12
ND
ND
KD
ND
N02
AM
_(_PPM)_.
ND
ND
0.028
0.013
ND
0.023
ND
ND
ND
ND
0.015
ND
ND
0.031
0.019
0.019
ND
ND
ND
ND
0.015
0.016
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.013
ND
ND
ND
IN
ND
ND
ND
ND
OZONE
2ND DMX
JPPM)
0.05
0.11
0.23
0.12
0.09
0.12
0.09
ND
0.09
ND
0.11
ND
0.12
0.12
• 0.11
0.10
0.10
ND
ND
ND
0.11
0.13
ND
0.10
ND
ND
0.10
0.09
0.13
0.13
ND
0.10
0.10
ND
0.11
0.11
ND
0.12
ND
ND
PB
QMAX
(UGMJ
0.04
ND
0.05
0,06
ND
1.13*
ND
ND
0.08
ND
0.05
ND
ND
0,08
ND
0.31
0.03
ND
0.02
ND
0.11
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.05
0.02
. ND
0.17
KD
ND
ND
KD
0.03

-------
LEXINGTON-PAYETTE, KY
LIMA, OH
LINCOLN, NE
LITTLE ROCK-NORTH LITTLE ROCK, AR
LONGVIEW-MARSHALL, TX
LORAIN-ELYRIA, OH
LOS ANGELES-LONG BEACH, CA
LOUISVILLE, KY-IN
LOWELL, MA-NH
LUBBOCK, TX
LYNCHBURG, VA
MACON-WARNER ROBINS, GA
MADISON, WI
MANCHESTER, NH
MANSFIELD, OH
MAYAGUEZ, PR
MCALLEN-EDINBURG-MISSION, TX
MEDFORD, OR
MELBQURNE-TITUSVILLE-PALM BAY, FL
MEMPHIS, TN-AR-MS
MERCED, CA
MIAMI-HIALEAH, FL
MIDDLESEX-SQMERSET-HUNTERDON, NJ
MIDDLETOWN, CT
MIDLAND, TX
MILWAUKEE, WI
MINNEAPOLIS-ST. PAUL, MN-WI
342,
156,
208,
512,
167,
268,
8,505,
967,
260,
228,
143,
283,
347,
146,
128,
210,
379,
143,
375,
972,
166,
1/791,
966,
85,
108,
1,389,
2,336,
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
ND
ND
34
33
ND
IN
64
38
ND
34
30
ND
IN
24
ND
ND
ND
51
ND
33
52
28
34
23
ND
40
33
0
0

0

0
0
0




0
0





0


0


0
0
.006
.006
ND
.002
ND
.007
.005
.012
ND
ND
ND
ND
.003
.009
ND
ND
ND
ND
ND
.009
ND
ND
.010
ND
ND
.007
.010
0
0

0

0
0
0




0
0





0


0


0
0
.034
.033
ND
.010
ND
.035
.021
.060
ND
ND
ND
ND
.016
.050
ND
ND
ND
ND
ND
.033
ND
ND
.037
ND
ND
.032
.072
6
ND
8
ND
ND
ND
18
7
5
ND
ND
ND
5
7
ND
ND
ND
12
ND
10
ND
8
5
ND
ND
6
11
0


0


0






0





0

0
0


0
0
.019
ND
ND
.009
ND
ND
.057
IN
ND
ND
ND
ND
ND
.022
ND
ND
ND
ND
ND
.026
ND
.018
.024
ND
ND
.029
.009
0.11
0.10
0.06
0.09
0.10
0.12
0.33
0.11
ND
ND
ND
ND
0.10
0.10
ND
ND
ND
0.09
0.10
0.12
ND
0.12
0.13
0.17
ND
0.15
0,10
ND
ND
ND
0.34
ND
ND
0.14
0.07
ND
ND
ND
ND
ND
0.03
ND
ND
ND
0.04
ND
0.19
ND
0.08
0.38
ND
ND
0.07
1.04#
PM1Q
S02

CO
N02
03
PB

ND
IN
  HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 50 ug/ra3)
  HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 0.03 ppm)
  HIGHEST SECOND MAXIMUM 24-HODR CONCENTRATION     (Applicable NAAQS is Q.-14 ppm)
  HIGHEST SECOND MAXIMUM NONOVERLAPPING 8-HOUR CONCENTRATION    (Applicable NAAQS is 9
  HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 0.053 ppm)
  HIGHEST SECOND DAILY MAXIMUM 1-HOUR CONCENTRATION     (Applicable NAAQS is 0,12 ppm)
  HIGHEST QUARTERLY MAXIMUM CONCENTRATION     (Applicable NAAQS is 1.15 ug/m3)
                ppm)
= INDICATES DATA NOT AVAILABLE
= INDICATES INSUFFICIENT DATA TO CALCULATE SUMMARY STATISTIC
UGM = UNITS ARE MICROGRAMS PER CUBIC METER
PPM = UNITS ARE PARTS PER MILLION
* - Impact from an industrial source in Indianapolis,  IN,

I - Impact from an industrial source in Eagan, MN.  Highest site in Minneapolis, MN is 0,05 ug/m3.

-------
                   TABLE 4-3.
1989 METROPOLITAN STATISTICAL AREA (MSA)  AIR QUALITY FACTBOOK
     PEAK STATISTICS FOR SELECTED POLLUTANTS BY MSA
METROPOLITAN STATISTICAL AREA
MOBILE, AL
MODESTO, CA
MONMOUTH-OCEAN, NJ
MONROE, LA
MONTGOMERY, AL
MUNCIE, IN
MUSKEGON,  MI
NAPLES, FL
NASHUA, NH
NASHVILLE, TN
NASSAU-SUFFOLK, NY
NEW BEDFORD, MA
NEK BRITAIN, CT
NEW HAVEN-MERIDEN, CT
NEW LONDON-NORWICH, CT-RI
NEW ORLEANS, LA
NEW YORK,  NY
NEWARK, NJ
NIAGARA PALLS, NY
NORFOLK-VIRGINIA BEACH-NEWPORT NEWS,
NORWALK, CT
OAKLAND, CA
OCALA, FL
ODESSA, TX
OKLAHOMA CITY, OK  "
OLYMPIA, WA
OMAHA, NE-IA
ORANGE COUNTY, NY
ORLANDO, FL
OWENSBORO, KY
OXNARD-VENTURA, CA
PANAMA CITY, FL
PARKERBURG-MARIETTA,  WV-OH
PASCAGOOLA, MS
PAWTUCKET-WOONSOCKET-ATTLEBORO, RI-M
PENSACOLA, FL
PEORIA, IL
PHILADELPHIA, PA-NJ
PHOENIX, AZ
PINE BLUFF, AR
1987
POPULATION

483,
327,
957,
146,
291,
121,
159,
128,
172,
956,
2,631,
166,
147,
519,
259,
1,321,
8,529,
1,891,
216,
1,346,
126,
1,968,
181,
127,
975,
151,
616,
288,
935,
88,
628,
122,
156,
128,
322,
344,
339,
4,866,
1,960,
91,

000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
PM10
AM
(UGM)
37
52
ND
IN
18
IN
IN
ND
24
IN
ND
ND
24
44
23
39
66
38
IN
29
37
37
ND
IN
27
28
46
IN
32
IN
40
ND
ND
ND
32
ND
28
46
70
IN

1
0
0






0
0
0

0
0
0
0
0
0
0
0

0


0

0

0
0
0

0
0
0
0
0
0
0

S02
AM
PPM)
.008
.001
ND
ND
ND
ND
ND
ND
.008
.013
.012
ND
.009
.016
.008
.004
.021
.013
.014
.006
ND
.003
ND
ND
.006
ND
.002
ND
.002
.010
.001
ND
.016
.006
.011
.006
.007
.015
.002
ND
S02
24-HR
i
0
0






0
0
0

0
0
0
0
0
0
0
0

0


0

0

0
0
0

0
0
0
0
0
0
0

PPM)
.063
.010
ND
ND
ND
ND
ND
ND
.042
.113
.050
ND
.048
,008
.027
.019
.081
.056
.059
.039
ND
.017
ND
ND
.016
ND
.008
ND
.006
.053
.007
ND
.076
.021
.040
.057
.056
.065
.006
ND
CO
8HR
(PPM)
ND
12
6
ND
ND
ND
ND
ND
8
9
7
ND
ND
6
ND
7
12
9
4
7
ND
6
ND
ND
9
ND
7
ND
5
6
4
ND
ND
ND
ND
ND
8
12
13
ND

1

0







0
0


0

0
0
0

0

0


0



0
0
0






0


N02
AM
PPM)
ND
.027
ND
ND
ND
ND
ND
ND
ND
.012
.029
ND
ND
.028
ND
.022
.049
.038
ND
.020
ND
.025
ND
ND
.015
ND
ND
ND
.013
.014
.027
ND
ND
ND
ND
ND
ND
.040
ND
ND
OZONE
2ND DMX
.(PPJJL
0.10
0.13
0.14
ND
0.08
ND
0.14
ND
0.09
0.14
0.15
0.12
ND
0.15
0.14
0.11
0.13
0.13
0.10
0.10
ND
0.13
ND
ND
0.11
ND
0.10
ND
0.11
0.10
0.17
ND
0.12
0.10
ND
0.09
0.11
0.16
0.11
ND
PB
QMAX
(UGM)
ND
ND
ND
ND
ND
ND
0.03
ND
0.03
1.13*
0.03
ND
ND
0.08
ND
0.09
0.12
0.41
ND
0.12
ND
0.21
ND
ND
0.07
ND
2.131
1.368
0.02
0.05
0.04
ND
0.04
ND
ND
N3
0.34
0.41
0.10
N3

-------
PITTSBURGH, PA
PITTSFIELD, MA
PONCE, PR
PORTLAND, ME
PORTLAND, OR-WA
PORTSMOUTH-DOVER-ROCHESTER, NH-ME
POUGHKEEPSIi, NY
PROVIDENCE, RI
PROVO-OREM, UT
PUEBLO, CO
RACINE, WI
RALEIGH-DURHAM, NC
RAPID CITY, SD
READING, PA
REDDING, CA
RENO, NV
RICHLAND-KENNEWICK-PASCO, WA
RICHMOND-PETERSBURG, VA
RIVERSIDE-SAN BERNARDINO, CA
ROANOKE, VA
ROCHESTER, MN
ROCHESTER, NY
ROCKFORD, IL
SACRAMENTO, CA
SAGINAW-BAY CITY-MIDLAND, MI
ST. CLOUD, MN
ST. JOSEPH, MO
2,105,
80,
235,
210,
1,168,
215,
258,
643,
242,
127,
173,
665,
80,
324,
136,
232,
, 150,
825,
2,119,
224,
98,
979,
281,
1,336,
404,
177,
85,
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
43
ND
46
24
33
IN
ND
39
52
33
ND
30
IN
IN
IN
47
29
30
93
IN
IN
IN
IN
43
29
17
45
0


0
0
0
0
0





0



0
0
0
0
0

0
0
0
0
.024
ND
ND
.010
.007
.008
.009
.015
ND
ND
ND
ND
ND
.010
ND
ND
ND
.014
.004
.005
.004
.016
ND
.006
.008
.002
.003
0


0
0
0
0
0





0



0
0
0
0
0

0
0
0
0
.106
ND
ND
.039
.023
.029
.042
.017
ND
ND
ND
ND
ND
.045
ND
ND
ND
.085
.023
.022
.028
.069
ND
.020
.061
.011
.037
8
ND
ND
4
10
ND
ND
8
16
ND
6
11
ND
5
2
10
ND
4
8
2
6
4
7
13
2
5
ND
0






0
0


0

0
0


0
0
0



0
0


.028
ND
ND
ND
IN
ND
ND
.024
.028
ND
ND
.012
ND
.023
.014
ND
ND
.025
.045
.014
ND
ND
ND
.025
.009
ND
ND
0.13
0.09
ND
0.13
0.09
0.11
0.08
0.13
0.11
ND
0.14
0.11
ND
0.11
0.09
0.10
ND
0.11
0.28
0.10
ND
0.11
0.10
0.14
ND
ND
ND
0.10
ND
ND
0.05
0.11
0.04
ND
0.21
ND
ND
ND
ND
ND
0.31
ND
ND
ND
ND
0.08
ND
ND
0.03
0.07
0.08
0.03
ND
ND
PM10 = HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 50 ug/m'>
S02  = HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 0.03 ppm)
       HIGHEST SECOND MAXIMUM 24-HOUR CONCENTRATION     (Applicable NAAQS is 0.14 ppm)
CO   = HIGHEST SECOND MAXIMUM NONOVERLAPPING 8-HOUR CONCENTRATION    (Applicable NRAQS is 9 ppm)
N02  = HIGHEST ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 0.053 ppm)
03   = HIGHEST SECOND DAILY MAXIMUM 1-HOUR CONCENTRATION     (Applicable NAAQS is 0.12 ppm)
PB   = HIGHEST QUARTERLY MAXIMUM CONCENTRATION     (Applicable NAAQS is 1.15 ug/m3)
ND   = INDICATES DATA NOT AVAILABLE
IN   = INDICATES INSUFFICIENT DATA TO CALCULATE SUMMARY STATISTIC
UGM = UNITS ARE MICROGRAMS PER CUBIC METER
PPM = UNITS ARE PARTS PER MILLION
* - Impact from an industrial source in Williamson County, TN.  Highest site in Nashville, TN is 0.16 ug/rn3.

# - Impact from an industrial source in Omaha, NE.

8 - Impact from an industrial source in Orange County, NY.

-------
                   TABLE 4-3.
                               1989 METROPOLITAN STATISTICAL AREA  (MSA) AIR QUALITY FACTBQOK
                                    PEAK STATISTICS FOR SELECTED POLLUTANTS BY MSA
METROPOLITAN STATISTICAL AREA
ST. LOUIS, MO-IL
SALEM, OR
SALEM-GLOUCESTER, MA
SALINAS-SEASIDE-MONTEREY, CA
SALT LAKE CITY-QGDEN, UT
SAN ANGELO, TX
SAN ANTONIO, TX
SAN DIEGO, CA
SAN FRANCISCO, CA
SAN JOSE, CA
SAN JUAN, PR
SANTA BARBARA-SANTA MARIA-LOMPOC, CA
SANTA CRUZ, CA
SANTA FE, NM
SANTA ROSA-PETALUMA, CA
SARASOTA, PL
SAVANNAH, GA
SCRANTQN-WILKES-BARRE, PA
SEATTLE, WA
SHARON, PA
SHEBOYGAN, WI
SHERMAN-DEN ISDN, TX
SHREVEPORT, LA
SIOUX CITY, IA-NS
SIOUX FALLS, SD
SOUTH BEND-MISHAWAKA, IN
SPOKANE, WA
SPRINGFIELD, IL
SPRINGFIELD, MO
SPRINGFIELD, MA
STAMFORD, CT
STATE COLLEGE, PA
STEUBENVILLE-WEIRTON, OH-WV
STOCKTON, CA
SYRACUSE, NY
TACOMA, WA
TALLAHASSEE, FL
TAMPA-ST. PETERSBURG-CLEARWATER, FL
TERRE HAUTE, IN
TEXARKANA, TX-AR
1981
POPULATION

2,458,000
266,000
258,000
343,000
1,055,000
99,000
1,307,000
2,286,000
1,590,000
1,415,000
1,541,000
341,000
222,000
111,000
354,000
256,000
241,000
731,000
1,796,000
123,000
102,000
100,000
364,000
115,000
124,000
242,000
355,000
191,000
229,000
517,000
193,000
115,000
149,000
443,000
647,000
545,000
223,000
1,965,000
132,000
120,000
PM10
AM
(UGMj
76
ND
ND
25
56
ND
28
44
36
41
IN
34 ,
IN
16
27
ND
ND
32
40
IN
ND
ND
IN
28
22
IN
44
IN
22
31
26
ND
45
51
28
39
ND
32
34
IN
S02
AM
J_PPMJ
0.018
ND
0,009
0.001
0.019
ND
ND
0.006
0.003
ND
0.003
0.002
0.001
ND
ND
0.003
0.003
0.009
0.007
0.011
0.004
ND
0.004
ND
ND
0.006
ND
0.007
0.009
0.013
0.011
ND
0.035
IN
0.005
0.007
ND
0.011
0.009
ND
S02
24-HR
(PPM)
0.102
ND
0.040
0.002
0.103
ND
ND
0.018
0.015
ND
6.019
0.010
0.004
ND
ND
0.017
0.016
0.048
0.023
0.043
0.015
ND
0.023
ND
ND
0.026
ND
0.047
0.073
0.055
0.047
ND
0.127
0.007
0.020
0.033
ND
0.039
0.046
ND
CO
8HR
JPPM)
8
4
ND
2
8
ND
7
10
8
12
6
7
1
4
5
6
ND
5
10
ND
ND
ND
ND
ND
ND
4
12
4
7
8
6
ND
13
10
10
10
ND
6
ND
ND
NO2
AM
(PPM)
0.026
ND
ND
0.014
0.034
ND
ND
0.032
0.026
0.032
ND
0.027
0.009
ND
0.015
ND
ND
0.021
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.010
0.029
ND
ND
0.023
0.026
ND
ND
ND
0.022
ND
ND
OZONE
2ND DMX
(PPH]_
0.13
ND
ND
0.11
0.15
ND
0.11
0.19
0.09
0.13
0.06
0.16
0.08
0.05
0.10
0.10
ND
0.11
0.09
0.11
0.11
ND
0.12
ND
ND
0.10
ND
0.11
0.09
0.13
0.16
ND
0.11
0.11
0.10
0.09
0.07
0.10
0.11
ND
PB
QMAX
tUGM)
2.29*
ND
ND
ND
0.15
ND
0.04
0.07
0.15
0.14
0.05
0.05
ND
ND
0.07
ND
ND
ND
0.31
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.06
ND
ND
0.00
0.05
O.C4
O.C4
ND
0.13
ND
ND

-------
TOLEDO, OH
TOPEKA, KS
TRENTON, NJ
TUCSON, AZ
TULSA, OK
TUSCALOQSA, AL
TYLER, TX
UTICA-ROME, NY
VALLEJO-FAIRFIELD-NAPA, CA
VANCOUVER, WA
VICTORIA, TX
VINELAND-MILLVILE-BRIDGETQN, NJ
VISALIA-TULARE-PORTERVILLE, CA
WACO, TX
WASHINGTON, DC-MD-VA
WATERBURY, CT
WATERLOO-CEDAR PALLS, IA
WAUSAU, WI
WEST PALM BEACH-BOCA RATQN-DSLRAY BE
WHEELING, WV-OH
WICHITA, KS
WICHITA FALLS, TX
WILLIAMSPORT, PA
WILMINGTON, DE-NJ-MD
WILMINGTON, NC
WORCESTER, MA
YAKIMA, WA
YORK, PA
YQUNGSTOWH-WARREN, OH
YOBA CITY, CA
611,
162,
327,
619,
733,
144,
1S3,
314,
404,
216,
75,
138,
292,
189,
3,646,
213,
149,
111,
790,
173,
475,
126,
117,
559,
116,
410,
183,
404,
503,
116,
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000
IN
IN
30
52
36
IN
ND
ND
32
ND
ND
ND
67
ND
43
33
ND
ND
IN
34
31
IN
29
35
27
27
IN
31
35
IN
0

0
0
0



0


0


0
0

0
0
0


0
0

0

0
0

.008
ND
.009
.002
.007
ND
ND
ND
.002
IN
ND
.008
IN
ND
.014
.011
ND
.010
.003
.026
ND
ND
.007
.018
ND
.010
ND
.007
.010
ND
0

0
0
0



0
0

0
0

0
0

0
0
0


0
0

0

0
0

.050
ND
.040
.008
.038
ND
ND
ND
.'010
.011
ND
.049
.006
ND
.046
.064
ND
.074
.008
.076
ND
ND
.042
.049
ND
.040
ND '
.035
.041
ND
5
ND
5
7
7
ND
ND
ND
10
10
ND
ND
6
ND
9
ND
ND
ND
4
5
9
ND
ND
5
ND
8
9
5
ND
ND



0
0



0



0

0



0
0



0

0

0


ND
ND
ND
.023
.020
ND
ND
ND
.019
ND
ND
ND
.021
ND
.031
ND
ND
ND
.013
.019
ND
ND
ND
.034
ND
.026
ND
.022
ND
ND
0.11
ND
0.14
0.10
0.12
ND
ND
0.09
0.11
0.09
0.10
0.13
0.15
ND
0.13
ND
ND
ND
0.11
0,11
0.09
ND
0.08
0.13
ND
0.10
ND
0.10
0.11
0.10
0.48
0.03
ND
0.06
0.20
ND
ND
ND
0.10
ND
ND
ND
ND
ND
0.10
0.06
ND
ND
ND
0.07
0.04
ND
ND
0.16
ND
ND
ND
ND
ND
ND
PM10
S02

CO
N02
03
PB
HIGHEST
HIGHEST
HIGHEST
HIGHEST
HIGHEST
HIGHEST
HIGHEST
ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 50 ug/nr1)
ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 0.03 ppm)
SECOND MAXIMUM 24-HOUR CONCENTRATION     (Applicable NAAQS is 0.14 ppm)
SECOND MAXIMUM NONOVERLAPPING 8-HOUR CONCENTRATION    {Applicable NAAQS is 9 ppm)
ARITHMETIC MEAN CONCENTRATION     (Applicable NAAQS is 0.053 ppm}
SECOND DAILY MAXIMUM 1-HOUR CONCENTRATION    (Applicable NAAQS is 0.12 ppm)
QUARTERLY MAXIMUM CONCENTRATION     (Applicable NAAQS is 1.15 ug/m*>
ND   = INDICATES DATA NOT AVAILABLE
IN   = INDICATES INSUFFICIENT DATA TO CALCULATE SUMMARY STATISTIC
                                                                     UGM = UNITS ARE MICROGRAMS PER CUBIC METER
                                                                     PPM = UNITS ARE PARTS PER MILLION
  - Impact from a lead smelter in Herculaneum, MO.  Highest site in St. Louis, MO is 0.23 ug/m3.

-------
5. SELECTED METROPOLITAN AREA TRENDS
    This chapter discusses
trends in major urban areas.
trends are presented include:
Offices (Boston, New York,
Chicago,  Dallas,  Kansas
Francisco, and Seattle) plus
(Houston,   Los   Angeles,
Washington, DC.)
1980-89 air quality
 The cities lor which
the ten EPA Regional
Philadelphia, Atlanta,
City,  Denver,  San
four additional cities
   Pittsburgh,  and
   The presentation of urban area trends includes
maps  of  the  urban  area  showing  their major
roadways, rivers, etc. as well as the location of the
air quality monitoring networks.   Various  new
graphical  displays are used to depict  urban air
quality trends.  These are primarily based on the
Pollutant Standards Index (PSI) as the measure of
air quality.

   The air quality data used for the trend statistics
were obtained from the EPA Aerometric Information
and Retrieval System (AIRS).  This year's report
analyzes trends using the PSI, which is used locally
in many areas to characterize and publicly report
air quality. The new PSI analyses will be based on
daily maximum statistics from selected monitoring
sites.  The urban area trends for CO and O3 use
the same  annual validity and site selection criteria
that were used for the national trends. It should be
noted that no interpolation is used in this chapter;
this corresponds with typical PSI reporting.
5.1  The Pollutant Standards Index

   The PSI is used as an air quality indicator for
describing urban area trends.  Only CO  and Oa
monitoring sites with  adequate historical data are
included in these PSI trend analyses. This criteria
was  not applied to the other pollutants, except for
SO2  in Pittsburgh, where this pollutant contributed
a significant number of days in the high PSI range.
Results for individual years could be  somewhat
different if data from all monitoring  sites  and all
pollutants  were considered in an area.   This  is
illustrated  for 1989, for which the  number of PSI
days from all monitoring sites are compared to the
results for the subset of trend sites.

   The PSI has found wide spread use in the air
pollution field as a  means of reporting daily air
quality to the general public.  The index integrates
information from many pollutants across an entire
monitoring  network  into a  single  number which
represents the worst daily air quality experienced in
the urban area.  The PSI is computed for PM10,
SO2, CO,  O3, and NO2 based on their short-term
NAAQS,  Federal Episode Criteria  and Significant
Harm Levels.  Lead  is the only criteria pollutant
which is not part of the index since it does not have
either  a  short-term  NAAQS,  Federal  Episode
Criteria or Significant Harm Level.

   The PSI converts daily monitoring information
into  a  single measure  of  air  quality   by  first
computing a separate sub-index for each pollutant
               Table 5-1.  PSI Categories and Health Effect Descriptor Words
INDEX RANGE
0 to 50
51 to 100
101 to 199
200 to 299
300 and Above
DESCRIPTOR WORDS
Good
Moderate
Unhealthful
Very Unhealthful
Hazardous
                                             5-1

-------
with data for the day. The PSI index value used in
this analysis represents the highest of the pollutant
sub-index values for all sites selected for the MSA,
This approach Is different from the way the index is
routinely used by most local agencies.  Usually only
selected monitoring sites are used to determine the
PSI value.

    The PSI simplifies the presentation of air quality
data by producing  a single dimensionless number
ranging from 0 to 500.  The PSI utilizes data from
all  selected  sites in  the  MSA and  combines
different air  pollutants  with  different  averaging
times,  different units of concentration,  and more
importantly, with different NAAQS, Federal Episode
Criteria and Significant Harm Levels.   Table  5-1
shows  the  5 PSI categories and  health  effect
descriptor words.  The PSI is  primarily used to
report the daily air  quality of a large urban area as
a single number or descriptor word.  Frequently,
the index is reported as a regular feature on local
TV or radio news programs or in newspapers.

    Throughout this section, emphasis is placed on
CO and O3, since they cause most of the NAAQS
violations in urban  areas.

5.2  Summary of FSI Analyses

    Table 5-2 shows the number of  PSI days
greater than 100 (unhealthful or worse days). The
impact of the very hot and dry summers in 1983
and 1988  in  the  eastern  United States  on O3
concentrations can clearly be seen.  Only in the
case of Pittsburgh  is there a significant  number of
these days for pollutants other than CO or O3.  For
Pittsburgh,  SO2 and PM10 account for the additional
days.  The two right most columns show the total
number of currently active monitoring sites and the
corresponding total number of  PSI days >-100,
using these sites.  Note that for alt urban  areas
except  Houston and New York there is  close
agreement between  both 1989  estimates.  The
differences are attributed to currently active sites
not in the trends analysis.

    For all  practical purposes CO, O3,  PM10 and
SO2 are the only pollutants which contribute to the
PSI  in  these analyses.  NO2 rarely is a factor
because it  doesn't  have a short-term NAAQS and
it can only be included when concentrations exceed
one of the Federal Episode Criteria or Significant
Harm levels.  TSP is not included in the index
because it no longer is a criteria pollutant. Lead is
the only criteria pollutant which is not considered in
the index, since  it does not have  neither a short-
term NAAQS nor Federal Criteria and Significant
Harm Levels.

   The pollutant having the highest sub-index
value, from all the monitoring sites considered in an
MSA, becomes the PSI value used for  that day.
Our  PSI  estimates   vary with  the  number  of
pollutants monitored  and with  the  number  of
monitoring sites  collecting data.  Therefore, the
more pollutants and sites that are available in an
area, the better the estimate is of the maximum PSI
for that day.  Ozone accounts for most of the days
with a  PSI  above 100, and  O3 air quality is
reasonably uniform over large areas. Thus, a small
number  of  sites  can  still   estimate  maximum
pollutant concentrations.  All  of the included cities
had  at least one trend site for both CO and 03.
Table 5-3 separately shows the number of CO and
O3 trend sites used in each of the MSA's.  The PSI
trend analyses are presented for the Primary MSA's
(PMSA)  in  all  cities studied,   not  the  larger
Consolidated Metropolitan Statistical Area (CMSA),
Looking at only the principal PMSA was done to
limit  the geographical  area  studied   and  to
emphasize the area having the highest population
density. For the  San Francisco area, some results
for the Oakland  PMSA are also presented.  The
PMSA monitors are in the core of the  urban area;
there are typically additional sites in surrounding
areas.  For example, while there are  18 active
monitors in the Los Angeles  PMSA in  1989, there
are more than 30 monitors for ozone alone in the
larger metropolitan area.

   There are  a  number of assumptions that are
implicit  in the PSI analysis.  Probably  the most
important is that the monitoring data available for a
given  area  provide  a  reasonable  estimate  of
maximum short-term concentration levels. The PSI
Note:  Urban lead concentrations have dropped precipitously
over the past 15 or so years (See Chapter 3). As a result, only
4 urban areas In 1989 violate the lead NAAQS.  Dallas is the
only one of tie 14 urban areas which has a 1989 lead violation.
In this case, the problem occurred near a smelter located outside
of Dallas County, in adjoining Collin County.
                                              5-2

-------
Table 5-2. Number of PSI Days Greater than 100 at trend sites, 1980-89, and all sites in 1989.
Number of PSI Days Greater than 100 at Trend Sites
YEAR
PMSA
ATLANTA
BOSTON
CHICAGO
DALLAS
DENVER
HOUSTON
KANSAS CITY
LOS ANGELES
NEW YORK
PHILADELPHIA
PITTSBURGH
SAN
FRANCISCO
SEATTLE
WASHINGTON

TOTAL
#
trend
sites
3
3
6
3
3
4
7
11
8
13
7
3
7
12

92
1980
7
8
34
10
35
10
13
220
119
52
20
2
33
38

601
1981
9
2
9
12
51
32
7
228
100
26
17
1
• 42
17

553
1982
5
5
32
11
48
18
0
195
69
36
14
2
19
21

475
1983
23
16
42
17
64
33
4
183
65
52
36
4
19
51

609
1984
8
6
19
10
51
23
12
205
53
26
24
2
4
24

467
1985
9
2
6
12
32
19
4
189
21
25
6
5
26
14

370
1986
17
0
5
5
42
24
8
208
16
20
9
4
18
10

386
1987
19
5
9
6
33
20
5
185
16
33
15
1
13
23

383
1988
15
11
18
3
15
25
3
218
35
34
31
1
8
34

451
1989
3
1
2
3
10
12
2
206
9
18
11
0
4
7

288
All active
monitoring
sites In PMSA
1989
total
#
sites
14
20
44
20
17
19
21
18
24
27
32
5
26
24

311
PSI
>
100
3
3
2
3
11
37
2
213
39
19
11
0
7
7

357

-------
      Table 5-3.  Number of Trend Monitoring Sites for the 14 Urban Area Analyses
Primary Metropolitan
Statistical Area (FMSA)
Atlanta, GA
Boston, MA
Chicago,!!.
Dallas, TX
Denver, CO
Houston, TX
Kansas City, MO-KS
Los Angeles, CA
New York, NY
Philadelphia, PA
Pittsburgh, PA
San Francisco, CA
Seattle, WA
Washington, DC-MD-VA
CO Sites
1
2
3
1
3
3
3
10
3
8
2
3
6
8
O, Sites
2
1
4
2
2
2
5
11
5
9
5
2
1
11
procedure uses the maximum concentration even
though  It does  not  represent the  air pollution
exposure for the entire area.  However, when the
downwind maximum concentration site is outside
the PMSA, these data are not used.  Finally, the
PSi  assumes  that  synergism  does not exist
between pollutants.   Each pollutant  is examined
independently. Combining pollutant concentrations
together is not possible at this time  because the
synergistic effects are not known.

5.3 Description of Graphics

    Each of  the fourteen  cities have all of  the
graphics and explanatory text presented on facing
pages.  The first page will include a map of the
area highlighting the location of the current ambient
monitoring network  as well as other important
features like rivers, lakes, and major highways.  At
each site, the shaded pie wedges of a circle identify
the pollutants monitored in 1989. Circles with four
tick marks denote trend sites.

    Figure  5-1   identifies  the  shaded  wedges
corresponding to  particular  pollutants.    The
pollutants generally associated with transportation
sources (CO, 03 and Lead) are found on the upper
half of the circle, while the other pollutants (PM10,
SO2,  and  NO2)  are on  the lower  half.   The
accompanying graphs  are  based on the PSI
methodology described earlier.  The  PSI graphs
feature a bar chart which shows the number of PSI
days in four PSI categories: 0-50,51-100,101-199
and >200.   Table 5-1 shows the  PSI descriptor
words associated with  these  categories.   Since
there were so few days in the hazardous category,
the very unhealthful and hazardous categories were
combined.  The total number  of unhealthful, very
                                             5-4

-------
unhealthful and hazardous days will be used as a
parameter with which to  track trends.   It  is
important to note that a PSI of 100 means that the
pollutant with the highest sub-index value is at the
level of its NAAQS.

   Because of numerical rounding, the number of
days  with  PSI >  100  does not  necessarily
correspond to the number of NAAQS exceedances.
A cumulative  plot is shown  for the trend  in the
number of days with a PSI > 100 (unhealthful days
or worse)  associated with  CO and O3,    As
mentioned earlier, other pollutants may contribute
to additional PSI days > 100.  In some areas, most
notably Pittsburgh, the total of the days shown for
CO and O3 does not represent all of the PSI days
> 100 (see table 5-2).  SO2 accounts  for most of
these additional days  in Pittsburgh. Other areas
with  PSI>100  days attributable to pollutants other
than CO or O3 are: Chicago, Kansas City,  and
Seattle.
   Also shown  are the trends  in average daily
maximum 1-hr concentrations for O3 and average
daily maximum 8-hour concentrations for CO, by
various temperature categories.   Maximum daily
temperatures are used for O3 and minimum daily
temperatures are used for CO, The O3 temperature
categories are: greater than or equal to 90, 80 to
89, 70 to 79 and less  than 70,  all  in degrees
Fahrenheit.  The CO temperature categories are:
greater than 40 and less than or equal to 40
degrees Fahrenheit. These plots are an attempt to
factor out the impact of temperature, an important
meteorological variable.  Concentrations of both CO
and O3 are  related either directly or indirectly to
temperature.  Ozone levels are  highest  in the
summer,  especially on  very hot stagnant days,
while  CO is highest usually in the  winter months.
The New York MSA is one exception; it appears
that higher temperatures are associated with higher
CO levels. To complement the ozone analyses, a
graph of the annual number  of days greater than
90° is also included. The following sections present
the metropolitan  areas analyses.
          KEY DISPLAYING ALL
                POLLUTANTS
                                                       DISPLAYING MONITORING
                                                          SITE FOR CO AND O,
                                                         Q
         DISPLAYING MONITORING
              SITE FOR PM1Q
       Figure 5-1.  Shaded wedges identifying pollutants monitored shown on
       metropolitan area maps.
                                           5-5

-------
         Number  of Days  in  PSI  Categories
     DAYS PSI > 100  fsr CO and 03  TREND SITES
                                      300
           Good H Woderote j§  Unhaa I I h f u I
           Very UnhenIthfuI/KoZBTdous
1910  1981 1912  188!  198+ 1985 1986  1987 1918 1919
5-6

-------
           Temp erature  Profile
 1110  III!  1112 1853  1184 1985  IIBI  III? 1919  t>8(
       A»j Doily  Uox 1-hr Omni fey Tinpe roly re
ID  91  It  83  14  IS  tt  17  II  It
   SO'F I Tun < 10'F
        Avg  Doily IIox 8-hr CO by  lemperoture
10  81  82  13  84  85  8( 87  It  91
      T«1i 3 tO'F
                  Tula < (O'F
                              Tmln - Minimum
                              Daily Temperature
Atlanta, GA

The Atlanta PMSA consists of 18 counties,
with the  majority of the people residing in
Fulton, Dekalb, and  Cobb Counties.  The
estimated 1988 population was 2.7 million.
Its  size  and  summertime   meteorology
contribute to the area's air pollution potential.
The Bermuda High has a dominant effect on
Atlanta's air quality,  especially during  the
summer  when the hot stagnant days  are
conducive to O3 formation. The map shows
14 currently active monitoring  sites.

The PSI trend  for Atlanta  is based on 3
sites: 1 for CO and 2  for O3. The CO site is
a population exposure site located in Dekalb
County.   The  O3 sites  are   a maximum
concentration site in Rockdale County and a
population exposure site in Dekalb County.
Ozone is the  pollutant in Atlanta  which
causes most of the unhealthful days.  The
number of days with an unhealthful or worse
rating ranges from 23 days in  1983 to a low
of 3 days in 1989.  In the 10-year period
only 1 day (in 1987) had a value in the very
unhealthful range.

The average CO and 03 concentrations by
temperature follow the expected pattern: Oa
levels are highest on the hotter days and CO
levels are higher on colder days.  Average
CO concentrations have dropped in both
temperature classes.  The sudden upturn in
1989  in  the highest  temperature category
results from higher CO levels in the August-
December period.   CO levels average 3
times higher in this period compared to the
other  months in 1989.  CO levels are very
low for Atlanta, because trend  data were not
available from the  maximum  concentration
site.  Sufficient  CO and O3 data were not
reported  for 1980.  Otherwise, the trend for
O3  in the  hottest  temperature  category
resembles  the  PSI  trends,  with  highest
averag,e  values in 1983 and 1987.   The
trend  in  average O3  concentrations  in  the
hottest category shows little change, while
the trend in the two intermediate temperature
categories show a small gradual increase
over the ten years.
                                          5-7

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                                                                    "*l '
           O


BAYS PSI  >  100 for CO and  03  TREHD SITES
                                  'jf  Ozone
                                  D  co
mi  1982  1993 1984 1995 1336  1987 1981 1989
      Number of  Days in PSi  Categories
 SO
 at
 62
 83
 B4
ies
 86
 87
                                                89  '•
                                                                       200
                                                                      Oa jia
                                                                                  300
                                                                                             40D
    Q Good g  Moderate • UnhegIthfut
    | Very Unheo I i ti f u I /Hoi o r dou s
                                           5-8

-------
           Temperoture  Profile
 Illft 1(11  tttt Ill]  1114  1915 till  1117 Hit  Kit
       Avg  Daily Uai 1-hr Ozone  by  Temperstur«
ID  II  12 13  II  li  IB  17  II
        Avj  Dally Hoi 8-hr CO by  Temperaturs
10  81  12  8}  14  IS  II  17  It  II
      Till * 4D'f •  Till < <0'F
Tinin - Minimum
Daily Temperature
Boston, MA

The Boston PMSA consists of Suffolk County
and parts of 6 other counties. The estimated
1988 population was 2.8 million, its size and
location as a part of the eastern seaboard
megalopolis contribute to the  area's  air
pollution potential.  There are 20 currently
active monitoring sites located on the map.

The  PSI trend  for Boston is based  on 3
sites; 2 for CO and 1 for O3.  The CO sites
are a maximum concentration site located at
Kenmore Square and a NAMS neighborhood
scale site located in  east Boston. The O3
site is a  maximum  concentration site  in
Sudbury (Middlesex County).  The trend in
the number of PSI days > 100 is similar to
the trend in the number of days above 90°,
shown in the temperature profile. This can
be seen in the PSI bar charts and also in the
breakouts for CO and O3.  The impact of the
very hot summers of 1983 and 1988 on O3
levels is  evident in both  PSI  displays.   In
Boston, 77 percent of the unhealthful or very
unhealthful PSI days are due to O3. In 1989
there was one day with a PSI value above
100. There were 7 days above 90° for this
year as compared  with 25 in 1988.  In the
entire 10-year period, only 1  day (in 1983}
had a value in the very unhealthful range.

The average CO and 03 concentrations by
temperature follow the expected pattern: O3
levels are highest on the hotter days and CO
levels are slightly higher on the colder days.
The O3 trends in the two highest temperature
categories  resemble the PSI  trends  with
concentrations generally highest in 1983 and
1988.  The exception is for 90° days when
the third  highest average occurred in 1985
and  not  1983.  The 1985  average  was
inflated due to 1 very high O3 day out of only
4 days reported for this year.  In contrast
1983 had 30 90° days. The O3 trend in the
two lowest temperature  categories is very
flat  for   the   decade.     Average  CO
concentrations declined in each temperature
category.
                                          5-9

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                       ki'«J.! :G "p 5 *» JL».-'4'
     DAYS PSI  >  100 for  CO and 03 TREND SITES
                                      j§  Ozone
                                      O  co
1880  1981  1982  1983 1984  1985 1986 1987  1989 1989
Number of Days  !n  PSI Categories
 Coed £ UodtraU  |  Unhtalthfgl
 Vary UnhiaIthful/Hazardous
                                             5-10

-------
           Temperature  Profile
 1110 1981  1912 1913  1184  1865 1991  1987  11(1 1919
       Avg  Doity Mot 1-hjf  Ozone  &>  Temperolure
80  81  82  81  H  85  19  11  81  91
             TEAR
—Tail <  TC'F • 70'F ( TBOI < ««'F
   BO'F f Tail < 90'F
                   Ta 100 is similar to
the trend in the number of days above 90°,
shown in the temperature  profile.   The
impact of the very hot summers of 1983 and
1988  on O3 levels is evident in both PSI
displays. CO accounts for most of the PSI
days > 100 in the first 5 years, while O3 is
the main contributor in the latter § years.
By 1989, there were only two such days in
the area. In the entire 10-year period only
3 days (2 in  1988 and 1 in 1982) were in
the very unhealthful  range,

O3  levels are highest on the hotter days,
while CO levels differ from most cities with
lower average  CO  levels  in  the  coldest
temperature category.  The O3 trend in the
highest temperature category resembles the
PSI trend.  The O3 trend in the 3 lowest
temperature categories is very flat over the
decade.    Average  CO  concentrations
decline in its two temperature categories.
However, the CO averages in 1988 and
1989  appear low, because the downtown
Chicago site was discontinued in 1987. The
percentage  decline  when  all  days  are
considered between 1980 and 1987 was 33
percent.
                                         5-11

-------
                               &:^4.:l'S^                      ^•V'Hf^
                                                                     ''
    8A»S PSI > 100 far CO  intf 03  TREND SUES
                                    f Ozone
                                    Q CO
1890 I9B1  1982 1983 19B4 1985 1986  1997 19B8 1989
     Number of 0«ys in PSI Categories
 BO
 81
 82
 83
 Bt
IBS
 86
 8T
 BB
 89
                                                            IOC
                                                                     fldjri
    Q  Good gj Modem le
    |  Vsry Unheol thful.
                                                                                300
                                                                          Vnhsalthful
                                                                                          400
                                            5-12

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           Temp eroture  Profile
 1110 III)  Ilt2 Ill]  118+  litS  1>H  lit?  IIB9  Illl
       A»o,  Dolly  Max  1-hr  Ozone by Tenper«firt
                                       1(1 dflj«
                                    , 'SJ *•!•
  llli < 70'F g IS'F '. TMI < 10'F

  I8'F i !• 10'F
Tfflax - Maximum
Dally Temperature
        Avg  dolly  Uox  3-hr  CO by Tompirolure
II  II  82  13  14  95  It  »J  II  9!
      lili ' «T
                  till < 40'F
                              Tmin - Minlmufn
                              Daily Temperature
Dallas, TX

The Dallas PMSA consists of 6 counties with
75 percent of the population residing in Dallas
County. The estimated 1988 population was
2.5  million.    Its  size  and  summertime
meteorology contribute  to  the  area's air
pollution  potential.   The map  shows 20
currently active monitoring sites for the area.

The PSI trend for Dallas is based on 3 sites:
\ for CO  and  2 for O3.  The  CO  site  is a
maximum concentration site located in Dallas
County.   The  O3  sites are  a  maximum
concentration site in Denton County and a
population exposure oriented site in Dallas
County. The trend in the number of days with
PSI>100 does  not correlate with the number
of days above 90°, shown in the temperature
profile. The  highest  number of PSI>100 days
(17) occurs in 1983,  while the number of days
above 90° dip for this year. In Dallas all but 1
of the  PS1>100 days are due to O3.  The
number and percent of PSI>100 days have
declined over the decade. This can be seen
in both of the PS! plots. In 1989 there were 3
days above  a PSI of 100. In the entire 10-
year period  only 1 day (in 1982) was in the
very unhealthful range.

The  average CO and O3 concentrations by
temperature follow the expected pattern, i.e.
O, levels are highest on the hotter days and
conversely CO levels are slightly higher on the
colder days.  Average O3 concentrations show
little  net change over the ten years for all
temperature categories.   The  O3 annual
average (0.057 ppm) for all days was exactly
the same for 1980  and  1989.  The peak in
1983 for PSI>100 days can also be seen in
the average O3 concentration plots; however,
average O3  concentrations level off over the
remainder of the decade while,  as mentioned
earlier, the PSI>100 days drop. Average CO
concentrations decline in the two temperature
categories. Note that CO data is not available
for 1980.  For the 1981-89 period, there was
a 56 and  40 percent decline in average CO
concentrations.  There  was a 51  percent
reduction  in   annual  average  CO
concentrations when all days are considered.
                                          5-13

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                                                           ?"  •-•••" -.--
                                                            :  •  •• -
  Number of Ooys  in  PSI Categories
     DAYS PSI > 100  for CO and 03  TREND SITES
Q Good H Uoderale  |  UnhigltMul
   Very Unhia I thfu I/Hn isrdous
1180  19(1 1982 1683  1984 1985 1886  198? II1B  I9B9
                                              5-14

-------
           Temperature  Profile
 IS30 1981  Itt2 1883  tilt 1919  1B««  III?  till  1911
       Avg  Ooily  Uo»  1-hr Ozone iy Ttmpsrs!urt
10  51  12  83  84  8!  II  17  88  II
                                        345 d«r«
   In a i < 70'F  •  70'f < Tnu < «»'F

   10'F { Tlltl < I9'F  •§  Tun I IC'F
Tmax - Maximum
Dally Temperature
        Avg  Nily  Uts  8-hr  CO  by  Temparoturs
It  11  II  83  14  IS  88  »7  SB  19
      lull i  4D'F
                  Till < 49'F
                              Train ™ Minimum
                              Daily Temperature
Denver, CO

The Denver PMSA consists of 5 counties, the
most populated of which is Denver which has
30 percent of the area's 1.6 million residents
estimated for 1988.   The  area's size  and
altitude contribute to its air pollution potential.
Seventeen monitoring sites  are currently
active and are shown on the area map.

The PSI trend for Denver is based on 3 sites:
2 where both CO and  O3 are monitored  plus
1  other  CO site.  The  CO sites  are  a
maximum  concentration  site  located  in
downtown Denver and  2 other  population
oriented  sites in Arapahoe and  Jefferson
Counties.   The  O3  sites  are  maximum
concentration sites in  Arapahoe  Co.  and a
population  exposure  site  in  Jefferson  Co.
The trend in the number of PSI days > 100
does not fluctuate with either the number  of
days above 90° or below 30°, as shown  in
the temperature profile. The figures reveal a
reduction  in these  unhealthful  and  very
unhealthful days.  Overall, the lowest number
of unhealthful days (10)  occurred in 1989.
The peak (64) occurs  in 1983. For the first
time in 1989, there were no very  unnealthful
days reported at these sites.  Three days in
the  10-year  period   were judged   to  be
hazardous,  the  last  occurring   in  1985.
Accordingly, the number of days classified  as
good more than doubled from 79 in 1980  to
174  in 1989. In  Denver, 92 percent of the
PSI days >100 were due to CO. Clearly, the
improvement in these  days is attributable  to
CO reductions.   These CO days declined
from a peak of 53 in 1983 to 9 in  1989.

03 levels are highest on  the hotter days and
CO levels are higher on the colder days.  The
O3 trend in all temperature categories peak in
1982 or  1983 and again in 1987 or 1988.
Overall, average O3 levels have not changed
much over the 10 years.  On the other hand,
CO  concentrations  declined 41   percent
overall and declined  in  each temperature
category. The  percent  change  over the
decade were, respectively, 47 and 38 percent
for the  >  40°  and <  40° temperature
categories.
                                           5-15

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                                    i	,,,,.
                               '•"•- ••'.  ••       -
     D»YS  PSI > 100 fur  CO  and 03 TREND  SITES
1980  1981 1982 1983  1914  1985  1986 1987  1998  1989
Number  of  Doys  in  PSi  Cglegories
                                                     SO
                                                     81
                                                     82
                                                     83
                                                     84
                                                     87
       ltd         zoo         :oo
                 Days
 Good  B  Moderole | Unheullhful
 Very  Unh«» I 1 h f tl 1 /Hoz( r dons
                                                                                                  400
                                               5-16

-------
           Temp e r o t u r»  Profile
 1985 Illl  i»t| lit]  1114  Ul$ tilt  1117 1181  IJ8»
           Daily Hox i-hr Ozone  by  Temperature
10  It  12  IJ  14  85  II  17  II 91
            Doily Ma* 8-hr CO by  Timpiroturi
It  II  82  tJ  14  15  58  II  IS  Bl
                              Tmin - Minimum
                              Daily Temperature
      Till » 4»'F
Houston, TX

The Houston PMSA consists of the principal
county of Harris and 4 other counties.  The
estimated 1988 population  was 3.2 million
with 86 percent residing in Harris county. Its
size  and  industry,   mainly  petroleum
refineries,  contribute   to  the  area's  air
pollution potential, its high temperatures and
proximity to the Texas  Gity-Galveston  area
are also factors which  contribute to it's air
pollution potential. There are 19 currently
active monitoring sites located on the map.

The PSI  trend for Houston is based on  4
sites; 1 site where both CO and 03 are
monitored, 2 additional sites for CO and  1
additional  site  for  O3. All of these sites are
located in Harris county  and include   a
maximum concentration  site for  each  of
these  pollutants.    The other sites are
population exposure oriented. The number
of PSI days >  100 varies from year to year
and does not  show a  clear trend.  When
additional sites are considered, however, the
number of PSI days > 100 shows  a steady
decline over the last 3 years.  During the
eighties,  21 (10%) out of  216 such days
were very unhealthful. The highest number
of very unhealthful days  (seven) occurs in
1981,  while 1989 only recorded  two.   In
Houston, 96 percent of the  PSI days > 100
are due to O3.

The average CO  and O3 concentrations by
temperature foUow the expected pattern, with
03 levels highest on the hotter days and CO
levels slightly higher on the colder days.  In
general, average ozone levels are highest in
1983  and  lowest in  1987  across all
temperature categories. Average 03 levels
show a slight decline over the decade with a
large reduction in  1989.  Average CO levels
peak in 1983 or 1984 for both temperature
categories, then drop 25 and 21 percent for
the warmer and colder days. When all days
are considered, annual average daily max 8-
hour CO was  essentially the same in 1980
and 1989.  Note that average CO levels are
very low in Houston.
                                          5-17

-------
                                            "Aii:- Ml E.K •": \' •-•V.1--' I
     DATS  PSI > 100 for  CO  gad  03 TREND SITES
1980  1981  1982 1913 198+  1965  1988  1987 1988 198!
Number  of  Days  in  PSi Categories
                                                     80
                                                     81
                                                     12
                                                     S3
                                                     84
                                                    las
                                                     86
                                                     87
                                                     US'. "
                                                                 too
                                                                            200
                                                                           Dap
                                                                                       190
                                                                                                   tog
       J  Moderate  j§  Unbetlthful
 Very  Unheo1 IhfuI/Hozardan 9
                                               5-18

-------
           Tempe roture  Profile
 1980 1981  1882 III}  1184 1985  1986 1987  1911  Kit
       Avg  Daily Vox 1-hr Oione by Tenpenlure
80  81  92 13  14  IS  85  «7 II  89
        Avg  Doll; Uq« 8-hr CO by Temperature
   I!   82  83  84  85  81  I?  5!  II
      iKln t 4fF
                  lull < 40'F
                              Train - Minimum
                              Daily Temperature
Kansas City, MO-KS

The Kansas City PMSA consists of 6 counties
in Missouri and 4 counties in Kansas.  The
estimated 1988 population was 1.6 million.
Its  size  and   summertime   meteorology
contribute to the area's air pollution potential.
Its chief air quality problems occur during the
summer  when the hot,  stagnant days  are
conducive to 03 formation. The map shows
21 currently active monitoring  sites  in  this
PMSA.

The PSI trend for Kansas City is based on 7
monitoring sites: 1 site where both CO and O3
are monitored plus 2 other CO and 4 other O3
sites.    The  CO sites  are  all  population
exposure oriented, while  the O3 sites include
1  maximum  concentration  site  and  4
population exposure sites.  The trend in the
number of days with PSI > 100  does  not
relate well with the pattern of the number of
days above  90°.  This is especially true for
1983, 1984  and 1988.    The absence of
stronger 1983 and 1988 peaks in the number
of PSI > 100 days is surprising, since in both
of these  years the summers were very hot.
There were 18 and 16 days in 1983 and 1988
respectively  when a temperature of 100 or
above was recorded. Even though in 1984
there were only 4 days with temperatures in
the  100  range,  this year had the second
highest  number  of sites (3)  exceeding  the
NAAQS.  However, 1984 had  several multi-
day episodes of exceedances.  The number
of days with an  unhealthful or worse rating
varies from  a low of 0 days in 1982 to 13
days in 1980.  In 1989,1 day was judged to
be unhealthful.  In the 10-year period there
were no days in the very unhealthful or worse
ranges.

Average  CO  and  Oa  concentrations   by
temperature  category  follow the  expected
pattern: O3 levels are highest on the hotter
days and CO levels are  generally higher on
colder days.  Average  CO concentrations
have dropped  in both  temperature classes.
The trend in average O3 levels is fairly stable,
excluding the 1980 and  1984 peaks for all
temperature  categories.
                                          5-19

-------
                                                          Number of Day 3
                  PSI Categories
OATS  PSI > lOt («r  CO  and 03 TREND SITES
      100        200        300
Good g iiodtrnU  |  ttnheo I thfg
Very Unhetl t h f u l/Nazorilous
HBO  1911 1982 1113  1904  1985 1981 19B7  19BB  1989
                                               5-20

-------
           Temperature  Profile
 1(10 1991  IIS1  111] 1114  1885  tilt 1(97  I98«  Itll
       A»g Doily \lti  1-hr Ozone by Timperjluri
10  II  82  11 It IS  (I  I?  II  19
                             Tmax » Maximum
                             Daily Temperature
        A»g Doily Mai  8-hr CO by Timpira ion
10  81  II  13  14  13  ti  67  || If
      fall 1 48'f
                  Till < 4*'F
                             Tailn - Minimum
                             Daily Temperature
Los Angeles, CA

The LA  PMSA consists of Los  Angeles
County, where an  estimated  8.5 million
people resided in  1988.  The LA "basin" is
bounded by the Pacific ocean on the west
and south and several mountain ranges on
the  north  and   east.     Its  complex
meteorology is characterized by a land-sea-
breeze circulation, frequent  inversions, and
a high incidence of sunlight. There are 18
currently active monitoring sites  located on
the map.

The PSI trend for LA is based on 11 sites:
10  where both CO  and Og are monitored
plus 1 other  O3 site.  For  each pollutant,
there is a NAMS maximum concentration
site; the others are  all population  oriented
SLAMS sites.  LA has the largest number of
PSI days >   100 of any  urban  area  -
averaging 204 per year for the decade.  The
trend in these days  is essentially  flat,
however, there has been  a 48  percent
reduction in the very unheaHhful days as
shown in the PSI bar charts. Conversely,
the  number  of  days  in the  unhealthful
category increased 41 percent because of
the shift from very unhealthful to unhealthful
days.   The  number of good  days  has
remained fairly constant during the 1980's.
In LA, 72 percent of the PSI  days > 100 are
due to O3. In 1989, there were 206 days in
the unhealthful or worse categories. In the
10-year period, only 4 days  (3 in i960 and
1 in 1982} were in the hazardous category.

The average CO and O3 concentrations by
temperature did not follow the expected
pattern because there are so few days in
some of the temperature categories.  For
example, for O3 there were only 57 days for
the 10-year period with corresponding air
quality data  in  the highest  temperature
category using LAX airport data.  When atl
days were considered, the annual CO and
O3  daily maximum averages dropped, 15
and 25 percent, respectively, over the 10
years.
                                         5-21

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     BUYS PSI > 180  for CO and  03 TREND SITES
                                      m
                                          Ozone
I9BO  1981 1982  1983 1984 1995  1986 198? 1988  1989
  Number of Days  in  PSI  Categories
                                                                                                400
Q Good H Uoderote  H  UnNalthfyl
| Very UnhegIthful/Kozordous
                                              5-22

-------
           Temperature  Profile
     1911  1912  1163 1184  1485  1181 1987  1981  lilt
       Avg  Doily Wax 1-hr  Ozone by Temperature
                                      211 daji
it  81  «2  83  84  85  19  17  88 89
             mi
n '•"  < ?0'F
              iff t last < U'l

   ff i Iriai < H'f •  Tim > ig'F
                              Tinax • Maximum
                              Dally Teaperature
       Avg Doily 8-hr  CO  by Temperature
tD  61  82  83  14  IS  IS  67  88  6f
      Till S «'F
                 Till < «'f
                             Train • Minimum
                             Daily Temperature
New York, NY

The New York PMSA consists of 8 counties
with 81 percent of the population residing in
Bronx, Kings,   New York, and  Queens
Counties.  The  estimated 1988 population
was 8.6 million. Its size and location as a
part of the eastern  seaboard megalopolis
contribute to the area's air pollution potential.
Twenty-four currently active monitoring sites
are shown on the map.

The PSI  trend for New York is based on
data from 8 sites: 3 for CO and  5 for O3.
The CO sites are 2 maximum concentration
sites  located in  Manhattan  (New York
County) and a population exposure site in
Kings  County.  The  03 sites include a
maximum concentration site in Westchester
County. PSI days >  100 are dominated by
CO and do not fluctuate with the number of
days  above 90°.  However, in 1983 and
1988 the  impact of the very hot  summers is
seen with the increase in the days due to O3.
The total  number of these days declined
from 119 in  1980 to 9 days in  1989.  The
most dramatic improvement has been in CO
where the number of these days declined
from 94 in 1980 to 4 in  1989. There was a
total of 11 very unhealthful days  reported,
including  1 each in 1987 and 1988 and none
in 1989. Also, there was an improvement in
the number of good days - from 11 in 1980
to 128 days in 1989.

O3 levels are highest  on the  hotter days.
Ozone averages in most of the temperature
categories show the impact of the  1983 and
1988  summers.   Average O3 levels for all
days during the 03 season have dropped 23
percent over the decade with most of  this
drop occurring from 1988 to 1989.  The 1989
O3 average  was the lowest for the entire
period.  New York City CO levels do  not
show  the usual seasonal pattern  of  low
summertime values.  Average CO levels in
the >40° category are higher than in  the
<40°  category.  The annual CO average,
when  all days are considered, decreased 40
percent over the period.
                                         5-23

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     DAYS PSI > !00  lor CO and OJ TREND SITES
I960  1981 1932 1983  1984  1985 I9B6 198?  1911 HB9
  Number of  Days  in PSI  Categories
                                                     80
                                                     81
                                                     62
                                                    es
                                                    88
                                                    87
                                                     69 '
                                                                 loo
                                                                           200
                                                                          Days
                                                                                      500
Q Good ^ Uodsrate • Unfieolthfu
| Very Unliea I t h f u I/Han Nous
                                               5-24

-------
            Temperoture  Profile
  lilt  1911 Mil
                   Hit  MSS 1IJI  1(87 lilt  1111
       Ayg Doily 1-hr liti Ozone  by  T«mp«raUr«
 II  II  12  I)  It IS  II
             YE»R
rn Tin < 7t-F
                       II  II


            70'F * Tit! < M'F
         mmm

10'F S Iioi  < t»-F
                    TIC. i SOT
                               Tmax - Maximum
                               Dally Temperature
                                  ra Iuri
SO  It  12  «} 14  15  16  tl II  19
       Till I (O'F  •  Till ( Iff
                              Train • Minimum
                              Daily Temperature
Philadelphia, PA

The   Philadelphia  PMSA  consists  of  8
counties, 5 in PA and 3 in NJ.  The most
populated  County  is  Philadelphia which
accounts  for 33  percent  of  the  total
population. The estimated 1988 population
was  4.9 million.  Its size and location as a
part of the eastern megalopolis contribute to
the area's air pollution potential.  There are
27 currently active air monitoring sites shown
on the map.

The  PSI trend tor Philadelphia is based on
data from 13 sites:  4 sites where both CO
and O3 are monitored, 4 CO sites, and 5 O3
sites.  The CO sites include  a maximum
concentration  site  located  in  downtown
Philadelphia.   The 03 sites  also include a
maximum concentration site in Gloucester
County, NJ. The trend in the PSI days > 100
varies with the number of days above 90°,
shown in the temperature profile. The impact
of the hot 1983  and 1988 summers on Oa
levels is  observed in the PSI  displays.   In
1987, the number of high PSI days and days
above 90° also coincide.  Ninety-four percent
of the PSI days > 100  are due to O3,   In
1989, there were 18 days in this range.  In
the  10 years, 14 days  were in the  very
unhealthful range. No days in the hazardous
range were reported.

O3 levels are highest on the hotter days,
while CO levels are higher on the colder
days.   The  O3 trend  in  the  2  highest
temperature  categories  resemble  the  PSI
trends since levels are generally highest  in
1983 and 1988. The principle exception  is
the 1984 peak in the >90° category.  This
peak is inflated because there were only 7
days represented, one  of  which  was the
highest measured O3 value for the 10-year
period.  Considering all days, average daily
maximum O3  levels decreased 21 percent
between  1980 and  1989.  Annual average
daily max 8-hour CO levels declined in both
temperature categories. This 10-year decline
was   19  percent  when  all   days were
considered.
                                           5-25

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     DAYS PSI > 100  for CO and 0] TREND SITES
1990  1991 1982 1*83  1914  1985 1996  1987  18JB 1989
                                                                           I A
Number  of  Days in PSI  Cotagories
                                                                 100
                                                                           200
                                                                           Day i
                             300



                      Unheal Shfut
Good f Uode r g t e  	


Very Untie g I t N f u I/Ho nr don 9
                                               5-26

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           Temperature  Profile
 1G80  191! lilt  1883  I8B* U85  lilt fill lilt  1911
      Avg Doily  tiox  1-hr Ojone !>y  Temptrotur*
   81  12  13  >* 85  IS  !?  II  IS
  Fun < 70'F g IB'F J Tnai < M'F

  «0'F « Tati < Id'F •  Tin I KO'F
Tmax - Maximum
Daily Temperature
       Avg Daily Uox  8-hr CO by Temperoturs
10  (I  12 II  14  15  M  «7  It II
      Till i 4t'f
                  Tail < t»'F
                             Trtiln - Minlnym
                             Dally Temperature
Pittsburgh, PA

The  Pittsburgh  PMSA   consists  of  4
counties, with 65 percent of the population
residing  in  Allegheny  County.    The
estimated 1988 population for the  entire
area was 2.1  million. Its  size and heavy
industry contribute to the area's air pollution
potential.   There are 32  currently active
monitoring sites shown on the map.

The PS! trend is principally based on data
from 7  sites; 2 CO, and  5 O3.  Each of
these pollutants had  a IMAMS maximum
concentration site in Allegheny County. The
other sites were all population  exposure
oriented, SO2 and PM,0 data are included
in the PSI bar charts only, based  on 8 and
20  sites respectively.  The trend in the
number of O3 days with PSI > 100 varies
with the number of 90° days. The impact of
the very hot 1983 and 1988 summers on O3
is evident in both PSI  displays.  Forty-four
percent of all PSI days > 100 are due to O3.
In fact, SO2 accounts for 33 percent.  The
remainder of high PSf  days come from CO
(15 percent) and PMto (8 percent). In 1989,
there were 4 days due to O3,1 day for S02
and 6 days attributable to PM10. In the 10-
year period, 3 days (the last in 1985) fell in
the very unhealthful category.

The temperature profile shows that 03 levels
are highest on the hotter days.  However,
for  most years the number of 90° days is
small, so that the O3 averages are variable.
The principal exception is 1988,  when 38
90° days were recorded. When all days are
considered, the O3 average is  down 13
percent  from  1980  and CO  average
concentrations  dropped 40  percent  from
1983 to 1989. Low CO in 1980 and 1981
are caused by missing data from the max
concentration site.  Annual  average SO2
levels, not shown here, dropped 24 percent
over the 10-year period.
                                         5-27

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     DAYS PSI > 100  for CO ond 03  TREND SITES
1110  19BI 1992 IS83  1984 1985 1981  19B7  1989 1919
  Kumbtr of Days  in  P5I.Cot«gories
                                                    81
                                                    82
                                                    83
                                                    84
                                                   !6S
                                                    86
                                                    87
                                                                100
                                                                          JOO
                                                                          Doy a
                                                                                      300
Q Good | UodaraU  |  ItnNo I t h f v I
B Very Unhca I thfu l/Nnzordous
                                                                                                400
                                               5-28

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           Tempero lure  Profile
 1110 1(11  1(12 1913 1184  I9B5 till  1117  1(88  1911
          Doily Max 1-hr  Oione  iy Temper 51«re
It  II  82  13  !«  IS  II  17  11  IS
Till < 70T    70T f  !»I <  IDT


JOT I Till < 10'F  •  T.li 1  iff
                              Tnax - Maximum
                              Daily Temperature
            Doily Hoi 8-hr  CO  by  Tamp aratur«
to  si  »l  13  14  IS  II 17  It  19
      Till I 4B'f
                  Till < «'F
                              Train - Minimum
                              Daily Temperature
San Francisco, CA

The San Francisco PMSA consists of Marin,
San  Francisco  and San Mateo Counties.
The  estimated  1988  population  was  1.6
million.  Its urban area size contributes to the
area's air pollution potential.  There are 5
currently active  monitoring sites located on
the map.

The PSI trend for San Francisco is based on
5  monitors (3 for CO and 2 for Cy at 3
distinct monitoring sites.  The CO sites are a
NAMS maximum concentration site located in
San  Francisco  County  and  2 population
exposure  sites  in  Marin and San Mateo
Counties.   The O3 data comes  from 2
population exposure sites in Marin and San
Mateo Counties. The number of PSI days >
100 and unhealtnful days average slightly
more than  2  days per year.  The largest
number of these days (5) occurred In 1985.
In 1989, for the  first time, there were no  PSi
days >  100 recorded.  Over the bay in the
Oakland PMSA, the number of PSI days >
100 averages about 7.  The largest number
of these days (14) occurred in 1983, and like
San  Francisco, 1989   had  the smallest
number (2).  In Oakland, ozone  accounted
for all of these days. In San Francisco, 73%
of the PSI days > 100 days are due to CO.
In the entire 10-year period, only 1 day (in
1985) was in the very unhealthful range.

O3 levels  are highest on the  hotter  days,
while CO  levels are slightly. higher on  the
colder days.  However, the number of high
pollution days are small.  The average 03
levels  are low in  San  Francisco  when
compared with  other urban  areas.   The
number of days are  low  in the  <  40°
temperature  category.    The  CO annual
averages for  ai! days and those days with
minimum temperatures > 40° are highest in
1984 and  1985, falling off before and after.
This pattern is  also observed in Oakland;
although the  average  CO levels there  are
lower than in San Francisco.  When all days
are considered,  there  is  essentially  no
difference in the 1980 and 1989 O3 annual
averages. This  is also the case in Oakland.
                                          5-29

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                                           -.60 LO  BAR
                                            Y .     «*•
                         /5NOOUALMI E


                         'i.
          Number  of Doys  in  PSI  Categories
     DAYS PSI > 100  for CO and 03  TREND SITES
                                       JOB



            Good B NoderaU  •  Unhealthful


            Very Unhg< I th I u I/Hg lordous
H80  1911 1982 1983  1984 I9B5 I98S  1987 1988 1919
5-30

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           T emp erature  Profile
 I960  UBI  1112 1911  1(14  1985  lilt 118?  lilt  lilt
       Avg  Daily Ucx 1-hr  Ozone by Ttmperoturt
                                       JO daji
                                      207 dor.
                                    354 d«r<
                                1153 doj.
80 SI  12  S3  84  li  li  87  91  89
             ¥€*(
O Tin < 70'F ^ TO'F t T>n < 80'F
   SO'F i Ton < 10'F
                   Tnii '. ID'F
Tmax » Maximum
Daily Temperature
        Avg  Doily Uai 8-hr  CO by Tamptraturt
 10  II  12  13  14  15  16 17 It  11
           4D'F
                  Till < 40'F
                             Train - Minimum
                             Daily Temperature
Seattle, WA

The  Seattle PMSA consists of King and
Snohomish  Counties.    Seventy-seven
percent of it's population reside  in King
County.  The  estimated  1988 population
was 1.9 million. Twenty-six currently active
monitoring sites are shown on the map.

The  PSI trend for Seattle is based on 7
sites: 6 CO and 1 for 03, all located in King
County.  All six of the CO sites can be
classified  as  maximum  concentration
sites.There are 2 maximum concentration
CO sites and 4 population exposure sites.
The 03 site is a population exposure site.
The  number  of  PSI  days > 100 are
dominated by CO, where  CO accounts for
175 (94%) of these days.  There has been
improvement in these days. Two of the 3
years with the smallest number occurred in
1988 and 1989. The percent of these days
dropped from 9  percent in  1980 to 1
percent in 1989.  The 2  very unhealthful
days   occurred   in   1982.     CO  was
responsible for both of these days.

The average CO and O3 concentrations by
temperature follow the expected  pattern,
i.e. O3 levels are highest on the hotter days
and conversely CO levels  are higher on the
colder days. The number of 90° days with
O3 data is very small. Over the  10-year
period, there doesn't  appear to be much
change  in average  O3  levels for  any
temperature category.  Average 03, levels
when  all  days  are   considered  are
essentially stable over  the period only
increasing slightly.   On  the other hand,
average CO levels have  declined.  There
were  35 and  32  percent  reductions,
respectively,   in  the  >40°  and  <40°
categories.   There  was a  34  percent
improvement  when   all   days   were
considered.
                                         5-31

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                    'CMTKER5BURG
*
     DAYS PSi > H«  for CO and 03  T8EHO SITES
HBO  1981 1982 198}  1984 1985 1986  I9B7 1989 1989
                   Number  of  Days  in  PSI  Categories
                                                                                                400
                 Q  Good  g  Uoderqte | Unheolltiful
                 B  Very  UnheaIthfuI/H
                                               5-32

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           Temperature  Profile
 tin mi  im ins  mi  ties  im  i»»7 tin  1111
       A«g  tidily \ttt I-tir Ozon«  by  lemptrotum
19  II  II II  14  85  II  IT  l« II
Q Tin < 70'F  ^  70'F <  T«>

• JOT f Tun < iH'F  •  !•«> >  10'F
                             Tfflax M Maximum
                             Dally Temperature
        A*g Doily Uai 8-hr CO by  Tempt rotit r t
       XT
19  II  12  13  14  15  tl  I?  II  It
                             Tnln " Minimum
                             Dally Temperature
Washington, DC-MD-VA

The  Washington  PMSA  consists  of  10
counties, the District of Columbia (DC), and
5  independent  cities.     The  principal
population centers are DC, Fairfax County in
Virginia,  and   Montgomery  and   Prince
Georges  Counties  in  Maryland.     The
estimated 1988 population was  3.7 million.
Its size and location as a part of the eastern
seaboard megalopolis contribute to the area's
air pollution potential. The map shows 24
currently active monitoring sites.

The Washington PSI trend is based on data
from 12 sites: 1 CO, 4 Q3 and 7 where both
pollutants are monitored.  All of the CO and
all but one of the O3 sites are population
exposure   oriented.     The   maximum
concentration O3 site is located in  Prince
Georges County. The trend of days with PSI
> 100 varies partly with the days above 90°,
shown in the temperature profile.  This is
seen both in the PSI bar chart and in the PSI
> 100 plot. The effect of the very hot 1983
and 1988 summers is seen on O3 levels.
Seventy-seven percent of the PSI days > 100
are due to  O3.   In  1989, there were 7
unheatthful days.  In the 10-year period, 6
days fell in the very unheatthful category; the
last occurred in 1987.

The temperature profiles show that O3 levels
are higher on hotter days while CO levels are
higher on colder days.  Average O3 levels
within a temperature category do not vary
much.  The 2 hottest categories show  the
impact of the  1983 and  1988  summers.
When data from all days are used, 1989 daily
maximum average Og is the  lowest  in 10
years; it is 12 percent lower than 1988 and
13 percent tower than 1980.  Average  CO
levels   declined   in   both  temperature
categories. The reason for the 1984 peak in
days less than 40° is unclear,  although a
peak is observed at most sites for this year.
High CO levels in  1984 also  produced  the
largest  number  of  NAAQS exceedances.
Considering all days,  daily maximum 8-hour
average CO declined 22 percent.
                                         5-33

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                                     TECHNICAL REPORT DATA
                              (Please read lasimctions on the reverse before completing)
1. REPORT NO,
  EPA 450/4-91-003
                               2.
4, TITLE AND SUBTITLE
  National Air Quality and Emissions Trends
  Report, 1989
                                            3. RECIPIENT'S ACCESSION NO.


                                            5. REPORT DATE
                                            6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
          T. Curran, R. Faora, T. Fitz-Simons, N, Frank,
  W. Freas, B. Beard. W. Frietsche. and W. F. Hunt, Jr.
                                                               8. PERFORMING ORGANIZATION REPORT NO.
9, PERFORMING ORGANIZATION NAME AND ADDRESS
  U. S. Environmental Protection Agency
  Office of Air and Radiation
  Office of Air Quality Planning and Standards
  Research Triangle Park, NO 27711
                                                               10. PROGRAM ELEMENT NO.
                                            11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
                                                               13. TYPE OF REPORT AND PERIOD COVERED
                                                               14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
  H. Hinton.
                  The computer graphics were prepared by W. Freas and the typing by
16. ABSTRACT
          This report presents national and regional trends in air quality from 1980 through
  1989 for total suspended paniculate, sulfur dioxide, carbon monoxide, nitrogen dioxide,
  ozone and lead.  Air quality trends are also presented for 14 metropolitan areas. Both
  national and regional trends in each of these pollutants are examined. National air quality
  trends are also presented for both the National Air Monitoring Sites (NAMS) and other site
  categories.   In addition to ambient air  quality, trends are  also presented  for  annual
  nationwide  emissions.   These emissions  are  estimated  using  the  best  available
  engineering  calculations;  the  ambient levels  presented  are  averages  of  direct
  measurements.

  This report also includes a section, Air Quality Levels in  Metropolitan Statistical Areas
  (MSAs).  Its  purpose  is to provide  interested members  of  the  air pollution control
  community, the private sector and the general public with greatly simplified air pollution
  information. Air quality statistics are presented for each of the pollutants for all MSAs with
  data in 1989.
17.
                                  KEY WORDS AND DOCUMENT ANALYSIS
                   DESCRIPTORS
                                                 bJOENTIFIERS/OPEN ENDED TERMS
                                                           c. COSATl Field/Group
  Air Pollution Trends  Air Pollution
  Emission Trends    Metropolitan
  Carbon Monoxide
  Nitrogen Dioxide
  Ozone
  Sulfur Dioxide
  Total Suspended Particulates
  Lead
  Statistical Area (MSA)
Air Quality Standards
National Air Monitoring
Stations (NAMS)
18. DISTRIBUTION STATEMENT
  Release Unlimited
                                                 19. SECURITY CLASS (ThisReport)
                                                           21. NO. OF PAGES
                                                                                    134
                              2Q. SECURITY CLASS (Thit page)
22. PRICE
EPA Form 2220-1 (9-73)

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