United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA 454/R-97-013 V*
January 1998
fl.l
National Air Quality and
Emissions Trends Report, 1996
Great Smoky MmmMrm National Pari

Visual Range -•

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454/R-97-013
National Air Quality and
Emissions Trends Report,
1996
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Emissions Monitoring and Analysis Division
Air Quality Trends Analysis Group
Research Triangle Park, North Carolina 27711
January 1998
Printed on recycled paper.
I

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About the Cover
The cover provides a visual air quality comparison of the
average best and worst visibility days at Great Smoky Mountain
National Park from 1992 to 1995. The image was generated
using software called WinHaze. WinHaze, developed by Air
Resource Specialists of Fort Collins, Colorado, uses visual range
parameters to degrade a pristine image, thus simulating what
a scene would look like with the given visibility parameters.
Images such as these are helpful in defining and communicating
the visibility problem and assessing any progress made.
Additional information on visibility can be found in Chapter 3
of this report.
Disclaimer
This report has been reviewed and approved for publication by
the U.S. Environmental Protection Agency's Office of Air
Quality Planning and Standards. Mention of trade names or
commercial products are not intended to constitute endorsement
or recommendation for use.
Acknowledgments
The Trends Team would like to acknowledge Kate Ramoth of
GeoLogics Corporation for assistance with layout, tables,
graphics, and technical editing; the parties who reviewed this
report prior to publication for their comments; and the following
individuals for their extensive contributions in a variety of areas:
Dr. John Ackermann, John Bachmann, Angela Bandemehr,
Desmond Bailey, Dr. Jane Caldwell, Rich Cook, William Cox,
Rich Damberg, Barbara Driscoll, Kathy Kaufmann, Mary
Manners, Dr. Karen Martin, Melissa McCullough, Dr. Dave
McKee, David Misenheimer, Dr. Diedre Murphy, Sharon Nizich,
Anne Pope, Kelly Rimer, Dr. Mary Ross, Dr. Roy Smith, Greg
Stella, Lori Stewart, and Dr. A1 Wehe.

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Preface
This is the twenty-fourth annual report on air pollution trends
in the United States issued by the U.S. Environmental Protection
Agency. The report is prepared by the Air Quality Trends
Analysis Group (AQTAG) in Research Triangle Park, North
Carolina and is directed toward both the technical air pollution
audience and other interested parties and individuals.
The report, complete with graphics and data tables, can be accessed
via the Internet at http://www.epa.gov/oar/aqtrnd96/.
AQTAG solicits comments on this report and welcomes
suggestions regarding techniques, interpretations, conclusions,
or methods of presentation. Comments can be submitted via the
website or mailed to:
Attn: Trends Team
AQTAG (MD 14)
U.S. EPA
Research Triangle Park, NC 27711
For additional air quality data, readers can access the
Aerometric Information Retrieval System's (AIRS) executive
software at http://www.epa.gov/oar/airs/aewin.

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IV

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Contents
CHAPTER 1
Executive Summary	1
Overview and Highlights	1
Improvement in the Face of Economic Growth	2
The Need for Continued Progress	3
References	4
CHAPTER 2
Air Quality Trends	7
Carbon Monoxide	9
Lead	13
Nitrogen Dioxide	17
Ozone	21
The New 8-hour Ozone Standards	27
Determining Compliance with the New 8-hour Ozone Standards	28
Particulate Matter	30
The New Particulate Matter Standards	34
Determining Compliance With the New PM Standards	35
Sulfur Dioxide	38
References	42
CHAPTER 3
Visibility Trends	43
Introduction	43
Nature and Sources of the Problem	43
Long-Term Trends	45
Recent Trends in Rural Areas: 1988-1995	45
Regional Trends	46
Current Conditions	48
Programs to Improve Visibility	49
References	52
CHAPTER 4
PAMS: Enhanced Ozone & Precursor Monitoring	53
Background	53
Network Requirements	53
Monitoring Requirements	54
Program Objectives	55
VOC Characterization	55
V

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CHAPTER 4
PAMS: Enhanced Ozone & Precursor Monitoring (continued)
Trends	55
NOx Versus VOC	57
Summary	58
References	58
CHAPTER 5
Air Toxics	61
Background	61
Ambient Air Quality Data	64
Air Toxics Control Program	65
Air Toxics Regulation and Implementation Status	66
Emissions Reductions Through the MACT Program	67
Residual Risk	67
Special Studies/Programs	67
References	70
CHAPTER 6
Nonattainment Areas	73
CHAPTER 7
Metropolitan Area Trends	75
Status: 1996 	75
Trends Analysis	75
The Pollutant Standards Index	76
Summary of PSI Analyses	76
References	78
APPENDIX A
Data Tables	79
APPENDIX B
Methodology	149
Air Quality Data Base	149
Air Quality Trend Statistics	150
References	152
VI

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Figures
Figure 1-1. Total U.S. population, vehicle miles traveled, U.S. gross domestic product, and aggregate emissions,
1970-1996	3
Figure 1-2. Number of people living in counties with air quality concentrations above the level of the
NAAQS in 1996	3
Figure 2-1. Trend in second maximum non-overlapping 8-hour average CO concentrations, 1987-1996	9
Figure 2-2. National total CO emissions trend, 1987-1996	 10
Figure 2-3. CO emissions by source category, 1996	 10
Figure 2-4. CO second maximum 8-hour concentration trends by location, 1987-1996	 11
Figure 2-5. Highest CO second maximum 8-hour concentration by county, 1996	 11
Figure 2-6. Long-term ambient CO trend, 1977-1996	 12
Figure 2-7. Trend in maximum quarterly average Pb concentrations (excluding source-oriented sites),
1987-1996	 13
Figure 2-8. National total Pb emissions trend, 1987-1996	 14
Figure 2-9. Pb maximum quarterly mean concentration trends by location (excluding source-oriented sites),
1987-1996	 14
Figure 2-10. Long-term ambient Pb trend, 1977-1996	 15
Figure 2-11. Pb emissions by source category, 1996	 15
Figure 2-12. Pb maximum quarterly concentration in the vicinity of Pb point sources, 1996	 16
Figure 2-13. Highest Pb maximum quarterly mean by county, 1996	 16
Figure 2-14. Trend in annual N02 concentrations, 1987-1996	 17
Figure 2-15. National total NOx emissions trend, 1987-1996	 18
Figure 2-16. NOx emissions by source category, 1996	 18
Figure 2-17. N02 annual mean concentration trend by location, 1987-1996	 19
Figure 2-18. Highest N02 annual mean concentration by county, 1996	 19
Figure 2-19. Long-term ambient N02 trend, 1977-1996	20
Figure 2-20. Number of summer days, June-August with temperatures >90°, 1995 vs. 1996	22
Figure 2-21. Trend in annual second daily maximum 1-hour 03 concentrations, 1987-1996	23
Figure 2-22. 03 second daily maximum 1-hour concentration trends by location, 1987-1996	23
Figure 2-23. Comparison of actual and meteorologically adjusted ozone trends, 1987-1996
(composite average of 99th percentile 1-hr daily max concentration)	24
Figure 2-24. Highest 03 second daily maximum concentration by county, 1996	24
Figure 2-25. Long-term trend in second daily maximum 1-hour 03 concentrations, 1977-1996	25
Figure 2-26. National total VOC emissions trend, 1987-1996	25
Figure 2-27. VOC emissions by source category, 1996	26
Figure 2-28. Trend in 2nd max 1-hr vs. 4th max 8-hr ozone concentrations, 1987-1996	28
Figure 2-29. Trend in annual mean PM10 concentrations, 1988-1996	30
Figure 2-30. National PM10 emissions trend, 1988-1996 (traditionally inventoried sources only)	31
Figure 2-31. PM10 annual mean concentration trends by location, 1988-1996	31
Figure 2-32. PM10emissions from traditionally inventoried source categories, 1996	32
Figure 2-33. Total PM10 emissions by source category, 1996	 32
Figure 2-34. Highest second maximum 24-hour PM10 concentration by county, 1996	33
Figure 2-35. PM10 trend in the average 99th percentile PM10 concentration, 1988-1996	34
Figure 2-36. Highest second maximum 24-hour S02 concentration by county, 1996	38
Figure 2-37. Trend in annual mean S02 concentrations, 1987-1996	39
VII

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Figure 2 38. National total S02 emissions trend, 1987-1996	39
Figure 2-39. S02 emissions by source category, 1996	40
Figure 2-40. S02 annual mean concentration trend by location, 1987-1996	40
Figure 2-41. Long-term ambient S02 trend, 1977-1996	41
Figure 3-1. Range of best and worst conditions at Acadia, Great Smoky Mountains, and Grand Canyon
national parks, 1992-1995	44
Figure 3-2. Long-term trend for 75th percentile light extinction coefficient from airport visual data
(July-September)	45
Figure 3-3. IMPROVE visibility monitoring network 30 sites with data for the period 1988-present	46
Figure 3-4a. Total light extinction trends for eastern Class I areas	47
Figure 3-4b. Total light extinction trends for western Class I areas	47
Figure 3-5a. Light extinction due to sulfate in eastern Class I areas	48
Figure 3-5b. Light extinction due to sulfate in western Class I areas	48
Figure 3-6a. Light extinction due to organic carbon in eastern Class I areas	48
Figure 3-6b. Light extinction due to organic carbon in western Class I areas	48
Figure 3-7a. Average aerosol light extinction in eastern Class I areas	49
Figure 3-7b. Average aerosol light extinction in western Class I areas	49
Figure 3-8. Annual average light extinction (Mm4), 1992-1995 IMPROVE data	50
Figure 3-9. Annual average visibility impairment in deciviews relative to pristine conditions of
deciviews = 0, 1992-1995 IMPROVE data	51
Figure 3-10. Shenandoah National Park on clear and hazy days, and the effect of adding 10 pg/m3 fine
particles to each	51
Figure 4-1. PAMS percent of total number of ozone nonattainment areas and 1996 ozone exceedance days
(total number of original classified and section 185a ozone nonattainment areas = 118; total number
of 1996 exceedance days in original nonattainment areas = 361.)	54
Figure 4-2. Comparison of actual and meteorologically adjusted ozone trends—PAMS metropolitan areas
versus non-PAMS areas, 1987-1996 (composite average of 99th percentile 1-hr. daily max. conc.)	58
Figure 5-1. Total national HAP emissions by source type, 1993. (tons per year)	62
Figure 5-2. HAP emissions by state, 1993 (tons/year)	62
Figure 5-3. MACT source categories	66
Figure 5-4. Emissions of 40 potential section 112 (k) HAPs by source type (tons/year)	68
Figure 5-5. Emissions of 40 potential section 112(k) HAPs by urban and rural classification (tons/year)	69
Figure 6-1. Location of nonattainment areas for criteria pollutants	73
Figure 6-2. Classified ozone nonattainment areas	74
Figure 7-1. Number of days with PSI values > 100, as a percentage of 1987 value	77
Figure A-1. (Multiple NA areas within a larger NA area) Two S02 areas inside the Pittsburgh-Beaver Valley
ozone NA. Counted as one NA area	115
Figure A-2. (Overlapping NA areas) Searles Valley PM10 NA partially overlaps the San Joaquin Valley ozone NA.
Counted as two NA areas	115
Figure B-l. Carbon monoxide monitoring network, 1996	 150
Figure B-2. Lead monitoring network, 1996	 150
Figure B-3. Nitrogen dioxide monitoring network, 1996	 151
Figure B-4. Ozone monitoring network, 1996	 151
Figure B-5. PM10 monitoring network, 1996	 152
Figure B-6. Sulfur dioxide monitoring network, 1996	 152
VIII

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Tables
Table 1-1.	Percent Change in National Air Quality Concentrations and Emissions, 1987-1996 	1
Table 1-2.	Long-term Percent Change in National Air Quality Concentrations and Emissions	3
Table 2-1.	NAAQS in Effect in 1996 	7
Table 3-1.	Summary of Class I Area Trend Analysis	50
Table 3-2.	IMPROVE Sites With Potential Upward Trends	50
Table 4-1.	Metropolitan Areas Requiring PAMS	53
Table 4-2.	PAMS Target List of VOCs	54
Table 4-3.	PAMS Targeted VOCs Ranked by Mean 6-9 am Concentration, Summer 1996 	 56
Table 4-4.	Number of Ozone NAAQS Exceedance Days, by PAMS Area	57
Table 4-5.	Summary of Changes in Summer Mean Concentrations for Ozone, NOx, and Selected VOCs,
1995-1996 and 1994-1996 	59
Table 5-1.	Top 20 Sources of 1993 Toxic Emissions of Hazardous Air Pollutants	63
Table 5-2.	Summary of Changes in Mean Concentration for HAPs Measured as a Part of the PAMS Program
(24-hour measurements), 1994-1996*	64
Table 5-3.	Comparison of Loading Estimates for the Great Lakes	64
Table 5-4.	List of Potential 112 (k) HAPs	68
Table 7-1.	Summary of MSA Trend Analysis, by Pollutant	76
Table 7-2.	Pollutant Standards Index Values with Pollutant Concentration, Health Descriptors, and PSI Colors	77
Table A-l.	National Air Quality Trends Statistics for Criteria Pollutants, 1987-1996	80
Table A-2.	National Carbon Monoxide Emissions Estimates, 1987-1996 (thousand short tons)	82
Table A-3.	National Lead Emissions Estimates, 1987-1996 (short tons)	83
Table A-4.	National Nitrogen Oxides Emissions Estimates, 1987-1996 (thousand short tons)	84
Table A-5.	National Volatile Organic Compounds Emissions Estimates, 1987-1996 (thousand short tons) 	85
Table A-6.	National Particulate Matter (PM10) Emissions Estimates, 1987-1996 (thousand short tons)	86
Table A-7.	Miscellaneous and Natural PM10 Emissions Estimates, 1987-1996 (thousand short tons) 	86
Table A-8.	National Sulfur Dioxide Emissions Estimates, 1987-1996 (thousand short tons)	87
Table A-9.	National Long-Term Air Quality Trends, 1977-1996 	88
Table A-10.	National Air Quality Trends Statistics by Monitoring Location, 1987-1996	89
Table A ll.	Maximum Air Quality Concentrations by County, 1996	90
Table A-12.	Trends From IMPROVE Monitoring Sites, 1988-1995 	104
Table A-13.	Condensed Nonattainment Areas List(a)	112
Table A-14.	Maximum Air Quality Concentrations by Metropolitan Statistical Area, 1996 	 116
Table A-15.	Metropolitan Statistical Area Air Quality Trends, 1987-1996 	 123
Table A-16.	Number of Days with PSI Values Greater Than 100 at Trend Sites, 1987-1996,
and All Sites in 1996 	 144
Table A-17.	(Ozone only) Number of Days with PSI Values Greater Than 100 at Trend Sites, 1987-1996,
and All Sites in 1996 	 146
Table A-18.	Total Number of Days with PSI Values Greater Than 100 at Trend Sites—Summary, 1987-1996 	 148
Table B-l.	Number of Ambient Monitors Reporting Data to AIRS	149
IX

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X

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Acronyms
AIRS
Aerometric Information Retrieval System
CAA
Clean Air Act
CAAA
Clean Air Act Amendments
CARB
California Air Resources Board
CASAC
Clean Air Scientific Advisory Committee
CEMs
Continuous Emissions Monitors
CFR
Code of Federal Regulations
CO
Carbon Monoxide
CMSA
Consolidated Metropolitan Statistical Area
DST
Daylight Savings Time
EPA
Environmental Protection Agency
GDP
Gross Domestic Product
HAPs
Hazardous Air Pollutants
IMPROVE
Interagency Monitoring of PROtected Environments
MACT
Maximum Achievable Control Technology
MARAMA
Mid-Atlantic Regional Air Management Association
MSA
Metropolitan Statistical Area
NAAQS
National Ambient Air Quality Standards
NAMS
National Air Monitoring Stations
NARSTO
North American Research Strategy for Tropospheric Ozone
NESCAUM
Northeast States for Coordinated Air Use Management
NMOC
Non-Methane Organic Compound
no2
Nitrogen Dioxide
NOx
Nitrogen Oxides
NTI
National Toxics Inventory
03
Ozone
OTAG
The Ozone Transport Assessment Group
PAHs
Polyaromatic Hydrocarbons
PAMS
Photochemical Assessment Monitoring Stations
Pb
Lead
PCBs
Polychlorinated Biphenyls
PM10
Particulate Matter of 10 micrometers in diameter or less
pm,5
Particulate Matter of 2.5 micrometers in diameter or less
POM
Polycyclic Organic Matter
ppm
Parts Per Million
PSI
Pollutant Standards Index
RFG
Reformulated Gasoline
SLAMS
State and Local Air Monitoring Stations
SNMOC
Speciated Non-Methane Organic Compound
so2
Sulfur Dioxide
sox
Sulfur Oxides
TRI
Toxic Release Inventory
TSP
Total Suspended Particulate
VMT
Vehicle Miles Traveled
VOCs
Volatile Organic Compounds
XI

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XII

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Chapter 1
Executive Summary
THIS is THE twenty-fourth annual re-
port documenting air pollution trends
in the United States.1-23 While in recent
years this report has widened its scope
to include air pollution topics such as
acid rain, visibility and air toxics, its
focus remains on those pollutants for
which the United States Environmental
Protection Agency (EPA) has estab-
lished National Ambient Air Quality
Standards (NAAQS). The Clean Air Act
(CAA) requires EPA to periodically re-
view and, if appropriate, revise ambi-
ent air quality standards to protect
public health and welfare. Primary
standards are designed to protect pub-
lic health, including sensitive popula-
tions such as children and the elderly,
while secondary standards protect
public welfare, such as the effects of air
pollution on vegetation, materials, and
visibility. There are six criteria pollut-
ants with primary standards: carbon
monoxide (CO), lead (Pb), nitrogen di-
oxide (N02), ozone (03), particulate
matter (PM), and sulfur dioxide (S02).
In July 1997, EPA revised the ozone
and particulate matter standards fol-
lowing a lengthy scientific review pro-
cess. Prior to this time, the PM standard
applied to particles whose aerody-
namic size is less than or equal to 10
micrometers, or PM10. The NAAQS re-
vision strengthened protection against
particles in the smaller part of that
range by adding an indicator for PM2.5
(those whose aerodynamic size is less
than or equal to 2.5 micrometers). The
combination of the PMi0 and PM2.5 in-
dicators will provide protection against
a wide array of particles.
Since this report deals with data for
and prior to 1996, the trend data for
ozone and PMi0 are compared to the
pre-existing NAAQS. However, the
new standards for both ozone and par-
ticulate matter are discussed in detail in
special sections in Chapter 2.
Overview and Highlights
The criteria pollutant analyses empha-
sized in Chapter 2 focus on national
trends in air quality concentrations and
emissions for the criteria pollutants. Air
quality concentrations are based on
actual direct measurements of pollut-
ant concentrations in the air at selected
monitoring sites across the country.
Emissions are calculated estimates of
the total tonnage of these pollutants, or
their precursors, released into the air
annually. Emissions estimates are de-
rived from many factors, including the
level of industrial activity, technology
changes, fuel consumption, vehicle
miles traveled (VMT), and other activi-
ties that affect air pollution. In 1994,
EPA began incorporating direct emis-
sions measurements of sulfur dioxide
and nitrogen oxides (NO*) for the elec-
tric utility industry. Additional emis-
sions information is contained in the
companion report, National Air Pollut-
ant Emission Trends, 1900-1996.24
Table 1-1 summarizes the 10-year
percent changes in national air quality
concentrations and emissions.
Table 1-1. Percent Change in National
Air Quality Concentrations and Emissions,
1987-1996
Air Quality
Concentration Emissions
% Change % Change
1987-1996 1987-1996
Carbon Monoxide
-37%
-18%
Lead
-75%
-50%
Nitrogen Dioxide
-10%
+3% (NQ,)
Ozone
-15%
-18% (VOC)
PM™
-25%
-12%+
Sulfur Dioxide
-37%
-14%
"Based on 1988 to 1996 data.
+lncludes only directly emitted particles. Second-
ary PM formed from SOx, NOx, and other gases
comprise a significant fraction of ambient PM.
The above table shows that air qual-
ity has continued to improve during
the past 10 years for all six pollutants.
Nationally, the 1996 air quality levels
are the best on record for all six criteria
pollutants. In fact, all the years in the
1990s have had better air quality than
all the years in the 1980s, showing a
steady trend of improvement.
Emissions of all criteria pollutants
have improved as well, with the excep-
tion of NOx. In October 1997, EPA pro-
posed a rule that will significantly
reduce regional emissions of NOx and,
in turn, reduce the regional transport of
ozone. This rule is discussed further in
the Ozone section of Chapter 2.
Chapter 3 presents trends in visibil-
ity for 29 national parks and wilderness
areas in the Interagency Monitoring of
PROtected Environments (IMPROVE)
visibility monitoring network. Data
collected at these areas show that vis-
CHAPTER 1: EXECUTIVE SUMMARY
1

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
ibility, in the form of average aerosol
light extinction, has improved 10 per-
cent in the eastern United States and 20
percent in the western United States
between 1988 and 1995. When the
haziest days are considered, however,
visibility worsened in the East and im-
proved in the West. Specifically, aero-
sol light extinction for the haziest
visibility days worsened in the East by
6 percent but improved in the West by
12 percent.
Chapter 4 highlights the Photo-
chemical Assessment Monitoring Sta-
tions (PAMS) program, which is an
intensive monitoring network set up to
increase our knowledge of the underly-
ing causes of ozone pollution and po-
tential control strategies. PAMS
monitoring sites are located in all
ozone nonattainment areas classified as
serious, severe, or extreme. The 21 af-
fected areas collect measurements of
ozone, NOx, and volatile organic com-
pounds (VOCs), as well as surface and
upper air meteorology. For a second
consecutive year, the majority of PAMS
sites show significant reductions in key
ozone precursors. However, the 1995 to
1996 reductions in benzene and other
mobile-related VOC concentrations
were not quite as large as those be-
tween 1994 and 1995. More detailed
information on the PAMS program can
be found on the Internet at http://
www.epa.gov/oar/oaqps/pams.
Chapter 5 presents information on
air toxics, another set of pollutants
regulated under the CAA which are
known to cause, or may cause, adverse
health effects or ecosystem damage.
The Office of Air Quality Planning and
Standards' (OAQPS) National Toxics
Inventory (NTI) estimates that 3.7 mil-
lion tons of air toxics are released to the
air annually. This is the second year
EPA has reported air toxics emissions
based on the NTI. Data from the Toxic
Release Inventory (TRI) were used as
the foundation of this inventory. The
development of the NTI represents a
significant improvement in character-
ization of air toxics because the NTI
shows that mobile and area sources,
which are not included in TRI, account
for approximately 75 percent of haz-
ardous air pollutant emissions. This
chapter reports analyses of PAMS data
indicating the usefulness of this network
for assessing the toxic air quality issue.
Chapter 6 summarizes the current
status of nonattainment areas, which are
those areas not meeting the NAAQS for
at least one of the six criteria pollutants.
Under the Clean Air Act Amendments
(CAAA) of 1990, there were 274 areas
designated nonattainment for at least
one ambient standard. As of September
1997,158 areas are still designated non-
attainment, with particulate matter
having the largest number (79), and
ozone the second largest number (59)
of areas. Note that in future years the
nonattainment area list will reflect ar-
eas not meeting the new ozone and
particulate matter standards. The cur-
rent nonattainment areas for each crite-
ria pollutant are displayed on one map
in this chapter, while a second map
depicts ozone nonattainment areas
alone, color-coded to indicate the se-
verity of the ozone problem in each area.
The condensed list of nonattainment ar-
eas as of September 1997 is presented in
Table A-13. This table is also on the
Internet at http://www.epa.gov/airs/
nonattn.html and is updated as areas
are redesignated.
Chapter 7 characterizes air quality
on a more local level, using three differ-
ent indicators. First, this chapter lists
peak air quality concentrations for 1996
for each Metropolitan Statistical Area
(MSA). Second, 10-year trends are as-
sessed for each MSA using a statistical
method to measure whether the trend
is up or down significantly. The results
show that 13 MS As have a statistically
significant upward trend in ambient
concentrations for at least one criteria
pollutant, while 217 MS As have a sta-
tistically significant downward trend
for at least one criteria pollutant. The
third way in which local air quality is
evaluated is by looking at the Pollutant
Standards Index (PSI) in the nation's
largest MSAs. The PSI analysis shows
that between 1987 and 1996 the total
number of "unhealthful" days de-
creased 51 percent in the Los Angeles
basin (which includes the Los Angeles
and Riverside MSAs) and 75 percent in
the remaining major cities across the
United States.
Finally, Appendix A provides ex-
panded tables of the air quality concen-
trations and emissions data described
throughout this report. Appendix B
summarizes the methodology which is
the basis for the trends analyses in
Chapter 2, and also provides maps of
the current monitoring network for
each criteria pollutant.
Improvement in the Face
of Economic Growth
National reductions in air quality con-
centrations and emissions continue to
occur in the face of economic growth.
Since 1970, total U.S. population in-
creased 29 percent, vehicle miles trav-
eled increased 121 percent, and the
gross domestic product (GDP) in-
creased 104 percent (see Figure
1-1)_25,26,27 During that same period,
notable reductions in air quality con-
centrations and emissions took place.
Aggregate criteria pollutant emissions
decreased 32 percent (see Figure 1-1).
When examined individually, emis-
sions for all criteria pollutants except
NOx decreased between 1970 and 1996
(see Table 1-2), the greatest improve-
ment being a 98-percent decrease in
2
CHAPTER 1: EXECUTIVE SUMMARY

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Percent of 1970 Valu e
250
200
150
100
50

VMT(+121%)

' GDP (+104%)

		 — —
	 "
Popubtion(+29%)

Errissions(-32%)
70
80
90
96
Figure 1-1. Total U.S. population, vehicle miles traveled, U.S. gross domestic product,
and aggregate emissions, 1970-1996.
PM10
Any NAAQS
lead emissions. Though air quality
trends are not available back to 1970, in
most cases they are available for the
past 20 years. Reductions in air quality
concentrations between 1977 and 1996
are impressive with CO, lead, and S02
decreasing by more than half. Because
of evolving monitoring networks, these
long-term changes in air quality con-
centrations are not as certain as long-
term changes in emissions, but they do
provide an accurate indication of the
general trend in air quality.
Table 1-2. Long-term Percent Change in
National Air Quality Concentrations and
Emissions
Air Quality
Concentration Emissions
% Change % Change
1977-1996 1970-1996
Carbon Monoxide
Lead
Nitrogen Dioxide
Ozone
PM-io
Sulfur Dioxide
-61%
-97%
-27%
-30%
-31%
-98%
+8% (NQ,)
-38% (VOC)
Data Not Available -73%+
-58% -39%
40	60
Millions of Persons
Figure 1-2. Number of people living in counties with air quality concentrations above the
level of the NAAQS in 1996.
+lncludes only directly emitted particles. Second-
ary PM formed from SOx, NOx, and other gases
comprise a significant fraction of ambient PM.
These air quality improvements are
a direct result of EPA working with
states, industry, and other partners to
effectively establish and implement
clean air laws and regulations.
The Need for Continued
Progress
While progress has been made, it is
important not to lose sight of the mag-
nitude of the air pollution problem that
still remains. Based upon monitoring
data submitted to EPA's data base, ap-
proximately 46 million people in the
United States reside in counties that
did not meet the air quality standard
for at least one of the NAAQS pollut-
ants for the single year 1996, as noted in
Figure 1-2.28 29 And in 1997, EPA re-
CHAPTER 1: EXECUTIVE SUMMARY
3

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
vised two criteria pollutant standards
that were not protective enough.
After conducting one of the most
extensive NAAQS reviews ever, EPA
concluded that the existing standards
for ozone and particulate matter were
not adequately protective of public
health. For ozone, several hour expo-
sures at levels below the pre-existing
standard were found to cause significant
health effects, including aggravation of
asthma, breathing and respiratory
problems, loss of lung function, and
possible long-term lung damage and
lowered immunity to disease. For par-
ticulate matter, concentrations below
those allowed by the previous standard
were associated with significant effects
including premature death, increased
hospital admissions, and increaesd res-
piratory symptoms and disease. The
scientific review concluded that addi-
tional standards should be set for fine
particles, orPM2.5. On July 16,1997, EPA
Administrator Carol Browner approved
new, more protective standards for ozone
and particulate matter. These stan-
dards, each year, will prevent approxi-
mately 15,000 premature deaths,
350,000 cases of aggravated asthma,
and 1 million cases of significantly de-
creased lung function in children. EPA
has developed a flexible, common-
sense, and cost-effective implementa-
tion plan to achieve these standards,
providing for both cleaner air and con-
tinued national economic progress.
The notices and support documents for
the new NAAQS are on the Internet at
http://www.epa.gov/airlinks.
References
1. The National Air Monitoring Program:
Air Quality and Emissions Trends—An-
nual Report, EPA-450/l-73-001a and
b, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, July 1973.
2.	Monitoring and Air Quality Trends Re-
port, 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 Re-
port, 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 Re-
port, 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 Plan-
ning and Standards, Research Trian-
gle 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 Plan-
ning and Standards, Research Trian-
gle 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 Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, December 1978.
8.	1980 Ambient Assessment—Air Por-
tion, EPA-450/4-81-014, U.S. Envi-
ronmental Protection Agency, Office
of Air Quality Planning and Stan-
dards, Research Triangle Park, NC
27711, December 1978.
9.	National Air Quality and Emissions
Trends Report, 1981, EPA-450/4-83-
011, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle 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 Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, March 1984.
11.	National Air Quality and Emissions
Trends Report, 1983, EPA-450/4-84-
029, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle 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 Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, February 1986.
13.	National Air Quality and Emissions
Trends Report, 1985, EPA-450/4-87-
001, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle 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 Plan-
ning and Standards, Research Trian-
gle 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 Plan-
ning and Standards, Research Trian-
gle 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 Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, March 1990.
17.	National Air Quality and Emissions
Trends Report, 1989, EPA-450/4-91-
003,	U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, February 1991.
4
CHAPTER 1: EXECUTIVE SUMMARY

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
18.	National Air Quality and Emissions
Trends Report, 1990, EPA-450/4-91-
023, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, November 1991.
19.	National Air Quality and Emissions
Trends Report, 1991, EPA-450/R-92-
001, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, October 1992.
20.	National Air Quality and Emissions
Trends Report, 1992, EPA-454/R-93-
031, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, October 1993.
21.	National Air Quality and Emissions
Trends Report, 1993, EPA-454/R-94-
026, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, October 1994.
22.	National Air Quality and Emissions
Trends Report, 1994, EPA-454/R-95-
014, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, October 1995.
23.	National Air Quality and Emissions
Trends Report, 1995, EPA-454/R-96-
005, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle Park, NC 27711, October 1996.
24.	National Air Pollutant Emission Trends,
1900-1996, EPA-454/R-97-011, U.S.
Environmental Protection Agency,
Office of Air Quality Planning and
Standards, Research Triangle Park,
NC 27711, December 1997.
25.	Statistical Abstract of the United States,
1996, U.S. Department of Commerce,
U.S. Bureau of the Census.
26.	Personal Communication with E.H.
Pechan & Associates on VMT Devel-
opment, Springfield, VA, August 18,
1997.
27.	The Bureau of Economic Analysis,
Department of Commerce, website
at http://www.bea.doc.gov/bea/.
28.	The population estimates in Figure
1-2 are based upon only a single year
of data, 1996, and only consider
counties with monitoring data for
each pollutant. They are intended to
provide a relative measure of the ex-
tent of the problem for each pollutant
in 1996. An individual living in a
county that had a measured concen-
tration above the level the NAAQS
may not actually be exposed to un-
healthy air.
29.	The number of people living in for-
mally designated nonattainment ar-
eas as of September 1997 was ap-
proximately 120 million. These
population estimates differ because
formal nonattainment designations
are based on multiple years of data
rather than a single year and gener-
ally do not follow county bound-
aries. For a pollutant such as ozone,
nonattainment areas typically com-
pose the entire metropolitan area,
which may include additional coun-
ties that do not contain monitors.
CHAPTER 1: EXECUTIVE SUMMARY
5

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
6 CHAPTER 1: EXECUTIVE SUMMARY

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Chapter 2
Air Quality Trends
THIS CHAPTER PRESENTS national air
quality trends for each of the pollutants
for which EPA has established NAAQS.
NAAQS are in place for the following
six criteria pollutants: carbon monox-
ide, lead, nitrogen dioxide, ozone, par-
ticulate matter whose aerodynamic
size is less than or equal to 10 microns,
and sulfur dioxide. Table 2-1 lists the
NAAQS for each pollutant in terms of
the level of the standard, the associated
averaging time, and the form of the sta-
tistic used to evaluate compliance. Just
recently, the NAAQS for ozone and for
particulate matter were revised. Since
these revisions did not take place until
1997, they were not included in Table
2-1, which covers the NAAQS in effect
in 1996. The revised standards, however,
are discussed in detail within this chap-
ter in special sections entitled "The New
Ozone Standards" and "The New Par-
ticulate Matter Standards."
There are two types of standards:
primary and secondary. Primary stan-
dards protect against adverse health
effects, whereas secondary standards
protect against welfare effects such as
damage to crops, vegetation, buildings,
and decreased visibility. There are pri-
mary standards for all of the criteria
pollutants, and some pollutants (PMio
and S02) have primary standards for
both long-term (annual average) and
short-term (24 hours or less) averaging
times. Short-term standards most di-
rectly protect people from any adverse
health effects associated with peak
short-term exposures to air pollution,
while long-term standards can protect
Table 2-1. NAAQS in Effect in 1996
Pollutant
Primary
(Health Related)
Type of Average Standard Level
Concentration3
Secondary
(Welfare Related)
Type of Average Standard Level
Concentration
CO
8-hourb
9 ppm
(10 mg/m3)
No Secondary Standard

1-hourb
35 ppm
(40 mg/m3)
No Secondary Standard
Pb
Maximum
Quarterly Average
1.5 |jg/m3
Same as Primary Standard
no2
Annual
Arithmetic Mean
0.053 ppm
(100 |jg/m3)
Same as Primary Standard
03
Maximum Daily
1-hour Average0
0.12 ppm
(235 |jg/m3)
Same as Primary Standard
PM,.
Annual
Arithmetic Meand
50 |jg/m3
Same as Primary Standard

24-hourd
150 |jg/m3
Same as Primary Standard
so2
Annual
Arithmetic Mean
24-hourb
0.03 ppm
(80 |jg/m3)
0.14 ppm
(365 |jg/m3)
3-hourb
0.50 ppm
(1,300 |jg/m3)
a Parenthetical value is an approximately equivalent concentration.
b Not to be exceeded more than once per year.
c 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 one,
as determined according to Appendix H of the Ozone NAAQS.
d Particulate standards use PM10 as the indicator pollutant. The annual standard is
attained when the expected annual arithmetic mean concentration is less than or
equal to 50 |jg/m3; the 24-hour standard is attained when the expected number of
days per calendar year above 150 |jg/m3 is equal to or less than one, as determined
according to Appendix K of the PM NAAQS.
CHAPTER 2: AIR QUALITY TRENDS 7

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
people from adverse health effects asso-
ciated with short- and long-term expo-
sures to air pollution. There are
secondary standards for each criteria
pollutant except CO. Secondary stan-
dards are identical to the primary stan-
dard with the exception of S02.
This chapter emphasizes the most
recent 10 years of air pollution trends,
from 1987 to 1996. Trends over a 15- or
20-year time frame are presented when
possible; however, the limited amount
of data available in the earliest years of
monitoring make them suitable only
for examining the general behavior of
ambient concentrations. In addition,
one-year changes in ambient concen-
trations are presented. These must also
be interpreted with a bit of caution, as
they can be heavily influenced by me-
teorological conditions.
Most of the trends information pre-
sented in this chapter is based on two
types of data: ambient concentrations
and emissions estimates. Ambient
concentrations are measurements of
pollutant concentrations in the ambient
air from monitoring sites across the
country. This year's report contains
data accumulated on the criteria pollut-
ants between 1987 and 1996 at 4,858
monitoring stations located in urban,
suburban, and some rural areas. The
trends presented here are derived from
the composite average of these direct
measurements (see Table A-10). The av-
eraging times and air quality statistics
used in the trends calculations relate di-
rectly to the NAAQS.
The second type of data presented in
this report is emissions estimates.
These are based on engineering calcu-
lations of the amounts and kinds of
pollutants emitted by automobiles, fac-
tories, and other sources over a given
period. There are also monitors known
as continuous emissions monitors
(CEMs) that have recently been in-
stalled at major electric utilities to mea-
sure actual emissions. This report
incorporates data from CEMs collected
between 1994 and 1996 for NOx and
S02 emissions at major electric utilities.
Changes in ambient concentrations
do not always track changes in emis-
sions estimates. There are four known
reasons for this. First, because most
monitors are positioned in urban,
population-oriented locales, air quality
trends are more likely to track changes
in urban emissions rather than changes
in total national emissions. Urban emis-
sions are generally dominated by mo-
bile sources, while rural areas may be
dominated by large stationary sources
such as power plants and smelters.
Second, emissions for some pollut-
ants are calculated or measured in a
different form than the primary air pol-
lutant. For example, concentrations of
ozone are caused by VOCs emissions of
as well as NOx emissions.
Third, the amount of some pollut-
ants measured at monitoring locations
depends on what chemical reactions, if
any, occur in the atmosphere during
the time it takes the pollutant to travel
from its source to the monitoring sta-
tion.
Finally, meteorological conditions
often control the formation and buildup
of pollutants in the ambient air. For ex-
ample, peak ozone concentrations typi-
cally occur during hot, dry, stagnant
summertime conditions; CO is pre-
dominately a cold weather problem;
and the amount of rainfall can affect
particulate matter levels and the fre-
quency of forest fires.
For a more detailed discussion of the
methodology used to compute the
trends estimates in this chapter, please
refer to Appendix B.
8 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Carbon Monoxide
Nature and Sources
Carbon monoxide is a colorless, odor-
less, and at higher levels, a poisonous
gas formed when carbon in fuels is not
burned completely. It is a product of
motor vehicle exhaust, which contrib-
utes about 60 percent of all CO emis-
sions nationwide. High concentrations
of CO generally occur in areas with
heavy traffic congestion. In cities, as
much as 95 percent of all CO emissions
may emanate from automobile ex-
haust. Other sources of CO emissions
include industrial processes, non-trans-
portation fuel combustion, and natural
sources such as wildfires. Peak CO con-
centrations typically occur during the
colder months of the year when CO au-
tomotive emissions are greater and
nighttime inversion conditions are
more frequent.
Health Effects
Carbon monoxide enters the blood-
stream through the lungs and reduces
oxygen delivery to the body's organs
and tissues. The health threat from CO
is most serious for those who suffer
from cardiovascular disease. At higher
levels of exposure, healthy individuals
are also affected. Visual impairment, re-
duced work capacity, reduced manual
dexterity, poor learning ability, and dif-
ficulty in performing complex tasks are
all associated with exposure to el-
evated CO levels.
Primary Standards
There are two primary NAAQS for
ambient CO, a 1-hour average of 35
parts per million (ppm) and an 8-hour
average of 9 ppm. These concentrations
are not to be exceeded more than once
per year. Secondary standards have not
been established for CO.
Trends
The consistent downward trend in con-
centrations and emissions of CO is
clear, with long-term improvements
continuing between 1987 and 1996.
Figure 2-1 shows that national average
CO concentrations decreased 37 per-
cent during the past 10 years as mea-
sured by the composite average of the
annual second highest 8-hour concen-
tration. These reductions in ambient
CO levels occurred despite a 28-percent
increase in VMT. Nationally, the com-
posite average of exceedances of the
CO NAAQS declined 92 percent since
Concentration, ppm
15
10
5
0
1987. The large difference between the
rate of change in concentrations and the
percentage change in exceedances is
due to the nature of the exceedance sta-
tistic (which is simply a count of a
pass/fail indicator). There are only a
few monitoring sites currently record-
ing exceedances of the level of the stan-
dard.
National total CO emissions have
decreased 18 percent since 1987 as illus-
trated in Figure 2-2. As expected, the
national CO air quality decrease of 37
percent from the urban CO monitoring
network, which is primarily mobile-
source oriented, more closely tracks the
estimated 26 percent reduction in high-
way vehicle emissions. Figure 2-3
shows that transportation sources now
account for 79 percent of the nation's
total CO emissions.
The CO air quality improvement
occurred across all monitoring environ-
ments—urban, suburban and rural
rp90th Percentile
345 Sites
L-l—10th Percentile
NAAQS
87 88 89 90 91 92 93 94 95 96
Figure 2-1. Trend in second maximum non-overlapping 8-hour average CO
concentrations, 1987-1996.
• Air Quality Concentrations
1987-96
37% decrease
1995-96
7% decrease
• Emissions

1987-96
18% decrease
1995-96
1% decrease
CHAPTER 2: AIR QUALITY TRENDS 9

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
monitoring sites. As expected, Figure
2-4 shows, that urban monitoring sites
record higher CO concentrations on
average, than suburban sites, with the
lowest levels found at 10 rural CO sites.
During the past 10 years, composite
mean CO 8-hour concentrations de-
creased 37 percent at 190 urban sites, 37
percent at 142 suburban locations, and
48 percent at the 10 rural monitoring
sites.
Between 1995 and 1996, national
composite average CO concentrations
decreased 7 percent. Eight of the 10
EPA Regions located throughout the
country experienced declines in com-
posite mean ambient CO levels be-
tween 1995 and 1996, while monitoring
sites in Regions 6 and 10 recorded
small increases in composite average
concentrations. Nationally, the 1996
composite average ambient concentra-
tion is the lowest level recorded during
the past 20 years of monitoring. Total
CO emissions decreased 1 percent since
1995, with CO emissions from highway
vehicles recording a 2-percent decline
since last year. These improvements in
highway vehicle emissions occurred
despite the 2-percent increase in VMT
since last year.
To reduce tail pipe emissions of CO
and to help attain the national standard
for CO, the 1990 Clean Air Act Amend-
ments (CAAA) require oxygenated
gasoline programs in several regions
during the winter months. Under the
program regulations, a minimum oxy-
gen content (2.7 percent by weight) is
required in gasoline to ensure more
complete fuel combustion.1,2 Of the 36
nonattainment areas that initially
implemented the program in 1992, 25
areas continue to use oxygenated fuels.
The White House Office of Science and
Technology Policy (OSTP) review of
the oxygenated fuels program, Inter-
agency Assessment of Oxygenated Fuels,3
Thousand Short Tons Per Year
140,000
~	Fuel Combustion | Industrial Processing
~	Transportation ~ Miscellaneous
120,000
100,000
80,000
60,000
40,000
20,000
87 88 89 90 91 92 93 94 95 96
Figure 2-2. National total CO emissions trend, 1987-1996.
Transportation 78.7%
Industrial Processes 6.5%
Fuel Combustion 6.7%
Miscellaneous 8.0%
Figure 2-3. CO emissions by source category, 1996.
10 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Concentration, ppm
8
Rural (10 sites) Suburban (142 sites) Urban (190 sites)
87 88 89 90 91 92 93 94 95 96
Figure 2-4. CO second maximum 8-hour concentration trends by location, 1987-1996.
stated that analyses of ambient CO
measurements in some cities with win-
ter oxygenated gasoline programs
showed reductions of about 10 percent.
In a regression analysis that expanded
on a recent EPA study the estimated
oxyfuel effect was an average total re-
duction in ambient CO concentrations
of 14 percent overall for the eight win-
ter seasons from 1986 through 1994.4-5
The map in Figure 2-5 shows the
variations in CO concentrations across
the country in 1996. The air quality in-
dicator is the highest annual second
maximum 8 hour concentration mea-
sured in each county. The bar chart to
the left of the map displays the number
of people living in counties within each
concentration range. The colors on the
map and bar chart correspond to the
colors of the concentration ranges dis-
played in the map legend. In 1996,
seven counties (with a total population
Figure 2-5. Highest CO second maximum 8-hour concentration by county, 1996.
Coreentfltbflfppir'fl	I •- i £		I	I B.E-1E.-4
CHAPTER 2: AIR QUALITY TRENDS 11

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
of approximately 13 million people)
had second maximum 8-hour concen-
trations greater than 9 ppm. These to-
tals are up slightly from 1995 totals of
six counties and 12 million people.
Figure 2-6 illustrates the improve-
ment in ambient CO air quality during
the past 20 years. Although there are
differences in the mix of trend sites for
the two periods (168 vs. 345 sites), there
is evidence of a consistent decline in
CO concentrations during the past
20 years.
The CO ambient trends plotting
points and emissions totals by source
category are listed in Tables A-l and
A-2. The plotting points for the 20-year
trend charts are listed in Table A-9.
Concentration, ppm
14
12
10
8
6
4
2
1977-86 1987-96
(168 sites) (345 sites)
77 79 81 83 85 87 89 91 93 95
Figure 2-6. Long-term ambient CO trend, 1977-1996.
12 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Lead
• Air Quality Concentrations
1987-96
75% decrease
1995-96
no change
• Emissions

1987-96
50% decrease
1995-96
2% decrease
Nature and Sources
In the past, automotive sources were
the major contributor of lead emissions
to the atmosphere. As a result of EPA's
regulatory efforts to reduce the content
of lead in gasoline, the contribution
from the transportation sector has de-
clined over the past decade. Today,
metals processing is the major source of
lead emissions to the atmosphere. The
highest concentrations of lead are
found in the vicinity of nonferrous and
ferrous smelters, battery manufactur-
ers, and other stationary sources of lead
emissions.
Health and Other Effects
Exposure to lead occurs mainly
through the inhalation of air and the
ingestion of lead in food, water, soil, or
dust. It accumulates in the blood,
bones, and soft tissues. Because it is not
readily excreted, lead can also adversely
affect the kidneys, liver, nervous system,
and other organs. Excessive exposure
to lead may cause neurological impair-
ments such as seizures, mental retarda-
tion, and/or behavioral disorders. Even
at low doses, lead exposure is associated
with changes in fundamental enzymatic,
energy transfer, and homeostatic mecha-
nisms in the body. At low doses, fetuses
and children often suffer from central
nervous system damage. Recent stud-
ies also show that lead may be a factor
in high blood pressure and subsequent
heart disease. Lead can also be deposited
on the leaves of plants, presenting a haz-
ard to grazing animals. Animals do not
appear to be more susceptible to adverse
effects from lead than humans however,
nor do adverse effects in animals occur at
lower levels of exposure than compa-
rable effects in humans. For these rea-
sons, the secondary standard for lead is
identical to the primary standard.
Primary and Secondary
Standards
The primary and secondary NAAQS for
lead is a quarterly average concentration
not to exceed 1.5 \ig/m3.
Trends
Figure 2-7 indicates that between 1987
and 1996 maximum quarterly average
lead concentrations decreased 75 per-
cent at population-oriented monitors.
Figure 2-8 shows that total lead emis-
sions decreased 50 percent. These re-
ductions are a direct result of the
Concentration, |jg/m3
2.0
1.5
1.0
0.5
0.0
phase-out of leaded gasoline. Table
A-3, which lists lead emissions by ma-
jor source category, shows that on-road
vehicles accounted for 95 percent of the
10-year lead emissions decline. Note
that previously published lead emis-
sions estimates have been recently re-
vised significantly downwards for the
on-road vehicle category.
Air quality trends segregated by lo-
cation (rural, suburban, and urban) are
provided in Figure 2-9. All three loca-
tion types show similar declines over
the past 10 years.
The effect of the conversion to un-
leaded gasoline usage on ambient lead
concentrations is even more impressive
when viewed over a longer period, as
illustrated in Figure 2-10. Between 1977
and 1996, ambient concentrations of
lead declined 97 percent. This large
decline tracks well with the emissions
trend, which shows a decline of 98 per-
cent between 1970 and 1996. Between
-90th Percentile
+ -I
Mean
Median
—'—10th Percentile
208 Sites
.NAAQS
S B—S—S—B—S—E
—i—i—i—i—i—i—i—i—i—i—
87 88 89 90 91 92 93 94 95 96
Figure 2-7. Trend in maximum quarterly average Pb concentrations (excluding
source-oriented sites), 1987-1996.
CHAPTER 2: AIR QUALITY TRENDS 13

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
1995 and 1996, national average lead
concentrations (approaching the mini-
mum detectable level) remained un-
changed, while lead emissions estimates
showed a 2-percent decline.
The large reductions in long-term
lead emissions from transportation
sources has changed the nature of the
ambient lead problem in the United
States. As Figure 2-11 shows, industrial
processes were the major source of lead
emissions in 1996, accounting for 73
percent of the total. The transportation
sector (on-road and non-road sources)
now accounts for only 15 percent of
total 1996 lead emissions; on-road ve-
hicles account for less than one half of
a percent. Because industrial processes
are now responsible for all violations of
the lead standard, the lead monitoring
strategy now focuses on these emis-
sions point sources. The map in Figure
2-12 shows the lead monitors oriented
in the vicinity of major sources of lead
emissions. In 1996, eight lead point
sources had one or more source-ori-
ented monitors that exceeded the
NAAQS. These eight sources are
ranked in Figure 2-12 according to the
site with greatest maximum quarterly
mean. Various enforcement and regula-
tory actions are being actively pursued
by EPA and the states for these sources.
The map in Figure 2-13 shows the
highest quarterly mean lead concentra-
tion by county in 1996. Eight counties,
with a total population of 4.7 million
and containing the point sources iden-
tified in Figure 2-12, did not meet the
lead NAAQS in 1996. Note that the
point-source oriented monitoring data
were excluded from trends analyses
presented in Figures 2-7 and 2-9 so as
not to mask the underlying urban
trends.
In an effort to reduce unnecessary
monitoring requirements and allow
Short Tons Per Year
10,000
8,000
6,000
4,000
2,000
0
87 88 89 90 91 92 93 94 95 96
Figure 2-8. National total Pb emissions trend, 1987-1996.
Concentration, |jg/m3
0.2
0.15
0.1
0.05
0
Figure 2-9. Pb maximum quarterly mean concentration trends by
location (excluding source-oriented sites), 1987-1996.
~ Fuel Combustion | Industrial Processing ~ Transportation
Rural (5 sites) Suburban (107 sites) Urban (96 sites)
87 88 89 90 91 92 93 94 95 96
14 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Concentration, |jg/m3
2
1.5
1
0.5
0
77 79 81 83 85 87 89 91 93 95
1977-86 1987-96
(122 sites) (208 sites)
diverted savings to be utilized for new
monitoring requirements, EPA has de-
cided to significantly reduce the mo-
bile-source oriented lead monitoring
requirement. Previously, regulations re-
quired that each urbanized area with a
population of 500,000 or more operate
at least two lead National Air Monitor-
ing Stations (NAMS); there are approxi-
mately 85 NAMS in operation and
reporting data for 1996. With the new
lead monitoring rule proposed in Sep-
tember 1997, NAMS monitoring will
only be required in the largest metro-
politan area in each of the 10 EPA Re-
gions, and also in each populated area
(either a MSA/CMSA, town, or
county) where lead violations have
been measured.
Figure 2-10. Long-term ambient Pb trend, 1977-1996.
Fuel Combustion 12.7%
Transportation 14.6%
Industrial Processes 72.7%
Figure 2-11. Pb emissions by source category, 1996.
CHAPTER 2: AIR QUALITY TRENDS 15

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
•	Exceeds the NAAQS
•	Meets the NAAQS
Note: Site markers may overlap.
Max Qtr Avg
|jg/m3
9.89
9.23
5.74
5.06
3.12
3.10
2.81
	2£l	
Rant
Emission Source
ASARCO (Glover)
Franklin Smelter
Doe Run (Herculeneum)
ASARCO (Omaha)
ASARCO (East Helena)
Chemetco
Gulf Coast Lead
Refined Metals	
Figure 2-12. Pb maximum quarterly concentration in the vicinity of Pb point sources, 1996,
Concentration [if Jnrflj
Figure 2-13. Highest Pb maximum quarterly mean by county, 1996.
16 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Nitrogen Dioxide
Nature and Sources
Nitrogen dioxide is a light brown gas
that can become an important compo-
nent of urban haze. Nitrogen oxides
usually enter the air as the result of
high-temperature combustion pro-
cesses, such as those occurring in auto-
mobiles and power plants. N02 plays
an important role in the atmospheric
reactions that generate ozone. Home
heaters and gas stoves also produce
substantial amounts of N02.
Health and Other Effects
Nitrogen dioxide can irritate the lungs
and lower resistance to respiratory in-
fections such as influenza. The effects
of short-term exposure are still unclear,
but continued or frequent exposure to
concentrations higher than those nor-
mally found in the ambient air may
cause increased incidence of acute res-
piratory disease in children.
Nitrogen oxides are an important
precursor to both ozone and acidic pre-
cipitation (acid rain) and can affect
both terrestrial and aquatic ecosystems.
The regional transport and deposition
of nitrogenous compounds arising
from emissions of NOx is a potentially
significant contributor to such environ-
mental effects as the growth of algae
and subsequent unhealthy or toxic con-
ditions for fish in the Chesapeake Bay
and other estuaries. In some parts of
the western United States, NOx have a
significant impact on particulate matter
concentrations.
Primary and Secondary
Standards
The ambient N02 primary and second-
ary NAAQS are an annual mean con-
centration not to exceed 0.053 ppm.
Trends
The trend in annual mean N02 concen-
trations measured at 214 sites across
the country between 1987 and 1996 is
shown in Figure 2-14. The trend shows
a 10-percent decrease in the national
composite mean. However, the trend in
total NOx emissions during the same
period shows a 3-percent increase, as
shown in Figure 2-15. Since most N02
monitors are located in urban, popula-
tion-oriented areas, the trend in ambient
concentrations is more representative of
the highway vehicle NOx emissions,
Concentration, ppm
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.00
which decreased 6 percent between 1987
and 1996.
The increase in total NOx emissions
is due, in large part, to emissions from
coal-fired electric utilities. NOx emis-
sions from these utilities account for
roughly one quarter of all NOx emis-
sions. Between 1987 and 1996, emis-
sions from these sources rose 3 percent.
In October 1997, EPA proposed a rule
that will reduce regional emissions of
NOx. Utilities and large utility point
sources are the most likely sources for
these emissions reductions. See the
ozone section, beginning on page 27, for
more information concerning this rule.
The two primary sources of NOx
emissions are fuel combustion and
transportation. Together these two
sources made up 95 percent of 1996 to-
tal NOx emissions. Table A-4 provides
a listing of NOx emissions by major
source category.
-p90th Percentile	214Sites
f-Mean
--Med ian
J-1 Oth_Percentile	NAAQS
"l	1	1	1	1	1	1	1	1	1—
87 88 89 90 91 92 93 94 95 96
• Air Quality Concentrations
1987-96
10% decrease
1995-96
no change
• Emissions

1987-96
3% increase
1995-96
2% decrease
Figure 2-14. Trend in annual NO2 concentrations, 1987-1996.
CHAPTER 2: AIR QUALITY TRENDS 17

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Title IV (Acid Deposition Control) of
the CAA specifies that between 1980
and 2010, total annual NOx emissions
will be reduced by approximately 10
percent (2 million tons). In 1996, NOx
emissions were reduced 33 percent
from 1990 levels at participating utili-
ties. It is important to note, however,
that these participating utilities made
up only three percent of total national
NOx emissions in 1996. Further, emis-
sions from these participating utilities
only made 12 percent of NOx emissions
from electric utilities in 1996. EPA's
rule to reduce the regional transport of
ozone will help to achieve important
additional reductions in emissions of
NOx.
Although higher ambient N02 lev-
els are typically observed in urban ar-
eas, Figure 2-17 shows that the ambient
N02 air quality trends are similar
across monitoring locations. Addition-
ally, 1996 is the fifth consecutive year
that all monitoring locations across the
nation, including Los Angeles, met the
national N02 air quality standard (see
Figure 2-18). Twenty-year trends in
ambient N02 concentrations show an
overall decrease of approximately 27
percent (see Figure 2-19).
Thousand Short Tons Per Year
30,000
25,000
20,000
15,000
10,000
5,000
~	Fuel Combustion | Industrial Processing
~	Transportation ~ Miscellaneous
Figure 2-15. National total NOx emissions trend, 1987-1996.
Fuel Combustion 46.2%
Industrial Processes 3.7%
Miscellaneous 1.0%
Transportation 49.2%
Figure 2-16. NOx emissions by source category, 1996.
18 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Concentration, ppm
0.03
0.025
0.02
0.015
0.01
0.005
Rural (46 sites) Suburban (89 sites) Urban (77 sites)
87 88 89 90 91 92 93 94 95 96
Figure 2-17. N02 annual mean concentration trend by location, 1987-1996.

Cp if;:^ ntrF.tijn [p pirfl
Figure 2-18. Highest N02 annual mean concentration by county, 1996.
CHAPTER 2: AIR QUALITY TRENDS 19

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Concentration, ppm
0.03
0.025
0.02
0.015
0.01
0.005
0
Figure 2-19. Long-term ambient N02 trend, 1977-1996.
1977-86 1987-96
(65 sites) (214 sites)
77 79 81 83 85 87 89 91 93 95
20 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Ozone
• Air Quality Concentrations (1 hour)
1987-96
15% decrease
1995-96
6% decrease
• Emissions

1987-96
18% decrease
1995-96
7% decrease
Nature and Sources
Ground level ozone (the primary con-
stituent of smog) has remained a per-
vasive pollution problem throughout
the United States. Ozone is not emitted
directly into the air but is formed by the
reaction of VOCs and NOx in the pres-
ence of heat and sunlight. Ground-level
ozone forms readily in the atmosphere,
usually during hot summer weather.
VOCs are emitted from a variety of
sources, including motor vehicles,
chemical plants, refineries, factories,
consumer and commercial products,
and other industrial sources. NOx is
emitted from motor vehicles, power
plants, and other sources of combus-
tion. Changing weather patterns con-
tribute to yearly differences in ozone
concentrations from city to city. Ozone
and the precursor pollutants that cause
ozone also can be transported into an
area from pollution sources found hun-
dreds of miles upwind.
Health and Other Effects
Ozone occurs naturally in the strato-
sphere and provides a protective layer
high above the earth. At ground-level,
however, it is the prime ingredient of
smog. Short-term exposures (1 to 3
hours) to ambient ozone concentra-
tions have been linked to increased
hospital admissions and emergency
room visits for respiratory causes. Re-
peated exposures to ozone can make
people more susceptible to respiratory
infection and lung inflammation, and
can aggravate preexisting respiratory
diseases such as asthma. Other health
effects attributed to short-term expo-
sures to ozone, generally while indi-
viduals are engaged in moderate or
heavy exertion, include significant de-
creases in lung function and increased
respiratory symptoms such as chest
pain and cough. Children active out-
doors during the summer when ozone
levels are at their highest are most at
risk of experiencing such effects. Other
at-risk groups include outdoor work-
ers, individuals with preexisting respi-
ratory disease such as asthma and
chronic obstructive lung disease, and
individuals who are unusually respon-
sive to ozone. Recent studies have at-
tributed these same health effects to
prolonged exposures (6 to 8 hours) to
relatively low ozone levels during pe-
riods of moderate exertion. In addi-
tion, long-term exposures to ozone
present the possibility of irreversible
changes in the lungs which could lead
to premature aging of the lungs and/or
chronic respiratory illnesses.
The recently completed review of
the ozone standard also highlighted
concerns associated with ozone effects
on vegetation for which the 1-hour
ozone standard did not provide ad-
equate protection. These effects include
reduction in agricultural and commer-
cial forest yields, reduced growth and
decreased survivability of tree seed-
lings, increased tree and plant suscep-
tibility to disease, pests, and other
environmental stresses, and potential
long-term effects on forests and ecosys-
tems. Because ground-level ozone in-
terferes with the ability of the plant to
produce and store food, plants become
more susceptible to disease, insect at-
tack, harsh weather and other environ-
mental stresses. In long-lived species,
these effects may only become evident
after several years or even decades.
Ozone also damages the foliage of trees
and other plants, decreasing the natu-
ral beauty of our national parks and
recreation areas, and reducing the qual-
ity of the habitat for wildlife, including
endangered species.
The Ozone Transport
Assessment Group
Through a 2-year effort known as the
Ozone Transport Assessment Group
(OTAG), EPA worked in partnership
with state and local government agen-
cies in the 37 easternmost states, indus-
try, and academia to address ozone
transport. Based on OTAG's extensive
analysis of ozone transport, on October
10,1997 EPA proposed a rule to reduce
the regional transport of ozone. This
rule sets a budget for emissions of NOx
for 22 states east of the Mississippi and
the District of Columbia and will sig-
nificantly reduce the transport of NOx
and ozone. EPA plans to finalize the
rule in September 1998. More detailed
information on the OTAG process and
details on information generated by the
OTAG workgroups are available on the
OTAG web page at http://
www.epa.gov/ttn/otag.
Primary and Secondary 1 -hour
Standards
In 1979, EPA established 1-hour pri-
mary and secondary standards for
ozone. The level of the 1-hour primary
NAAQS is 0.12 ppm daily maximum
1-hour ozone concentration that is not
to be exceeded more than once per year
on average. The secondary standard
was set identical to the primary stan-
dard.
The New Primary and Secondary
8-hour Ozone Standards
On July 18,1997, EPA replaced the pre-
vious 1-hour primary standard (health-
based) with a new 8-hour standard to
CHAPTER 2: AIR QUALITY TRENDS 21

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
NUMBER OF DAYS
I Bag TO 92
~75 TO 09
5D TO 74 ,
125 TO 49
ID TO 24
ll TO 9
Natiotttf lYeaiJter Service
Wfltfcmrf Centers for
EtrnromweMtat Prediction
NaSomi Carters for
Etrvirott/Kentei FretSction
dinsate Prediction Center
FIGURE 1. The number of days during Summer (June - August) with highs > 90°F, 1996 (top) vs. 1995 (bottom).
Only stations vjith reports for at least 91 days firing the 92-day period- were included in the analyses. Sharp
gradients near major coastlines and in regions of irregular terrain maybe under-represented. Mexican areas were
not analyzed due to the spar sens ss of reliable data. This summer, hot days were unusually frequent in western
North America while Jerjj instances of90°F+ heat occurred across the northeastern quarter of the United States
ctnd southeastern Can ada. These conditions are nearly the opposite of those observed during Summer 1995 when
heat and humidity were common-Hoce in the East and cooler than normal conditions dominated the West.
Figure 2-20. Number of summer days, June-August with temperatures >90°,
1995 vs. 1996.
protect against longer exposure periods
that are of concern at ozone concentra-
tions below the level of the previous
1-hour standard.6 The secondary stan-
dard (welfare-based) was set identical
to the 8-hour primary standard. EPA
also announced that it will expand the
rural ozone monitoring network to fo-
cus on ozone-related vegetation re-
search. Although the following trends
discussion focuses on the 1-hour
NAAQS in place in 1996, a description
of the new 8-hour ozone NAAQS and
some preliminary 8-hour trends results
immediately follows. Subsequent re-
ports will feature trends and status for
daily maximum 8-hour concentrations.
Trends
Ambient ozone trends are influenced
by year-to-year changes in meteoro-
logical conditions, population growth,
VOC to NOx ratios, and by changes in
emissions from ongoing control mea-
sures. Unlike the hot, dry meteorologi-
cal conditions in 1995 that were highly
conducive to peak ozone formation,
the summer of 1996 in most of the cen-
tral and eastern United States was wet
and cool, while: excessive heat, and
minimal precipitation affected the
west.7 As shown in Figure 2-20, fre-
quent cloudiness and precipitation of-
ten kept highs below 90°F across areas
to the north and east of the central
Great Plains, in dramatic contrast to the
excessive heat that periodically cov-
ered these regions during the summer
of 1995. Figure 2-21 reveals that the
1996 composite national average daily
maximum 1 hour ozone concentration
is 15 percent lower than the 1987 level.
Nationally, the 1996 composite mean
concentration is 6 percent lower than
1995 and tied with 1992 as the lowest
composite mean during this 10-year
period. The highest national composite
mean level was recorded in 1988. Since:
1987, the composite mean of the num-
ber of exceedances of the ozone
NAAQS has declined 73 percent. Na-
tionally, the composite average esti-
mated exceedance rate declined 37
percent between 1995 and 1996. Signifi-
cant reductions in ozone concentra-
tions were seen in the Northeast, North
Central, Southwest and the California
coastal regions.
The reductions in ozone levels de-
scribed above, however, do not affect
all environments equally. Although the
general pattern of ozone trends across
rural, suburban, and urban environ-
ments are similar, the magnitudes of
the reductions differ. Figure 2-22 shows
the trends in composite mean second
daily maximum 1-hour concentrations
for all three monitor settings. The high-
est concentration levels are typically
found at suburban sites. During the
past 10 years, the composite mean at
276 suburban sites and at 113 urban
sites recorded the same 16 percent re-
duction in ozone, composite mean con-
22 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Concentration, ppm
0.25
0.20
0.15
0.10
0.05
0.00
Figure 2-21. Trend in annual second daily maximum 1-hour 03
concentrations, 1987-1996.
Concentration, ppm
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
Figure 2-22. 03 second daily maximum 1-hour concentration trends by
location, 1987-1996.
—90th Percentile
¦Mean
-Median
-10th Percentile
600 Sites
NAAQS
87 88 89 90 91 92 93 94 95 96
Rural (194 sites) Suburban (276 sites) Urban (113 sites)
87 88 89 90 91 92 93 94 95 96
centrations. Since 1987, ozone levels
declined 10 percent at 194 sites in rural
locations.
As noted in a study by the National
Academy of Science, and in previous
Trends Reports, ozone trends are af-
fected by changing meteorological con-
ditions that are conducive to ozone
formation.8,9 EPA has developed a sta-
tistical model that attempts to account
for meteorological effects and helps to
normalize the resulting trend estimates
across years.10 The model, based on the
Weibull probability distribution, in-
cludes a trend component that adjusts
the annual rate of change in ozone for
concurrent impacts of meteorological
conditions, including surface tempera-
ture and wind speed. Figure 2-23
shows the results from application of
the model in 41 major urban areas.
While the raw data trends reflect the
year-to-year variability in ozone con-
ducive conditions, the meteorologically
adjusted ozone composite trend pro-
vides a better indicator of ozone trends
due to emissions trends. For these 41
metropolitan areas, the adjusted trend
shows continued improvement with an
average decrease of about 1 percent per
year since 1987.
The map in Figure 2-24 presents the
highest second daily maximum 1-hour
concentration by county in 1996. The
accompanying bar chart to the left of
the map reveals that in 1996 approxi-
mately 39 million people lived in 52
counties where the second daily maxi-
mum 1-hour concentration was above
the level of the ozone NAAQS. These
numbers represent a significant im-
provement from the 70 million people
(living in 108 counties) with ozone con-
centrations above the level of the ozone
NAAQS in 1995. As noted previously,
differences in meteorological condi-
tions between 1995 and 1996, are likely
responsible for much of this decline.
CHAPTER 2: AIR QUALITY TRENDS 23

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
The population totals for 1996 are
similar to those recorded in 1994. Na-
tionally, peak 1 hour ozone levels
show large spatial differences. Los
Angeles has the highest number of
exceedances of the ozone NAAQS, fol-
lowed by Houston and metropolitan
areas in California and the northeast
United States.
Long-term, quantitative ambient
ozone trends are difficult to estimate
due to changes in network design, sit-
ing criteria, spatial coverage and
monitoring instrument calibration
procedures over the past two decades.
For example, in Figure 2-25, the
shaded area in the late 1970s shows
the period corresponding to the old
calibration procedure where concen
tration levels are less certain. Figure
2-25 contrasts the 1977-1986 compos-
ite trend line based on 238 sites with
the current 1987-1996 composite trend
Eortcefttation |pp«V
Figure 2-24. Highest 03 second daily maximum concentration by county, 1996.
Concentration, ppm
0.18
0.16
0.14
0.12
0.10
0.08
0,06
0.04
0.02
0.00
Actual (41 MSAs) Met Adjusted (41 MSAs) National (600 Sites)
(99th Percentile) (99th Percentile) (2nd Daily Max 1-hr)
87 88 89 90 91 92 93 94 95 96
Figure 2-23. Comparison of actual and meteorologically adjusted ozone trends,
1987-1996 (composite average of 99th percentile 1-hr daily max concentration).
24 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Concentration, ppm
0.15
0.1
0.05
0
Figure 2-25. Long-term trend in second daily maximum 1-hour O3
concentrations, 1977-1996.
Thousand Short Tons Per Year
35,000
30,000
25,000
20,000
15,000
10,000
5,000
0
87 88 89 90 91 92 93 94 95 96
Figure 2-26. National total VOC emissions trend, 1987-1996.
1977-86 1987-96
(238 sites) (600 sites)
77 79 81 83 85 87 89 91 93 95
~	Fuel Combustion | Industrial Processing
~	Transportation ~ Miscellaneous
line for the 600 trend sites, revealing
about a 30-percent decline in ozone
concentrations during the past 20
years. Although the overall trend is
downward, short-term upturns corre-
sponding to ozone-conducive meteo-
rology are evident.
Figure 2-26 shows that national total
VOC emissions (which contribute to
ozone formation) decreased 18 percent
between 1987 and 1996. National total
NOx emissions (the other major precur-
sor to ozone formation) increased 5
percent between 1987 and 1996. Recent
control measures to reduce emissions
include regulations to lower fuel vola-
tility and to reduce NOx and VOC
emissions from tailpipes.11 The effec-
tiveness of these control measures is
reflected in the 26-percent decrease in
VOC emissions from transportation
sources. VOC emissions from highway
vehicles have declined 35 percent since
1987, while highway vehicle NOx emis-
sions have declined 7 percent since
their peak level in 1994. Nationally the
two major sources of VOC emissions
are industrial processes (50 percent)
and transportation sources (42 percent)
as shown in Figure 2-27 and in Table
A-5. Solvent use comprises 66 percent
of the industrial process emissions cat-
egory and 33 percent of total VOC
emissions.
To further understand the air qual-
ity problems in metropolitan areas, the
CAA called for improved monitoring
of ozone and its precursors (VOC and
NOx). PAMS are found in all ozone
nonattainment areas classified as seri-
ous, severe, or extreme. The 21 affected
areas collect measurements of ozone,
NOx (NO, N02, and total NOx), and
many VOCs, as well as surface and
upper air meteorological data. Between
1995 and 1996, a majority of the PAMS
sites showed decreases in the concen-
trations of key ozone-forming VOCs.
CHAPTER 2: AIR QUALITY TRENDS 25

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
For a more detailed discussion of the
PAMS program and VOC reductions,
see Chapter 4, "PAMS: Enhanced
Ozone and Precursor Monitoring."
As required by the CAA, a cleaner
burning fuel known as reformulated
gasoline has been sold since January 1,
1995 in those areas of the country with
the worst ozone or smog problems.
RFC is formulated to reduce automo-
tive emissions of ozone-forming pollut-
ants and toxic chemicals—it is estimated
to reduce both VOC and toxic emissions
by more than 15 percent. RFC sold dur-
ing the summer ozone season has
lower volatility than most conventional
gasoline.12 The RFC program is man-
dated year-round in 10 areas of the
country (Los Angeles, San Diego, Hart-	Figure 2-27. VOC emissions by source category, 1996.
ford, New York, Philadelphia, Chicago,
Baltimore, Houston, Milwaukee, and
Sacramento). Besides these required
areas, several other parts of the country
exceeding the ozone standard have
voluntarily entered the RFC program.13
For a more detailed discussion of the
VOC reductions that have been achieved
since the start of the RFC program, see
Chapter 4.
Fuel Combustion 5.6%
Miscellaneous 3.1%
Industrial Processes 49.7%
Transportation 41.5%
26 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
The New 8-hour Ozone Standards
ON JULY 18,1997, EPAannounced revi-
sions to the NAAQS for ground-level
ozone, the primary constituent of
smog. After a lengthy scientific review
process, including extensive external
scientific review, and public review and
comment, the EPA Administrator de-
termined that the previous 1-hour
ozone standard should be replaced
with a new 8-hour standard to protect
both public health and the environ-
ment. Many new health studies show
that health effects occur at levels lower
than the previous standard and that ex-
posure times longer than one hour (as
reflected in the previous standard) are
of concern.
The ozone primary and secondary
standards, when last revised in 1979,
were set at 0.12 ppm for one hour and
was expressed as a "one-expected-
exceedance" form. As the Clean Air Sci-
entific Advisory Committee (CASAC)
unanimously recommended, EPA
changed the ozone standard averaging
time to eight hours. EPA also changed
the form of the primary standard,
consistent with CASAC recommenda-
tions, from an expected-exceedance form
to a concentration-based form because
it relates more directly to ozone concen-
trations associated with health effects.
It also avoids exceedances, regardless
of magnitude, from being counted
equally in the attainment tests. The
new 8-hour primary standard was set
at 0.08 ppm for the 3-year average of
the annual 4th-highest daily maximum
8-hour ozone concentrations. The pre-
vious secondary standard (to protect
the environment, i.e., agricultural
crops, national parks, and forests) was
replaced with a standard identical to
the new primary standard.
Based on the most recent health
studies, prolonged exposures (6 to 8
hours) to relatively low ozone levels
during periods of moderate exertion
can result in significant decreases in
lung function, increased respiratory
symptoms such as chest pain and
cough, increased susceptibility to respi-
ratory infection and lung inflamma-
tion, and aggravation of preexisting
respiratory diseases such as asthma.
Exposures to ambient ozone concentra-
tions have also been linked to increased
hospital admissions and emergency
room visits for respiratory causes. Chil-
dren active outdoors during the sum-
mertime when ozone levels are at their
highest are most at risk of experiencing
such effects. Other at-risk groups in-
clude outdoor workers, individuals
with preexisting respiratory disease
such as asthma and chronic obstructive
lung disease, and individuals who are
unusually responsive to ozone. In ad-
dition, long-term exposures to ozone
present the possibility of irreversible
changes in the lungs which could lead
to premature aging of the lungs and/or
chronic respiratory illness.
In setting the 8-hour standard at
0.08 ppm, the EPA Administrator rec-
ognized that since there is no discern-
ible threshold below which no adverse
health effects occur, no level would
eliminate all risk. Thus, a zero-risk
standard is not possible, nor is it re-
quired by the Clean Air Act. The se-
lected 0.08 ppm level is based on the
judgment that at this level, public
health will be protected with an ad-
equate margin of safety.
The scientific review also high-
lighted concerns associated with ozone
effects on vegetation for which the pre-
vious ozone standard did not provide
adequate protection. These effects in-
clude reduction in agricultural and
commercial forest yields; reduced
growth and decreased survivability of
tree seedlings; increased tree and plant
susceptibility to disease, pests, and
other environmental stresses; and po-
tential long-term effects on forests and
ecosystems. Many studies suggested
that the degree of ozone damage to
plants depends as much on the total
seasonal cumulative ozone dose the
plant receives as it does on the magni-
tude of any one particular acute ozone
episode. Thus, during this current
ozone NAAQS review, discussions on
possible forms for a new secondary
standard included a seasonal, cumula-
tive index. Although a separate sea-
sonal secondary standard was not set
at this time, EPA believes attainment of
the new 8-hour primary standard will
substantially protect vegetation. EPA is
committed to enhancing rural ozone
monitoring, working in conjunction
with other federal agencies, and con-
sidering long-term cumulative effects
of ozone on plants as additional infor-
mation becomes available.
The averaging times and air quality
statistics used to track national air qual-
ity trends relate directly to the form of
the respective national ambient air
quality standard. For the 1-hour ozone
standard, the solid line in Figure 2-28
shows the trend in the composite aver-
age of the annual second daily maxi-
mum 1-hour ozone concentrations. For
the new 8-hour ozone standard, the
CHAPTER 2: AIR QUALITY TRENDS 27

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
dashed line shows the trend in the
composite average of the annual fourth
highest daily maximum 8-hour ozone
concentrations. Between 1987 and
1996, the composite average of the
1-hour daily maximum ozone concen-
trations declined 15 percent, while the
composite average of 8-hour fourth
highest daily maximum concentrations
decreased by 11 percent. The 1997
Trends Report will mark the transition to
the 8-hour standard for tracking air
quality status and trends.
The new 8-hour standard became
effective on September 16, 1997, while
the 1-hour standard will remain in effect
in an area until EPA determines that the
area has met the 1-hour standard.
A copy of the Federal Register Notice
(62FR 38856) for the new standard can be
downloaded from EPA's homepage on
the Internet. The address is: http://
www.epa.gov/ttn/oarpg/rules.html.
Determining Compliance
with the New 8-hour
Ozone Standards
The Standards
The level of the national 8-hour pri-
mary and secondary ambient air qual-
ity standards for ozone is 0.08 ppm,
daily maximum 8-hour average. The
8-hour air quality standards are met at
an ambient air quality monitoring site
when the average of the annual fourth-
highest daily maximum 8-hour aver-
age ozone concentration is less than or
equal to 0.08 ppm. (Computational
details are specified in Appendix I to
Part 50.10 of Title 40 of the Code of Fed-
eral Regulations.)
The Attainment Test
As shown in Example 1, the primary
and secondary standards are met at
this monitoring site because the 3-year
average of the annual fourth-highest
daily maximum 8-hour average ozone
0.16
0.14
2nd max 1-hr
0.12
1 -hr NAAQS
0.10
0.08
5-hr NAAQS
0.06
0.04
0.02
0.00
87
88
89
90
91
92
93
94
95
96
Figure 2-28. Trend in 2nd max 1-hr vs. 4th max 8-hr ozone concentrations, 1987-1996.
Example 1. Ambient monitoring site attaining the primary and secondary O3 standards.
Highest 2nd Highest 3rd Highest 4th Highest
Daily Max Daily Max Daily Max Daily Max
Year
Percent
Valid Days
8-hour Cone,
(ppm)
8-hour Cone. 8-hour Cone,
(ppm) (ppm)
8-hour Cone,
(ppm)
1993
100 percent
0.092
0.091 0.090
0.088
1994
96 percent
0.090
0.089 0.086
0.084
1995
98 percent
0.087
0.085 0.083
0.080
Average
98 percent


0.084
Example 2. Ambient monitoring site failing to meet the primary and secondary O3
standards.
Highest 2nd Highest 3rd Highest 4th Highest
Daily Max Daily Max Daily Max Daily Max
Percent 8-hour Cone. 8-hour Cone. 8-hour Cone. 8-hour Cone.
Year	Valid Days (ppm)	(ppm)	(ppm)	(ppm)
1993
96 percent
0.105
0.103
0.103
0.102
1994
74 percent
0.090
0.085
0.082
0.080
1995
98 percent
0.103
0.101
0.101
0.097
Average
89 percent



0.093
28 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
concentrations (0.084 ppm) is less than
or equal to 0.08 ppm. The data com-
pleteness requirement is also met be-
cause the average percent of days with
valid ambient monitoring data is
greater than 90 percent, and no single
year has less than 75 percent data com-
pleteness.
Example 2 shows that the primary
and secondary standards are not met at
this monitoring site because the 3-year
average of the fourth-highest daily
maximum 8-hour average ozone con-
centrations (0.093 ppm) is greater than
0.08 ppm. The ozone concentration
data for 1994 is used in these computa-
tions even though the data capture is
less than 75 percent, because the aver-
age fourth-highest daily maximum
8-hour average concentration is greater
than 0.08 ppm.
The Design Value
The air quality design value at a moni-
toring site is defined as the concentra-
tion that when reduced to the level of
the standard ensures that the site meets
the standard. For a concentration-
based standard, the air quality design
value is simply the standard-related
test statistic. Thus, for the primary and
secondary ozone standards, the 3-year
average of the annual fourth-highest
daily maximum 8-hour average ozone
concentration is also the air quality de-
sign value for the site.
CHAPTER 2: AIR QUALITY TRENDS 29

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Particu ate Matter
Particulate Matter
•	Air Quality Concentrations (PM10)
1988-96 25% decrease
1995-96 4% decrease
•	Emissions (PMJ
1988-96 12% decrease
1995-96	no change
jncentration, |jg/m3
-90th Percentile
-Mean
Median
—10th Percentile

900 Sites
	NAA.QS-
—i	1	1	1	1	1	1	1	1—
88 89 90 91 92 93 94 95 96
Figure 2-29. Trend in annual mean PM10 concentrations, 1988-1996.
Nature and Sources
Particulate matter is the general term
used for a mixture of solid particles and
liquid droplets found in the air. These
particles, which come in a wide range
of sizes, originate from many different
stationary and mobile sources as well
as from natural sources. They may be
emitted directly by a source or formed
in the atmosphere by the transforma-
tion of gaseous emissions. Their
chemical and physical compositions
vary depending on location, time of
year, and meteorology.
Health and Other Effects
Scientific studies show a link between
particulate matter (alone, or combined
with other pollutants in the air) and a
series of significant health effects.
These health effects include premature
death, increased hospital admissions
and emergency room visits, increased
respiratory symptoms and disease, and
decreased lung function, and alter-
ations in lung tissue and structure and
in respiratory tract defense mecha-
nisms. Sensitive groups that appear to
be at greater risk to such effects include
the elderly, individuals with cardiopul-
monary disease such as asthma, and
children. In addition to health prob-
lems, particulate matter is the major
cause of reduced visibility in many parts
of the United States. Airborne particles
also can cause soiling and damage to
materials.
60
50
40
30
20
10
0
Primary and Secondary PMig
Standards
There are both short- and long-term
PMio NAAQS. The long-term standard
specifies an expected annual arithmetic
mean not to exceed 50 \ig/m3 averaged
over three years. The short-term
(24-hour) standard of 150 |ig/m3 is not
to be exceeded more than once per year
on average over three years. Together,
these make up the primary, or health-
based, PM10 standards. The secondary,
or welfare-based, standards for PMi0
are identical to the primary standards.
The New PM Standards
The original standard for particulate
matter was a Total Suspended Particu-
late (TSP) standard, established in 1971.
In 1987, EPAreplaced the TSP standard
with a PM10 standard to focus on
smaller particles of aerodynamic diam-
eter less than or equal to 10 microme-
ters. These smaller particles caused the
greatest health concern because of their
ability to penetrate into sensitive re-
gions of the respiratory tract. The most
recent review of the particulate matter
standards concluded that still more
protection from adverse health effects
was needed. On July 18, 1997 EPA re-
vised the particulate matter standards
by adding new standards for PM2.5
(particles of aerodynamic diameter less
than or equal to 2.5 micrometers) and
by adjusting the form of the PM10
24-hour standard.14 Additional details
for the revised standards are provided
in the next section, "The New Particu-
late Matter Standards." The trends dis-
cussion of this section will focus on the
PMio standards that were in place
when the 1987-1996 data presented in
this report were collected.
30 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Thousand Short Tons Per Year
4,000
3,000
2,000
1,000
n Fuel Combustion H Industrial Processing fl Transportation
88 89 90 91 92 93 94 95 96
Figure 2-30. National PM10 emissions trend, 1988-1996 (traditionally inventoried
sources only).
Concentration, |jg/m3
35
Rural (119 sites) Suburban (356 sites) Urban (404 sites)
88 89 90 91 92 93 94 95 96
Figure 2-31. PM-io annual mean concentration trends by location, 1988-1996.
Trends
The first complete year of PMi0 trends
data for most monitors is 1988, so the
trends in this section begin there. Fig-
ure 2 29 shows a 25-percent decrease in
annual mean PM10 concentrations mea-
sured at monitoring sites across the
country between 1988 and 1996. The
change in direct emissions of PMi0,
which are based on engineering esti-
mates, is shown in Figure 2-30. For the
same time period (1988-1996), direct
emissions decreased 12 percent, while
emissions of S02, a major precursor of
fine particulate matter, decreased by
about the same amount. The 1-year
change between 1995 and 1996 showed
a 4-percent decrease in annual mean
PMio concentrations, while PMi0 emis-
sions remained about the same.
As shown in Figure 2-31, urban and
suburban sites have similar trends and
comparable average concentrations.
The trends at rural sites are consistent
with these urban and suburban pat-
terns, although the composite mean
level is significantly lower.
Direct PMi0 emissions are generally
examined in two separate groups. The
first is the more traditionally invento-
ried sources, including fuel combustion,
industrial processes, and transportation,
as shown in Figure 2-32. The second
group is a combination of miscellaneous
and natural sources including agricul-
ture and forestry wildfires and man-
aged burning, fugitive dust from
paved and unpaved roads, and wind
erosion. As Figure 2-33 shows, these
miscellaneous and natural sources ac-
tually account for almost 90 percent of
the total direct PMio emissions nation-
wide, although they can be difficult to
quantify compared to the traditionally
inventoried sources. The emissions
trend for the traditionally inventoried
sources shows a 12-percent decrease
since 1988. Because the emissions in
CHAPTER 2: AIR QUALITY TRENDS 31

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
the miscellaneous/natural group tend
to fluctuate a great deal from year to
year, the trend from one year to the
next or over several years may not be
particularly meaningful. Table A-6 lists
PMio emissions estimates for the tradi-
tionally inventoried sources for 1987
1996. Miscellaneous and natural
source PMi0 emissions estimates are
provided in Table A-7.
The map in Figure 2 34 displays the
highest second maximum 24-hour
PM10 concentration by county in 1996.
Three counties had a monitor with a
very high 24-hour PMi0 second maxi-
mum concentration. The highest was
recorded in Howell County, Missouri at
a monitor adjacent to a charcoal kiln
facility. The next highest was a moni-
tor in Imperial County, California at a
site just 1/4 mile from the border with
Mexico. The third highest second
maximum concentration was recorded
at the Franklin Smelter in Philadelphia.
The bar chart which accompanies the
national map shows that in 1996, ap-
proximately 5 million people lived in
11 counties where the second highest
maximum 24-hour PMi0 concentration
was above the level of the 24-hour
PMio NAAQS. When both the annual
and 24-hour standards are considered,
there were 7 million people living in 15
counties with PMio concentrations
above the PMio NAAQS in 1996.
Fuel Combustion 36.1%
Industrial Processes 37.5%
Transportation 26.4%
Figure 2-32. PM10 emissions from traditionally inventoried source categories, 1996.
Other Combustion
2.5%
Agriculture & Forestry 15%
Fugitive Dust
55%
Wind Erosion 17%
Traditionally
Inventoried
Sources
10.5%
Figure 2-33. Total PM10 emissions by source category, 1996.
32 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
ComentHtbrt
Figure 2-34. Highest second maximum 24-hour PM-io concentration by county, 1996.
CHAPTER 2: AIR QUALITY TRENDS 33

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
The New Particulate Matter Standards
Revisions to the particulate matter
standards were announced July 18,
1997. The review of hundreds of peer-
reviewed scientific studies, published
since the original PM10 standards were
established, provided evidence that
significant health effects are associated
with exposures to ambient levels of fine
particles allowed by the PM10 stan-
dards. Consistent with the advice given
by CASAC, the EPAAdministrator de-
termined that adding new standards
was necessary to protect the health of
the public and the environment.
The primary (health-based) stan-
dards were revised to add two new
PM2.5 standards, set at 15|ig/m3 and 65
|ig/m3, respectively, for the annual and
24-hour standards, and to change the
form of the 24-hour PMi0 standard. In
setting these levels, the EPAAdminis-
trator recognized that since there is no
discernible threshold below which no
adverse health effects occur, no level
would eliminate all risk. Therefore, a
zero-risk standard is not possible, nor is
it required by the CAA. The selected
levels are based on the judgement that
public health will be protected with an
adequate margin of safety. The secondary
(welfare-based) standards were revised
by making them identical to the primary
standards. In conjunction with the Re-
gional Haze Program, the secondary
standards will protect against major PM
welfare effects, such as visibility impair-
ment, soiling, and materials damage.
PM2.5 consists of those particles that
are less than 2.5 micrometers in diam-
eter. They are also referred to as "fine"
particles, while those between 2.5 and
10 micrometers are known as "coarse"
particles. Fine particles result from fuel
combustion from motor vehicles,
power generation, and industrial facili-
Concentration, |jg/m3
180
160	900 sites
140	NAAQS
120
100
80
60
40
20
0
88 89 90 91 92 93 94 95 96
Figure 2-35. PM10 trend in the average 99th percentile PM10 concentration, 1988-1996.
ties, as well as from residential fire-
places and wood stoves. Fine particles
can also be formed in the atmosphere
by the transformation of gaseous emis-
sions such as S02, NOx, and VOCs.
Coarse particles are generally emitted
from sources such as vehicles traveling
on unpaved roads, materials handling,
and crushing and grinding operations,
as well as windblown dust.
Both coarse and fine particles can
accumulate in the respiratory system
and are associated with numerous
health effects. Exposure to coarse frac-
tion particles is primarily associated
with the aggravation of respiratory
conditions such as asthma. Fine par-
ticles are most closely associated with
such health effects as premature death,
increased hospital admissions and
emergency room visits, increased respi-
ratory symptoms and disease, and de-
creased lung function. Sensitive groups
that appear to be at greatest risk to such
effects include the elderly, individuals
with cardiopulmonary disease such as
asthma, and children.
The form of the 24-hour PM10 stan-
dard changed from the one-expected-
exceedance form to a concentration-based
99th percentile form, averaged over
three years. EPA changed the form of
the 24-hour PM10 standard from an ex-
pected-exceedance form to a concentra-
tion-based form because the new form
relates more directly to PM concentra-
tions associated with health effects.
The concentration-based form also
avoids exceedances, regardless of size,
from being counted equally in attain-
ment tests. The method for computing
the 99th percentile for comparison to
the 24-hour standard is found in the
Code of Federal Regulations (40 CFR Part
34 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
50, Appendix N) and is described
briefly in the pages that follow.
Figure 2-35 shows a trend of the av-
erage 99th percentile for 900 sites
across the country. The 99th percentile
shown in the trend is computed by the
Aerometric Information Retrieval Sys-
tem (AIRS), so it differs slightly from
the data handling procedures found in
the Code of Federal Regulations (CFR).
The data displayed in the figure also
differ from the regulatory data han-
dling procedures in that only one year
of data are presented, whereas an ac-
tual comparison to the standards is al-
ways based on an average of three
years of data. The trend data show a
23-percent increase in average 99th
percentile concentration between 1988
and 1996.
The form of the 24-hour PM2.5 stan-
dard is also a percentile form, although
it is a 98th percentile. Like PMi0, it is
averaged over three years. The form of
the annual standard for PM2.5 is a 3-
year average of the annual arithmetic
mean, just as for the PM10 standard.
However, unlike PM10, compliance
with the PM2.5 annual standard may be
judged from single or multiple com-
munity-oriented monitors reflective of
a community-based spatial average. A
spatial average is more closely linked
to the underlying health effects infor-
mation. A trend of PM2.5 data is not pre-
sented here because there are not
enough monitors in place at this time to
portray an accurate national trend. The
network of monitors required for the
new PM2.5 standard will be phased in
over the next three to four years.
A copy of the Federal Register No-
tice for the new PM standard (62FR
38652) can be downloaded from EPA's
homepage on the Internet. The address is
http:/ /www. epa.gov/ ttn/ oarpg/
rules.html.
Determining Compliance
With the New PM Standards
Appendix N to 40 CFR Part 50 contains
the data handling regulations for the
new particulate matter standards.
Some of those requirements are illus-
trated in the examples provided here,
but Appendix N includes additional
details, requirements, and examples
(including examples for spatial averag-
ing and for data which do not meet
data completeness requirements).
The levels, forms, and rounding con-
ventions of the particulate matter stan-
dards can be summarized as follows:
Annual PMig Standard
Level: 50|ig/m3
Form: At each site, calculate the
annual mean from 4
quarterly means. Average
the annual means for 3
years.
Rounding: 50.4 rounds to 50
50.5 rounds to 51 (first
value above the stan-
dard) .
24-Hour PMW Standard
Level: 150|ig/m3
Form: At each site, calculate the
99th percentile for the
year. Average the 99th
percentiles for 3 years.
Rounding: 154 rounds to 150
155 rounds to 160 (first
value above the standard).
Annual PM2 5 Standard
Level: 15.0|ig/m3
Form: At each site, calculate the
annual mean from 4
quarterly means. If spatial
averaging is used,
average the annual means
of the designated moni-
tors in the area to get an
annual spatial mean. Then
average the annual spatial
means for 3 years.
Rounding: 15.04 rounds to 15.0
15.05 rounds to 15.1 (first
value above the standard).
24-Hour PM2 5 Standard
Level: 65|ig/m3
Form: At each site, calculate the
98th percentile for the
year. Average the 98th
percentiles for 3 years.
Rounding: 65.4 rounds to 65
65.5 rounds to 66 (first
value above the stan-
dard).
Sample Calculation of the 3-Year
Average Annual Mean for PM10
Assume data completeness require-
ments have been met for this example.
At each site, average all the 24-hour
measurements in a quarter to find the
quarterly mean. Then average the 4
quarterly means to find the annual
mean. In this example, the 4 quarterly
means for the first year are 43.23, 54.72,
50.96, and 60.77 \ig/m3. Find the an-
nual mean for the first year.
43.23 + 54.7? + 50.% + fiO.77 = 52.42 |jg/m3
4
Similarly, the annual means for the sec-
ond and third year are calculated to be
82.17 and 63.23 \ig/m3. Find the 3-year
average annual mean.
52.42 +82.17+ R3.23 = 65.94 |jg/m3
3
Round 65.94 to 66 |ig/m3 before com-
paring to the standard. This example
does not meet the PM10 annual standard.
CHAPTER 2: AIR QUALITY TRENDS 35

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Sample Calculation of the 3-Year
Average 99th Percentile for PM10
Assume for this example that the data
completeness requirements have been
met. At each site, sort all values col-
lected in a year from lowest to highest.
Number their rankings as in the fol-
lowing table:
Year 1
Rank	Value
(MQ/m3)
1

85
2

87
3

88
108

120
109

128
110

130
Rank
Year 2
Value
(MQ/m3)
1

90
2

93
3

97
96

143
97

148
98

150
Rank
Year 3
Value
(MQ/m3)
1

40
2

48
3

52
98

140
99

144
100

147
In this example, the site collected 110
out of a possible 121 samples in Year 1;
98 out of 121 in Year 2; and 100 out of
121 in Year 3. Calculate the 99th percen-
tile for each year.
0.99 x 110 = 108.9
0.99 x 98 = 97.02
0.99 x 100 = 99
Take the integer part of the product and
add 1 to find which ranking corre-
sponds to the 99th percentile.
108 + 1 = 109
97 + 1 = 98
99 + 1 = 100
Find the value which corresponds to
the ranking using the table above.
109 corresponds to 128 |jg/m3
98 corresponds to 150 |jg/m3
100 corresponds to 147 |jg/m3
Find the 3-year average of the 99th per-
centiles.
178 + 150 + 147 = 141.66667 |jg/m3
3
Round 141.66667 to 140 |ig/m3 before
comparing to the standard. This ex-
ample meets the PM10 24-hour standard.
Sample Calculation of the 3-Year
Average of the Spatially
Averaged Annual Means for PM2
Assume data completeness require-
ments have been met for this example.
Given an area designated for spatial
averaging and three monitors desig-
nated for spatial averaging within the
area, first average all the 24-hour mea-
surements in each quarter at each site
to find the 4 quarterly means. Then cal-
culate the annual mean from the 4
quarterly means. If, for this example,
the 4 quarterly means for first site for
the first year are 11.6, 12.4, 15.1, and
12.1 |ig/m3, find the annual mean for
this site and year.
11.6 + 17.4 + 15.1 +17.1 =17.8 pg/m3
4
Similarly, the annual means for the
other sites and the other years can be
calculated. The results appear in the
following table.
Annual Means (|jg/m3)
Site 1 Site 2 Site 3
Year 1	12.8 14.2 13.6
Year 2	13.0 13.5 12.9
Year 3	15.2 14.8 17.1
For Year 1, find the annual spatial mean
of the designated monitors in the area.
17.8 + 14.7 + 13.6 = 13.533333 [jg/m3
3
Similarly, the annual spatial means for
Year 2 and Year 3 are calculated to be
13.13 and 15.7 pg/m3. Find the 3-year
average annual spatial mean.
13.533333 + 13.13 + 15.7 = 14.171111 |jg/m3
3
Round 14.121111 to 14.1 \ig/m3 before
comparing to the standard. This ex-
ample meets the PM2.s annual standard.
Sample Calculation of the 3-Year
Average 98th Percentile for PM2 5
Assume for this example that the data
completeness requirements have been
met. At each site, sort all values col-
lected in a year from lowest to highest.
Number their rankings as in the fol-
lowing table:
Year 1
Rank	Value
(MQ/m3)
—

—
275

57.9
276

59.0
277

62.2
Rank
Year 2
Value
(MQ/m3)
296

54.3
297

57.1
298

63.0
Rank
Year 3
Value
(MQ/m3)
290

66.0
291

68.4
36 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
292	69.8
In this example, the site collected
281 samples out of possible 365
samples in Year 1; 304 out of 365 in Year
2; and 296 out of 365 in Year 3. Calcu-
late the 98th percentile for each year.
0.98 x 281 = 275.38
0.98 x 304 = 297.92
0.98 x 296 = 290.07
Take the integer part of the product and
add 1 to find which ranking corre-
sponds to the 98th percentile.
275 + 1 = 276
297 + 1 = 298
290 + 1 = 291
Find the value which corresponds to
the ranking using the table above.
276 corresponds to 59.0 |jg/m3
298 corresponds to 63.0 |jg/m3
291 corresponds to 68.4 |jg/m3
Find the 3-year average of the 98th per-
centiles.
59.0 + 610 + fifi.4 = 63.466667 [jg/m3
3
Round 63.466667 to 63 |ig/m3 before
comparing to the standard. This ex-
ample meets the PM2,5 24-hour standard.
CHAPTER 2: AIR QUALITY TRENDS 37

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Sulfur Dioxide
Nature and Sources
Sulfur dioxide belongs to the family of
sulfur oxide gases. These gases are
formed when fuel containing sulfur
(mainly coal and oil) is burned, and
during metal smelting and other indus-
trial processes. Most S02 monitoring
stations are located in urban areas. The
highest monitored concentrations of
S02 are recorded in the vicinity of.large:
industrial facilities.
Health and Other Effects
The major health concerns associated
with exposure to high concentrations of
S02 include effects on breathing, respi
ratory illness, alterations in the lungs'
defenses, and aggravation of existing
cardiovascular disease. Major sub
groups of the population that are most
sensitive to S02 include asthmatics and
individuals with cardiovascular dis-
ease or chronic lung disease, as well as
children and the elderly.
Together, S02 and NOx are the ma-
jor precursors to acidic deposition (acid
rain), which is associated with the
acidification of lakes and streams, ac-
celerated corrosion of buildings and
monuments, and reduced visibility
S02 is a major precursor to PM25,
which, as discussed in the previous sec-
tion (beginning on page 34), is of sig-
nificant concern to health as well as a
main pollutant that impairs Visibility.
Primary and Secondary
Standards
There are two primary N AAQS for S02
that address these health concerns: an
annual mean Concentration of 0.030
ppm (80 |ig/m3) not to be exceeded,
and a 24-hour daily concentration of
0.14 ppm (365 fig/m3) not to be ex-
ceeded more than once per year.
The secondary S02 NAAQS is a
3-hour average concentration of 0.50
ppm (1,300 )ig/m3) not to be exceeded
more than once per year.
Trends
The map in Figure 2-36 displays the
highest second maximum 24-hour S02
concentration by county in 1996. Only
• Air Quality Concentrations
1987-96
37% decrease
1995-96
no change
• Emissions

1987-96
14% decrease
1995-96
3% increase
cones ntifltion [ppii^
Figure 2-36. Highest second maximum 24-hour SO2 concentration by county, 1996,
38 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
one county, Linn County, Iowa, con-
taining a major S02 point source, failed
to meet the ambient S02 NAAQS in
1996.
The national composite average of
S02 annual mean concentrations de-
creased 37 percent between 1987 and
1996 (see Figure 2-37), while S02 emis-
sions decreased 12 percent (see Figure
2-38). Between 1995 and 1996, there
was no change in the national compos-
ite average of S02 annual mean concen-
trations, while S02 emissions increased
3 percent.
Historically, networks are posi-
tioned in population-oriented locales.
As seen in Figure 2-39, eighty-eight
percent of total national S02 emissions,
however, result from fuel combustion
sources that tend to be located in less
populated areas. Thus, it is important
to emphasize that current S02 prob-
lems in the United States are caused by
point sources that are usually identi-
fied by modeling rather than routine
ambient monitoring. Figure 2-40 re-
veals that composite annual mean con-
centrations at sites in suburban and
urban locations decreased 38 and 41
percent, respectively, while ambient
levels decreased 29 percent at rural
sites.
The progress in reducing ambient
S02 concentrations during the past 20
years is shown in Figure 2-41. This re-
duction was accomplished by install-
ing flue-gas control equipment at
coal-fired generating plants, reducing
emissions from industrial processing
facilities such as smelters and sulfuric
acid manufacturing plants, reducing
the average sulfur content of fuels
burned, and using cleaner fuels in resi-
dential and commercial burners.
Established by EPA under Title IV of
the CAA, the Acid Rain Program's
principal goal is to achieve significant
reductions in S02 and NOx emissions.
Concentration, ppm
0.04
0.03
0.02
0.01
0.00
Figure 2-37. Trend in annual mean S02 concentrations, 1987-1996.
Thousand Short Tons Per Year
30,000
~	Fuel Combustion | Industrial Processing
~	Transportation ~ Miscellaneous
25,000
20,000
15,000
10,000
5,000
87 88 89 90 91 92 93 94 95 96
Figure 2-38. National total S02 emissions trend, 1987-1996.
479 Sites
	NAAQS.

87 88 89 90 91 92 93 94 95 96
CHAPTER 2: AIR QUALITY TRENDS 39

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Fuel Combustion
Miscellaneous 0%
Transportation 3.5%
Industrial Processes 8.5%
Figure 2-39. SO2 emissions by source category, 1996.
Concentration, ppm
0.012
0.01
0.008
0.006
0.004
0.002
Rural (138 sites) Suburban (191 sites) Urban (139 sites)
Phase I of EPA's Acid Rain Program
reduced S02 emissions at participating
utilities from 10.9 million tons in 1980
to 5.3 million tons in 1995. This level
was 39 percent below 8.7 million tons,
the allowable emissions level for 1995
required by the CAAA. In 1996, S02
emissions at the participating utilities
rose to 5.4 million tons, an increase of
approximately 100,000 tons from 1995.
This is still 35 percent below the 1996
allowable level of 8.3 million tons. Re-
view of the largest emission increases
between 1995 and 1996 reveals that in-
creased utilization seems to be at least
a contributing factor, if not the sole fac-
tor, for most of the increases. At several
units, for example, the rise occurred
due to increased utilization coupled
with the use of higher sulfur coal in
response to the market providing this
coal (and allowances) less expensively.
Another case reflects a utilization in-
crease coupled with scrubber difficul-
ties, resulting in lower removal
efficiencies than in 1995. A final case
where a substantial increase in emis-
sions occurred is due solely to a utiliza-
tion increase; the unit underwent an
extended outage in 1995, but operated
throughout 1996.15 For more informa-
tion, visit the Acid Rain Program Home
Page at http:/7www.epa.gov/acidrain.
87 88 89 90 91 92 93 94 95 96
Figure 2-40. S02 annual mean concentration trend by location, 1987-1996.
40 CHAPTER 2: AIR QUALITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Concentration, ppm
0.014
0.012
0.01
0.008
0.006
0.004
0.002
0
Figure 2-41. Long-term ambient SO2 trend, 1977-1996.
1977-86 1987-96
(278 sites) (479 sites)
77 79 81 83 85 87 89 91 93 95
CHAPTER 2: AIR QUALITY TRENDS 41

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
References
1.	Oxygenated Gasoline Implementation
Guidelines, EPA, Office of Mobile
Sources, Washington, DC, July 27,
1992.
2.	Guidelines for Oxygenated Gasoline
Credit Programs and Guidelines on Es-
tablishment of Control Periods Under
Section 211 (m) of the Clean Air Act as
Amended. 57 FR 47853 (October 20,
1992).
3.	Interagency Assessment of Oxygenated
Fuels, National Science and Technol-
ogy Council, Executive Office of the
President, Washington, DC, June
1997.
4.	G. Whitten, J. Cohen, and A. Kuklin,
Regression Modeling of Oxyfuel Effects
on Ambient CO Concentrations: Final
Report, SYSAPP-96/78, prepared for
the Renewable Fuels Association and
Oxygenated Fuels Association by
System Applications International,
Inc., San Rafael, CA, January 1997.
5.	Cook, J.R., P. Enns, and M.S. Sklar,
Regression Analysis of Ambient CO
Data from Oxy fuel and Nonoxyfuel Ar-
eas, Paper No. 97-RP139.02, Air and
Waste Management Association 90th
Annual Meeting, Toronto, Ontario,
June 1997.
6.	National Ambient Air Quality Stan-
dards for Ozone: Final Rule. 62 FR
38856, July 18, 1997.
7.	National Weather Service, National
Climate Prediction Center WebPage,
September 1996 Report.
8.	Rethinking the Ozone Problem in Urban
and Regional Air Pollution, National
Research Council, National Acade-
my Press, Washington, DC, Decem-
ber 1991.
9.	National Air Quality and Emissions
Trends Report, 1993, EPA-454/R-94-
026, U.S. Environmental Protection
Agency, Office of Air Quality Plan-
ning and Standards, Research Trian-
gle Park, NC, October 1994.
10.	W.M. Cox and S.H. Chu, "Meteoro-
logically Adjusted Ozone Trends in
Urban Areas: A Probabilistic Ap-
proach," Atmospheric Environment,
Vol. 27B, No. 4, Pergamon Press,
Great Britain, 1993.
11.	Volatility Regulations for Gasoline and
Alcohol Blends Sold in Calendar Years
1989 and Beyond, 54 FR 11868, March
22, 1989.
12.	Reformulated Gasoline: A Major Step
Toward Cleaner Air. EPA-420-B-94-
004, U.S. Environmental Protection
Agency, Office of Air and Radiation,
Washington, DC, September 1994.
13.	Requirements for Reformulated Gaso-
line. 59 FR 7716, February 16, 1994.
14.	National Ambient Air Quality Stan-
dards for Particula te Ma tter: Final Rule,
July 18, 1997.
15.1996 Compliance Report Acid Rain Pro-
gram, EPA-430-R-97-025, U.S. Envi-
ronmental Protection Agency, Office
of Air and Radiation, Acid Rain Pro-
gram Information 401 M Street, SW,
Mail Code 6204J, Washington, DC
20460, June 1997.
42 CHAPTER 2: AIR QUALITY TRENDS

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Chapter 3
Visibility Trends
Introduction
The CAA requires EPA to protect vis-
ibility, or visual air quality, through
a number of programs. These pro-
grams include the national visibility
program under sections 169a and 169b
of the Act, the Prevention of Significant
Deterioration program for the review
of potential impacts from new and
modified sources, and the secondary
NAAQS for PMi0 and PM2.5. The na-
tional visibility program established in
1980 requires the protection of visibil-
ity in 156 mandatory Federal Class I
areas across the country (primarily na-
tional parks and wilderness areas). The
CAA established as a national visibility
goal, "the prevention of any future,
and the remedying of any existing,
impairment of visibility in mandatory
Federal Class I areas in which impair-
ment results from manmade air pollu-
tion." The Act also calls for state
programs to make" reasonable progress"
toward the national goal.
In 1987, the IMPROVE visibility
monitoring network was established as
a cooperative effort between EPA, Na-
tional Park Service, U.S. Forest Service,
Bureau of Land Management, U.S. Fish
& Wildlife Service, and state govern-
ments. The objectives of the network
are to establish current conditions, to
track progress toward the national vis-
ibility goal by documenting long-term
trends, and to provide information for
determining the types of pollutants
and sources primarily responsible for
visibility impairment. Chemical analy-
sis of aerosol measurements provides
ambient concentrations and associated
light extinction for PM10, PM2.5, sul-
fates, nitrates, organic and elemental
carbon, soil dust, and a number of
other elements. The IMPROVE pro-
gram has established protocols for
aerosol, optical, and photographic
monitoring methods, and these meth-
ods are employed at more than 70
Class I sites. The analyses presented in
this chapter are based on data from the
IMPROVE network which can be found
on the Internet at ftp://alta_vista.cira.
colostate.edu/IMPROVE.
This chapter evaluates data col-
lected from 1988-1995 at 30 Class I ar-
eas in the IMPROVE network. To
assess progress in preventing future
impairment and remedying existing
impairment, the chapter in some cases
presents trends of the average "best,"
"worst," and "average" 20 percent of
the data under consideration (i.e.,
"best" is the average of the 20 percent
lowest values, also referred to as the
10th percentile. Likewise, the terms,
"worst" and "average" refer to an av-
erage of the upper 20 percent range—
80 percent to 100 percent, and middle
20 percent range 40-60 percent, re-
corded annually). Figure 3-1 provides
a visual illustration that contrasts vi-
sual air quality from the average best
and worst conditions at Acadia, Great
Smoky Mountains, and Grand Canyon
national parks.1
Nature and Sources of the
Problem
Visibility impairment occurs as a result
of the scattering and absorption of light
by particles and gases in the atmo-
sphere. It is most simply described as
the haze that obscures the clarity, color,
texture, and form of what we see. The
same particles linked to serious health
and environmental effects (sulfates,
nitrates, organic carbon, elemental car-
bon—commonly called soot—and soil
dust) can also significantly affect our
ability to see.
Both primary releases and second-
ary formation of particles contribute to
visibility impairment. Primary par-
ticles, such as dust from roads and ag-
ricultural operations or elemental
carbon from diesel and wood combus-
tion, are emitted directly into the atmo-
sphere. Secondary particles formed in
the atmosphere from primary gaseous
emissions include sulfate formed from
sulfur dioxide emissions, nitrates from
nitrogen oxide emissions, and organic
carbon particles formed from hydrocar-
bon emissions. In the eastern United
States, reduced visibility is mainly at-
tributable to secondarily formed par-
ticles, particularly those less than a few
micrometers in diameter. While sec-
ondarily formed particles still domi-
nate in the West, primary emissions
CHAPTER 3: VISIBILITY TRENDS
43

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
from sources such as woodsmoke con-
tribute a larger percentage of the total
particulate load than in the East, The
only primary gaseous pollutant that di-
rectly reduces visibility is nitrogen di-
oxide.
In general, visibility conditions in
rural Class I areas vary regionally
across the United States. Rural areas in
the East generally have higher levels of
impairment than most remote sites in
the West. Higher eastern levels are
generally due to higher concentrations
of anthropogenic pollution, higher es-
timated background levels of fine par-
ticles, and higher average relative:
humidity levels. Humidity can signifi-
cantly increase the effect of pollution
on visibility. Some particles, such as
sulfates, accumulate water and grow in
size, becoming more efficient at scatter-
ing light. Annual average relative hu-
midity levels are 70-80 percent in the
East as compared to 50-60 percent in
the West. Poor summer visibility in the
eastern United States, is primarily the
result of high sulfate concentrations
combined with high humidity levels.
Visibility conditions are commonly
expressed in terms of three mathemati-
cally related metrics: visual range, light
extinction, and deciviews. Visual range
is the maximum distance at which one
can identify a black object against the
horizon, and is typically described in
miles or kilometers. Light extinction,
inversely related to visual range, is the
sum of light scattering and light ab-
sorption by particles and gases in the
atmosphere. It is typically .expressed in
terms of inverse megameters (Mm4),
with larger values representing poorer
visibility. The IMPROVE network
measures two parameters, light extinc-
tion using transmissometers, and light
scattering using nephelometers. From
these two parameters other parameters
Acadia National Park
Visual Range = 16 miles	Visual Range = 71 miles
Great Smoky Mountains National Park
Visual Range = 13 miles	Visual Range = 51 miles
Grand Canyon National Park
Visual Range = 60 miles	Visual Range = 124 miles
Figure 3-1. Range of best and worst conditions at Acadia, Great Smoky Mountains, and
Grand Canyon national parks, 1992-1995.
44 CHAPTER 3: VISIBILITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Figure 3-2. Long-term trend for 75th percentile light extinction coefficient from airport
visual data (July-September).
such as visual range or deciviews may
be calculated.
Equal changes in visual range and
light extinction are not proportional to
human perception, however. For exr
ample, a 5-mile change in visual range
can be either very apparent or not per-
ceptible, depending on the base line
level of ambient pollution (see Figure
3-1). The deciview metric provides a
linear scale for perceived visual
changes over the entire range of condi-
tions, from clear to hazy, analogous to
the decibel scale for sound. Under
many scenic conditions, a change Of
one deciview is considered perceptible
by the average person. A deciview of
zero represents pristine conditions.
Long-Term Trends
Visibility impairment has been ana-
lyzed using visual range data collected
since 1960 at 280 monitoring stations
located at airports across the country.
Trends in visibility impairment can be
inferred from these long-term records
of visual range. Figure 3-2 describes
long-term U.S. visibility impairment
trends derived from such data.2 The
maps show the amount of haze during
the summer months of 1970, 1980, and
1990. The dark blue color represents
the best visibility, and red represents
the worst visibility. Overall, these
maps show that summer visibility im-
pairment in the eastern United States
increased greatly between 1970 and
1980, and decreased slightly between
1980 and 1990. These trends follow
overall trends in emissions of sulfur
oxides during these periods.
Recent Trends in Rural
Areas: 1988-1995
Aerosol and light extinction data have
been collected for eight consecutive
years (1988-1995) at 30 sites in thelM
PROVE network (see Figure 3-3). Of
CHAPTER 3: VISIBILITY TRENDS
45

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Mt. Rainier
lGlacier NP
Crater Lake NP.
rstonefJF
Badlands (W)
Lassen A/olcanic NP
/	• Rocky Mounts ins NPV
9 Canyon lands NP	v.
¦Bryce canyon NP
—'Mesa Verce NP
	* 'rrffat Sand Dunes (W
Weminuche (m)	
Petrififed • Bandilier (W]
Foresft NP	J
Yosemite NP
inacles (W4
GraiWcanyon NP
ireat smoky Mtns NP
Guadalupe Mtns. (NP)
Legend
NP= National Park
W = Wilderness
NS= Nat'l Seashore
NM = Nat'l Monument
Figure 3-3. IMPROVE visibility monitoring network 30 sites with data for the period 1988-present.
these 30 sites, Washington, DC is the
only urban location. The remaining 29
represent rural Class I areas: three are
located in the East (Acadia National
Park, Maine; Shenandoah National
Park, Virginia; and Great Smoky
Mountains National Park, Tennessee),
and 26 are located in the West. Because
of the significant regional variations in
visibility conditions, this section does
not look at aggregate national trends,
but groups existing sites into eastern
and western regions. As noted earlier,
the values representing the "best" and
"worst" days are presented in addition
to median values. For the purposes of
this report, these terms correspond to
the 10th, 50th and 90th percentiles.
Regional Trends
Figures 3-4a and 3-4b illustrate eastern
and western trends for total light ex-
tinction. These figures indicate that, in
general, aerosol light extinction for the
best days (10th percentile) and median
days (50th percentile) showed down-
ward trends over the eight-year period
for both eastern and western regions,
indicating overall improvement in vis-
ibility. Reductions of light extinction
between 1988 and 1995 for the best and
median days ranged from 9-20 percent
in the east and 10-30 percent in the
West. The East showed a degradation
of visibility with a 6-percent increase in
light extinction for the worst days (90th
percentile), whereas western sites, on
the other hand, showed general im-
provement.
Figures 3-5 and 3-6 show eastern
and western trends in light extinction
due to sulfate and light extinction due
to organic carbon. Light extinction due
to organic carbon dropped significantly
between 1988 and 1995 for the 10th,
50th, and 90th percentile values in both
the eastern (24-47 percent) and western
regions (30-52 percent). Sulfate light
extinction, on the other hand, was
much more variable in both regions.
Seasonal averages for light extinction
due to sulfate over the 1988-1995 time
period generally increased in the sum-
mer. In the East, light extinction due to
sulfate in 1995 shows a 21-percent in-
crease from 1988 levels for the worst
visibility days, but median sulfate ex-
tinction shows a 7-percent improve-
ment for the same period, with lowest
46
CHAPTER 3: VISIBILITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
levels occurring in 1994 and 1995. In
the West, it appears that sulfate extinc-
tion increased between 6-9 percent be-
tween 1988 and 1995 for the median
and worst visibility days, although
gradual improvements are seen after
levels peaked in 1992. Note that the
vertical scales for Figures 3-3 to 3-6
have been altered to better view trends,
since light extinction due to sulfate is
much greater in the East.
Figures 3-7a and 3-7b show the rela-
tive contribution to median (50th per-
centile) eastern and western aerosol
light extinction, respectively, for the
five principal constituents measured at
IMPROVE sites. These graphs illus-
trate that sulfate, organic carbon, and
elemental carbon are the largest con-
tributors to aerosol light extinction,
with sulfate playing a larger role in the
East and West. Nationally, light extinc-
tion from sulfate, nitrate, and soil dust
appear to have remained fairly con-
stant over the eight-year period, while
organic carbon and elemental carbon
appear to be declining.
Class I Area Trends. IMPROVE
data from 30 Class I area monitoring
sites in place from 1988-1995 were ana-
lyzed using a nonparametric regression
methodology described in Chapter 7,
Metropolitan Area Trends. Trends are
reported in Table A-12 according to
their significance, upward or down-
ward, or as not significant.
Table 3-1 summarizes the trends
analysis performed on these 30 sites for
total light extinction (expressed in
deciviews), light extinction due to sul-
fate, and light extinction due to organic
carbon. Because of the importance of
tracking progress in the entire distribu-
tion of visibility conditions, trends in
the 10th, 50th, and 90th percentile val-
ues were analyzed. No sites were
found to have statistically significant
upward trends for any of the param-
250
E
200" ~
o
c
X
HI
-a-
88
89
90
91
92
93
94
95
Year
90th %-Q— 50th %-Q— 10th %
Figure 3-4a. Total light extinction trends for eastern Class I areas.
_ 250"
! 200— - -- -- -- --
| 150— - -- -- -- --
0
c
1	100- - -- -- -- --
i, "t	 "—I—¦"	1	3*—-—¦ 	a	 _
~ 505	~	~	~	~	~	~	n
~	~	~	~	~	~	~ H
0-1	1	1	1	1	1	1	1
88	89	90	91	92	93	94	95
Year
¦ 90th %
50th °b—Q— 10th %
Figure 3-4b. Total light extinction trends for western Class I areas.
eters evaluated. Several sites, however,
did have positive slopes for various pa-
rameters, indicating some degree of an
upward trend.
On an annual average basis, about
one-third have significant downward
trends in deciviews. Only one site had
a downward trend for sulfate, whereas
close to 20 of the 30 sites have a down-
ward trend for organic carbon.
Fewer sites were found to have sig-
nificant trends in hazy day conditions
than for the cleanest days. Only five
sites showed significant downward
trends in deciviews for the haziest
days, whereas one-third to two-thirds
of the sites showed significant trends
for the cleanest days. Many more sites
had significant downward trends in
organic carbon light extinction than for
sulfate light extinction.
Although the nonparametric analy-
sis described above does not reveal any
sites with significant upward trends in
visibility impairment, a review of an-
nual data plotted for each site shows
several sites that should be monitored
closely for gradual upward trends for
either the best, median, or worst days.
Table 3-2 lists those sites which may be
of potential concern.
CHAPTER 3: VISIBILITY TRENDS
47

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Current Conditions
On an annual average basis, natural
visibility conditions have been esti-
mated at approximately 80-90 miles in
the East and up to 140 miles in the
West.3 Natural visibility varies by re-
gion primarily because of higher esti-
mated background levels of PM2i5
particles in the East, and the more sig-
nificant effect of relative humidity on
particle concentrations in the East than
in the West. Current annual average
conditions range from about 18-40
miles in the rural East and about 35-90
miles in the rural West.
Figure 3-8 illustrates annual average
visibility impairment in terms of light
extinction captured at IMPROVE sites
between 1992 and 1995. The pie charts
show the relative contribution of differ-
ent particle constituents to visibility
impairment. Annual average total light
extinction due to these particles is indi-
cated by the value next to each pie and
by the size of each pie.4
Figure 3-8 also shows that visibility
impairment is generally greater in the
rural East compared to most of the
West. In the rural East, sulfates account
for about 50-70 percent of annual aver-
age light extinction. Sulfate plays a par-
ticularly significant role in the humid
summer months, most notably in the
Appalachian, northeast, and mid-south
regions. Nitrates and organic and el-
emental carbon all account for between
10-15 percent of total light extinction in
most Eastern locations.
In the rural West, sulfates also play
a significant role, accounting for about
25-40 percent of total light extinction in
most regions. Sulfates, however, ac-
count for over 50 percent of annual
average light extinction in the Cascades
of Oregon. Organic carbon typically is
responsible for 15-35 percent of total
light extinction in the rural West, el-
emental carbon (absorption) accounts
88 89 90 91 92 93 94 95
Year
90th VcT0— 50th	10th %
Figure 3-5a. Light extinction due to sulfate in eastern Class I areas.
¦ 90th % 50th % ~D— 10th%
Figure 3-5b. Light extinction due to sulfate in western Class I areas.
£
O
15*~
|
x
LU
£
100=-

'3 5"~
88
89
90
91
92
93
94
95
Year
~90th YcT0— 50th "/p-"— 10th %
Figure 3-6a. Light extinction due to organic carbon in eastern Class I areas.
£
O
0
c
1
i:
"~=-
CT)
~
88
89
90
91
92
93
94
95
Year
90th	50th "XT"0- 10th %
Figure 3-6b. Light extinction due to organic carbon in western Class I areas.
48
CHAPTER 3: VISIBILITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
o
x
LU
O)
¦	Sulfate
~	Elemental Carbon
~	Organic Carbon
¦	Nitrate
~	Soil
91 92
Year
Figure 3-7a. Average aerosol light extinction in eastern Class I areas.
O 20
¦	Sulfate
C Elemental Carbon
1=1 Organic Carbon
¦	Nitrate
~ Soil
88 89 90 91 92 93 94 95
Year
Figure 3-7b. Average aerosol light extinction in western Class I areas.
for about 15-25 percent, and soil dust
(coarse PM) accounts for about 10-20
percent. Nitrates typically account for
less than 10 percent of total light extinc-
tion in western locations, except in the
southern California region, where it
accounts for almost 40 percent.
Figure 3-9 also illustrates annual
average visibility impairment from
IMPROVE data for 1992-1995, ex-
pressed in deciviews.4 Note that the
deciview scale is more compressed
than the scale for visual range or light
extinction with larger values represent-
ing greater visibility degradation.
Most of the sites in the intermountain
West and Colorado Plateau have an-
nual impairment of 12 deciviews or
less, whereas many rural locations in
the East have values exceeding 23
deciviews.
One key to understanding visibility
effects is understanding that the same
amount of pollution can have dramati-
cally different effects on visibility de-
pending on existing conditions. Most
importantly, visibility in cleaner envi-
ronments is more sensitive to increases
in PM2.5 particle concentrations than
visibility in more polluted areas. This
principle is illustrated in Figure 3-10,
which characterizes visibility at
Shenandoah National Park under a
range of conditions.5 A clear day at
Shenandoah can be represented by a vi-
sual range of 80 miles, with conditions
approximating naturally-occurring vis-
ibility (i.e., without pollution created
by human activities). An average day
at Shenandoah is represented by a vi-
sual range of 18 miles, and is the result
of an additional lOjig/m3 of fine par-
ticles in the atmosphere. The two bot-
tom scenes, with visual ranges of eight
and six miles respectively, illustrate
that the perceived change in visibility
due to an additional lOjig/m3 of fine
particles to an already degraded atmo-
sphere is much less perceptible than
adding this amount to a clean atmo-
sphere. Thus, to achieve a given level
of perceived visibility improvement, a
larger reduction in fine particle concen-
trations is needed in more polluted ar-
eas. Conversely, a small amount of
pollution in a clean area can dramati-
cally decrease visibility.
Programs to Improve
Visibility
In the recent review of the particulate
matter NAAQS, EPA concluded that
the most appropriate way of address-
ing visibility effects associated with PM
was to establish secondary standards
for PM equivalent to the suite of pri-
mary standards in conjunction with
establishment of a new regional haze
program. In July 1997, EPA proposed a
new regional haze program to address
visibility impairment in national parks
and wilderness areas caused by numer-
ous sources located over broad regions.
The proposed program takes into con-
sideration recommendations from the
National Academy of Sciences, the
Grand Canyon Visibility Transport
Commission, and a Federal Advisory
Committee on Ozone, Particulate Mat-
ter, and Regional Haze Implementation
CHAPTER 3: VISIBILITY TRENDS
49

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table 3-1. Summary of Class I Area Trend Analysis
Programs. The: proposal lays out a
framework within which states are to
conduct regional planning and develop
implementation plans which are to
achieve "reasonable progress" toward
the national visibility goal of no
human-caused impairment. Because of
the common precursors and the re-
gional nature of the ozone, PM, and
regional haze problems, EPA is devel-
oping these implementation programs
together to integrate future planning
and control strategy efforts to the great-
est extent possible. Implementation of
the NAAQS in conjunction with a fu-
ture regional haze program is antici-
pated to improve visibility in urban
and rural areas across the country.
Other air quality programs are ex-
pected to lead to emissions reductions
that will improve visibility in certain
regions of the country. The Acid Rain
program is designed to achieve signifi-
cant reductions in sulfur oxide emis-
sions, which is expected to reduce
sulfate haze particularly in the eastern
United States. Additional control pro-
grams on sources of nitrogen oxides to
reduce formation of ozorte can also
improve regional visibility conditions.
In addition, the NAAQS, mobile source,
and woodstove programs to reduce fuel
combustion and soot emissions can ben-
efit areas adversely impacted by visibil-
ity impairment due to sources of
organic and elemental carbon.
PARAMETER	
Deciviews, average days
Deciviews, clean days
Deciviews, hazy days
Extinction due to sulfate, average days
Extinction due to sulfate, clean days
Extinction due to sulfate, hazy days
Extinction due to organic carbon, average days
Extinction due to organic carbon, clean days
Extinction due to organic carbon, hazy days
Sites with	Sites with
Significant	Significant
Downward Trend U pward Trend
8
0
11
0
5
0
1
0
1
0
0
0
26
0
27
0
12
0
Worst Days
(90th Percentile)
Acadia
Badlands
Big Bend
Chiricahua
Crater Lake
Glacier
Great Smoky Mountains
Point Reyes
Shenandoah
Washington
Table 3-2. IMPROVE Sites With Potential Upward Trends
Best Days	Median Days
(10th Percentile)	(50th Percentile)
Weminuche	Crater Lake
Great Smoky Mountains
Mount Rainier
Vteshington, DC
Yosemite
Figure 3-8. Annual average light extinction (Mm-1), 1992-1995 IMPROVE data.
v-
¦ SULFATE
El NiTSAf£ [.J ABSORPTION
jgg WGANtC-S r j COARSE
50
CHAPTER 3: VISIBILITY TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Figure 3-9. Annual average visibility impairment in deciviews relative to pristine conditions
of deciviews = 0, 1992-1995 IMPROVE data.
Clear Day + ID ,ug/m
Visual Range « IS Mltet
Haiy Day + 10 jug/m
Hazy Day
Visual Range - 80 Rilt«$
Clear Day
Figure 3-10. Shenandoah National Park on clear and hazy days, and the effect of adding
10 ^jg/m3 fine particles to each.
CHAPTER 3: VISIBILITY TRENDS
51

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
References
1.	Images were created with WinHaze
Software, John Molenar, Air Resource
Specialists, Inc., Fort Collins, Colo-
rado 80525.
2.	R.B. Husar, J.B. Elkins, W.E. Wilson,
"U.S. Visibility Trends, 1906-1992,"
Air and Waste Management Associa-
tion 87th Annual Meeting and Exhibi-
tion, Cincinnati, OH, 1994.
3.	Irving, Patricia M., e.d., Acid Deposi-
tion: State of Science and Technology,
Volume III, Terrestrial, Materials,
Health, and Visibility Effects, The
U.S. National Acid Precipitation As-
sessment Program, Chapter 24, page
24-76.
4.	Sisler, J. Spatial and Seasonal Patterns
and Long-Term Variability of the Compo-
sition of the Haze in the United States:
An Analysis of Data from the IMPROVE
Network. Colorado State University,
Cooperative Institute for Research in
the Atmosphere. Fort Collins, CO.,
1996.
5.	Cooperative Institute for Research in
the Atmosphere (CIRA), Colorado
State University, Fort Collins, CO.
52
CHAPTER 3: VISIBILITY TRENDS

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Chapter 4
PAMS: Enhanced Ozone
& Precursor Monitoring
Background
Of the six criteria pollutants, ozone is
the most pervasive. The most prevalent
photochemical oxidant and an important
contributor to "smog," ozone is unique
among the criteria pollutants because it
is not emitted directly into the air. In-
stead, it results from complex chemical
reactions in the atmosphere between
VOCs and NOx in the presence of sun-
light. There are thousands of sources of
VOCs and NOx located across the
country. To track and control ozone,
EPA must create an understanding of
not only the pollutant itself, but the
chemicals, reactions, and conditions
that contribute to its formation as well.
Section 182(c)(1) of the CAA called
for improved monitoring of ozone and
its precursors, VOC and NOx, to obtain
more comprehensive and representa-
tive data on ozone air pollution. Re-
sponding to this requirement, EPA
promulgated regulations to initiate the
Photochemical Assessment Monitoring
Stations (PAMS) program in February
1993. The PAMS program requires the
establishment of an enhanced monitor-
ing network in all ozone nonattain-
ment areas classified as serious, severe,
or extreme. The 21 affected ozone areas
listed in Table 4-1 have a total popula-
tion of 78 million. Although only en-
compassing 18 percent of the total
number of original ozone nonattain-
ment areas, PAMS areas account for 79
percent of the total number of non-
attainment area ozone exceedance
days, as seen in Figure 4-1.
Network Requirements
Each PAMS network consists of as
many as five monitoring stations, de-
pending on the area's population.
These stations are carefully located ac-
cording to meteorology, topography,
and relative proximity to emissions
sources of VOC and NOx. Each PAMS
network generally consists of four dif-
ferent monitoring sites (Types 1, 2, 3,
and 4) designed to fulfill unique data
collection objectives.
•	The Type 1 sites are located upwind
of the metropolitan area to measure
ozone and precursors being trans-
ported into the area.
•	The Type 2 sites are referred to as
maximum precursor emissions im-
pact sites. As the name implies, they
are designed to collect data on the
type and magnitude of ozone pre-
cursor emissions emanating from
the metropolitan area. Type 2 sites
are typically located immediately
downwind of the central business
district and operate according to a
more intensive monitoring schedule
than other PAMS stations. Type 2
sites also measure a greater array of
precursors than other PAMS sites
and are suited for the evaluation of
Table 4-1.
PAMS
Metropolitan Areas Requiring
EXTREME
1. Los Angeles-South Coast Air Basin,
CA1
SEVERE
2.	Baltimore, MD
3.	Chicago-Gary-Lake County (IL),
IL-IN-WI2
4.	Houston-Galveston-Brazoria, TX
5.	Milwaukee-Racine, Wl2
6.	New York-New Jersey-Long Island,
NY-NJ-CT
7.	Philadelphia-Wilmington-Trenton,
PA-NJ-DE-MD
8.	Sacramento, CA
9.	SE Desert Modified AQMA, CA1
10.	Ventura County, CA
SERIOUS
11.	Atlanta, GA
12.	Baton Rouge, LA
13.	Boston-Lawrence-Worchester, MA-NH
14.	Greater Connecticut, CT
15.	El Paso, TX
16.	Portsmouth-Dover-Rochester, NH-E
17.	Providence-Pawtucket-Fall River, l-MA
18.	San Diego, CA
19.	San Joaquin Valley, CA
20.	Springfield, MA
21.	Washington, DC-MD-VA
1.	Los Angeles-South Coast and SE Desert
Modified AQMA are combined into one
PAMS area referred to as South Coast /
SEDAB.
2.	Chicago and Milwaukee are combined
into one PAMS area referred to as Lake
Michigan.
CHAPTER 4: PAMS: ENHANCED OZONE & PRECURSOR MONITORING 53

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
urban air toxics. For larger non-
attainment areas, a second Type 2
site is required in the second-most
predominant wind direction.
•	The Type 3 stations are intended to
measure maximum ozone concen-
trations and are sited farther down-
wind of the urban area than the
Type 2 sites.
•	The Type 4 PAMS sites are located
downwind of the nonattainment
area to assess ozone and precursor
levels exiting the area and potential-
ly contributing to the ozone prob-
lem in other areas.
In addition to the surface monitor-
ing sites described above, each PAMS
area also is required to monitor upper
air meteorology at one representative
site. Regulations allow a 5-year transi-
tion or phase-in schedule for the pro-
gram at a rate of at least one station per
area per year. The first official year of
implementation for PAMS was 1994.
As of September 1997, there were 75
operating PAMS sites.
Monitoring Requirements
The data collected at the PAMS sites
include measurements of ozone, NOx,
a target list of VOCs (including several
carbonyls, see Table 4-2), plus surface
and upper air meteorology. Most
PAMS sites measure 56 target hydro-
carbons on an hourly or 3-hour basis
during the PAMS monitoring season.
The Type 2 sites also collect data on
three carbonyl compounds (formalde-
hyde, acetaldehyde, and acetone). In-
cluded in the monitored VOC species
are 10 compounds classified as hazard-
ous air pollutants (HAPs). The PAMS
program is the only federally man-
dated initiative that requires routine
monitoring of HAPs; for more informa-
tion on HAPs see Chapter 5, "Air Tox-
ics." All PAMS stations measure ozone,
Number Of Ozone
Nonattainment Areas
Number Of Exceedance Days in
Ozone Nonattainment Areas, 1996
~ PAMS~ Other NA Areas
Figure 4-1. PAMS percent of total number of ozone nonattainment areas and 1996
ozone exceedance days (total number of original classified and section 185a ozone
nonattainment areas = 118; total number of 1996 exceedance days in original
nonattainment areas = 361.)
Table 4-2. PAMS Target List of VOCs
Hydrocarbons
Ethylene
2,3-Dimethylbutane
3-Methylheptane
Acetylene
2-Methylpentane
n-Octane
Ethane
3-Methylpentane
*Ethylbenzene
Propylene
2-Methyl-1 -Pentene
*m&p-Xylenes
Propane
*n-Hexane
*Styrene
Iso butane
Methylcyclopentane
*o-Xylene
1-Butene
2,4-Dimethylpentane
n-Nonane
n-Butane
*Benzene
Isopropylbenzene
t-2-Butene
Cyclohexane
n-Propylbenzene
c-2-Butene
2-Methylhexane
m-Ethyltoluene
Isopentane
2,3-Dimethylpentane
p-Ethyltoluene
1-Pentene
3-Methylhexane
1,3,5-Trimethylbenzene
n-Pentane
*2,2,4-Trimethylpentane
o-Ethyltoluene
Isoprene
n-Heptane
1,2,4-Trimethylbenzene
t-2-Pentene
Methylcyclohexane
n-Decane
c-2-Pentene
2,3,4-Trimethylpentane
1,2,3-Trimethylbenzene
2,2-Dimethylbutane
"Toluene
m-Diethylbenzene
Cyclopentane
2-Methylheptane
p-Diethylbenzene


n-Undecane
Carbonyls
'Formaldehyde
Acetone
'Acetaldehyde

'Hazardous Air Pollutants

54 CHAPTER 4: PAMS: ENHANCED OZONE & PRECURSOR MONITORING

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
NOx, and surface meteorological pa-
rameters on an hourly basis. In general,
the PAMS monitoring season spans the
three summer months when weather
conditions are most conducive for
ozone formation. EPA allows states flex-
ibility in network design and sampling
plans in recognition of the fact that each
PAMS area has its own unique charac-
teristics and demands.
Program Objectives
EPA believes that data gathered by
PAMS will greatly enhance the ability
of state and local air pollution control
agencies to effectively evaluate ozone
nonattainment conditions and identify
cost-effective control strategies. The
Agency also anticipates that the mea-
surements will be of substantial value
in verifying ozone precursor emissions
inventories and in corroborating esti-
mates of area-wide emissions reduc-
tions. The data will be used by states to
evaluate, adjust, and provide input to
the photochemical grid models used to
develop ozone control strategies, as
well as demonstrate their success.
PAMS will provide information to
evaluate population risk exposure, ex-
pand the data base available to confirm
attainment/nonattainment decisions,
and develop ozone and ozone precur-
sor trends.
EPA is extremely committed to the
analysis and interpretation of PAMS
data. Federal grant funds are allocated
annually to state, local, and consoli-
dated environmental agencies for data
characterization and analysis. Exten-
sive in-house PAMS analyses are also
being performed at EPA. There are a
number of tools and techniques avail-
able for PAMS analysis; EPA continues
to develope and refine these tools as
well as coordinate workshops and train-
ing. A new PAMS web site (http://
www.epa.gov/oar/oaqps/pams) has
been introduced to help disseminate
PAMS analysis-related information as
well as general program material.
VOC Characterization
As previously mentioned, each PAMS
area has its own unique characteristics.
Although the mix of VOC emission
point sources affecting PAMS areas
vary significantly by area, there are
some mobile and area VOC emission
sources that are common to all. These
sources produce similarities in the
overall composition of VOC in the am-
bient area. Table 4-3 shows 1996 com-
posite rankings for 45 reporting sites of
6-9 am mean concentrations (in parts
per billion Carbon [ppbC]) of the PAMS
VOC target list. Morning hours are
generally considered an appropriate
indicator for VOC emissions since
emission source activity is high and
photochemical reactivity and mixing
heights are still low. On average, the
top 10 compounds at each site ac-
counted for about 65 percent of the to-
tal targeted ppbC.
Though all the PAMS-targeted
VOCs (as well as additional reactive
sources of carbon) contribute to the for-
mation of ozone, each VOC reacts at a
different rate and with different reac-
tion mechanisms. Ozone yield for a
VOC depends significantly on the con-
ditions within the polluted atmosphere
in which it reacts, such as VOC to NOx
ratio, VOC composition, and sunlight
intensity. Although faster reacting
VOCs may produce more ozone in a
shorter time period than do slower re-
acting ones (under similar conditions),
the ozone yields may be more compa-
rable when viewed over a longer time
span. How this affects a particular lo-
cality would depend on weather pat-
terns and the possibility of stagnant air
masses developing. Since 1977, EPA's
reactivity policy has been to define as
VOCs subject to air pollution regula-
tion all organic compounds which par-
ticipate in atmospheric photochemical
reactions, except certain compounds
that EPA has defined as having negli-
gible reactivity. These negligibly reac-
tive compounds are not considered to
be VOC for regulatory purposes. Two
PAMS target compounds, ethane and
acetone, are in this group. With the
exception of the negligibly reactive
compounds, all VOCs are required to
be controlled equally. An alternative
approach to ozone forming potential
was developed by Dr. William Carter of
the University of California. In 1994,
Carter published a set of "ozone form-
ing potential" factors known as the
Maximum Incremental Reactivity
(MIR) scale.1 Carter's MIR factors
were derived by adjusting the NOx
concentration in the base case scenario
to yield the highest incremental reactiv-
ity for each evaluated VOC; the factors
also were based on ozone yields pro-
duced per single day of sunlight expo-
sure. Carter's MIR technique was
adapted by the State of California in
setting automotive emissions stan-
dards. Applying Carter's MIR factors
to the means used in Table 4-3 changes
the relative ranking and conditional
importance of the PAMS target list.
The overall top 10 reactivity-weighted
compounds (using Carter's MIR fac-
tors) at operating PAMS sites in 1996
were: formaldehyde; ethylene; m&p-
xylenes; propylene; toluene; isopentane;
acetaldehyde; 1,2,4-trimethylbenzene o-
xylene; and isoprene. These 10 com-
pounds accounted for approximately
70 percent of the total PAMS targeted
ozone-forming potential.
Trends
Between 1995 and 1996, the number of
ozone NAAQS exceedance days in
PAMS areas declined 26 percent; be-
CHAPTER 4: PAMS: ENHANCED OZONE & PRECURSOR MONITORING 55

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table 4-3. PAMS Targeted VOCs Ranked by Mean 6-9 am
Concentration, Summer 1996

AIRS

# of Sites
Parameter
Code
Rank
Reporting
Propane
43204
1
49
Isopentane
43221
2
51
Ethane
43202
3
49
Toluene
45202
4
53
n-Butane
43212
5
53
n-Pentane
43220
6
53
Ethylene
43203
7
49
Formaldehyde
43502
8
22
Acetone
43551
9
21
m&p-Xylenes
45109
10
53
Benzene
45201
11
53
2-Methylpentane
43285
12
53
Acetylene
43206
13
49
Isobutane
43214
14
52
2,2,4-Trimethylpentane
43250
15
53
Isoprene
43243
16
53
n-Hexane
43231
17
53
Propylene
43205
18
49
3-Methylpentane
43230
19
53
Acetaldehyde
43503
20
22
1,2,4-Trimethylbenzene
45208
21
53
o-Xylene
45204
22
53
3-Methylhexane
43249
23
53
Ethylbenzene
45203
24
53
Methylcyclopentane
43262
25
53
1,2,3-Trimethylbenzene
45225
26
44
2,3-Dimethylbutane
43284
27
53
2-Methylhexane
43263
28
53
n-Heptane
43232
29
53
2,3-Dimethylpentanane
43291
30
53
n-Undecane
43954
31
51
n-Decane
43238
32
51
m-Ethyltoluene
45212
33
46
2,3,4-Trimethylpentane
43252
34
53
Methylcyclohexane
43261
35
53
1-Butene
43280
36
50
p-Ethyltoluene
45213
37
46
Cyclopentane
43242
38
51
n-Octane
43233
39
53
2,4-Dimethylpentane
43247
40
53
1-Pentene
43224
41
53
Styrene
45220
42
53
2,2-Dimethylbutane
43244
43
53
1,3,5-Trimethylbenzene
45207
44
53
Cyclohexane
43248
45
53
n-Nonane
43235
46
53
o-Ethyltoluene
45211
47
46
t-2-Pentene
43226
48
50
3-Methylheptane
43253
49
53
n-Propylbenzene
45209
50
53
2-Methylheptane
43960
51
53
2-Methyl-1-Pentene
43246
52
52
p-Diethylbenzene
45219
53
44
t-2-Butene
43216
54
50
m-Diethylbenzene
45218
55
44
c-2-Butene
43217
56
50
c-2-Pentene
43227
57
50
tween 1994 and 1996 the number
dropped by 21 percent. Table 4-4
shows the counts by individual area.
Average summer daily ozone maxima
declined 8 percent between 1995 and
1996 and 3 percent between 1994 and
1996. A summary of the 2-year and 3-
year changes for ozone, selected VOCs,
and NOx is shown in Table 4-5. Meteo-
rologically adjusted ozone trends have
been steadily declining across the
United States in the past 10 years as
seen in Figure 2-21 of Chapter 2.2 Me-
teorological-adjusted ozone concentra-
tions appear to be declining faster in
the PAMS areas than elsewhere, espe-
cially in the last two years. Of the 41
MSAs evaluated with the referenced
EPA adjustment technique ("Cox-
Chu"), 18 of the MSAs correspond
fairly well to PAMS areas. In Figure
4-3, data for those 18 areas are con-
trasted with the 23 non-PAMS areas.
Meteorologically adjusted ozone con-
centrations are, most likely, declining
as a result of VOC emissions controls.
For the second consecutive year,
many PAMS sites showed significant
reductions in total VOC and "key"
ozone precursors. (Although a certain
amount of caution should be exercised
in using relative VOC reactivity
rankings, this section does focus some-
what on the top 10 reactivity-weighted
compounds mentioned in the previous
section as computed using Carter's
MIR technique. Space limitations of
this report prohibit inclusion of a more
comprehensive summary.) Ambient
levels of total VOC declined by around
15 percent between 1995 and 1996 (16
percent for "All Reported Hours" and
14 percent for "6:00-9:00 am"). This
change corroborates well with emis-
sions inventory data. Aggregate VOC
emissions inventory estimates for the
21 PAMS nonattainment areas showed
a drop of 12 percent between 1995 and
56 CHAPTER 4: PAMS: ENHANCED OZONE & PRECURSOR MONITORING

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table 4-4. Number of Ozone NAAQS Exceedance Days, by PAMS Area
Area
1994
1995
1996
Los Angeles-South Coast Air Basin, CA
118
98
85
Baltimore, MD
10
13
4
Baton Rouge, LA
4
11
4
Chicago-Gary-Lake County (IL), IL-IN-WI
2
4
5
Houston-Galveston-Brazoria, TX
24
48
26
Milwaukee-Racine, Wl
3
5
2
New York-New Jersey-Long Island, NY-NJ-CT
11
16
9
Philadelphia-Wilmington-Trenton, PA-NJ-DE-MD
8
11
5
San Diego, CA
9
12
2
SE Desert Modified AQMA, CA
81
43
45
Ventura County, CA
17
23
17
Atlanta, GA
3
13
7
Boston-Lawrence-Worchester, MA-NH
3
5
2
Greater Connecticut, CT
5
10
2
El Paso, TX
6
4
2
Portsmouth-Dover-Rochester, NH-ME
1
3
0
Providence-Pawtucket-Fall River, RI-MA
1
4
0
Sacramento, CA
6
11
11
San Joaquin Valley, CA
43
42
56
Springfield, MA
3
2
0
Washington, DC-MD-VA
4
6
1
Total RAMS Areas
362
384
285
Total All Ozone Nonattainment Areas1
439
557
361
1Original classified, unclassified, and section 185a ozone nonattainment areas.

1996. Of the 11 evaluated VOCs, only
m&p-xylenes had a median site per-
cent change increase between 1995 and
1996 ("All Reported Hours" and "6:00-
9:00 am"); the median percent changes
showed declines for all other param-
eters. Benzene, another VOC though
not a major ozone precursor, is also
highlighted in Table 4-5 as a follow-on
to last year's analysis which showed a
significant 1994-1995 reduction in ben-
zene and other mobile-related VOC
concentrations as a possible result of
federally mandated RFC. Federally
mandated RFC was implemented in
most PAMS areas at the beginning of
1995. The 1995-1996 reductions in ben-
zene and other mobile-related VOC
concentrations were not quite as large
as those seen from 1994 to 1995. Aver-
age benzene concentrations declined
by a median 38 percent in 1995—the
first year of the RFC program—as com-
pared to an 8-percent reduction in 1996.
This smaller reduction in 1996 was not
only expected since RFC was in place
in both 1995 and 1996, but it supports
the supposition that RFC contributed
to the significant emission reductions
between 1994-1995. The Office of Mo-
bile Sources (OMS) is currently spon-
soring an analysis of PAMS data to help
verify the contribution of RFC to the
large emissions reductions in 1995. For
more information on benzene, see
Chapter 5.
Between 1994 and 1996, the number
of sites with significant declines out-
number the sites showing increases for
all 11 highlighted VOCs. Like ozone,
annual variations in VOC concentra-
tions can result from changes in meteo-
rological conditions. Nationwide, the
summer of 1996 was cooler than the
summer of 1994 and wetter than the
summer of 1995, especially in some of
the regions where many PAMS sites are
located (e.g., Northeast and the South).3
Hot and dry conditions are more con-
ducive for photochemistry and thus,
secondary production of VOCs, than
are cool and wet conditions. Ambient
concentrations of isoprene, a VOC of
predominantly biogenic origin, are par-
ticularly sensitive to meteorological
factors. Some of the VOC reductions
seen between 1994 and 1996 and be-
tween 1995 and 1996 may, therefore, be
explained by differing meteorological
conditions. However, the large reduc-
tions seen since 1994 are too large to be
credible without some human inter-
vention (i.e., anthropogenic emissions
reductions). The NOx concentration
changes were fairly mixed over the
three years evaluated. Between 1995
and 1996, reporting PAMS sites showed
a median increase of 3 percent in daily
concentrations and a 1-percent increase
in 6-9 am levels. Between 1994 and
1996, NOx concentrations declined 6
percent.
NO Versus VOC
X
Although the highlighted VOCs (mi-
nus benzene) shown in Table 4-5 have
the highest (MIR method) ozone-form-
ing potential overall at reporting PAMS
sites, a blanket reduction in these com-
pounds may not necessarily reduce
ozone levels. Sometimes NOx reduc-
tions as opposed to VOC reductions
will contribute more to reducing ozone
concentrations. Ozone concentrations
are sensitive to shifts in the relative
abundance of VOC and NOx. In addi-
tion to local factors of influence (area
emissions of VOCs and NOx, and me-
teorological conditions), ozone concen-
trations can be significantly impacted
CHAPTER 4: PAMS: ENHANCED OZONE & PRECURSOR MONITORING 57

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
PAMS Areas (18 MSAs)
Adjusted
Actua
Adjusted
Non-PAMS Areas (23 MSAs)
Actual
Actual (18 MSAs, PAMS Areas) Adjusted (18 MSAs, PAMS Areas)
Actual (23 MSAs, Not PAMS) Adjusted (23 MSAs, Not PAMS)
87
88 89 90 91
92 93 94 95
96
Figure 4-2. Comparison of actual and meteorologically adjusted ozone trends—PAMS
metropolitan areas versus non-PAMS areas, 1987-1996 (composite average of 99th
percentile 1-hr. daily max. conc.)
by incoming transported ozone and
ozone precursors. This is especially
true in the northeastern United States
where nonattainment areas lie in close
proximity to each other. The PAMS
networks are designed with the ability
of quantifying the incoming and outgo-
ing transport (i.e., Type 1 and Type 4
sites). The Ozone Transport Assessment
Group (OTAG) identified areas that
"contribute significantly" to ozone
problems in downwind areas. On Oc-
tober 10, 1997 EPA proposed a rule to
significantly reduce the transport of
NOx and ozone. For an expanded dis-
cussion of the proposed rule, see the
Ozone section of Chapter 2.
Summary
The PAMS networks produce a myriad
of information invaluable to the devel-
opment and evaluation of ozone con-
trol strategies and programs. A few
examples include: VOC to NOx ratios
helpful for deciding what type of con-
trols to seek; upper air and surface me-
teorological data capable of identifying
transport trajectories; inter-species (ben-
zene/toluene, xylene/toluene) compo-
nents sufficient to quantify airmass
aging; inputs to statistical models (re-
gression and neural network analysis)
capable of forecasting high ozone con-
centrations and identifying vital VOC
species; and continuous speciated de-
tail useful for corroborating inventories
0.20
0.18
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0.00
and validating photochemical models
(for detailed discussion of these topics,
see the Data Analysis Support section
of the PAMS web site). Further, the
networks will provide long-term per-
spectives on changes in atmospheric
concentrations of ozone and its precur-
sors, provide information to evaluate
population exposure, and most impor-
tantly, deliver a more complete under-
standing of the complex problem of
ozone so that we can continue to de-
velop strategies to reduce ozone con-
centrations and thereby protect public
health and welfare.
References
1 W.P.L Carter (1994), Development of
Ozone Reactivity Scales for Volatile Or-
ganic Compounds, J. Air & Waste Man-
age. Assoc. 44:881-899.
2.	W.M. Cox and S.H. Chu, "Meteoro-
logically Adjusted Ozone Trends in
Urban Areas: A Probabilistic Ap-
proach," Atmospheric Environment,
Vol. 27B, No. 4, Pergamon Press,
Great Britain, 1993.
3.	D.T. Bailey, "Summer 1997 in Perspec-
tive," http://www.epa.gov/oar/
oaqps/pams/summer97.pdf, 1997.
58 CHAPTER 4: PAMS: ENHANCED OZONE & PRECURSOR MONITORING

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table 4-5. Summary of Changes in Summer Mean Concentrations for Ozone, NOx,
and Selected VOCs, 1995-1996 and 1994-1996

2-Year Change, 1995 to 1996





All Reported Hours

6:00 to 9:00 am


# of Sites

Median
# of Sites
Median
Parameter

Total
#Up #Down Change
Total
#Up #Down Change
Ozone (44201)—Avg. Daily
Max.
66
3
30
-8%
—
—
— —
Oxides of Nitrogen (42603)

51
24
18
3%
51
18
17 1%
Total NMOC (43102)

32
9
16
-16%
32
6
14 -14%
Ethylene (43203)

39
13
12
-4%
39
11
10 -2%
Propylene (43205)

39
10
16
-1%
39
10
13 -2%
Isopentane (43221)

36
9
10
-1%
36
8
5 -3%
Isoprene (43243)

39
8
22
-22%
39
4
15 -15%
Formaldehyde (43502)

18
1
13
-28%
18
2
10 -26%
Acetaldehyde (43503)

18
4
10
-10%
18
3
9 -16%
M&P-Xylenes (45109)

38
15
8
9%
38
12
6 2%
Toluene (45202)

39
12
12
0%
39
8
7 -4%
O-Xylene (45204)

39
12
17
-8%
39
10
13 -3%
1,2,4-Trimethylbenzene (45208)
38
10
22
-31%
38
8
17 -23%
Benzene (45201)

39
11
15
-8%
39
8
*
lo
o

3-Year Change, 1994 to 1996





All Reported Hours

6:00 to 9:00 am


# of Sites

Median
# of Sites
Median
Parameter

Total
#Up #Down
Change
Total
#Up #Down Change
Ozone (44201)—Avg. Daily
Max.
54
9
19
-3%
—
—
— —
Oxides of Nitrogen (42603)

34
12
19
-6%
33
8
13 -6%
Total NMOC (43102)

16
3
11
-28%
15
0
9 -29%
Ethylene (43203)

19
2
13
-26%
16
1
11 -26%
Propylene (43205)

18
2
10
-21%
15
2
-v]
00
*
Isopentane (43221)

19
1
11
-21%
16
1
10 -28%
Isoprene (43243)

17
4
10
-16%
14
2
8 -28%
Formaldehyde (43502)

7
1
5
-26%
6
0
5 -29%
Acetaldehyde (43503)

7
1
6
-35%
6
1
5 -40%
M&P-Xylenes (45109)

18
2
12
-18%
16
0
11 -34%
Toluene (45202)

19
1
14
-26%
16
0
11 -31 %
O-Xylene (45204)

19
2
14
-29%
16
0
13 -34%
1,2,4-Trimethylbenzene (45208)
16
2
10
-35%
14
2
9 -38%
Benzene (45201)

19
2
17
-42%
16
0
13 -44%
1.	Note that the terms "#Up" and "#Down"
refer to the number of sites in which the
change in summer mean concentrations be-
tween 1994 and 1995, or 1994 and 1996, is a
statistically significant increase or decrease
(as determined by a t-test with a significance
level of .05). The total number of sites ("To-
tal") may not necessarily equal the sum of
the corresponding "#Up" and "#Down" cat-
egories.
2.	Data qualifications
a)	Because states are permitted, with EPA
consent, to customize their network
sampling plans, the "all hours reported"
means may not encompass all hours of
the day or may encompass different
hours from year to year and, therefore,
may not be comparable. Annual ap-
proved network sampling plans are
posted on the PAMS web site. Changes
in sampling equipment and/or meth-
ods may also contribute to differences in
yearly means. Data shown in the "Me-
dian Change" column are the medians
of the individual site percent changes in
summer means for all reporting ("To-
tal") sites. [Summer means were com-
puted for every sites that reported both
years. The year-to-year percent change
in these summer means were arrayed by
magnitude. The middle value is the
"Median Change."]
b)	Although data submitted to EPA's Aer-
ometric Information and Retrieval Sys-
tem (AIRS) follow quality assurance
procedures, EPA recognizes the com-
plexity of the VOC monitoring and anal-
ysis systems and realizes that errors
may exist in the database. In general,
VOC data quality has been improving
over the lifetime of PAMS data.
c)	Measurements of carbonyl compounds
(formaldehyde and acetaldehyde) have
recently come under enhanced scrutiny
at EPA. Development of a carbonyl field
audit program is being planned for
PAMS in order to help determine the
overall quality of carbonyl measure-
ments made for the program. Current-
ly, the National Performance Audit Pro-
gram (NPAP) does an excellent job in
determining the analytical accuracy but
an assessment of the field sampling
component is also needed.
CHAPTER 4: PAMS: ENHANCED OZONE & PRECURSOR MONITORING 59

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
60 CHAPTER 4: PAMS: ENHANCED OZONE & PRECURSOR MONITORING

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Chapter 5
Air Toxics
Background
Hazardous air pollutants (HAPs), com-
monly referred to as air toxics or toxic
air pollutants, are pollutants that cause,
or may cause, adverse health effects or
ecosystem damage. The CAA lists 188
pollutants or chemical groups as haz-
ardous air pollutants in section 112
(b)(1) and targets sources emitting
them for regulation.1 Examples of air
toxics include heavy metals like mer-
cury and chromium; organic chemicals
like benzene, 1,3-butadiene, perchloroet-
hylene (PERC), dioxins, and poly cyclic
organic matter (POM); and pesticides
such as chlordane and toxaphene.
HAPs are emitted from literally
thousands of sources including station-
ary (large industrial facilities such as
utilities and smaller, area sources like
neighborhood dry cleaners) as well as
mobile sources (automobiles). Adverse
effects to human health and the envi-
ronment due to HAPs can result from
exposure to air toxics from individual
facilities, exposure to mixtures of pol-
lutants found in urban settings, or ex-
posure to pollutants emitted from
distant sources that are transported
through the atmosphere over regional,
national or even global air sheds. Ex-
posures to HAPs can be either short-
term or long-term in nature. In some
cases, effects can be seen immediately,
such as those rare instances in which
there is a catastrophic release of a lethal
pollutant, or when a respiratory irritant
is regularly released in sufficient levels
to cause immediate effects. In other
cases, the resulting effects may be expe-
rienced from long-term exposure (e.g.,
from mercury), over a period of several
months or years.
In addition to breathing air contami-
nated with air toxics, people can also be
exposed to some HAPs through other,
less direct pathways such as through
the ingestion of food from contami-
nated waters. Some air toxics bio-accu-
mulate in body tissues, resulting in
predators building up large concentra-
tions from consuming contaminated
prey, thereby magnifying up the food
chain (i.e., each level accumulates the
toxics and passes the burden along to
the next level of the food web.) Pres-
ently, over 2,100 U.S. water bodies are
currently under fish consumption advi-
sories, representing approximately 15
percent of the nation's total lake acre-
age, and 5 percent of the nation's river
miles. In addition, the Great Lakes and
a large portion of the U.S. coastal areas
are also under fish consumption advi-
sories. Mercury, polychlorinated bi-
phenyls (PCBs), chlordane, dioxins,
and dichlorodiphenyltrichloroethane
(DDT) and its degradation products:
dichlorodiphenyldichloroethylene
(DDE) and dichlorodiphenyldichloro-
ethane (DDD), were responsible for al-
most 95 percent of all fish consumption
advisories in effect in 1996.2
Health and Ecological Effects
Compared to information for the crite-
ria pollutants previously described in
other chapters, the information con-
cerning potential health effects of the
HAPs (and their ambient concentra-
tions) is relatively incomplete. Most of
the information on potential health ef-
fects of these pollutants is derived from
experimental animal data. Enough
evidence exists, however, to conclude
that air toxics may pose a risk of harm-
ful effects to public health and the en-
vironment. Potential health effects
resulting from exposure to HAPs in-
clude leukemia and other cancers; re-
productive and developmental effects
such as impaired development in new-
borns and young children, inability to
complete a pregnancy and decreased
fertility; and damage to the pulmonary
system. Of the 188 HAPs referenced
previously, almost 60 percent are clas-
sified by EPA as known, probable or
possible carcinogens. Nearly 30 percent
of the HAPs have some evidence of re-
productive or developmental effects
(mostly in experimental animal data);
about 13 percent are suspected endo-
crine disruptors; and approximately 60
percent may effect the central nervous
system (CNS) and/or create other ad-
verse effects such as irritation of the
lungs. The extent to which these effects
actually occur in the population de-
pends on a number of factors, includ-
CHAPTER 5: AIR TOXICS
61

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
ing the level and duration of the expo-
sure to the pollutant(s).
Toxic air pollutants can have a num-
ber of environmental impacts in addi-
tion to the threats they pose to human
health. Animals, like humans, may ex-
perience health problems if they
breathe sufficient concentrations of
HAPs over time. Little quantitative in-
formation currently exists, however,
describing the nature and scope of the
effects of air toxics on non-human spe-
cies. One of the more documented eco-
logical concerns associated with toxic
air pollutants is the potential for some
to damage aquatic ecosystems. In
some cases, deposited air pollutants
can be significant contributors to over-
all pollutant loadings entering water
bodies. For the Great Lakes, interna-
tional workshops have examined the
importance of deposition of air toxics,
relative to other loadings. While data
are presently insufficient for quantita-
tive estimates comparing air deposition
and other loading pathways (especially
for persistent chemicals which con-
tinue to move among air, water, and
sediments), deposition of air toxics to
the Great Lakes is considered poten-
tially significant and continues to be
investigated under a binational moni-
toring network.3 A number of studies
suggest that deposited air toxics con-
tribute to deleterious effects such as
birth defects, reproductive failures,
developmental disorders, disease, and
premature death in fish and wildlife
species native to the Great Lakes. Per-
sistent air toxics are of particular con-
cern in these aquatic ecosystems, as
levels bio-accumulate in animals at the
top of the food chain resulting in expo-
sure many times higher than that indi-
cated from the water or air.
Mobile 41.5%
Area 34.6%
Point 23.9%
Total National Emissions: 3.7 million tons/year
Figure 5-1. Total national HAP emissions by source type, 1993.
State Classification
] High (> 90,000) I I Medium (45-90,000) I I Low (< 45, 000)
Figure 5-2. HAP emissions by state, 1993 (tons/year).
62
CHAPTER 5: AIR TOXICS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table 5-1. Top 20 Sources of 1993 Toxic Emissions of Hazardous Air Pollutants
Rank Source Category Emissions(tpy)
Major HAPs
by mass/category
1.
Mobile Sources: On-Road Vehicles
1,389,111
Acetaldehyde, Benzene,
1,3-Butadiene, Formaldehyde,
Toluene, Xylenes
2.
Consumer & Commercial Product Solvent Use
414,096
Methanol, Methyl chloroform, Toluene,
Xylenes
3.
Open burning: Forests and Wildfires
207,663
Acetaldehyde, Acrolein, Benzene,
1,3-Butadiene, Formaldehyde,
Toluene, Xylenes4
4.
Glycol Dehydrators (Oil and Gas Production)
206,065
Benzene, Toluene, Xylenes
5.
Mobile Sources: Non-Road Vehicles & Equip.
145,866
Acetaldehyde, Benzene,
1,3-Butadiene, Formaldehyde
6.
Open Burning: Prescribed Burnings
134,149
Acetaldehyde, Acrolein, Benzene,
Formaldehyde4
7.
Residential Boilers: Wood/Wood Residue
98,646
Acetaldehyde, Benzene, POM
Combustion5
8.
Dry Cleaning: Perchloroethylene
95,700
Perchloroethylene
9.
Organic Chemical Manufacturing
91,419
Benzene, Ethylene glycol, Hydrogen
chloride, Methanol, Methyl chloride,
Toluene
10.
Pulp and Paper Production
88,579
Acetaldehyde, Benzene, Carbon
tetrachloride, Formaldehyde,
Hydrochloric acid, Methanol,
Methylene chloride
11.
Halogenate Solvent Cleaning (Degreasing)
61,374
Methyl chloroform, Methylene
chloride, Perchloroethylene, Trichlo-
roethylene
12.
Primary Nonferrous Metals Production
37,980
Chlorine, Hydrogen chloride, Metals
13.
Cellulosic Man-Made Fibers
37,605
Carbon disulfide, Hydrogen chloride
14.
Petroleum Refining (All Processes)
27,115
Benzene, Hydrochloric acid, Toluene,
Xylenes
15.
Municipal Waste Combustion
24,777
Formaldehyde, Hydrogen chloride,
Manganese, Mercury, Lead
16.
Motor \fehicles (Surface Coating)
23,081
Methyl chloroform, Toluene, Xylenes
17.
Gasoline Distribution Stage II
21,512
Benzene, Glycol ethers, Naphthalene,
Toluene
18.
Utility Boilers: Coal Combustion
21,404
Hydrogen fluoride, Manganese,
Methylene chloride, Selenium6
19.
Plastics Materials and Resins Manufacturing
20,830
Methanol, Methylene chloride,
Styrene, Vinyl acetate
20.
Flexible Polyurethane Foam Production
19,550
Methylene chloride
Emissions Data
There are approximately 3.7 million
tons of air toxics released to the air each
year according to OAQPS' NTI. Air
toxics are emitted from all types of
manmade sources, including large in-
dustrial sources, small stationary
sources, and mobile sources. As shown
in Figure 5-1, the NTI estimates of the
area source (sources of HAPs emitting
less than 10 tons per year of an indi-
vidual HAP or 25 tons per year of ag-
gregate emissions of HAPs each) and
mobile source contributions to the na-
tional emissions of HAPs are approxi-
mately 35 and 41 percent respectively.
As part of the characterization of
sources of HAPs nationwide, a listing
of the sources emitting the greatest
quantities of HAPs is presented in
Table 5-1 for the 1993 inventory. These
sources do not necessarily represent
those which pose greatest risk. HAP
emissions are not equivalent to risks
posed by exposure to these compounds
because some of the HAPs are more
toxic than others, and actual exposures
will vary by site-specific conditions
such as stack height, topography, wind
speed and direction, and receptor loca-
tion. The data in Table 5-1, however, do
provide an indication of the variety of
sources and HAPs which are emitted
from such sources in relatively large
quantities.
Table 5-1 also shows the major con-
tributing HAPs for each of the top 20
source categories. The 20 sources listed
in Table 5-1 accounted for 87 percent of
total emissions of the 188 HAPs for the
year 1993. The first two source catego-
ries, on-road motor vehicles (a mobile
source category) and consumer/com-
mercial solvent use (an area source cat-
egory) account for approximately 47
percent of the 188 HAPs emitted annu-
ally. Figure 5-2 is presented to illustrate
the geographic distribution of emis-
sions of HAPs by mass. This figure
shows total emissions of HAPs for each
state and does not necessarily imply
relative health risk by exposure to
HAPs by state. The categorization of
pollutant emissions as high, medium,
and low provides a rough sense of the
distribution of emissions. In addition,
some states may show relatively high
emissions as a result of very large emis-
sions from a few facilities or show rela-
tively large emissions as a result from
many very small point sources.
The NTI, which is currently being
updated, includes emissions informa-
tion for 188 HAPs from 913 point-,
CHAPTER 5: AIR TOXICS
63

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
area-, and mobile-source categories.
TRI data were used as the foundation
of this inventory. The TRI data, how-
ever, are significantly limited in several
key aspects as a tool for comprehen-
sively characterizing the scope of the
air toxics issue. For example, TRI does
not include estimates of air toxics emis-
sions from mobile and area sources.7
The NTI suggests that the TRI data
alone represent less than half of the to-
tal emissions from the point source cat-
egory. Therefore, the NTI has
incorporated other data to create a
more complete inventory.
Data from OAQPS studies, such as
the Mercury Report,8 and 112c(6) and
112 (k) inventory reports, and data col-
lected during development of Maxi-
mum Achievable Control Technology
(MACT) Standards under section
112 (d), supplement the TRI data in the
NTI. In addition, state and local data
such as the California Air Resource
Board's (CARB) Hot Spots Inventory,
Houston Inventory, and the Arizona
HAP Study were incorporated in the
1993 NTI. The use of non-TRI data
from other sources is particularly im-
portant for providing estimates of area-
and mobile-source contributions to to-
tal HAP emissions. Note that develop-
ment of the NTI is continuing and that
additional information concerning
emissions from sources regulated un-
der the MACT program will be added,
as well as additional state and local emis-
sions data submitted as part of Title V
operating permit surveys of the Act.
Ambient Air Quality Data
Presently, there is no national ambient
air quality monitoring network de-
signed to perform routine measure-
ments of air toxics levels. Therefore,
ambient data for individual air toxic
pollutants is limited (both spatially and
temporally) in comparison to the data
Table 5-2. Summary of Changes in Mean Concentration for HAPs Measured as a Part
of the PAMS Program (24-hour measurements), 1994-1996*


1994 to 1995


1995 to 1996

HAP
# Sites
# Up
# Down
# Sites
# Up
# Down
Acetaldehyde
0
n/a
n/a
2
0
0
Benzene
7
0
4
5
1
2
Ethyl benzene
8
0
2
5
0
2
Formaldehyde
0
n/a
n/a
2
0
0
Hexane
5
2
0
4
0
0
Toluene
8
0
5
5
0
1
Styrene
7
0
1
5
1
2
m/p-Xylene
8
0
4
5
0
0
o-Xylene
7
0
1
5
0
1
2,2,4-Trimethylpentane 4
1
1
5
0
3
Note that the terms "#Up" and "IDown" refer to the number of sites in which the change in
annual mean concentration between 1994 and 1995, or 1995 and 1996, is a statistically signifi-
cantly increase or decrease. The total number of sites (# sites) may not necessarily equal the
sum of the corresponding "#Up" and "IDown" categories.
Table 5-3. Comparison of Loading Estimates for the Great Lakes
Chemical
Year
Superior
Michigan
Huron
Erie
Ontario


(kg/yr)
(kg/yr)
(kg/yr)
(kg/yr)
(kg/yr)
PCBs (wet/dry)
1988
550
400
400
180
140

1992
160
110
110
53
42

1994
85
69
180
37
64
DDT (wet/dry)
1988
90
64
65
33
26

1992
34
25
25
12
10

1994
17
32
37
46
16
B(a)P
1988
69
180
180
81
62

1992
120
84
84
39
31

1994
200
250
na
240
120
Pb (wet/dry)
1988
230,000
540,000
400,000
230,000
220,000

1992
67,000
26,000
10,000
97,000
48,000

1994
51,000
72,000
100,000
65,000
45,000
available from the long-term, nation-
wide monitoring for the six criteria
pollutants. EPA has several efforts un-
derway which, although less optimal
than a comprehensive and routine
HAPs network, will provide some in-
formation useful to assessing the toxics
issue.
The Agency's PAMS collect data on
concentrations of ozone and its precur-
sors in 21 areas across the nation clas-
sified as serious, severe or extreme
nonattainment areas for ozone. Be-
cause several ozone precursors are also
air toxics, ambient data collected from
PAMS sites can be used for limited
evaluations of toxics problems in se-
lected urban areas as well as assess-
ment of the tropospheric ozone
formation. Despite some limitations,
the PAMS sites will provide consistent,
long-term measurements of selected
toxics in major metropolitan areas. The
PAMS program requires routine mea-
surement of 10 HAPs: acetaldehyde,
benzene, ethyl benzene, formaldehyde,
64 CHAPTER 5: AIR TOXICS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
hexane, styrene, toluene, m/p-xylene,
o-xylene and 2,2,4-trimethlypentane.
Preliminary analysis of measure-
ments of selected HAPs in PAMS areas
indicate that concentrations of certain
toxic VOCs in those areas appear to be
declining. Table 5-2 shows 2-year com-
parisons for 24-hour measurements for
nine air toxics measured at PAMS sites
for the periods 1994-1995 and 1995
1996.9 The only pollutant with more
sites significantly increasing (at the
5-percent level) than those significantly
decreasing (at the 5-percent level) for
either time period, is hexane between
1994 and 1995. For a more detailed dis-
cussion of the PAMS program, see
Chapter 4 of this report.
In addition to the PAMS program,
EPA continues to administer and sup-
port voluntary programs through
which states may collect ambient air
quality measurements for suites of tox-
ics. These programs include the Urban
Air Toxics Monitoring Program
(UATMP), as well as the Non-Methane
Organic Compound (NMOC) and Speci-
ated Non-Methane Organic Compound
(SNMOC) monitoring programs. The
UATMP is the "participatory" program
dedicated to toxics monitoring which
involves measurements of 37 VOCs
and 13 carbonyl compounds.10 In the
current programs, five states are par-
ticipating and operating 15 ambient
measurement sites for toxics.11
Further, the Integrated Atmospheric
Deposition Network (IADN), a joint
U.S./Canada measurement program,
was initiated in 1990 to assess the rela-
tive importance of atmospheric deposi-
tion to the Great Lakes, and to provide
information about sources of these pol-
lutants.12 The network consists of mas-
ter (research-grade) stations on each
lake, with additional satellite stations.
There are two master stations in
Canada and three in the United States
that were chosen to be representative of
regional deposition patterns. In addi-
tion to precipitation rates, temperature,
relative humidity, wind speed and di-
rection, and solar radiation collected at
each site, concentrations of target
chemicals are measured in rain and
snow (wet deposition), airborne par-
ticles (dry deposition), and airborne
organic vapors.13
The results of a comparison of depo-
sition estimates from studies per-
formed in 1988, 1992, and 1994 are
presented in Table 5-3. Since the earlier
estimates were based on sparse and
uncertain data, these results are diffi-
cult to interpret definitively. The most
consistent trend, however, is the reduc-
tion in 1994 lead deposition versus
1988 values for all the lakes, which is
not surprising given the ban of leaded
gas in the United States. Estimates of
wet and dry deposition of PCBs to the
lakes for 1994 show a decline com-
pared to past estimates.14 In addition,
measurements of ambient air quality
levels of PCBs at surface sites near Lake
Superior appear to have remained con-
stant over time compared to ambient
levels near Lakes Erie and Michigan
which have indeed declined. These
downward trends in ambient air qual-
ity concentrations support estimations
of an atmospheric half-life for PCBs of
approximately six years which corre-
sponds well to PCB half-lives seen in
other environmental media.15 The
loading of one of the most toxic poly-
nuclear aromatic hydrocarbons (PAH)
yet characterized, benzo(a)pyrene
(B(a)P), to the lakes seems to have in-
creased; however, this is probably due to
an underestimation of B(a)P in the 1992
studies.16 Finally, the 1994 results show
that DDT wet and dry deposition de-
clined between 1988 and 1992, but rose
slightly for all lakes except Superior in
1994.17
Concurrent with these monitoring
efforts, EPA has recently initiated a pro-
gram to identify, compile and cata-
logue all previously collected
monitoring data for air toxics which is
not now centrally archived. This effort
is focusing presently on the compila-
tion of measurements previously made
by state and local agencies. These data
will contribute to the development of
an expanded and enhanced informa-
tion infrastructure for air toxics.18 All
data completed as a result of this effort
will be made universally accessible to
all interested programs and analysts.
In addition, the Agency is also spon-
soring a related project to develop en-
vironmental indicators based on air
quality monitoring data, emissions
data, modeling data, and administra-
tive/ programmatic data that can effec-
tively demonstrate the extent and
severity of the air toxics problem, and
any progress made toward solving it in
future years through regulatory or vol-
untary programs. Indicators will be
included that consider population ex-
posure and health risk, as well as am-
bient concentrations and emissions.
Such indicators will be used to make
geographic comparisons and assess
temporal trends in subsequent trends
reports.19
Air Toxics Control
Program
The Regulatory Response
In 1990, Congress amended section 112
of the CAAby adding a new approach
to the regulation of HAPs. This new
approach first requires the develop-
ment of technology-based emissions
standards for the major sources of the
188 HAPs under section 112(d). The
overall approach is to use available
control technologies or changes in
work practice to get emission reduc-
tions for as many of the listed HAPs as
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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Sep-93 Oct-93 Feb-94 Jul-94 Nov-94 Feb-95 May-95 Jul-95 Nov-95 May-96 Jul-96 Sep-97
Date MACT Standard Promulgated
possible, regardless of the HAP's inher-
ent toxicity and potential risk. This
technology-based standards program
is commonly referred to as the MACT
program. Although there is no health
test in this phase, it is intended that ef-
fective MACT standards will reduce a
majority of the HAP emissions and po-
tential risks. Under Section 112(d)(6), the
MACT standards are subject to periodic
review and potential revision.
In addition, the CAAA calls for an
evaluation of the health and environ-
mental risks remaining after tech-
nology-based standards have been set
(i.e., residual risks) and requires more
stringent regulation if certain risk crite-
ria are not met. Specifically, its focus is
to achieve a level of protection that pro-
vides the public health with an " ample
margin of safety" while also ensuring
that residual emissions do not result in
"adverse environmental effects."
Under the Urban Area Source Pro-
gram, EPA is identifying at least 30
HAPs that are of particular concern
when emitted in urban areas, espe-
cially from area sources. EPA currently
is developing a plan to reduce emis-
sions of such chemicals by regulating
sources that account for 90 percent of
the emissions and to reduce cancer in-
cidence by 75 percent.
The CAAA also require EPA to con-
duct specific studies to evaluate other
potential human health and ecological
problems and to determine if regula-
tion is necessary. The Agency is cur-
rently conducting studies of the
atmospheric deposition to the Great
Lakes and coastal waters,20 the electric
utility industry, and mercury. Updates
for these studies are highlighted at the
end of this chapter. EPA also is re-
quired under section 112(c)(6) of the
CAA to identify sources of seven spe-
cific pollutants and to regulate sources
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accounting for 90 percent of the emis-
sions of each.21
The air toxics program and the
NAAQS program complement each
other. Many air toxics are emitted in
the form of particles or as VOCs which
can be ozone precursors. Control ef-
forts to meet the NAAQS for ozone and
PMio also reduce air toxic emissions.
Furthermore, as air pollution control
strategies for automobiles become
more stringent, air toxic emissions from
vehicles also are reduced. Require-
ments under the air toxics program can
also significantly reduce emissions of
some of the six NAAQS pollutants. For
example, EPA's final air toxics rule for
organic chemical manufacturing is ex-
pected to reduce VOC emissions by
nearly 1 million tons annually.
The CAA recognizes that not all
problems are national problems or
have a single solution. National emis-
sion standards must be promulgated to
decrease the emissions of as many
HAPs as possible from major sources,
but authority is also provided to look at
smaller scale problems such as the ur-
ban environment or the deposition to
water bodies in order to address spe-
cific concerns. The Act also recognizes
the need to focus or rank efforts to meet
specific needs, such as a concern for a
class of toxic and persistent HAPs.
There are mechanisms for increasing
partnerships among EPA, states, and
local programs in order to address
problems specific to these regional and
local environments.
Air Toxics Regulation and
Implementation Status
The CAA greatly expanded the number
of industries affected by national air
toxic emissions controls. Large indus-
trial complexes (major sources) such as
chemical plants, oil refineries, marine
tank vessel loading, aerospace manu-
facturers, steel mills, and a number of
surface coating operations are some of
the industries being controlled for toxic
air pollution. Where warranted,
smaller sources (area sources) of toxic
air pollution such as dry cleaning op-
erations, solvent cleaning, commercial
sterilizers, secondary lead smelters,
and chrome plating also are affected.
EPA estimates that over the next 10
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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
years the air toxics program will reduce
emissions by 1.5 million tons per year.22
The emissions reductions are begin-
ning to be realized for many industries.
As many as 16 major- and eight area-
source categories have begun to take
some action toward complying with
the controls required by the 2- and 4-
year regulations. The extent of this
compliance depends on the require-
ments of the regulations and actions
taken by the industries to meet these
requirements.
Emissions Reductions
Through the MACT
Program
The regulation of air toxics emissions
through the process outlined in section
112 of the CAA, referred to as MACT
regulations, is beginning to achieve sig-
nificant emissions reductions of HAPs
as well as criteria pollutants. As Figure
5-3 shows, as of September 1997 MACT
standards have been promulgated for
48 source categories, representing all
MACT standards in the 2- and 4-year
groups plus one standard in the 7-year
group. Sources are required to comply
with these standards within three years
of the effective date of the regulation,
with some exceptions. Just recently to
comply with section 112 (s), EPA re-
leased a report to Congress describing
the status of the HAP program under
the CAA. EPA estimates that the 2- and
4-year standards will reduce HAP
emissions by approximately 980,000
tons/year when fully implemented.22
Concurrent control of particulate mat-
ter and VOC as ozone precursors by
MACT standards, is estimated to re-
duce approximately 1,810,000 tons per
year in combined emissions, a reduc-
tion that would not have occurred
through other more conventional regu-
latory programs for these specific pol-
lutants.
In addition, EPA has promulgated
regulations on municipal waste com-
bustors and hospital/medical/infec-
tious waste incinerators under section
129 of the CAA which will significantly
reduce emissions of the listed section
129 pollutants from these sources.
These pollutants include particulate
matter, sulfur dioxide, hydrogen chlo-
ride, oxides of nitrogen, carbon monox-
ide, lead, mercury, dioxins and
dibenzofurans. For example, mercury
emissions from municipal waste com-
bustors are estimated to be reduced in
the year 2000 by about 98 percent from
1990 levels. Mercury emissions from
hospital/medical/infectious waste in-
cinerators are estimated to be reduced
by 93-95 percent, from 1995 levels,
when the regulations become fully ef-
fective.
Residual Risk
To determine whether "post-MACT"
risks are acceptable, Congress added a
human health risk and adverse envi-
ronmental effects-based "needs test" in
the second regulatory phase. In this
phase, referred to as "residual risk"
standard setting, EPA is required to
promulgate additional standards for
those source categories that are emit-
ting HAPs at levels that present an un-
acceptable risk to the public or the
environment. Congress directed that
such residual risk standards should
"provide an ample margin of safety to
protect public health." Non-cancer hu-
man health risks and adverse environ-
mental effects will also be considered in
setting residual risk standards. Using
a risk management framework, EPA
will determine whether technology-
based emission standards sufficiently
protect human health.
EPAis required by section 112(f) (l)of
the Act to provide a report to Congress
describing the methodology of ap-
proaches assessing these residual risks,
the public health significance of any re-
maining risks, and technical and eco-
nomic issues associated with
controlling the risks. The report is cur-
rently scheduled for publication in
1999.
Special Studies/Programs
As mentioned previously, the CAA re-
quires EPA to conduct special studies to
assess the magnitude and effects of air
toxics focusing on specific sources, re-
ceptors, and pollutants. Summaries of
the main efforts follow.
The Great Waters Program
Section 112(m) of the CAA requires the
Agency to study and report to Con-
gress every two years on the extent of
atmospheric deposition of HAPs and
other pollutants to the Great Lakes, the
Chesapeake Bay, Lake Champlain, and
coastal waters, and the need for new
regulations to protect these water bod-
ies. The pollutants of concern to this
effort include nitrogen compounds,
mercury, and pesticides in addition to
other persistent, bioaccumulating
HAPs. This program coordinates with
extensive research programs to provide
new understanding of the complicated
issue of atmospheric deposition of air
pollution to water bodies. New scien-
tific findings will be incorporated into
each required biennial report to Con-
gress and appropriate regulatory rec-
ommendations will be made based on
those findings. This statute provides
the authority to introduce new regula-
tions or influence those under develop-
ment in order to prevent adverse effects
from these pollutants to human health
and the environment.
The Mercury Study
The Mercury Study is a comprehensive
study of mercury emissions from an-
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67

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
thropogenic sources in the United
States, an assessment of the public
health and ecological effects of such
emissions, an analysis of technologies
to control mercury emissions, and the
costs of such control. The study is man-
dated by section 112(n)(l)(B) of the
CAA because mercury is, as an ele-
ment, eternally persistent as well as
being bioaccumulative and the cause of
fish consumption advisories in more
than 39 states. A number of observa-
tions can be made regarding trends in
mercury use and emissions. The over-
all use of mercury by industrial and
manufacturing source categories has
significantly declined. Industrial use of
mercury declined by nearly 75 percent
between 1988 and 1995. Much of this
decline can be attributed to the elimi-
nation of mercury as a paint additive
and the phase-out of mercury in house-
hold batteries. Reducing mercury in
manufactured products is important
because emissions of mercury are most
likely to occur when these products are
broken or discarded. Based on trends
in mercury use, EPA predicts that
manufacturing use of mercury will
continue to decline. Chlorine produc-
tion from mercury cell chlor-alkali
plants will continue to account for most
of the use in, and emissions from, the
manufacturing sector. This industry
has pledged, however, to voluntarily
reduce mercury use by 50 percent by
2006. Secondary production of mer-
cury may increase as more recycling fa-
cilities begin operations to recover
mercury from discarded products and
wastes. A significant decrease will oc-
cur in mercury emissions from munici-
pal waste combustors and medical
waste incinerators when the final regu-
lations promulgated by EPA for these
source categories are fully imple-
mented. Emissions from both catego-
ries will decline by at least 90 percent
Table 5-4. List of Potential 112(k) HAPs
CAS	Name
Number
79345 1,1,2,2-Tetrachloroethane
140885 Ethyl acrylate
79005 1,1,2-trichloroethane
106934 Ethylene dibromide
(dibromoethane)
78875 1,2-Dichloropropane (propylene
dichloride)
75218 Ethylene oxide
106990 1,3-Butadiene
107062 Ethylene dichloride
(1,2-dichloroethane)
542756 1,3-Dichloropropene
50000 Formaldehyde
106467 1,4-dichlorobenzene
302012 Hydrazine
75070 Acetaldehyde
Lead compounds
107028 Acrolein
Manganese compounds
79061 Acrylamide
Mercury compounds
107131 Acrylonitrile
74873 Methyl chloride (chloromethane)
Arsenic compounds
CAS	Name
Number
75092 Methylene chloride
(dichloromethane)
71432 Benzene
101688 Methylene diphenyl diisocyanate
(MDI)
Beryllium compounds
Nickel compounds
117817 Bis(2-ethylhexyl)phthalate (DEHP)
Polycyclic organic matter
Cadmium compounds
91225 Quinoline
56235 Carbon tetrachloride
100425 Styrene
67663 Chloroform
127184 Tetrachloroethylene
(perchloroethylene)
Chromium compounds
79016 Trichloroethylene
Coke oven emissions
75014 Vinyl chloride
Dioxins/furans
75354 Vinylidene chloride
(1,1-Dichloroethylene)
Mobile 37.2%
Point 23.1%
Figure 5-4. Emissions of 40 potential section 112(k) HAPs by source type (tons/year)
68
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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Urban 66.6%
Rural 33.4%
Figure 5-5. Emissions of 40 potential section 112(k) HAPs by urban and rural
classification (tons/year).
from 1995 levels; to roughly 6 tons per
year from municipal waste combustors
and 1 ton per year from medical waste
incinerators. In addition, EPA has pro-
posed mercury emission limits for haz-
ardous waste combustors. Based on
1995 estimates, coal-fired utility boilers
are the largest remaining source cat-
egory at 52 tons per year. Future mer-
cury emissions from utility boilers
depend on a number of factors includ-
ing the nation's energy needs, fuel
choices, industry restructuring and
other requirements under the CAA
(e.g., the Acid Rain Program). Arecent
EPA analysis also predicted mercury
emissions will decline at least 11 tons
per year as a result of implementation
of the ambient standards for fine par-
ticulate matter. International efforts to
reduce greenhouse gases will also re-
duce mercury emissions. The Mercury
Study Report to Congress was com-
pleted in December 1997.
The Specific Pollutants Strategy
Section 112(c)(6) of the CAA requires
EPA to identify sources of alkylated
lead compounds, POM, mercury,
hexachlorobenzene, PCBs, 2,3,7,8-tetra-
chlorodibenzo-p-dioxin, and 2,3,7,8-
tetrachlorodibenzofuran, and then to
subject sources accounting for not less
than 90 percent of the aggregate emis-
sions of each pollutant to standards.22
Standards must be developed by EPA
for sources of these HAPs that are not
subject to current standards. In order
to meet the requirements of section
112(c) (6), EPA compiled national inven-
tories of sources and emissions of each
of the seven HAPs.23
The Urban Area Source Program
Sections 112(c)(3) and 112 (k) of the
CAA require EPA to identify categories
and subcategories of area sources of
HAPs in urban areas that pose a threat
to human health. Specifically, EPA
must identify at least 30 HAPs that
present the greatest threat to urban
populations, and assure that sources
accounting for 90 percent or more of
the aggregate emissions of these 30
HAPs are subject to regulation. In ad-
dition, a national strategy must be de-
veloped to reduce cancer incidence
attributable to these pollutants by at
least 75 percent. In order to address the
requirements of sections 112(c)(3) and
112(k), EPA compiled draft air emis-
sions inventories of 40 potential urban
HAPs, as seen in Table 5-4.24
Figures 5-4 and 5-5 present sum-
mary data from the draft urban air
emissions inventory. Figure 5-4 indi-
cates that: area sources account for 40
percent of emissions of the 40 potential
urban HAPs, mobile sources account
for 37 percent, and point (major)
sources account for 23 percent. Figure
5-5 shows that urban emissions of the
40 potential HAPs account for 67 per-
cent, and rural emissions account for 33
percent of the 40 potential HAPs.
It is important to note that emissions
estimates do not necessarily reflect po-
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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
tential health risk from exposure to
these HAPs. Further analyses will be
performed in conjunction with the de-
velopment of the urban air toxics strat-
egy. The development of the inventories
for the potential urban pollutants, how-
ever, is a critical element in the regula-
tory strategy to reduce emissions of
HAPs from area sources in urban geo-
graphic areas.
The Utility Air Toxics Study
As mandated by section 112(n)(l)(A) of
the CAA, the Agency is studying HAP
emissions from fossil fuel-fired (coal,
oil, and gas) electric utilities and the
associated hazards to public health. A
draft utility report identifies 67 HAPs
in the emissions database. The report
predicts that over the next two decades
there will be roughly a 30-percent in-
crease in HAP emissions from coal-fired
utilities and roughly a 50-percent de-
cline in HAP emissions from oil-fired
utilities. These projections are prima-
rily based on anticipated energy de-
mands and changes in fuel usage but
also account for other factors such as
expected controls.
References
1.	This list originally included 189
chemicals. The CAA allows EPA to
modify this list if new scientific infor-
mation becomes available that indi-
cates a change should be made. Using
this authority the Agency modified the
list to remove caprolactam in 1996, re-
ducing the list to 188 pollutants (Haz-
ardous Air Pollutant List; Modification,
61 FR 30816, June 18, 1996).
2.	"Update: Listing of Fish and Wildlife
Advisories," announcing the avail-
ability of the 1996 update for the da-
tabase: Listing of Fish and Wildlife
Advisories (LFWA); U.S. EPA Fact
Sheet, EPA-823-97-007, June 1997.
3.	Hillery, B.R., Hoff, R.M., and Hites,
R.A. 1997. "Atmospheric contami-
nant deposition to the Great Lakes
determined from the Integrated At-
mospheric Deposition Network."
Chapter 15 in Atmospheric Deposition
of Contaminants to the Great Lakes and
Coastal Waters. 1997, Joel E. Baker, Edi-
tor. SETAC Press. (Society of Environ-
mental Toxicology and Chemistry.)
4.	POM is also a constituent of emis-
sions of this source category, although
not a major contributor to emissions
on a mass basis.
5.	One of the HAPs that is emitted from
residential wood combustion is POM,
which is a class of hundreds of com-
pounds of varying toxicity. POM is
defined in the NTI as the sum of 16
PAH compounds to provide a work-
able definition of the more toxic com-
ponents of the class.
6.	Mercury and hydrochloric acid are
also constituents of emissions of this
source category, although not major
contributors to emissions on a mass
basis.
7.	In addition to the absence of emis-
sions estimates for area and mobile
source categories, there are other sig-
nificant limitations in the TRI's por-
trayal of overall HAP emissions.
First, facilities with Standard Indus-
trial Classification (SIC) codes outside
the range of 20 to 39 (the manufactur-
ing SICs) are not required to report.
Therefore, HAP emissions from facil-
ities such as mining operations, elec-
tric utilities, and oil and gas produc-
tion operations are not represented in
the TRI. Further, TRI data are
self-reported by the emitting facili-
ties, and TRI does not require facili-
ties to perform any actual monitoring
or testing to develop their reported
estimates. Consequently, the accura-
cy of the reported data may vary from
facility to facility and from year to
year. Finally, the original TRI list only
required reporting for 173 of the 188
HAPs identified in the CAA.
8.	Mercury Report to Congress, SAB re-
view Draft. Volume II. An Invento-
ry of Anthropogenic Mercury Emis-
sions in the United States. EPA-452/
R-96-001b.
9.	Summaries of the health effects asso-
ciated with the compounds included
in this analysis are provided below:
Acetaldehyde: The primary effects
on humans, reported from short-term
exposure to low to moderate levels of
acetaldehyde, are irritation of eyes,
skin, and respiratory tract. Short-
term exposure effects on animals also
include slowed respiration and ele-
vated blood pressure. Effects on hu-
mans from long-term acetaldehyde
exposure resemble those of alcohol-
ism. Long-term exposures of animals
have resulted in changes in respirato-
ry tract tissues, as well as growth re-
tardation, anemia, and kidney effects.
While no information is available on
acetaldehyde effects on human repro-
duction or development, both such
effects have been observed in animal
tests. Based on evidence of tumors in
animals, EPA has classified acetalde-
hyde as a probable human carcinogen
of relatively low carcinogenic hazard.
Benzene: Reported effects on hu-
mans, from short-term exposure to
low to moderate benzene levels, in-
clude drowsiness, dizziness, head-
ache, and unconsciousness as well as
eye, skin and respiratory tract irrita-
tion. Effects on both humans and
animals from long-term benzene ex-
posure include blood and immune
system disorders. Reproductive ef-
fects have been reported for women
exposed to high benzene levels and
adverse effects on the developing fe-
tus have been observed in animal
tests. Changes in human chromo-
some number and structure have
been reported under certain expo-
sures. EPA has classified benzene as
a known human carcinogen of medi-
um carcinogenic hazard.
Formaldehyde: Reported effects on
humans, from short-term and long-
term exposure to formaldehyde, are
mainly irritation of eyes, nose, throat,
and, at higher levels, the respiratory
tract. Long-term exposures of ani-
mals have also resulted in damage to
respiratory tract tissues. Although
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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
little information is available on de-
velopmental effects to humans, ani-
mal tests do not indicate effects on
fetal development. EPA has classified
formaldehyde as a probable human
carcinogen of medium carcinogenic
hazard based on sufficient animal
and limited human evidence.
Toluene: Effects on the CNS of hu-
mans and animals have been report-
ed, from short-term exposure to low
to moderate levels of toluene, and in-
clude dysfunction, fatigue, sleepiness,
headaches, and nausea. Short-term ex-
posure effects also include cardiovascu-
lar symptoms in humans and depres-
sion of the immune system in animals.
CNS effects are also observed in long-
term exposures of humans and ani-
mals. Additional long-term exposure
effects include irritation of eyes, throat
and respiratory tract in humans and
changes in respiratory tract tissue of
animals. Repeated toluene exposure
has been observed to adversely affect
the developing fetus in humans and
animals. Due to a lack of information
for humans and inadequate animal
evidence, EPA does not consider tol-
uene classifiable as to human carcino-
genicity.
Xylenes: Reported effects on hu-
mans, from short-term exposure to
high levels of xylenes, include irrita-
tion of eyes, nose, and throat, difficul-
ty breathing, impairment of the CNS
and gastrointestinal effects. Similar
effects have been reported in animals
in addition to effects on the kidney.
Human effects from long-term expo-
sure to xylenes are to the CNS, respi-
ratory and cardiovascular systems,
blood, and kidney. Long-term animal
exposures to high levels of xylenes
have shown effects on the liver. Ef-
fects on the developing fetus have
been observed in animal studies. Due
to a lack of information for humans
and inadequate animal evidence, EPA
does not consider xylenes classifiable
as to human carcinogenicity.
Ethyl benzene: Effects reported, from
short-term exposures of humans to
high levels of ethyl benzene, include
dizziness, depression of the CNS, eye,
mucous membrane, nose and respira-
tory tract irritation, and difficulty
breathing. In short-term exposures of
laboratory animals, additional effects
on the liver, kidney and pulmonary
system have also been reported.
Long-term exposures of animals have
demonstrated effects on blood cells,
the liver and kidneys. Effects on fe-
tal development have also been ob-
served in animal exposures. Due to a
lack of information for humans and
inadequate animal evidence, EPA
does not consider ethyl benzene clas-
sifiable as to human carcinogenicity.
Styrene: Exposure to styrene vapors
can cause irritation of eyes, nose,
throat and respiratory tract in hu-
mans. Effects on the CNS of humans
including dizziness, fatigue, sleepi-
ness, headaches, nausea, and effects
on intellectual function and memory
have also been reported from long-
term exposure to styrene. Long-term
exposures of animals have demon-
strated effects on the CNS, liver and
kidney as well as eye and nasal irri-
tation. Although the available infor-
mation for humans is inconclusive,
animal tests do not indicate effects on
reproduction or fetal development.
The carcinogenicity of styrene is cur-
rently under review by EPA. When
absorbed into the human body, sty-
rene is metabolized into styrene ox-
ide, a direct acting mutagen that caus-
es cancer in test animals.
Hexane: Reported effects on humans,
from short-term exposure to high lev-
els of hexane, include irritation of
eyes, mucous membranes, throat and
skin, as well as impairment of the
CNS including dizziness, giddiness,
headaches, and slight nausea. Long-
term human exposure from inhala-
tion is associated with a slowing of
peripheral nerve signal conduction
which causes numbness in the ex-
tremities and muscular weakness, as
well as changes to the retina which
causes blurred vision. Animal expo-
sures to hexane have resulted in dam-
age to nasal, respiratory tract, lung
and peripheral nerve tissues, as well
as effects on the CNS. No informa-
tion is available on hexane effects on
human reproduction or development.
Limited laboratory animal data indi-
cate a potential for testicular damage
in adults, while several animal stud-
ies show no effect on fetal develop-
ment. Due to a lack of information for
humans and inadequate animal evi-
dence, EPA does not consider hexane
classifiable as to human carcinogenic-
ity
2,2,4-Trimethylpentane: Little infor
mation is available on the effects of
2,2,4-trimethylpentane overexposure
in humans. Laboratory animals ex-
posed to high levels for short periods
have developed irritation, fluid
build-up and bleeding in the lungs, as
well as depression of CNS function.
Kidney and liver effects have been
reported from long-term animal ex-
posures. No information is available
on the potential for reproductive or
developmental effects or on the carci-
nogenic potential of 2,2,4-trimethyl-
pentane.
10.Twenty-eight	of the 37 VOCs, and
four of the 13 carbonyls measured as
a part of the UATMP are defined as
HAPs in section 112(b)(1) ofthe CAA.
11.The	following states are presently
participating in the UATMP: Arkan-
sas, Louisiana, New Jersey, Texas, and
Vermont.
12.The	IADN fulfills legislative man-
dates in Canada and the United States
that address the monitoring of air tox-
ics. An international Great Lakes
deposition network is mandated by
Annex 15 of the Great Lakes Water
Quality Agreement between the United
States and Canada. In the United
States, the CAA requires a Great
Lakes deposition network.
13.The	target chemicals include PCBs,
pesticides, PAHs and metals. The
compounds included as "target
chemicals" were selected based on
the following criteria: presence on
List 1 of Annex 1 of the Great Lakes
Water Quality Agreement (substanc-
es believed to be toxic and present in
the Great Lakes): established or per-
ceived water quality problem; pres-
ence on the International Joint Com-
mission's Water Quality Board's list
of criteria pollutants: evidence of
presence in the atmosphere and an
important deposition pathway; and
feasibility of measurement in a rou-
tine monitoring network.
14.Hornbuckle,	K.C., Jeremaison, J.D.,
Sweet, C.W., Eisenreich, S., "Season-
al Variations in Air-Water Exchange
CHAPTER 5: AIR TOXICS
71

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
of Poly chlorinated Biphenyls in Lake
Superior", J. Environ. Sci. Technol.
1994, 28, 1491-1501.
15.Hillery,	B.R., Basu I., Sweet, C.W.,
Hites, R.A., Temporal and Spatial Trends
in a Long-Term Study of Gas-Phase PCB
Concentrations near the Great Lakes,
Environ. Sci. Technol. 1997, 31,
1811-1816.
16.Hoff,	R.M., Strachan, W.M.J., Sweet,
C.W., D.F. Gatz, Harlin, K., Shackle-
ton, M., Cussion, S., Chan, C.H.,
Brice, K.A., Shroeder, W.H., Bidle-
man, T.F., Atmospheric Deposition of
Toxic Chemicals to the Great Lakes: A
Review of Data Through 1994, At-
mos. Environ., 1996, 30, 3505-3527.
17.Hillery,	B.R., Hoff, R.M., Hites, R. At-
mospheric Contaminant Deposition
to the Great Lakes Determined from
the International Atmospheric Depo-
sition Network, In Atmospheric Dep-
osition of Contaminants to the Great
Lakes and Coastal Water, Baker, J.E.,
ed., Society for Environmental Toxi-
cology and Chemistry, 1997.
18.	Interest in participation in this volun-
tary effort and/or requests for further
information about this data catalogu-
ing effort should be directed to James
Hemby, Office of Air Quality Plan-
ning and Standards, Mail Drop 14,
Research Triangle Park, North Caro-
lina 27711; 919-541-5459; and
hemby.james@epamail.epa.gov.
19.The	scheduled completion date for
this project is September 1998; how-
ever, interim products will be re-
leased as completed. Additional in-
formation on this project is also
available through James Hemby.
Please see address and phone num-
ber above.
20.Section 112 (m) is commonly referred
to as the "Great Waters" program.
21.These compounds, known as the sec-
tion 112(c)(6) specific pollutants, are
alkylated lead compounds, polycyclic
organic matter, hexachlorobenzene,
mercury, polychlorinated biphenyls,
2,3,7,8-tetrachlorodibenzofurans, and
2,3,7,8-tetrachlorodibenzo-p-dioxin.
22.Second Report to Congress on the Sta-
tus of the Hazardous Air Pollutant
Program Under the CAA, Draft.
EPA-453/R-96-015. October 1997.
23.The	final inventory report is available
at the following Internet address:
www.epa.gov / ttn / uatw/
112cfac.html.
24.The	draft inventory report is available
at the following Internet address:
www.epa.gov / ttn / uatw/
112kfac.html.
72
CHAPTER 5: AIR TOXICS

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Chapter 6
Nonattainment Areas
THIS CHAPTER PROVIDES general infor-
mation on geographical regions known
as nonattainment areas. When an area
does not meet the air quality standard
for one of the criteria pollutants, it may
be subject to the formal rule-making
process which designates it as non-
attainment. The C AAA further classify
ozone, carbon monoxide, and some
particulate matter nonattainment areas
based on the magnitude of an area's
problem. Nonattainment classifica-
tions may be used to specify what air
pollution reduction measures an area
must adopt, and when the area must
reach attainment. The technical details
underlying these classifications are dis-
cussed in the Code of Federal Regulations,
Part 81 (40 CFR81).
Figure 6-1 shows the location of the
nonattainment areas for each criteria
pollutant. Figure 6-2 identifies the
ozone nonattainment areas by degree
of severity. A summary of nonattain-
O Eagle River
	 O Juneau
Q Anchorage J Fairbanks
North Star
GUAM
Plant
o PM10 (CIRCLE DIAMETER INDICATES RELATIVE
Note: Incomplete data areas and section 185a areas are not shown.	SIZE 0F affected POPULATION)
Designated Nonattainment Areas as of September 1997	° S02
Figure 6-1. Location of nonattainment areas for criteria pollutants.
CHAPTER 6: NONATTAINMENT AREAS
73

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Classifications	¦ Extreme (LA) & Severe ~Serious	I I Moderate ¦Marginal
As of September, 1997
Incomplete data areas and section 185a areas are not shown.
Figure 6-2. Classified ozone nonattainment areas.
ment areas can be found in Table A-13
in Appendix A. This condensed list is
also located on the Internet at http://
www.epa.gov/airs/nonattn.html and is
updated as areas are redesignated. Note
that Section 185a areas (formerly
known as "transitional areas") and in-
complete areas are excluded from the
counts in Table A-13. For information
on these areas see the EPA Green Book
site located at http://www.epa.gov/
oar/oaqps/greenbk.
As of September 1997, there were a
total of 158 nonattainment areas on the
condensed nonattainment list. The ar-
eas on the condensed list are displayed
alphabetically by state. There are ap-
proximately 119 million people living
in areas currently designated as non-
attainment.
Areas redesignated to attainment
between September 1996 and Septem-
ber 1997 are listed below by pollutant.
Ozone
•	Nashville, TN
•	Seattle-Tacoma, WA
•	Monterey Bay, CA
•	Hancock and Waldo Cos, ME
•	Lake Charles, LA
•	Portland-Vancouver, OR-WA
•	Norfolk-VA Beach-Newport News,
VA
•	Salt Lake and Davis Co's, UT
•	Reading, PA
CO
•	Seattle-Tacoma, WA
•	Vancouver, WA
PM10
•	Oglesby, IL
•	Detroit (Wayne Co), MI
SO,
•	Marion Co, IN
•	LaPorte Co, IN
•	Wayne Co, IN
•	Vigo Co, IN
•	Millinocket, ME
Nitrogen dioxide and lead counts
remained the same since September
1996.
74 CHAPTER 6: NONATTAINMENT AREAS

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Chapter 7
Metropolitan Area Trends
WHILE MOST OF this report discusses
air quality trends on a national scale,
there is interest in information about
local air quality. This chapter presents
status and trends in criteria pollutants
for MSAs in the United States. A com-
plete list of MSAs and their boundaries
can be found in the Statistical Abstract of
the United States.1 The status and trends
of metropolitan areas are based on four
tables found in Appendix A (A-14
through A-17). Table A-14 gives the
1996 peak statistics for all MSAs, pro-
viding the status of the most recent
year. Ten-year trends are shown for the
258 MSAs having data that met the
trends criteria explained in Appen-
dix B. Table A-15 lists these MSAs and
reports criteria pollutant trends as " up-
ward" or "downward," or "notsignifi-
cant." These rankings are based on a
statistical test, known as the Theil test,
which is described later in this chapter.
Another way to assess trends in MSAs
is to examine PSI values.2,3 The PSI is
used to combine daily information on
one or more criteria pollutants into an
easily understood format, which can
then be presented to the public in a
timely manner. Tables A-16 and A-17
list the number of days with PSI values
greater than 100 (unhealthful) for the
nation's 94 largest metropolitan areas
(population greater than 500,000).
Table A-16 lists PSI values based on all
pollutants while Table A-17 lists PSI
values based on ozone alone.
All MSAs do not appear in these
tables because of the availability of
data or the size of the MSA. There are
MSAs with no ongoing air pollution
monitoring because these areas do not
have pollution problems. The same is
true for certain combinations of MSAs
and pollutants. There are also MSAs
with so little information that the crite-
ria for trends analysis are not met (see
Appendix B). Finally, there are MSAs
that do not meet size criteria for certain
tables and, therefore, are not included.
Status: 1996
The air quality status for MSAs can be
found in Table A-14 (for related infor-
mation, see Table A ll—peak concen-
trations for all counties with monitors
that reported to the AIRS data base).
Table A-14 lists peak statistics for all
criteria pollutants measured in an
MSA. Since certain areas are not con-
sidered to have a problem with all cri-
teria pollutants, all criteria pollutants
are not measured in all MSAs and,
therefore, are designated as "ND" (no
data) for those pollutants. Examining
Table A-14 shows that 45 areas had
peak concentrations from at least one
criteria pollutant exceeding standard
levels. These areas represent 27 percent
of the U.S. population. Similarly, there
were 10 areas representing 10 percent
of the population that had peak statis-
tics that exceeded two or more stan-
dards. Only one area, (Philadelphia,
PA) representing 2 percent of the U.S.
population, had peak statistics from
three pollutants that exceeded the re-
spective standards. High values for
two pollutants, PMi0 and lead, are due
to one localized industrial source.
There were no areas, however, that vio-
lated four or more standards. In fact,
1996 was the fifth year in a row that
there were no violations of the N02
standards in the United States.
Trends Analysis
Air quality trends for MSAs are exam-
ined in TableA-15. The data in this table
are based on pollutant concentrations
from the subset of ambient monitoring
sites that meet the same trends criteria
explained in Appendix B. Atotal of 258
MSAs had at least one monitoring site
that met these criteria. As stated previ-
ously, not all pollutants are measured
in every MSA.
From 1987 to 1996, statistics based
on the NAAQS were calculated for
each site and pollutant with available
data. Spatial averages were obtained
for each of the 258 MSAs by averaging
these statistics across all sites in an
MSA. This process resulted in one
value per MSA per year for each pollut-
ant. Although there are seasonal as-
pects of certain pollutants and,
therefore, seasonality in monitoring in-
tensity among MSAs, the averages for
CHAPTER 7: METROPOLITAN AREA TRENDS
75

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table 7-1. Summary of MSA Trend Analysis, by Pollutant
every MSA and year provide a consis-
tent value with which to assess trends.
To assess upward or downward
trends, a linear regression was applied
to these data. Since the underlying
pollutant distributions do not meet the
usual assumptions required for com-
mon least squares regression, the re-
gression analysis was based upon a
nonparametric method commonly re-
ferred to as the Theil test.4-5-6 Because
linear regression estimates the trend
from changes during the entire 10-year
period, it is possible to detect an up-
ward or downward trend even when
the concentration level of the first year
equals the concentration level of the
last year. Because this method uses a
median estimator, it is not influenced
by single extreme values. Since air
pollution levels are affected by varia-
tions in meteorology, emissions, and
day-to-day activities of populations in
MS As, trends in air pollution levels are
not always well defined. Another ad-
vantage of using the regression analy-
sis is the ability to test whether or not
the upward or downward trend is real
(significant) or just a chance product of
year-to-year variation (not significant).
Table 7-1 summarizes the trend
analysis performed on the 258 MSAs.
It shows that there were no upward
trends in CO, lead, and PMio (annual
mean) at any of the MSAs over the past
decade. Of the 258 MSAs, 217 had
downward trends in at least one of the
criteria pollutants, and only 13 had
upward trends. A closer look at these
13 MSAs reveals that all are well below
the NAAQS for the respective pollut-
ant, meaning that their upward trends
are not immediately in danger of vio-
lating the NAAQS (in fact, none of
these areas are classified as nonattain-
mentfor a NAAQS). These results dem-
onstrate significant improvements in
urban air quality over the past decade.
CO	Second Max, 8-hour
Lead	Max Quarterly Mean
NOz	Arithmetic Mean
Ozone	Second Daily Max, 1-hour
PM10	Second Max, 24-hour
PM10	Weighted Annual Mean
SOz	Arithmetic Mean
SOz	Second Max, 24-hour
The Pollutant Standards
Index
PSI values are derived from pollutant
concentrations. They are reported
daily in all metropolitan areas of the
United States with populations exceed-
ing 200,000, and are used to report air
quality over large urban areas. The PSI
is reported as a value between zero and
500 or a descriptive word (e.g., "un-
healthful") and is featured on local TV
or radio news programs and in news-
papers.
Based on their short-term NAAQS,
Federal Episode Criteria,7 and Signifi-
cant Harm Levels,8 the PSI is computed
for PMio, S02, CO, O3, and N02. Lead
is the only criteria pollutant not in-
cluded in the index because it does not
have a short-term NAAQS, a Federal
Episode Criteria, or a Significant Harm
Level. Since the PSI is a tool used to
communicate pollution concerns to a
wide audience, there are also colors
linked to the general descriptors of air
quality. The five PSI color categories
and their respective health effects de-
scriptors are listed in Table 7-2.
The PSI integrates information on
criteria pollutant concentrations across
an entire monitoring network into a
single number that represents the
worst daily air quality experienced in
Total #
MSAs
# MSAs
Up
# MSAs
Down
# MSAs
with No
Significant
Change
140
0
99
41
95
0
76
19
90
2
50
38
192
1
51
140
216
6
96
114
216
0
153
63
143
4
98
41
143
4
79
60
an urban area. For each of the criteria
pollutants, concentrations are con-
verted into an index value between
zero and 500. The pollutant with the
highest index value is reported as the
PSI for that day. Therefore, the PSI does
not take into account the possible ad-
verse effects associated with combina-
tions of pollutants (i.e., synergism).2,3
A PSI value of 100 corresponds to
the standard established under the
CAA. A PSI value greater than 100 in-
dicates that at least one criteria pollut-
ant (with the exception of N02) exceeded
the level of the NAAQS, therefore desig-
nating air quality to be in the unhealth-
ful range on that day. Relatively high
PSI values activate public health warn-
ings. For example, a PSI of 200 initiates
a First Stage Alert at which time sensi-
tive populations (e.g., the elderly and
persons with respiratory illnesses) are
advised to remain indoors and reduce
physical activity. A PSI of 300 initiates
a Second Stage Alert at which time the
general public is advised to avoid out-
door activity.
Summary of PSI Analyses
Of the five criteria pollutants used to
calculate the PSI, CO, 03, PM10, and
SO2 generally contribute to the PSI
value. Nitrogen dioxide is rarely the
76 CHAPTER 7: METROPOLITAN AREA TRENDS

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table 7-2. Pollutant Standards Index Values with Pollutant Concentration,
Health Descriptors, and PSI Colors
INDEX
VALUE
POLLUTANT LEVELS
QUALITY PM-10
LEVEL
SO,
CO
(8-hour)
PPm
o, no2
(1-hour) (1-hour)
ppm	ppm
HEALTH
EFFECT
DESCRIPTOR
PSI
COLORS
500-
400-
300-
200-
100-
SIGNIFICANT
HARM	
600	2,620
EMERGENCY	500	2,100-
WARNING	420	1,600 -
ALERT	350	 800
NAAQS	150	 365
50% OF
NAAQS
50	80
50	0.6	2.0
40	0.5
30	0.4
15	0.2 -
9	0.12-
4.5	0.06-
1.2
HAZARDOUS
VERY
UNHEALTHFUL
0.6
MODERATE
GOOD
RED
ORANGE
UNHEALTHFUL YELLOW
GREEN
BLUE
a No index values reported at concentration levels below those specified by "Alert Level" criteria,
k Annual primary NAAQS.
Percent of 1987 Value
140
120
100
LA Basin All Others
87 88 89 90 91 92 93 94 95 96
* Los Angeles, CA
Riverside, CA
Figure 7-1. Number of days with PSI values > 100, as a percentage of 1987 value.
highest pollutant measured because it
does not have a short-term NAAQS
and can only be included when concen-
trations exceed one of the Federal Epi-
sode Criteria or Significant Harm
Levels. Ten-year PSI trends are based
on daily maximum pollutant concen-
trations from the subset of ambient
monitoring sites that meet the trends
criteria inAppendix B.
Since a PSI value greater than 100
indicates that the level of the NAAQS
for at least one criteria pollutant has
been exceeded on a given day the
number of days with PSI values greater
than 100 provides an indicator of air
quality in urban areas. Figure 7-1
shows the trend in the number of days
with PSI values greater than 100
summed across the nation's 94 largest
metropolitan areas as a percentage of
the 1987 value. Because of their mag-
nitude, PSI totals for Los Angeles, CA
and Riverside, CA are shown sepa-
rately as the LA Basin. Plotting these
values as a percentage of 1987 values,
allows two trends of different magni-
tudes to be compared on the same
graph. The long-term air quality im-
provement in urban areas is evident in
this figure. Between 1987 and 1996, the
total number of days with PSI values
greater than 100 decreased 51 percent
in the Los Angeles Basin and 75 percent
in the remaining major cities across the
United States.
PSI estimates depend on the num-
ber of pollutants monitored as well as
the number of monitoring sites where
data are collected. The more pollutants
measured and sites that are available in
an area, the better the estimate of the
maximum PSI for a given day. Ozone
accounts for the majority of days with
PSI values above 100, but is collected at
only a small number of sites in each
area. Table A-18 shows that the per-
centage of days with PSI values greater
CHAPTER 7: METROPOLITAN AREA TRENDS 77

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
than 100 that could be attributed to
ozone alone has increased from 78 per-
cent in 1987 to 89 percent in 1996. This
increase reveals that ozone increasingly
accounts for those days above the 100
level and reflects the success in achiev-
ing lower CO and PMi0 concentrations.
However, the typical one-in-six day
sampling schedule for most PMi0 sites
limits the number of days that PMi0
can factor into the PSI determination.
The PSI is currently undergoing re-
vision to reflect the changes in the
ozone and PM NAAQS. These revi-
sions will be proposed in the Spring of
1998 and should be finalized by the
end of 1998. Concurrently the Federal
Episode Criteria and Significant Harm
Levels for ozone and PM are being re-
vised to reflect the health effects data
that motivated the revisions to the
ozone and PM NAAQS.
References
1.	Statistical Abstracts of the United States,
1997, U.S. Department of Commerce,
U.S. Bureau of the Census.
2.	Measuring Air Quality, The Pollutant
Standards Index, EPA-451/K-94-001,
U.S. Environmental Protection Agen-
cy, Office of Air Quality Planning and
Standards, Research Triangle Park,
NC, February 1994.
3.	Code of Federal Regulations, 40 CFR
Part 58, Appendix G.
4.	T. Fitz-Simons and D. Mintz, "Assess-
ing Environmental Trends with Non-
parametric Regression in the SAS
Data Step," American Statistical As-
sociation 1995 Winter Conference,
Raleigh, NC, January, 1995.
5.	Freas, W.P. and E.A. Sieurin, "A Non-
parametric Calibration Procedure for
Multi-source Urban Air Pollution Dis-
persion Models," presented at the
Fifth Conference on Probability and
Statistics in Atmospheric Sciences,
American Meteorological Society, Las
Vegas, NV, November 1977.
6.	M. Hollander and D.A. Wolfe,Nonpara-
metric Statistical Methods, John Wiley
and Sons, Inc., New York, NY, 1973.
7.	Code of Federal Regulations, 40 CFR
Part 51, Appendix L.
8.	Code of Federal Regulations, 40 CFR
Part 51, section 51.151.
78 CHAPTER 7: METROPOLITAN AREA TRENDS

-------
Appendix A
Data Tables
APPENDIX A 79

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-1. National Air Quality Trends Statistics for Criteria Pollutants, 1987-1996
Statistic
Percentile
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
95th
11.9
11.2
11.1
10.6
9.9
8.6
8.1
8.1
7.7
7.3
90th
10.0
10.3
9.8
00
00
00
00
7.9
7.3
7.6
7.0
6.5
75th
8.3
7.8
7.8
7.1
6.9
6.4
5.8
6.2
5.5
5.1
50th
6.3
6.1
6.0
5.5
5.2
4.8
4.7
4.9
4.2
3.9
25th
4.7
4.3
4.4
4.2
3.9
3.7
3.6
3.8
3.2
3.0
10th
3.6
3.4
3.5
3.1
3.0
2.8
2.9
2.8
2.5
2.4
5th
3.0
3.0
2.8
2.6
2.4
2.5
2.3
2.3
2.3
2.1
Arith. Mean
6.7
6.4
6.4
5.9
5.6
5.2
4.9
5.1
4.5
4.2
Carbon Monoxide
2nd Max. 8hr.
PPM
345
Lead
Max. Qtr.
|jg/m3
208
95th
0.41
0.37
0.27
0.26
0.19
0.17
0.16
0.13
0.11
0.12
90th
0.24
0.22
0.17
0.17
0.15
0.12
0.10
0.09
0.08
0.08
75th
0.14
0.13
0.11
0.09
0.07
0.06
0.06
0.05
0.05
0.04
50th
0.09
0.08
0.06
0.05
0.04
0.03
0.03
0.03
0.03
0.02
25th
0.06
0.04
0.04
0.03
0.02
0.02
0.02
0.02
0.01
0.01
10 th
0.04
0.03
0.03
0.02
0.01
0.01
0.01
0.01
0.01
0.01
5th
0.03
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Arith. Mean
0.16
0.12
0.09
0.09
0.07
0.06
0.05
0.04
0.04
0.04
Nitrogen Dioxide
Arith. Mean
PPM
214
95th
0.043
0.046
0.043
0.041
0.043
0.039
0.037
0.041
0.039
0.038
90th
0.038
0.037
0.035
0.034
0.033
0.033
0.033
0.034
0.032
0.032
75th
0.027
0.027
0.027
0.026
0.025
0.024
0.025
0.025
0.024
0.024
50th
0.020
0.021
0.020
0.019
0.019
0.019
0.019
0.020
0.019
0.018
25th
0.013
0.013
0.013
0.012
0.012
0.012
0.012
0.012
0.012
0.012
10 th
0.006
0.007
0.007
0.006
0.006
0.006
0.006
0.006
0.005
0.006
5th
0.004
0.003
0.003
0.003
0.003
0.004
0.004
0.004
0.004
0.004
Arith. Mean
0.021
0.022
0.021
0.020
0.020
0.019
0.019
0.020
0.019
0.019
Ozone
2nd Max. 1 hr.
PPM
600
95th
0.183
0.202
0.190
0.177
0.175
0.160
0.160
0.154
0.158
0.145
90th
0.166
0.180
0.151
0.150
0.150
0.133
0.140
0.133
0.140
0.129
75th
0.140
0.151
0.125
0.121
0.124
0.113
0.120
0.118
0.124
0.115
50th
0.117
0.128
0.107
0.108
0.108
0.100
0.105
0.105
0.111
0.104
25th
0.102
0.109
0.096
0.095
0.095
0.090
0.092
0.093
0.099
0.094
10th
0.090
0.092
0.085
0.083
0.082
0.082
0.080
0.082
0.085
0.085
5th
0.083
0.083
0.080
0.074
0.075
0.076
0.074
0.075
0.077
0.079
Arith. Mean
0.124
0.133
0.116
0.113
0.114
0.106
0.108
0.108
0.113
0.106
80 APPENDIX A: DATA TABLES

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-1. National Air Quality Trends Statistics for Criteria Pollutants, 1987-1996 (continued)
Statistic
Percentile
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
95th

52.5
52.7
46.2
46.1
42.1
41.5
40.0
39.6
38.4
90th
	
44.0
43.9
39.7
39.5
36.4
36.0
36.6
35.0
33.6
75th
	
37.6
36.8
34.2
33.4
31.0
30.1
30.5
29.3
27.9
50th
	
30.5
30.1
28.0
28.2
25.6
25.4
25.4
24.3
23.3
25th
	
25.8
25.6
23.4
23.5
21.9
21.0
21.1
20.0
19.4
10th
	
20.6
20.6
19.1
18.5
17.9
16.8
16.8
15.9
16.0
5th
	
17.5
17.4
16.4
15.1
13.9
13.4
13.1
12.7
13.2
Arith. Mean
	
32.2
32.0
29.4
29.1
26.8
26.0
26.2
25.1
24.2
PM,
Annual Avg.
|jg/m
900
Sulfur Dioxide
Arith. Mean
PPM
479
95th
90th
75th
50th
25th
10th
5th
Arith. Mean
0.0183
0.0154
0.0116
0.0083
0.0053
0.0021
0.0013
0.0089
0.0195
0.0155
0.0116
0.0084
0.0053
0.0023
0.0016
0.0089
0.0182
0.0153
0.0114
0.0081
0.0050
0.0023
0.0016
0.0087
0.0165
0.0144
0.0105
0.0076
0.0045
0.0020
0.0014
0.0081
0.0160
0.0132
0.0099
0.0075
0.0046
0.0020
0.0015
0.0078
0.0153
0.0127
0.0095
0.0068
0.0043
0.0020
0.0013
0.0073
0.0146
0.0124
0.0092
0.0067
0.0040
0.0021
0.0014
0.0071
0.0137
0.0121
0.0089
0.0064
0.0037
0.0020
0.0015
0.0068
0.0115
0.0100
0.0073
0.0051
0.0033
0.0017
0.0014
0.0056
0.0113
0.0098
0.0074
0.0053
0.0033
0.0017
0.0014
0.0056
2nd Max. 24hr.
PPM
480
95th
90th
75th
50th
25th
10th
5th
Arith. Mean
0.0915
0.0725
0.0530
0.0390
0.0245
0.0100
0.0055
0.0420
0.0920
0.0720
0.0560
0.0400
0.0260
0.0125
0.0065
0.0439
0.0935
0.0760
0.0530
0.0390
0.0240
0.0120
0.0065
0.0420
0.0810
0.0650
0.0500
0.0340
0.0215
0.0100
0.0050
0.0380
0.0710
0.0600
0.0455
0.0320
0.0210
0.0100
0.0060
0.0347
0.0710
0.0590
0.0443
0.0310
0.0190
0.0100
0.0045
0.0335
0.0680
0.0580
0.0420
0.0285
0.0190
0.0100
0.0050
0.0326
0.0710
0.0590
0.0440
0.0320
0.0190
0.0080
0.0050
0.0335
0.0570
0.0470
0.0330
0.0220
0.0160
0.0080
0.0040
0.0259
0.0590
0.0465
0.0340
0.0235
0.0160
0.0085
0.0040
0.0268
APPENDIX A: DATA TABLES 81

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-2. National Carbon Monoxide Emissions Estimates, 1987-1996 (thousand short tons)
Source Cateqorv
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
FUEL COMBUSTION
6,967
7,379
7,449
5,510
5,856
6,155
5,586
5,519
5,934
5,962
Electric Utilities
307
320
327
363
349
350
363
370
372
377
coal
223
236
239
234
234
236
246
247
250
263
oil
20
25
26
20
19
15
16
15
10
11
gas
53
48
51
51
51
51
49
53
55
44
internal combustion
10
11
11
57
45
47
51
55
58
59
Industrial
649
669
672
879
920
955
1,043
1,041
1,056
1,072
coal
85
87
87
105
101
102
101
100
98
99
oil
46
46
46
74
60
64
66
66
71
72
gas
252
265
271
226
284
300
322
337
345
348
other
171
173
173
279
267
264
286
287
297
305
internal combustion
96
98
96
195
208
227
268
251
245
247
Other
6,011
6,390
6,450
4,269
4,587
4,849
4,181
4,108
4,506
4,513
residential ™od
5,719
6,086
6,161
3,781
4,090
4,332
3,679
3,607
3,999
3,993
other
292
303
288
488
497
517
502
502
506
520
INDUSTRIAL PROCESSES
6,851
7,034
7,013
5,852
5,740
5,683
5,898
5,839
5,790
5,817
Chemical & Allied Processing
1,798
1,917
1,925
1,183
1,127
1,112
1,093
1,171
1,223
1,223
Metals Processing
1,984
2,101
2,132
2,640
2,571
2,496
2,536
2,475
2,380
2,378
Petroleum & Related Industries
455
441
436
333
345
371
371
338
348
348
Other Industrial Processes
713
711
716
537
548
544
594
600
624
635
Solvent Utilization
2
2
2
5
5
5
5
5
6
6
Storage & Transport
50
56
55
76
28
17
51
24
25
25
l/l£sfe Disposal & Recycling
1,850
1,806
1,747
1,079
1,116
1,138
1,248
1,225
1,185
1,203
TRANSPORTATION
86,209
86,861
81,832
73,965
78,114
76,233
76,794
78,706
70,947
69,946
On-Road Vehicles
71,250
71,081
66,050
57,848
62,074
59,859
60,202
61,833
54,106
52,944
Non-Road Sources
14,959
15,780
15,781
16,117
16,040
16,374
16,592
16,873
16,841
17,002
MISCELLANEOUS
8,852
15,895
8,153
11,208
8,751
7,052
7,013
9,614
7,050
7,099
Structural Fires
242
242
242
164
166
168
169
170
171
172
Agricultural Fires
483
612
571
415
413
421
415
441
465
475
Prescribed Burning
4,332
4,332
4,332
4,668
4,713
4,760
4,810
4,860
4,916
4,955
Forest 1Mdfires
3,795
10,709
3,009
5,928
3,430
1,674
1,586
4,114
1,469
1,469
Other
NA
NA
NA
32
28
30
34
28
28
27
TOTAL ALL SOURCES	108,879 117,169 104,447 96,535 98,461 95,123 95,291 99,677 89,721 88,822
Note: Some columns may not sum to totals due to rounding.
82 APPENDIX A: DATA TABLES

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-3. National Lead Emissions Estimates, 1987-1996 (short tons)
Source Category
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
FUEL COMBUSTION
510
511
505
500
495
491
495
494
487
493
Electric Utilities
64
66
67
64
61
59
61
61
57
62
coal
48
46
46
46
46
47
49
49
50
50
oil
16
20
21
18
15
12
12
12
7
12
Industrial
22
19
18
18
18
18
19
18
16
17
coal
14
14
14
14
15
14
14
14
14
14
oil
8
5
4
3
3
4
5
4
3
3
Other
425
426
420
418
416
414
415
415
414
414
commercial/institutional coal
5
5
4
4
3
4
4
3
3
3
commercial/institutional oil
5
5
4
4
4
4
3
3
3
4
misc. fuel comb, (except res.)
400
400
400
400
400
400
400
400
400
400
residential other
14
16
12
10
9
7
8
8
8
7
INUSTRIAL PROCESSES
3,004
3,090
3,161
3,278
3,081
2,734
2,869
3,005
2,892
2,812
Chemical & Allied Processing
123
136
136
136
132
93
92
96
144
117
Metals Processing
1,835
1,965
2,088
2,169
1,975
1,773
1,899
2,027
2,067
2,000
Other Industrial Processes
202
172
173
169
167
56
54
53
59
57
Waste Disposal & Recycling
844
817
765
804
807
812
824
829
622
638
TRANSPORTAVON
4,167
3,452
1,802
1,197
592
584
547
544
564
564
On-Road Vehicles
3,317
2,567
982
421
18
18
19
19
19
19
Non-Road Sources
850
885
820
776
574
565
529
525
545
545
TOTAL ALL SOURCES
7,681
7,053
5,468
4,975
4,168
3,808
3,911
4,043
3,943
3,869
Note: Some columns may not sum to totals due to rounding.
APPENDIX A: DATA TABLES 83

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-4. National Nitrogen Oxides Emissions Estimates, 1987-1996 (thousand short tons)
Source Category
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
FUEL COMBUSTION
10,014
10,472
10,537
10,895
10,779
10,928
11,111
11,015
10,827
10,494
Electric Utilities
6,246
6,545
6,593
6,663
6,519
6,504
6,651
6,565
6,384
6,034
coal
5,376
5,666
5,676
5,642
5,559
5,579
5,744
5,636
5,579
5,517
oil
217
273
285
221
212
170
180
163
96
96
gas
605
557
582
565
580
579
551
591
562
461
internal combustion
48
50
49
235
168
175
176
175
148
151
Industrial
3,063
3,187
3,209
3,035
2,979
3,071
3,151
3,147
3,144
3,170
coal
596
617
615
585
570
574
589
602
597
599
oil
292
296
294
265
237
244
245
241
247
246
gas
1,505
1,584
1,625
1,182
1,250
1,301
1,330
1,333
1,324
1,336
other
119
121
120
131
129
126
124
124
123
125
internal combustion
552
569
556
874
793
825
863
846
854
864
Other
706
740
736
1,196
1,281
1,353
1,308
1,303
1,298
1,289
commercial/institutional coal
37
39
38
40
36
38
40
40
38
38
commercial/institutional oil
121
117
106
97
88
93
93
95
103
102
commercial/institutional gas
144
157
159
200
210
225
232
237
231
234
misc. fuel comb, (except res.)
11
11
11
34
32
28
31
31
30
29
residential wood
69
74
75
46
50
53
45
44
49
48
residential other
323
343
347
780
865
916
867
857
847
838
INDUSTRIAL PROCESSES
841
860
852
892
816
857
861
878
873
880
Chemical & Allied Processing
255
274
273
168
165
163
155
160
158
159
Metals Processing
75
82
83
97
76
81
83
91
98
98
Petroleum & Related Industries
101
100
97
153
121
148
123
117
110
110
Other Industrial Processes
320
315
311
378
352
361
370
389
399
403
Solvent Utilization
3
3
3
1
2
3
3
3
3
3
Storage & Transport
2
2
2
3
6
5
5
5
6
6
Waste Disposal & Recycling
85
85
84
91
95
96
123
114
99
100
TRANSPORTATION
11,598
12,467
12,374
11,633
11,891
12,098
12,285
12,616
11,998
11,781
On-Road Vehicles
7,651
7,661
7,682
7,040
7,373
7,440
7,510
7,672
7,323
7,171
Non-Road Sources
3,947
4,806
4,693
4,593
4,518
4,658
4,776
4,944
4,675
4,610
MISCELLANEOUS
352
727
293
371
286
254
225
383
237
239
TOTAL ALL SOURCES
22,806
24,526
24,057
23,792
23,772
24,137
24,482
24,892
23,935
23,393
Note: Some columns may not sum to totals due to rounding.
84 APPENDIX A: DATA TABLES

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-5. National Volatile Organic Compounds Emissions Estimates, 1987-1996 (thousand short tons)
Source Category
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
FUEL COMBUSTION
1,283
1,360
1,372
1,005
1,075
1,114
993
989
1,073
1,075
Electric Utilities
35
37
38
47
44
44
45
45
44
45
coal
25
27
27
27
27
27
29
29
29
31
oil
6
7
7
6
5
4
4
4
3
3
gas
2
2
2
2
2
2
2
2
2
2
internal combustion
1
1
1
12
10
10
10
10
10
10
Industrial
131
136
134
182
196
187
186
196
206
208
coal
7
7
7
7
6
7
6
8
6
6
oil
16
16
16
12
11
12
12
12
12
12
gas
57
61
61
58
60
52
51
63
73
73
other
36
36
36
51
51
49
51
50
50
51
internal combustion
15
15
15
54
68
66
66
64
65
66
Other
1,117
1,188
1,200
776
835
884
762
748
823
822
residential wood
1,085
1,155
1,169
718
776
822
698
684
759
758
other
32
33
31
58
59
62
64
63
64
64
INDUSTRIAL PROCESSES
10,535
10,854
10,755
10,000
10,178
10,380
10,578
10,738
10,780
9,482
Chemical & Allied Processing
923
982
980
634
710
715
701
691
660
436
Metals Processing
70
74
74
122
123
124
124
126
125
70
Petroleum & Related Industries
655
645
639
612
640
632
649
647
642
517
Other Industrial Processes
394
408
403
401
391
414
442
438
450
439
Solvent Utilization
5,743
5,945
5,964
5,750
5,782
5,901
6,016
6,162
6,183
6,273
Storage & Transport
1,801
1,842
1,753
1,495
1,532
1,583
1,600
1,629
1,652
1,312
Waste Disposal & Recycling
950
959
941
986
999
1,010
1,046
1,046
1,067
433
TRANSPORTATION
10,721
10,722
9,613
8,815
9,003
8,622
8,684
9,021
8,135
7,928
On-Road Vehicles
8,477
8,290
7,192
6,313
6,499
6,072
6,103
6,401
5,701
5,502
Non-Road Sources
2,244
2,432
2,422
2,502
2,503
2,551
2,581
2,619
2,433
2,426
MISCELLANEOUS
655
1,230
642
1,164
845
579
641
798
599
601
Other Combustion
655
1,230
641
1,064
756
485
535
710
511
516
structural fires
44
44
44
29
30
30
30
30
31
31
agricultural fires
67
85
79
48
48
49
48
51
54
55
slash/prescribed burning
182
182
182
234
236
239
241
246
252
256
forest wildfires
361
918
335
749
439
164
212
379
171
171
other
NA
NA
NA
3
3
3
3
3
3
3
Other
0
1
1
100
89
94
105
88
88
85
TOTAL ALL SOURCES
23,194
24,167
22,383
20,985
21,100
20,695
20,895
21,546
20,586
19,086
Note: Some columns may not sum to totals due to rounding.
APPENDIX A: DATA TABLES 85

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-6. National Particulate Matter (PM10) Emissions Estimates, 1987-1996 (thousand short tons)
Source Category
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
FUEL COMBUSTION
1,335
1,384
1,386
1,196
1,147
1,183
1,124
1,113
1,179
1,186
Electric Utilities
284
279
274
295
257
257
279
273
268
282
coal
271
265
259
265
232
234
253
246
244
258
oil
9
10
11
9
10
7
9
8
5
5
gas
1
1
1
1
1
0
1
1
1
1
internal combustion
3
3
3
20
15
16
17
17
18
18
Industrial
239
244
243
270
233
243
257
270
302
306
coal
67
70
70
84
72
74
71
70
70
71
oil
48
48
48
52
44
45
45
44
49
50
gas
44
45
44
41
34
40
43
43
45
45
other
78
79
78
87
72
74
86
74
73
75
internal combustion
3
3
3
6
10
11
12
38
64
65
Other
812
862
869
631
657
683
588
570
610
598
residential wood
758
807
817
501
535
558
464
446
484
472
other
54
55
52
130
122
124
124
125
126
126
INUDSTRIAL PROCESSES
1,288
1,294
1,276
1,306
1,264
1,269
1,240
1,219
1,231
1,232
Chemical & Allied Processing
58
62
63
77
68
71
66
76
67
67
Metals Processing
194
208
211
214
251
250
181
184
212
211
Petroleum & Related Industries
62
60
58
55
43
43
38
38
40
40
Other Industrial Processes
606
601
591
583
520
506
501
495
511
510
Solvent Utilization
2
2
2
4
5
5
6
6
6
6
Storage & Transport
100
101
101
102
101
117
114
106
109
109
Waste Disposal & Recycling
265
259
251
271
276
278
334
313
287
290
TRANSPORTATION
881
1,041
1,016
934
947
961
954
972
883
869
On-Road Vehicles
360
369
367
336
349
343
321
320
293
274
Non-Road Sources
520
672
649
598
598
618
633
652
590
595
TOTAL ALL SOURCES
3,504
3,721
3,678
3,436
3,358
3,413
3,318
3,305
3,293
3,288
Table A-7. Miscellaneous and Natural PM10 Emissions Estimates, 1987-1996 (thousand short tons)
Source Category
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
MISCELLANEOUS
37,453
39,444
37,461
24,419
24,122
23,865
24,196
25,461
22,454
22,702
Agriculture & Forestry
7,326
7,453
7,320
5,146
5,106
4,909
4,475
4,690
4,661
4,708
Other Combustion
988
1,704
912
1,203
941
785
768
1,048
778
783
wildfires
389
1,086
300
601
332
171
152
424
145
145
managed burning
540
559
553
558
563
568
570
578
586
591
other
59
59
59
45
45
46
46
46
46
47
Cooling Towers
NA
NA
NA
0
0
0
0
0
1
1
Fugitive Dust
29,139
30,287
29,229
18,069
18,076
18,171
18,954
19,722
17,013
17,209
wind erosion
0
0
0
1
1
1
1
1
1
1
un paved roads
11,110
12,379
11,798
11,234
11,206
10,918
11,430
11,370
10,362
10,303
paved roads
5,530
5,900
5,769
2,248
2,399
2,423
2,462
2,538
2,409
2,417
construction
12,121
11,662
11,269
4,249
4,092
4,460
4,651
5,245
3,654
3,950
other
377
346
392
336
377
369
409
569
586
538
NAT. SOURCES (wind erosion)
1,577
18,110
12,101
2,092
2,077
2,227
509
2,160
1,146
5,316
TOTAL ALL SOURCES
39,030
57,555
49,562
26,512
26,199
26,093
24,706
27,621
23,599
28,018
Note: Some columns may not sum to totals due to rounding.
86 APPENDIX A: DATA TABLES

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-8. National Sulfur Dioxide Emissions Estimates, 1987-1996 (thousand short tons)
Source Cateaorv
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
FUEL COMBUSTION
19,549
19,881
20,050
20,290
19,796
19,493
19,245
18,887
16,230
16,786
Electric Utilities
15,819
16,110
16,340
15,909
15,784
15,416
15,189
14,889
12,080
12,604
coal
15,138
15,344
15,529
15,220
15,087
14,824
14,527
14,313
11,603
12,114
oil
651
15,344
15,529
639
652
546
612
522
413
412
gas
1
1
1
1
1
1
1
1
9
21
internal combustion
29
31
30
49
45
46
49
53
55
57
Industrial
3,068
3,111
3,086
3,550
3,256
3,292
3,284
3,218
3,357
3,399
coal
1,817
1,856
1,840
1,914
1,805
1,783
1,763
1,740
1,728
1,762
oil
807
806
812
927
779
801
809
111
912
918
gas
356
360
346
543
516
552
555
542
548
548
other
82
83
82
158
142
140
140
141
147
147
internal combustion
6
6
6
9
14
16
17
19
23
23
Other
662
660
624
831
755
784
772
780
793
782
commercial/institutional coal
164
172
169
212
184
190
193
192
200
200
commercial/institutional oil
310
295
274
425
376
396
381
391
397
389
commercial/institutional gas
2
2
2
7
7
7
8
8
8
8
misc. fuel comb, (except res.)
1
1
1
6
6
6
6
6
5
5
residential wood
10
11
11
7
7
8
6
6
7
7
other
175
180
167
175
176
177
178
177
176
173
INDUSTRIAL PROCESSES
1,976
2,052
2,010
1,900
1,721
1,758
1,723
1,676
1,637
1,644
Chemical & Allied Processing
425
449
440
297
280
278
269
275
286
287
Metals Processing
648
707
695
726
612
615
603
562
530
530
Petroleum & Related Industries
445
443
429
430
378
416
383
379
369
368
Other Industrial Processes
418
411
405
399
396
396
392
398
403
409
Solvent Utilization
1
1
1
0
0
1
1
1
1
1
Storage & Transport
4
5
5
7
10
9
5
2
2
2
Waste Disposal & Recycling
35
36
36
42
44
44
71
60
47
48
TRANSPORTATION
771
806
837
934
969
980
903
685
676
674
On-Road Vehicles
538
553
570
542
570
578
517
301
304
307
Non-Road Sources
233
253
267
392
399
402
385
384
372
368
TOTAL ALL SOURCES
22,308
22,767
22,907
23,136
22,496
22,240
21,879
21,262
18,552
19,113
Note: Some columns may not sum to totals due to rounding.
APPENDIX A: DATA TABLES 87

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-9. National Long-Term Air Quality Trends, 1977-1996
Year
CO
2nd Max. 8hr.
ppm
Pb
Max. Qtr.
uq/m3
no2
Arith. Mean
ppm
Ozone
2nd Max. 1hr.
ppm
PM10
Wtd. Arith. Mean
ua/m3
so2
Arith. Mean
ppm
1977-86
(168 sites)
(122 sites)
(65 sites)
(238 sites)
	
(278 sites)
1977
10.9
1.35
0.026
0.152
—
0.0133
1978
10.5
1.26
0.027
0.156
—
0.0128
1979
10.1
1.06
0.026
0.141
—
0.0125
1980
9.3
0.73
0.024
0.143
—
0.0112
1981
8.9
0.59
0.023
0.131
—
0.0108
1982
8.2
0.50
0.022
0.127
—
0.0100
1983
8.2
0.40
0.022
0.144
—
0.0098
1984
8.1
0.36
0.023
0.128
—
0.0099
1985
7.3
0.25
0.023
0.127
—
0.0092
1986
7.3
0.16
0.022
0.122

0.0091
1987-96
(345 sites)
(208 sites)
(214 sites)
(600 sites)
(900 sites)
(479 sites)
1987
6.7
0.16
0.021
0.124
—
0.0089
1988
6.4
0.12
0.022
0.133
32.2
0.0089
1989
6.4
0.09
0.021
0.116
32.0
0.0087
1990
5.9
0.09
0.020
0.113
29.4
0.0081
1991
5.6
0.07
0.020
0.114
29.1
0.0078
1992
5.2
0.06
0.019
0.106
26.8
0.0073
1993
4.9
0.05
0.019
0.108
26.0
0.0071
1994
5.1
0.04
0.020
0.108
26.2
0.0068
1995
4.5
0.04
0.019
0.113
25.1
0.0056
1996
4.2
0.04
0.019
0.106
24.2
0.0056
88 APPENDIX A: DATA TABLES

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-10. National Air Quality Trends Statistics by Monitoring Location, 1987-1996
#of
Statistic
Units
Sites
Location
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
Carbon Monoxide













2nd Max. 8hr.
ppm
10
Rural
3.5
3.1
2.8
2.6
2.4
2.4
2.1
2.3
2.2
1.9
"
"
142
Suburban
6.3
6.0
6.0
5.5
5.2
4.9
4.8
4.9
4.3
4.0
"
"
190
Urban
7.2
6.9
6.8
6.3
6.0
5.5
5.1
5.4
4.8
4.5
Lead













Max. Qtr.
ug/m3
5
Rural
0.08
0.06
0.05
0.05
0.05
0.04
0.04
0.02
0.03
0.02
"
"
107
Suburban
0.13
0.09
0.08
0.07
0.06
0.05
0.04
0.04
0.04
0.03
"
"
96
Urban
0.19
0.15
0.10
0.11
0.07
0.06
0.06
0.05
0.05
0.05
Nitrogen Dioxide













Arith. Mean
ppm
46
Rural
0.008
0.009
0.008
0.008
0.008
0.008
0.007
0.008
0.007
0.007
"
"
89
Suburban
0.023
0.023
0.023
0.022
0.022
0.021
0.020
0.021
0.020
0.020
"
"
77
Urban
0.027
0.027
0.027
0.025
0.025
0.024
0.024
0.025
0.024
0.024
Ozone













2nd Max. 1 hr.
ppm
194
Rural
0.115
0.124
0.110
0.109
0.107
0.102
0.104
0.103
0.108
0.104
"
"
276
Suburban
0.129
0.140
0.119
0.116
0.119
0.110
0.112
0.112
0.117
0.108
113
Urban
0.127 0.134 0.115 0.111
0.112 0.104 0.105 0.106 0.110 0.106
PM io
Wtd. Arith. Mean ug/m3
119
Rural
356 Suburban
404
Urban
25.3
33.3
33.4
25.5
32.9
33.1
23.9
30.3
30.4
22.8
29.9
30.4
21.4
27.7
27.8
19.9
27.0
27.2
20.2
27.0
27.3
19.3
26.1
26.0
19.3
24.9
25.2
Sulfur Dioxide
Arith. Mean
ppm
138
191
139
Rural
Suburban
Urban
0.0073
0.0094
0.0099
0.0073
0.0095
0.0101
0.0071
0.0091
0.0099
0.0067
0.0085
0.0090
0.0065
0.0082
0.0086
0.0063
0.0077
0.0079
0.0063
0.0075
0.0076
0.0060
0.0071
0.0075
0.0054
0.0057
0.0059
0.0052
0.0058
0.0058
APPENDIX A: DATA TABLES 89

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996
State
County

CO
Pb
no2
Os
PM
r™10
so2


1990
8-hr
QMAX
AM
2nd MAX 2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
AL
CALHOUN
116,034




31

AL
CLAY
13,252



0.102


AL
COLBERT
51,666




46
0.019
AL
DE KALB
54,651




45

AL
ELMORE
49,210



0.102


AL
ESCAMBIA
35,518




41

AL
ETOWAH
99,840

0.26


50

AL
FRANKLIN
27,814




45

AL
GENEVA
23,647



0.077


AL
HOUSTON
81,331




54

AL
JACKSON
47,796




33
0.027
AL
JEFFERSON
651,525
5.7
0.13

0.141
100
0.015
AL
LAWRENCE
31,513



0.096


AL
LIMESTONE
54,135




43

AL
MADISON
238,912
3


0.102
54

AL
MARENGO
23,084




52

AL
MOBILE
378,643



0.104
91
0.07
AL
MONTGOMERY
209,085
1.5

0.01
0.091
39
0.022
AL
MORGAN
100,043



0.114
45
0.001
AL
PIKE
27,595

0.79


45

AL
RUSSELL
46,860




38

AL
SHELBY
99,358


0.01
0.127
42

AL
SUMTER
16,174



0.08


AL
TALLADEGA
74,107




53

AL
TUSCALOOSA
150,522




58

AL
WALKER
67,670




46

AK
ANCHORAGE BOROUGH
226,338
10.5



133

AK
FAIRBANKS NORTH STAR BOROUGH
77,720
8.6





AK
JUNEAU BOROUGH
26,751




79

AK
YUKDN-KDYUKUK CA
8,478



0.057


AZ
COCHISE
97,624



0.079
69

AZ
COCONINO
96,591



0.082
31

AZ
GILA
40,216




66

AZ
GRAHAM
26,554




84

AZ
MARICOPA
2,122,101
10
0.05
0.0316
0.122
130
0.017
AZ
NAVAJO
77,658




28

AZ
PIMA
666,880
5.1
0.05
0.019
0.092
81
0.004
AZ
PINAL
116,379





0.02
AZ
SANTA CRUZ
29,676




88

AZ
YAVAPAI
107,714




22

AZ
YUMA
106,895



0.098
59

AR
ARKANSAS
21,653




70

AR
ASHLEY
24,319




55

AR
CRAIGHEAD
68,956




53

AR
CRITTENDEN
49,939



0.114
58

AR
GARLAND
73,397




40

AR
JEFFERSON
85,487




51

AR
MARION
12,001




51

AR
MILLER
38,467




50

AR
MONTGOMERY
7,841



0.07


AR
NEWTON
7,666



0.08


AR
OUACHITA
30,574




45

AR
PHILLIPS
28,838




64

AR
POLK
17,347




47

AR
POPE
45,883




46

AR
PULASKI
349,660
3.8

0.0108
0.102
52
0.009
AR
SEBASTIAN
99,590




47

AR
UNION
46,719




47
0.023
AR
WASHINGTON
113,409




48

AR
WHITE
54,676




49

CA
ALAMEDA
1,279,182
3.8
0
0.0218
0.137
44

CA
AMADOR
30,039
1.4


0.127


CA
BUTTE
182,120
5.3
0
0.013
0.096
62

CA
CALAVERAS
31,998
0.8


0.13
33

CA
COLUSA
16,275



0.101
73

CA
CONTRA COSTA
803,732
2.7
0.02
0.0172
0.117
45

CA
DEL NORTE
23,460




40

CA
EL DORADO
125,995
4.8

0.0107
0.13
64

CA
FRESNO
667,490
6.7
0
0.0214
0.151
101
0.008
CA
GLENN
24,798



0.092
79

CA
HUMBOLDT
119,118

0


56

CA
IMPERIAL
109,303
14.1
0.05
0.0143
0.143
440
0.013
90 APPENDIX A: DATA TABLES

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
03
PM
' m10
so2


1990
8-hr
QMAX
AM
2nd MAX 2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
CA
INYO
18,281



0.091
221

CA
KERN
543,477
5.6
0
0.029
0.163
110
0.009
CA
KINGS
101,469


0.0144
0.139
138

CA
LAKE
50,631



0.08
20

CA
LASSEN
27,598




35

CA
LOS ANGELES
8,863,164
14.5
0.06
0.0481
0.197
109

CA
MADERA
88,090



0.128
68

CA
MARIN
230,096
3.4

0.0181
0.095
47

CA
MARIPOSA
14,302



0.11
96

CA
MENDOCINO
80,345
2.4

0.0125
0.055
49

CA
MERCED
178,403


0.0116
0.124
57

CA
MODOC
9,678




53

CA
MONO
9,956
3


0.09
81

CA
MONTEREY
355,660
2.4

0.0105
0.091
40

CA
NAPA
110,765
3.8

0.0141
0.089
39

CA
NEVADA
78,510



0.111
86

CA
ORANGE
2,410,556
6.6

0.0351
0.144
77
0.004
CA
PLACER
172,796
2.3
0
0.0156
0.131
45

CA
PLUMAS
19,739



0.09
61

CA
RIVERSIDE
1,170,413
5
0.04
0.0286
0.182
155
0.004
CA
SACRAMENTO
1,041,219
7.1
0.01
0.022
0.138
80
0.005
CA
SAN BENITO
36,697



0.118
35

CA
SAN BERNARDINO
1,418,380
6.6
0.04
0.0383
0.215
123

CA
SAN DIEGO
2,498,016
6
0.02
0.0218
0.133
92

CA
SAN FRANCISCO
723,959
5.1
0.01
0.0215
0.061
59

CA
SAN JOAQUIN
480,628
6.7
0
0.0232
0.126
61

CA
SAN LUIS OBISPO
217,162
2.3

0.0125
0.109


CA
SAN MATEO
649,623
3.4

0.0196
0.091
45

CA
SANTA BARBARA
369,608
4.5
0
0.0191
0.13
63

CA
SANTA CLARA
1,497,577
5.8
0.01
0.0251
0.115
68

CA
SANTA CRUZ
229,734
0.7

0.0054
0.102
69

CA
SHASTA
147,036



0.11
50

CA
SIERRA
3,318




114

CA
SISKIYOU
43,531



0.07
35

CA
SOLANO
340,421
4.5

0.0147
0.117
43
0.006
CA
SONOMA
388,222
3

0.0139
0.085
39

CA
STANISLAUS
370,522
5.6
0
0.0219
0.125
83

CA
SUTTER
64,415
4.1

0.0123
0.108
69

CA
TEHAMA
49,625



0.09
49

CA
TRINITY
13,063




63

CA
TULARE
311,921
3.9

0.0182
0.139
87

CA
TUOLUMNE
48,456
2.5


0.117


CA
VENTURA
669,016
3.3
0
0.0223
0.144
79
0.003
CA
YOLO
141,092
1.3

0.0107
0.113
65

CO
ADAMS
265,038
3.9
0.05
0.0215
0.089
96
0.015
CO
ALAMOSA
13,617




92

CO
ARAPAHOE
391,511
2.6

0.0316
0.103


CO
ARCHULETA
5,345




85

CO
BOULDER
225,339
5.5


0.092
59

CO
DELTA
20,980




67

CO
DENVER
467,610
7.3
0.05
0.0331
0.092
70
0.024
CO
DOUGLAS
60,391



0.102
26

CO
EAGLE
21,928




52

CO
EL PASO
397,014
5
0.01

0.077
76

CO
FREMONT
32,273




37

CO
GARFIELD
29,974




78

CO
GUNNISON
10,273



0.086
91

CO
JEFFERSON
438,430
4.3

0.009
0.107
39

CO
LAKE
6,007

0.04




CO
LA PLATA
32,284




92

CO
LARIME
186,136
5.1


0.093
52

CO
MESA
93,145
5.8



63

CO
MONTEZUMA
18,672

0.01

0.077


CO
MONTROSE
24,423




60

CO
PITKIN
12,661




66

CO
PROWERS
13,347




80

CO
PUEBLO
123,051




49

CO
ROUTT
14,088




137

CO
SAN MIGUEL
3,653




105

CO
SUMMIT
12,881




56

CO
TELLER
12,468




195

CO
WELD
131,821
7


0.097
56

APPENDIX A: DATA TABLES 91

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
03
PM
10
so2


1990
8-hr
QMAX
AM
2nd MAX
2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
CT
FAIRFIELD
827,645
4.1
0.02
0.0235
0.126
65
0.026
CT
HARTFORD
851,783
4.5
0.03
0.0161
0.091
49
0.022
CT
LITCHFIELD
174,092



0.112
50

CT
MIDDLESEX
143,196



0.102
38

CT
NEW HAVEN
804,219
2.9
0.05
0.026
0.12
109

CT
NEW LONDON
254,957



0.121
56

CT
TOLLAND
128,699


0.006
0.101

0.013
CT
WINDHAM
102,525




35

DE
KENT
110,993



0.11


DE
NEW CASTLE
441,946
3.6

0.019
0.108
81

DE
SUSSEX
113,229



0.109
50
0.023
DC
WASHINGTON
606,900
4.5
0.02
0.0264
0.11
49
0.025
FL
ALACHUA
181,596




44

FL
BAY
126,994




50

FL
BREVARD
398,978



0.087
44

FL
BROWARD
1,255,488
4.4
0.05
0.0095
0.103
48
0.008
FL
CALHOUN
11,011



0.08


FL
COLLIER
152,099




45

FL
DADE
1,937,094
4.6
0.01
0.016
0.097
62
0.005
FL
DUVAL
672,971
3.8
0.02
0.0149
0.096
53
0.024
FL
ESCAMBIA
262,798



0.098
37
0.033
FL
GULF
11,504




47

FL
HAMILTON
10,930




62
0.019
FL
HILLSBOROUGH
834,054
3.9
2.81
0.0098
0.113
81
0.087
FL
LEE
335,113



0.08
38

FL
LEON
192,493



0.087
33

FL
MANATEE
211,707



0.091
48

FL
MARTIN
100,900




42

FL
NASSAU
43,941




61
0.03
FL
ORANGE
677,491
4.1
0
0.0126
0.104
67
0.008
FL
OSCEOLA
107,728



0.096


FL
PALM BEACH
863,518
3.6
0
0.012
0.09
56

FL
PASCO
281,131



0.086


FL
PINELLAS
851,659
2.8
0
0.0112
0.092
50
0.033
FL
POLK
405,382



0.092
45
0.021
FL
PUTNAM
65,070




45
0.019
FL
ST JOHNS
83,829



0.09


FL
ST LUCIE
150,171



0.072


FL
SARASOTA
277,776
5.1


0.094
73
0.018
FL
SEMINOLE
287,529



0.092
49

FL
VOLUSIA
370,712



0.085
63

GA
BARTOW
55,911





0.014
GA
BIBB
149,967




34

GA
CHATHAM
216,935



0.085

0.03
GA
CHATTOOGA
22,242




51

GA
DE KALB
545,837
3.7
0.02
0.0175
0.13
56

GA
DOUGHERTY
96,311




21

GA
ELBERT
18,949




48

GA
FANNIN
15,992



0.091

0.033
GA
FLOYD
81,251





0.016
GA
FULTON
648,951
3.8
0.03
0.0266
0.137
60
0.022
GA
GLYNN
62,496



0.086
30

GA
GWINNETT
352,910



0.109


GA
MUSCOGEE
179,278

0.65

0.095
58

GA
PAULDING
41,611


0.0052
0.114


GA
RICHMOND
189,719



0.099
44

GA
ROCKDALE
54,091


0.0059
0.123


GA
SPALDING
54,457




48

GA
WASHINGTON
19,112




59

HI
HONOLULU
836,231
3
0.03
0.0031
0.047
29
0.009
HI
KAUAI
51,177




36

ID
ADA
205,775
5

0.0228

90

ID
BANNOCK
66,026


0.0144

89
0.03
ID
BLAINE
13,552




52

ID
BONNER
26,622




78

ID
BONNEVILLE
72,207




76

ID
BUTTE
2,918



0.081


ID
CANYON
90,076




74

ID
CARIBOU
6,963




72

ID
KOOTENAI
69,795




76

ID
LEMHI
6,899




100

ID
LEWIS
3,516




63

92 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
03
PM
' m10
so2


1990
8-hr
QMAX
AM
2nd MAX 2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
ID
MADISON
23,674




67

ID
MINIDOKA
19,361




62

ID
NEZ PERCE
33,754
5.9



63

ID
SHOSHONE
13,931

0.1


101

ID
TWIN FALLS
53,580




64

IL
ADAMS
66,090



0.099
41
0.03
IL
CHAMPAIGN
173,025



0.094
39
0.013
IL
COLES
51,644




44

IL
COOK
5,105,067
4.9
0.54
0.032
0.117
122
0.032
IL
DU PAGE
781,666

0.05

0.087
56

IL
EFFINGHAM
31,704



0.097


IL
JACKSON
61,067




37

IL
JERSEY
20,539



0.102


IL
KANE
317,471



0.096


IL
LAKE
516,418


0.008
0.125


IL
LA SALLE
106,913




111

IL
MC HENRY
183,241



0.094


IL
MACON
117,206

0.02

0.1
53
0.022
IL
MACOUPIN
47,679
0.7
0.01

0.102
39
0.012
IL
MADISON
249,238
2.5
3.1

0.127
107
0.102
IL
PEORIA
182,827
4.6
0.02

0.091
43
0.047
IL
RANDOLPH
34,583



0.093
89
0.06
IL
ROCK ISLAND
148,723

0.02

0.081
48

IL
ST CLAIR
262,852

0.11
0.0202
0.089
63

IL
SANGAMON
178,386
3


0.098
26
0.061
IL
TAZEWELL
123,692




44
0.043
IL
WABASH
13,111





0.043
IL
WILL
357,313
0.9
0.02
0.009
0.093
47
0.023
IL
WINNEBAGO
252,913
3.2
0.05

0.089
36

IN
ALLEN
300,836
2.7
0.02

0.105
70

IN
CLARK
87,777



0.098
54

IN
DAVIESS
27,533





0.05
IN
DEARBORN
38,835





0.045
IN
DE KALB
35,324
0.7
0
0.0074
0.082
80

IN
DELAWARE
119,659

0.94




IN
DUBOIS
36,616




52

IN
ELKHART
156,198



0.115


IN
FLOYD
64,404



0.119

0.038
IN
FOUNTAIN
17,808





0.037
IN
GIBSON
31,913





0.076
IN
HAMILTON
108,936



0.116


IN
HANCOCK
45,527



0.12


IN
JASPER
24,960




41
0.012
IN
JEFFERSON
29,797





0.013
IN
KNOX
39,884



0.103


IN
LAKE
475,594
3.7
0.21
0.0208
0.113
95
0.031
IN
LA PORTE
107,066



0.128


IN
MADISON
130,669



0.121
46

IN
MARION
797,159
3.1
0.16
0.0179
0.121
71
0.041
IN
MORGAN
55,920





0.027
IN
PIKE
12,509





0.054
IN
PORTER
128,932



0.132
208
0.026
IN
POSEY
25,968



0.064

0.04
IN
ST JOSEPH
247,052
2.5

0.0155
0.11
45

IN
SPENCER
19,490





0.03
IN
SULLIVAN
18,993





0.022
IN
TIPPECANOE
130,598
1.1

0.0126

34
0.02
IN
VANDERBURGH
165,058
4.1

0.0117
0.105
45
0.04
IN
VERMILLION
16,773




44

IN
VIGO
106,107
2.6


0.112
53
0.039
IN
WARRICK
44,920



0.115

0.097
IN
WAYNE
71,951





0.036
IA
BLACK HAWK
123,798




59

IA
CERRO GORDO
46,733




151

IA
CLINTON
51,040




78
0.042
IA
DELAWARE
18,035




45

IA
DUBUQUE
86,403





0.022
IA
EMMET
11,569




39

IA
LEE
38,687





0.045
IA
LINN
168,767
7.8


0.073
65
0.2
IA
MUSCATINE
39,907




72
0.086
IA
POLK
327,140
4


0.082
130

APPENDIX A: DATA TABLES 93

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
o3
PM
10
so2


1990
8-hr
QMAX
AM
2nd MAX
2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
IA
POTTAWATTAMIE
82,628

0.37




IA
SCOTT
150,979



0.09
153
0.024
IA
UNION
12,750




49

IA
VAN BUREN
7,676



0.082


IA
WOODBURY
98,276




95

KS
CLOUD
11,023

0.01


48

KS
FORD
27,463

0.01


48

KS
GREELEY
1,774

0.01


102

KS
JOHNSON
355,054

0.01


67

KS
KEARNEY
4,027




69

KS
MIAMI
23,466



0.1


KS
MORTON
3,480

0.01


81

KS
PAWNEE
7,555
0.3


0.08

0.001
KS
SEDGWICK
403,662
6.4
0.02

0.095
119
0.007
KS
SHAWNEE
160,976

0.01


58

KS
SHERMAN
6,926
0.3
0.01

0.05
74
0.001
KS
WYANDOTTE
161,993
2.7
0.07
0.0216
0.106
120
0.057
KY
BELL
31,506
3.5


0.092
47

KY
BOONE
57,589



0.101


KY
BOYD
51,150
3.7

0.013
0.102
86
0.057
KY
BULLITT
47,567


0.0133
0.11
49

KY
CAMPBELL
83,866


0.0185
0.115
62
0.029
KY
CHRISTIAN
68,941



0.1
39
0.019
KY
DAVIESS
87,189
2.7

0.0114
0.107
59
0.02
KY
EDMONSON
10,357



0.107


KY
FAYETTE
225,366
3.1

0.0137
0.096
60
0.02
KY
FLOYD
43,586




50

KY
GRAVES
33,550



0.086


KY
GREENUP
36,742

0.02

0.097

0.023
KY
HANCOCK
7,864



0.11

0.025
KY
HARDIN
89,240



0.093
49

KY
HARLAN
36,574




51

KY
HENDERSON
43,044
2

0.0173
0.108
59
0.041
KY
JEFFERSON
664,937
5.6
0.02
0.0202
0.121
61
0.03
KY
JESSAMINE
30,508



0.082


KY
KENTON
142,031
3.3

0.0192
0.112
56

KY
LAWRENCE
13,998



0.082
54
0
KY
LIVINGSTON
9,062



0.105
51
0.021
KY
MC CRACKEN
62,879
3.2

0.0116
0.087
61

KY
MC LEAN
9,628



0.094


KY
MADISON
57,508




53

KY
MARSHALL
27,205




54

KY
OLDHAM
33,263



0.109


KY
PERRY
30,283



0.09
43

KY
PIKE
72,583



0.087
37

KY
PULASKI
49,489



0.083
55

KY
SCOTT
23,867



0.095


KY
SIMPSON
15,145


0.0141
0.094


KY
TRIGG
10,361



0.101


KY
WARREN
76,673




46

KY
WHITLEY
33,326




44

KY
WOODFORD
19,955

0.04




LA
ASCENSION PARISH
58,214



0.121


LA
BEAUREGARD PARISH
30,083


0.0054
0.092


LA
BOSSIER PARISH
86,088



0.096
44
0.004
LA
CADDO PARISH
248,253



0.1
47

LA
CALCASIEU PARISH
168,134


0.0056
0.101
33
0.018
LA
EAST BATON ROUGE PARISH
380,105
4.7
0.15
0.0208
0.118


LA
GRANT PARISH
17,526



0.085


LA
IBERVILLE PARISH
31,049


0.0105
0.139
42

LA
JEFFERSON PARISH
448,306


0.0118
0.1


LA
LAFAYETTE PARISH
164,762



0.098
25

LA
LAFOURCHE PARISH
85,860



0.094


LA
LIVINGSTON PARISH
70,526


0.0051
0.116


LA
ORLEANS PARISH
496,938
4
0.02
0.0178
0.091
44

LA
OUACHITA PARISH
142,191



0.089
76
0.007
LA
POINTE COUPEE PARISH
22,540


0.0068
0.102


LA
RAPIDES PARISH
131,556




42

LA
ST BERNARD PARISH
66,631



0.105


LA
ST CHARLES PARISH
42,437



0.102
64

LA
ST JAMES PARISH
20,879


0.0133
0.113


LA
ST JOHN THE BAPTIST PARISH
39,996

0.09




94 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
03
PM
10
so2


1990
8-hr
QMAX
AM
2nd MAX
2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
LA
ST MARY PARISH
58,086



0.092


LA
WEST BATON ROUGE PARISH
19,419

0.03
0.0153
0.114


ME
ANDROSCOGGIN
105,259




37
0.018
ME
AROOSTOOK
86,936




104
0.04
ME
CUMBERLAND
243,135



0.1
61
0.021
ME
FRANKLIN
29,008




39

ME
HANCOCK
46,948


0.001
0.1
51

ME
KENNEBEC
115,904



0.096
64

ME
KNOX
36,310



0.104
39

ME
OXFORD
52,602



0.079
41
0.013
ME
PENOBSCOT
146,601



0.082
70
0.02
ME
PISCATAQUIS
18,653



0.07


ME
SAGADAHOC
33,535



0.108


ME
SOMERSET
49,767



0.093
26

ME
YORK
164,587


0.0106
0.104
37

MD
ALLEGANY
74,946




47
0.019
MD
ANNE ARUNDEL
427,239



0.126
44

MD
BALTIMORE
692,134
3

0.019
0.122
44

MD
CALVERT
51,372



0.094


MD
CARROLL
123,372



0.113


MD
CECIL
71,347



0.119
41

MD
CHARLES
101,154



0.099


MD
GARRETT
28,138




61

MD
HARFORD
182,132


0.0092
0.131


MD
KENT
17,842



0.107


MD
MONTGOMERY
757,027
3


0.108


MD
PRINCE GEORGES
729,268
4.5


0.116
50

MD
WICOMICO
74,339




34

MD
BALTIMORE
736,014
4.2
0.03
0.0269
0.108
75
0.024
MA
BARNSTABLE
186,605



0.124


MA
BERKSHIRE
139,352



0.108


MA
BRISTOL
506,325


0.0075
0.118
44
0.043
MA
ESSEX
670,080


0.0157
0.105
34
0.027
MA
HAMPDEN
456,310
7.7

0.0238
0.108
67
0.028
MA
HAMPSHIRE
146,568


0.0074
0.11
40
0.017
MA
MIDDLESEX
1,398,468
4.5


0.102
51
0.032
MA
NORFOLK
616,087




55

MA
PLYMOUTH
435,276



0.088


MA
SUFFOLK
663,906
4.7

0.031
0.089
80
0.037
MA
WORCESTER
709,705
5.3

0.0193
0.091
46
0.021
Ml
ALLEGAN
90,509


0.0091
0.123


Ml
BENZIE
12,200



0.108


Ml
BERRIEN
161,378



0.125


Ml
CALHOUN
135,982




57

Ml
CASS
49,477



0.115


Ml
CLINTON
57,883



0.077


Ml
DELTA
37,780





0.011
Ml
GENESEE
430,459

0.01

0.113
45
0.012
Ml
HURON
34,951



0.098


Ml
INGHAM
281,912



0.096


Ml
KALAMAZOO
223,411
1.5
0.01
0.0114
0.102
33
0.011
Ml
KENT
500,631
3.3
0.01

0.127
71
0.011
Ml
LENAWEE
91,476



0.104


Ml
MACOMB
717,400
2.8

0.012
0.108

0.022
Ml
MARQUETTE
70,887




78

Ml
MASON
25,537



0.128


Ml
MECOSTA
37,308



0.11


Ml
MONROE
133,600




45

Ml
MUSKEGON
158,983

0.01

0.123


Ml
OAKLAND
1,083,592
2.6


0.09


Ml
OTTAWA
187,768



0.113


Ml
ROSCOMMON
19,776



0.099


Ml
ST CLAIR
145,607



0.113


Ml
VAN BUREN
70,060

0.01
0.0083



Ml
WASHTENAW
282,937



0.099


Ml
WAYNE
2,111,687
6.2
0.04
0.0214
0.098
106
0.079
MN
ANOKA
243,641



0.078


MN
CARLTON
29,259




27

MN
DAKOTA
275,227
1.1
0.55
0.0157
0.081

0.024
MN
DOUGLAS
28,674




6

MN
GOODHUE
40,690




19

MN
HENNEPIN
1,032,431
4.7
0.01
0.0281

91
0.013
APPENDIX A: DATA TABLES 95

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
03
PM
10
so2


1990
8-hr
QMAX
AM
2nd MAX
2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
MN
KOOCHICHING
16,299



0.074
22
0.011
MN
LAKE
10,415



0.074


MN
MORRISON
29,604




24

MN
OLMSTED
106,470




44
0.016
MN
PINE
21,264




13

MN
PIPESTONE
10,491




21

MN
RAMSEY
485,765
7.3
0.01
0.0193

89
0.01
MN
ST LOUIS
198,213
4.5


0.074
58

MN
SHERBURNE
41,945




38
0.011
MN
STEARNS
118,791
4





MN
WASHINGTON
145,896



0.09
48
0.041
MN
WRIGHT
68,710


0.0083


0.007
MS
ADAMS
35,356



0.094


MS
CHOCTAW
9,071
1.2
0.01
0.0043
0.055
14
0.006
MS
COAHOMA
31,665




37

MS
DE SOTO
67,910



0.145


MS
HANCOCK
31,760



0.104


MS
HARRISON
165,365





0.043
MS
HINDS
254,441
4.8


0.097
55
0.008
MS
JACKSON
115,243



0.101
33
0.017
MS
JONES
62,031




44

MS
LAUDERDALE
75,555



0.091


MS
LEE
65,581



0.086


MS
MADISON
53,794



0.088


MS
SHARKEY
7,066



0.09


MS
WARREN
47,880



0.097
40

MS
WASHINGTON
67,935




39

MO
AUDRAIN
23,599




40

MO
BUCHANAN
83,083




126
0.079
MO
CHRISTIAN
32,644




148

MO
CLAY
153,411
4.4

0.0132
0.114

0.009
MO
GREENE
207,949
3.3

0.0113
0.095
101
0.089
MO
HOLT
6,034

0.82




MO
HOWELL
31,447




1321

MO
IRON
10,726

9.89



0.084
MO
JACKSON
633,232
3.8
0.01
0.0178
0.094
73
0.033
MO
JEFFERSON
171,380

5.74

0.113
43
0.078
MO
MARION
27,682




34

MO
MONROE
9,104



0.098
35
0.01
MO
PLATTE
57,867


0.0124
0.092

0.008
MO
ST CHARLES
212,907


0.0107
0.122
41

MO
STE GENEVIEVE
16,037


0.004
0.122
47

MO
ST LOUIS
993,529
4.2
0.03
0.0218
0.11
57

MO
TANEY
25,561
1.1





MO
ST LOUIS
396,685
6.4

0.0248
0.116
85
0.04
MT
BIG HORN
11,337




103

MT
BROADWATER
3,318




61
0.014
MT
CASCADE
77,691
5.4



59
0.02
MT
FERGUS
12,083




38

MT
FLATHEAD
59,218
11.1


0.064
91

MT
GALLATIN
50,463




74

MT
GLACIER
12,121




54

MT
JEFFERSON
7,939




34
0.055
MT
LAKE
21,041




122

MT
LEWIS AND CLARK
47,495

3.12




MT
LINCOLN
17,481




94

MT
MADISON
5,989




30

MT
MISSOULA
78,687
5.6



112

MT
PARK
14,562




48

MT
PHILLIPS
5,163




30

MT
RAVALLI
25,010




69

MT
ROOSEVELT
10,999




53

MT
ROSEBUD
10,505


0.0057

120
0.011
MT
SANDERS
8,669




109

MT
SILVER BOW
33,941




90

MT
STILLWATER
6,536




35

MT
YELLOWSTONE
113,419
7.1



75
0.099
NE
ADAMS
29,625




60

NE
BUFFALO
37,447




74

NE
CASS
21,318




145

NE
DAWSON
19,940




99

NE
DOUGLAS
416,444
6.9
5.06

0.074
81
0.051
96 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
03
PM
r™m
so2


1990
8-hr
QMAX
AM
2nd MAX 2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
NE
LANCASTER
213,641
4.7


0.06
63

NE
OTOE
14,252




41

NE
SCOTTS BLUFF
36,025




51

NV
CHURCHILL
17,938




61

NV
CLARK
741,459
10.1

0.0271
0.096
328

NV
DOUGLAS
27,637
2.1

0.0101
0.083
82

NV
ELKO
33,530




107

NV
LANDER
6,266




143

NV
PERSHING
4,336




144

NV
WASHOE
254,667
7.6


0.096
131

NV
WHITE PINE
9,264



0.081
55

NV
CARSON CITY
40,443




52

NH
BELKNAP
49,216



0.088


NH
CARROLL
35,410



0.079


NH
CHESHIRE
70,121



0.091
46
0.024
NH
COOS
34,828




61
0.045
NH
GRAFTON
74,929



0.07


NH
HILLSBOROUGH
336,073
7.6

0.0192
0.103
44
0.026
NH
MERRIMACK
120,005



0.095
38
0.033
NH
ROCKINGHAM
245,845


0.0125
0.107
42
0.015
NH
STRAFFORD
104,233



0.098
38

NH
SULLIVAN
38,592



0.09
37
0.017
NJ
ATLANTIC
224,327
3.6
0.01

0.108
40
0.014
NJ
BERGEN
825,380
4

0.0278
0.106
61
0.026
NJ
BURLINGTON
395,066
4.6




0.023
NJ
CAMDEN
502,824
5
0.08
0.0235
0.125
65
0.027
NJ
CUMBERLAND
138,053



0.105

0.016
NJ
ESSEX
778,206
3.8
0.07
0.0322
0.115
67
0.027
NJ
GLOUCESTER
230,082



0.118
43
0.024
NJ
HUDSON
553,099
6.7
0.03
0.0272
0.12
83
0.03
NJ
HUNTERDON
107,776



0.108


NJ
MERCER
325,824


0.0169
0.121
59

NJ
MIDDLESEX
671,780
3.3
0.06
0.0203
0.125
46
0.024
NJ
MONMOUTH
553,124
4.6


0.123


NJ
MORRIS
421,353
5.4

0.0114
0.114

0.023
NJ
OCEAN
433,203
4.2


0.118


NJ
PASSAIC
453,060

0


48

NJ
SALEM
65,294

0.02




NJ
UNION
493,819
6

0.0412
0.111
60
0.03
NJ
WARREN
91,607




53

NM
BERNALILLO
480,577
7.1

0.022
0.098
94

NM
CHAVES
57,849




37

NM
CIBOLA
23,794




18

NM
DONA ANA
135,510
4.3
0.07
0.009
0.124
143

NM
EDDY
48,605


0.0051


0.007
NM
GRANT
27,676




40
0.02
NM
HIDALGO
5,958




35
0.022
NM
LEA
55,765




35

NM
LUNA
18,110




49

NM
MC KINLEY
60,686




34

NM
OTERO
51,928




70

NM
SANDOVAL
63,319
1.4

0.0077
0.088
39

NM
SAN JUAN
91,605
2.9

0.0068

31

NM
SANTA FE
98,928
2.2



33

NM
TAOS
23,118




103

NM
VALENCIA
45,235



0.079


NY
ALBANY
292,594

0.03
0.0146
0.105
45
0.025
NY
BRONX
1,203,789
3.3

0.0355
0.122
55
0.055
NY
BROOME
212,160




34

NY
CHAUTAUQUA
141,895



0.097
33
0.039
NY
CHEMUNG
95,195



0.088
24
0.016
NY
DUTCHESS
259,462



0.109


NY
ERIE
968,532
3.7
0.03
0.0224
0.091
39
0.041
NY
ESSEX
37,152



0.093
25
0.009
NY
GREENE
44,739




49

NY
HAMILTON
5,279



0.076

0.008
NY
HERKIMER
65,797



0.073
30
0.009
NY
JEFFERSON
110,943



0.084


NY
KINGS
2,300,664
6.1
0.16
0.0347
0.114
57
0.038
NY
MADISON
69,120



0.082

0.015
NY
MONROE
713,968
3.9
0.04

0.083
54
0.041
NY
NASSAU
1,287,348
4.9

0.0258

55
0.031
APPENDIX A: DATA TABLES 97

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
03
PM
r™m
so2


1990
8-hr
QMAX
AM
2nd MAX
2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
NY
NEW YORK
1,487,536
6.3
0.06
0.0422

87

NY
NIAGARA
220,756
2.7
0.02

0.099
78
0.048
NY
ONEIDA
250,836



0.076
43

NY
ONONDAGA
468,973
3.9


0.088
61
0.012
NY
ORANGE
307,647

0.06

0.12


NY
PUTNAM
83,941



0.122
37
0.015
NY
QUEENS
1,951,598



0.108

0.035
NY
RENSSELAER
154,429




42
0.011
NY
RICHMOND
378,977

0.04

0.117
45
0.027
NY
ROCKLAND
265,475




50

NY
SARATOGA
181,276



0.091
45

NY
SCHENECTADY
149,285
3.7


0.085
48
0.021
NY
STEUBEN
99,088




26

NY
SUFFOLK
1,321,864



0.12
40
0.025
NY
ULSTER
165,304



0.095
51
0.011
NY
WARREN
59,209




40
0.013
NY
WAYNE
89,123



0.086


NY
WESTCHESTER
874,866



0.115


NC
ALAMANCE
108,213




50

NC
ALEXANDER
27,544



0.094
60
0.012
NC
BEAUFORT
42,283




33
0.024
NC
BUNCOMBE
174,821



0.084
76

NC
CABARRUS
98,935




46

NC
CARTERET
52,556



0.09


NC
CASWELL
20,693
0.4


0.108


NC
CATAWBA
118,412




50

NC
CHATHAM
38,759



0.1
37

NC
COLUMBUS
49,587





0.006
NC
CUMBERLAND
274,566
4.1


0.106
53
0.012
NC
DAVIDSON
126,677




49

NC
DAVIE
27,859



0.103


NC
DUPLIN
39,995



0.083

0.01
NC
DURHAM
181,835
5.4


0.103
46

NC
EDGECOMBE
56,558



0.091
39
0.01
NC
FORSYTH
265,878
4.3

0.0164
0.119
58
0.026
NC
FRANKLIN
36,414
0.8


0.107


NC
GASTON
175,093
3.6



52

NC
GRANVILLE
38,345
0.7


0.124
44

NC
GUILFORD
347,420
3.8


0.109
54

NC
HALIFAX
55,516




51

NC
HARNETT
67,822




45

NC
HAYWOOD
46,942



0.095
49

NC
HENDERSON
69,285




53

NC
JOHNSTON
81,306



0.102

0.01
NC
LINCOLN
50,319



0.1
50
0.013
NC
MC DOWELL
35,681




59

NC
MACON
23,499



0.08


NC
MECKLENBURG
511,433
5.1

0.0163
0.13
53
0.015
NC
MITCHELL
14,433




59

NC
NEW HANOVER
120,284



0.09
46

NC
NORTHAMPTON
20,798





0.012
NC
ONSLOW
149,838




37

NC
ORANGE
93,851
5.1





NC
PASQUOTANK
31,298




33

NC
PITT
107,924



0.097
36

NC
ROBESON
105,179




53

NC
ROCKINGHAM
86,064



0.123


NC
ROWAN
110,605
0.8

0.008
0.133
47

NC
SWAIN
11,268



0.075
48
0.01
NC
WAKE
423,380
5.6


0.107
49

NC
WATAUGA
36,952




46

NC
WAYNE
104,666




43

NC
WILSON
66,061




41

NC
YANCEY
15,419



0.09

0.003
ND
BILLINGS
1,108





0.007
ND
BURLEIGH
60,131




27

ND
CASS
102,874


0.008
0.075
54
0.008
ND
DUNN
4,005





0.007
ND
GRAND FORKS
70,683




53

ND
MC KENZIE
6,383



0.063


ND
MERCER
9,808


0.0043
0.062
45
0.033
ND
MORTON
23,700





0.056
98 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
03
PM
10
so2


1990
8-hr
QMAX
AM
2nd MAX
2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
ND
OLIVER
2,381


0.003
0.063

0.013
ND
STARK
22,832




23

ND
STEELE
2,420


0.0027
0.068
38
0.006
ND
WILLIAMS
21,129




23
0.013
OH
ADAMS
25,371





0.026
OH
ALLEN
109,755



0.11
44
0.015
OH
ASHTABULA
99,821



0.105

0.022
OH
ATHENS
59,549




47

OH
BELMONT
71,074




86
0.057
OH
BUTLER
291,479

0.05

0.115
78
0.026
OH
CLARK
147,548



0.116

0.031
OH
CLERMONT
150,187



0.104

0.025
OH
CLINTON
35,415



0.118


OH
COLUMBIANA
108,276

0.04
0.0191

86
0.057
OH
CUYAHOGA
1,412,140
9.4
1.06
0.0259
0.108
123
0.049
OH
FRANKLIN
961,437
2.7
0.07

0.107
66
0.021
OH
FULTON
38,498

0.44




OH
GREENE
136,731




27

OH
HAMILTON
866,228
2.8
0.22
0.0285
0.107
72
0.036
OH
HANCOCK
65,536




44

OH
JEFFERSON
80,298
5.3

0.0197
0.094
126
0.055
OH
KNOX
47,473



0.113


OH
LAKE
215,499
1.9


0.117
42
0.037
OH
LAWRENCE
61,834



0.123
53
0.018
OH
LICKING
128,300



0.108
20

OH
LOGAN
42,310

0.26

0.097


OH
LORAIN
271,126



0.099
67
0.032
OH
LUCAS
462,361
2.6


0.113
69
0.049
OH
MADISON
37,068



0.107


OH
MAHONING
264,806



0.102
47
0.03
OH
MEDINA
122,354



0.096


OH
MEIGS
22,987





0.027
OH
MIAMI
93,182



0.11


OH
MONROE
15,497




66

OH
MONTGOMERY
573,809
3
0.05

0.112
66
0.022
OH
MORGAN
14,194





0.057
OH
NOBLE
11,336




48

OH
OTTAWA
40,029




38

OH
PORTAGE
142,585



0.107


OH
PREBLE
40,113



0.111


OH
RICHLAND
126,137




68

OH
SANDUSKY
61,963




79

OH
SCIOTO
80,327




60
0.023
OH
SENECA
59,733




58

OH
STARK
367,585
2.5


0.097
68
0.032
OH
SUMMIT
514,990
3.4
0.04

0.103
73
0.042
OH
TRUMBULL
227,813



0.107
43

OH
TUSCARAWAS
84,090





0.034
OH
WARREN
113,909



0.11


OH
WASHINGTON
62,254



0.105
78

OH
WYANDOT
22,254




66

OK
CARTER
42,919




52

OK
CLEVELAND
174,253
2.7

0.0132
0.088
56

OK
COMANCHE
111,486
1.6

0.0087
0.077
56

OK
GARFIELD
56,735


0.0094



OK
GARVIN
26,605





0.014
OK
KAY
48,056




70
0.02
OK
MCCLAIN
22,795



0.089


OK
MAYES
33,366




60

OK
MUSKOGEE
68,078


0.0085

91
0.021
OK
OKLAHOMA
599,611
7.9
0.01
0.0139
0.102
54
0.005
OK
TULSA
503,341
6.8
0.11
0.015
0.115
76
0.042
OK
WOODWARD
18,976




69

OR
CLACKAMAS
278,850



0.133
39

OR
COLUMBIA
37,557



0.094


OR
DESCHUTES
74,958
5.3



123

OR
JACKSON
146,389
6.6
0.02

0.101
82

OR
JOSEPHINE
62,649
6



62

OR
KLAMATH
57,702
4.8



86

OR
LAKE
7,186




68

OR
LANE
282,912
5.7
0.02

0.111
78

OR
MARION
228,483
7.1


0.117


APPENDIX A: DATA TABLES 99

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
o3
PM
10
so2


1990
8-hr
QMAX
AM
2nd MAX
2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
OR
MULTNOMAH
583,887
6.5
0.02
0.0182

70

OR
UMATILLA
59,249




66

OR
UNION
23,598




121

OR
YAMHILL
65,551

0.11




PA
ADAMS
78,274



0.099


PA
ALLEGHENY
1,336,449
4.3
0.07
0.0303
0.113
123
0.07
PA
BEAVER
186,093
2.1
0.06
0.018
0.105
76
0.058
PA
BERKS
336,523
3.4
0.82
0.0219
0.11
66
0.037
PA
BLAIR
130,542
1.9

0.0134
0.101
60
0.033
PA
BUCKS
541,174
4.7

0.0211
0.12
58
0.028
PA
CAMBRIA
163,029
4.8
0.05
0.0175
0.098
63
0.034
PA
CARBON
56,846

0.08




PA
CENTRE
123,786



0.089


PA
CHESTER
376,396




69

PA
DAUPHIN
237,813
2.3
0.04
0.021
0.104
63
0.022
PA
DELAWARE
547,651

0.04
0.0214
0.117
69
0.025
PA
ERIE
275,572


0.0148
0.1
56
0.066
PA
FRANKLIN
121,082



0.096


PA
LACKAWANNA
219,039
3.5

0.0176
0.113
61
0.033
PA
LANCASTER
422,822
2.6
0.04
0.0172
0.101
69
0.021
PA
LAWRENCE
96,246
3.5

0.0237
0.097
91
0.034
PA
LEHIGH
291,130
3.2

0.0175
0.114
54
0.035
PA
LUZERNE
328,149
4.1

0.0176
0.105
60
0.023
PA
LYCOMING
118,710



0.082
46
0.028
PA
MERCER
121,003

0.07

0.103
52
0.029
PA
MONTGOMERY
678,111
2.9
0.04
0.0209
0.118
58
0.028
PA
NORTHAMPTON
247,105
3.1
0.04
0.0238
0.11
65
0.033
PA
PERRY
41,172


0.0083
0.09
39
0.02
PA
PHILADELPHIA
1,585,577
5.6
9.23
0.0339
0.13
356
0.063
PA
SCHUYLKILL
152,585
2.2




0.027
PA
WARREN
45,050





0.032
PA
WASHINGTON
204,584
2.5

0.0173
0.103
72
0.035
PA
WESTMORELAND
370,321

0.04

0.104
43

PA
YORK
339,574
2.8
0.07
0.0206
0.098
53
0.022
Rl
KENT
161,135


0.0031
0.107
33

Rl
PROVIDENCE
596,270
4.4

0.0249
0.112
83
0.032
SO
ABBEVILLE
23,862



0.083


SO
AIKEN
120,940

0

0.105
41

SO
ANDERSON
145,196

0.01

0.098
54

SO
BARNWELL
20,293



0.095
39

SO
BEAUFORT
86,425

0.01




SO
BERKELEY
128,776



0.099


SO
CHARLESTON
295,039
4.7
0.02
0.0102
0.099
54
0.021
SO
CHEROKEE
44,506



0.103


SO
CHESTER
32,170



0.095


SO
DARLINGTON
61,851



0.093


so
EDGEFIELD
18,375



0.092


so
FAIRFIELD
22,295




46

so
FLORENCE
114,344

0.01




so
GEORGETOWN
46,302

0.02


94
0.011
so
GREENVILLE
320,167
4.6
0.01
0.0158

77
0.012
so
GREENWOOD
59,567

0.01




so
LEXINGTON
167,611




117
0.02
so
OCONEE
57,494



0.082

0.008
so
PICKENS
93,894



0.11


so
RICHLAND
285,720
3.4
0.02
0.0126
0.099
115
0.011
so
SPARTANBURG
226,800

0

0.11
50

so
SUMTER
102,637

0.01




so
UNION
30,337



0.091


so
WILLIAMSBURG
36,815



0.085


so
YORK
131,497

0.01

0.105
49

SD
BROOKINGS
25,207




64

SD
MINNEHAHA
123,809




53

SD
PENNINGTON
81,343




137

TN
ANDERSON
68,250



0.102

0.035
TN
BENTON
14,524




55

TN
BLOUNT
85,969



0.102
42
0.058
TN
BRADLEY
73,712


0.0137

42
0.036
TN
COFFEE
40,339


0.0068

32
0.014
TN
DAVIDSON
510,784
5
0.08
0.0119
0.11
66
0.022
TN
DICKSON
35,061

0.01
0.0078

47
0.006
TN
GILES
25,741



0.104
48

100 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
03
PM
' m10
so2


1990
8-hr
QMAX
AM
2nd MAX 2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
TN
HAMILTON
285,536



0.114
65

TN
HARDIN
22,633





0.018
TN
HAWKINS
44,565





0.052
TN
HAYWOOD
19,437



0.1


IN
HENRY
27,888




53

TN
HUMPHREYS
15,795



0.102
51
0.02
TN
JEFFERSON
33,016



0.125


TN
KNOX
335,749
3.3


0.114
66

TN
LOUDON
31,255
0.9

0.0141
0.112
43
0.024
TN
MC MINN
42,383


0.0143

60

TN
MADISON
77,982

0.02


45

TN
MAURY
54,812




51

TN
MONTGOMERY
100,498




56
0.023
TN
POLK
13,643





0.037
TN
PUTNAM
51,373


0.0065

39
0.008
TN
ROANE
47,227

0.17


53
0.021
TN
RUTHERFORD
118,570



0.092

0.006
TN
SEVIER
51,043



0.107


TN
SHELBY
826,330
6.5
2.81
0.0241
0.122
60
0.017
TN
STEWART
9,479





0.019
TN
SULLIVAN
143,596
3
0.13
0.0176
0.104
67
0.05
TN
SUMNER
103,281



0.119

0.076
TN
UNION
13,694




78

TN
WASHINGTON
92,315




48

TN
WILLIAMSON
81,021

0.9

0.106

0.005
TN
WILSON
67,675



0.115

0.009
TX
BELL
191,088




41

TX
BEXAR
1,185,394
5
0.02
0.009
0.126
38

TX
BRAZORIA
191,707



0.11


TX
BREWSTER
8,681



0.084


TX
CAMERON
260,120
2.2
0.02

0.077
40
0.004
TX
COLLIN
264,036

0.7

0.114
65

TX
DALLAS
1,852,810
5.5
0.17
0.019
0.135
87
0.008
TX
DENTON
273,525


0.01
0.131


TX
ECTOR
118,934




59

TX
ELLIS
85,167

0.27
0.007
0.108
102
0.046
TX
EL PASO
591,610
10.3
0.4
0.0351
0.123
158

TX
GALVESTON
217,399

0.02
0.0051
0.107
52
0.067
TX
GREGG
104,948



0.106


TX
HARRIS
2,818,199
7
0.02
0.0233
0.18
68
0.046
TX
HIDALGO
383,545



0.063
111

TX
JEFFERSON
239,397
2.1
0.02
0.0083
0.117
34
0.044
TX
KAUFMAN
52,220

0.03




TX
LUBBOCK
222,636




85

TX
NUECES
291,145



0.103
45
0.015
TX
ORANGE
80,509


0.0111
0.119


TX
POTTER
97,874




38

TX
SMITH
151,309



0.104
30

TX
TARRANT
1,170,103
3.2
0.02
0.021
0.131
56
0.011
TX
TRAVIS
576,407
3.2

0.0182
0.098
32

TX
VICTORIA
74,361



0.087


TX
WEBB
133,239
5.5


0.069
103

TX
WICHITA
122,378




50

UT
CACHE
70,183
5.7


0.083
109

UT
DAVIS
187,941
4

0.0204
0.114
109
0.013
UT
GRAND
6,620




52

UT
IRON
20,789




38

UT
SALT LAKE
725,956
6.9
0.03
0.0253
0.124
157

UT
SAN JUAN
12,621



0.077


UT
TOOELE
26,601




50
0.002
UT
UTAH
263,590
9.1

0.0242
0.105
141

UT
WASHINGTON
48,560
3.4


0.086
85

UT
WEBER
158,330
7

0.0263
0.103
98

VT
BENNINGTON
35,845



0.098
41

VT
CHITTENDEN
131,761
3.3

0.0165
0.075
37
0.014
VT
RUTLAND
62,142
3.6

0.0124

39
0.032
VT
WASHINGTON
54,928




38

VT
WINDHAM
41,588




41

VA
ARLINGTON
170,936
4

0.0243
0.112
38

VA
CAROLINE
19,217


0.0073
0.097


VA
CARROLL
26,594




46

VA
CHARLES CITY
6,282


0.0102
0.104


APPENDIX A: DATA TABLES 101

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State
County

CO
Pb
no2
03
PM
10
so2


1990
8-hr
QMAX
AM
2nd MAX
2nd MAX
24-hr


Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(ppm)
VA
CHESTERFIELD
209,274



0.106
69

VA
CULPEPER
27,791




37

VA
FAIRFAX
818,584
4.4
0.02
0.0218
0.116
50
0.04
VA
FAUQUIER
48,741



0.094


VA
FREDERICK
45,723



0.095


VA
HANOVER
63,306



0.099


VA
HENRICO
217,881



0.102
64

VA
HENRY
56,942



0.104


VA
KING WILLIAM
10,913




56

VA
LOUDOUN
86,129




56

VA
MADISON
11,949



0.093


VA
NORTHUMBERLAND
10,524




45

VA
PRINCE WILLIAM
215,686


0.0113
0.098
36

VA
ROANOKE
79,332


0.0128
0.084

0.014
VA
SMYTH
32,370




40

VA
STAFFORD
61,236



0.1


VA
TAZEWELL
45,960




61

VA
WARREN
26,142




37

VA
WISE
39,573




61

VA
WYTHE
25,466



0.084


VA
ALEXANDRIA
111,183
3.7

0.0263
0.093
57
0.048
VA
BRISTOL
18,426




39

VA
CHARLOTTESVILLE
40,341




39

VA
CHESAPEAKE
151,976

0.03


38

VA
COVINGTON
6,991




47

VA
FREDERICKSBURG
19,027




38

VA
HAMPTON
133,793



0.097
50
0.019
VA
LYNCHBURG
66,049




41

VA
MARTINSVILLE
16,162




49

VA
NEWPORT NEWS
170,045
2.8





VA
NORFOLK
261,229
5.9

0.0179

36
0.025
VA
RICHMOND
203,056
3.2
0.01
0.0222

56
0.027
VA
ROANOKE
96,397
5.9



78

VA
SUFFOLK
52,141



0.093
46

VA
WINCHESTER
21,947




45

WA
ASOTIN
17,605




75

WA
BENTON
112,560




82

WA
CHELAN
52,250




37

WA
CLALLAM
56,464



0.058
43
0.085
WA
CLARK
238,053
6.4


0.108
44

WA
COWLITZ
82,119




55

WA
KING
1,507,319
6.8
0.66
0.0201
0.118
93
0.019
WA
KITSAP
189,731
3.5



41

WA
PIERCE
586,203
6.3


0.097
74
0.028
WA
SKAGIT
79,555



0.064

0.031
WA
SNOHOMISH
465,642
4.9


0.076
80
0.014
WA
SPOKANE
361,364
9


0.079
110

WA
THURSTON
161,238
4



53

WA
WALLA WALLA
48,439




122

WA
WHATCOM
127,780



0.078
37
0.013
WA
YAKIMA
188,823
7.4



112

WV
BERKELEY
59,253

0.01




WV
BROOKE
26,992




87
0.04
WV
CABELL
96,827

0.05

0.113

0.023
WV
FAYETTE
47,952




46

WV
GREENBRIER
34,693


0.0047
0.09

0.019
WV
HANCOCK
35,233
6.2
0.04
0.0158
0.099
170
0.066
WV
HARRISON
69,371

0.01




WV
KANAWHA
207,619
2.3
0.02
0.0197
0.104
50
0.039
WV
MARION
57,249

0.03




WV
MARSHALL
37,356




49
0.072
WV
MONONGALIA
75,509

0.01


57
0.042
WV
OHIO
50,871
3.5


0.105
48
0.045
WV
PUTNAM
42,835




48

WV
TUCKER
7,728



0.096


WV
WAYNE
41,636




51
0.035
WV
WOOD
86,915

0.02

0.108
50
0.046
w
BROWN
194,594



0.105

0.011
w
COLUMBIA
45,088



0.093


w
DANE
367,085
4.1


0.094
44
0.01
w
DODGE
76,559



0.092


w
DOOR
25,690



0.107


102 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-11. Maximum Air Quality Concentrations by County, 1996 (continued)
State County
CO	Pb	N02	03 PM10	S02
1990	8-hr QMAX AM 2nd MAX 2nd MAX 24-hr
Population (ppm) (pgm) (ppm) (ppm) (pgm) (ppm)
Wl
DOUGLAS
41,758
Wl
FLORENCE
4,590
Wl
FOND DU LAC
90,083
Wl
JEFFERSON
67,783
Wl
KENOSHA
128,181
Wl
KEWAUNEE
18,878
Wl
MANITOWOC
80,421
Wl
MARATHON
115,400
Wl
MILWAUKEE
959,275
Wl
ONEIDA
31,679
Wl
OUTAGAMIE
140,510
Wl
OZAUKEE
72,831
Wl
POLK
34,773
Wl
RACINE
175,034
Wl
ROCK
139,510
Wl
ST CROIX
50,251
Wl
SAUK
46,975
Wl
SHEBOYGAN
103,877
Wl
TAYLOR
18,901
Wl
VERNON
25,617
Wl
VILAS
17,707
Wl
WALWORTH
75,000
Wl
WASHINGTON
95,328
Wl
WAUKESHA
304,715
Wl
WINNEBAGO
140,320
WY
ALBANY
30,797
WY
CAMPBELL
29,370
WY
FREMONT
33,662
WY
LARAMIE
73,142
WY
NATRONA
61,226
WY
PARK
23,178
WY
SHERIDAN
23,562
WY
SWEETWATER
38,823
WY
TETON
11,172
03
0034
021
0065
0046
0.081
0.096
0.091
0.141
0.097
0.126
0.079
0.119
0.078
0.094
0.11
0.08
0.129
0.103
0.083
0.082
0.105
0.073
0.077
0.1
0.095
0.093
0.094
0.08
44
50
52
0.072
30
30
55
101
78
31
36
23
93
015
028
067
CO = Highest second maximum non-overlapping 8-hour concentration (Applicable NAAQS is 9 ppm)
Pb = Highest quarterly maximum concentration (Applicable NAAQS is 1.5 ug/rrf)
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)
PM-10 = Highest second maximum 24-hour concentration (Applicable NAAQS is 150 ug/rr?)
Data from exceptional events not included.
SO, = Highest second maximum 24-hour concentration (Applicable NAAQS is 0.14 ppm)
WTD = Weighted
AM = Annual mean
UGM = Units are micrograms per cubic meter
PPM = Units are parts per million
Note: The reader is cautioned that this summary is not adequate in itself to numerically rank counties according to their air quality. The
monitoring data represent the quality of air in the vicinity of the monitoring site but may not necessarily represent urban-wide air quality.
APPENDIX A: DATA TABLES 103

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-12. Trends From IMPROVE Monitoring Sites, 1988-1995
TOTAL LIGHT EXTINCTION (Mm1)
SITE
PERCENTILE
OBSERVED
SIGNIFICANCE
SLOPE LEVEL
1988
1989
1990
1991
1992
1993
1994
1995
Acadia NP
10TH
-.0377*
.0156
36.5
40.9
41.4
38.3
32.1
35.4
30.9
30.8
Badlands (W)
10TH
-.0222
.0543
28.0
25.8
26.4
26.5
27.2
25.8
24.3
21.9
Bandelier (W)
10TH
-.0323
.0894
22.6
26.5
28.2
25.4
23.5
24.2
22.9
18.3
Big Bend NP
10TH
-.0222
.0894
27.4
27.9
29.1
25.9
22.8
26.2
23.5
24.9
Bryce Canyon NP
10TH
-.0311
.0894
19.4
17.9
19.7
20.5
19.6
18.6
16.9
15.2
Bridger (W)
10TH
-.0253
.0543
16.5
17.2
19.3
16.5
17.0
15.4
16.2
13.7
Canyonlands NP
10TH
-.0386
.0543
20.3
22.0
24.6
23.0
20.0
21.0
19.4
16.4
Chiricahua (W)
10TH
-.0167*
.0305
22.7
22.1
23.0
22.3
20.5
21.7
20.4
20.8
Crater Lake NP
10TH
-.0242
.0543
17.9
19.2
19.3
19.2
18.8
16.6
17.3
14.6
Denali NP
10TH
-.0246*
.0071
17.2
16.4
21.5
17.0
15.7
15.2
15.2
14.5
Glacier NP
10TH
-.0169
.2742
29.7
31.3
33 9
35.7
35.1
32.3
27.9
26.4
Grand Canyon NP
10TH
-.0116
.2742
17.9
18.4
22.4
20.6
20.3
18.1
17.0
18.3
Great Sand Dunes (W)
10TH
-.0629*
.0071
23.6
22.2
26.4
24.8
21.2
19.9
18.5
15.8
Great Smoky Mtns NP
10TH
-.0190*
.0305
48.9
51.4
50.2
50.7
46.8
47.6
44.9
45.7
Guadalupe Mtns NP
10TH
-.0171
.1375
27.1
30.2
28.1
23.1
25.3
26.9
23.7
26.0
Lassen Vblcanic NP
10TH
-.0311
.0543
17.5
18.8
20.4
16.0
18.5
16.2
16.0
14.9
Mesa Verde NP
10TH
-.0415
.0894
21.6
19.6
25.2
22.6
20.2
19.1
20.2
15.7
Mt. Rainier NP
10TH
-.0305
.2742
24.7
23.4
27.4
27.9
32.7
25.4
21.1
19.0
Petrified Forest NP
10TH
-.0547*
.0305
23.3
28.0
28.4
27.7
24.0
22.2
22.4
19.5
Pinnacles (W)
10TH
-.0389*
.0156
31.9
32.8
41.1
29.5
27.7
31.6
25.7
25.1
Pt. Reyes NS
10TH
-.0257
.1375
32.0
33.7
42.8
35.5
33.0
35.2
31.0
27.8
Redwood NP
10TH
-.0316*
.0071
28.7
26.2
31.1
26.1
27.5
23.7
23 3
23.0
Rocky Mtns NP
10TH
-.0168
.1375
19.8
17.9
19.4
18.1
18.6
18.1
18.4
14.9
San Gorgonio (W)
10TH
-.0265
.1994
23.1
22.0
30.8
21.9
19.8
22.1
18.2
22.5
Shenandoah NP
10TH
-.0150
.1375
63.2
54.5
58.3
60.8
48.7
59.8
48.6
56.1
Tonto NM
10TH
-.0289*
.0156
27.8
27.1
29.8
25.3
25.9
24.1
22.5
24.4
Washington, DC
10TH
-.0021
.4524
88.0
93 3
95.6
92.2
93.4
107.5
91.9
68.9
Weminuche (W)
10TH
0.0016
.5476
17.6
18.4
19.7
20.9
20.6
18.1
20.5
15.4
Yellowstone NP
10TH
-.0550*
.0071
22.8
21.6
24.4
22.2
19.4
16.8
17.1
16.4
Yosemite NP
10TH
-.0060
.1994
18.1
17.1
24.2
17.9
18.8
18.0
16.4
17.7
Acadia NP
50TH
-.0314
.1375
61.0
75.9
65.0
66.4
59.5
61.0
61.5
53.2
Badlands (W)
50TH
-.0170
.0543
43.9
46.1
43.5
45.1
44.4
38.2
40.2
39.7
Bandelier (W)
50TH
-.0466*
.0071
32 9
34.6
35.6
33.7
32.0
30.8
28.9
24.8
Big Bend NP
50TH
-.0069
.1375
42.2
44.9
42.2
41.0
40.9
41.3
42.6
40.3
Bryce Canyon NP
50TH
-.0198
.1375
31.4
31.5
28.8
31.6
28.7
28.8
30.4
24.1
Bridger (W)
50TH
-.0242
.1375
24.5
24.9
27.6
26.1
27.0
22.4
23.6
21.0
Canyonlands NP
50TH
-.0264
.0894
29.7
29.2
34.7
33 2
29.5
29.2
29.3
23.1
Chiricahua (W)
50TH
-.0218*
.0305
34.4
32.8
34.5
32.0
30.1
32.8
31.1
29.1
Crater Lake NP
50TH
0.0065
.4524
24.0
28.1
30.2
32.2
30.4
25.2
31.4
22.4
Denali NP
50TH
-.0366*
.0156
22.5
24.3
27.5
21.1
19.5
19.4
21.0
18.0
Glacier NP
50TH
-.0152
.1994
52.7
51.0
54.0
55.0
54.5
48.6
51.0
44.1
Grand Canyon NP
50TH
-.0287
.0543
27.7
29.5
32.7
30.7
29.2
27.4
27.4
25.3
Great Sand Dunes (W)
50TH
-.0401*
.0156
30.5
33.4
33.1
31.9
30.7
26.4
27.1
23.9
Great Smoky Mtns NP
50TH
0.0105
.4524
86.3
93.1
94.5
85.8
100.2
104.8
76.3
90.7
Guadalupe Mtns NP
50TH
-.0093
.2742
39.7
42.1
45.6
37.6
34.2
37.4
41.0
37.9
Lassen Vblcanic NP
50TH
-.0210*
.0305
29.7
29.0
29.3
25.7
27.5
26.7
27.6
24.5
Mesa Verde NP
50TH
-.0176
.1994
29.5
27.2
28.2
30.7
26.7
27.2
29.0
23.6
Mt. Rainier NP
50TH
0.0037
.5476
58.0
54.3
55.0
65.7
69.7
67.8
57.2
48.5
104 APPENDIX A: DATA TABLES

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-12. Trends From IMPROVE Monitoring Sites, 1988-1995 (continued)
TOTAL LIGHT EXTINCTION (Mm1)
SITE
PERCENTILE
SLOPE
OBSERVED
SIGNIFICANCE
LEVEL 1988
1989
1990
1991
1992
1993
1994
1995
Petrified Forest NP
50TH
-.0416*
.0305
36.1
37.2
40.4
39.2
35.2
31.1
32.6
27.6
Pinnacles (W)
50TH
-.0323
.0894
55.1
58.1
63.5
55.1
52.3
55.5
46.2
47.6
Pt. Reyes NS
50TH
-.0375
.0543
56.8
62.6
68.7
59.6
51.5
53.3
55.2
44.5
Redwood NP
50TH
-.0191
.0894
48.7
52.3
58.5
51.6
50.5
43.5
48.7
46.7
Rocky Mtns NP
50TH
-.0186
.0894
30.5
31.3
31.8
30.2
31.9
27.7
30.1
23.7
San Gorgonio (W)
50TH
-.0178
.1994
65.0
71.3
70.3
73.8
57.5
72.7
62.2
55.9
Shenandoah NP
50TH
-.0126
.1375
125.7
105.6
117.8
124.0
125.6
122.5
109.1
103.8
Tonto NM
50TH
-.0252*
.0305
38.1
42.1
39 3
38.5
39.0
37.4
34.7
34.7
Washington, DC
50TH
0.0059
.2742
121.0
154.8
152.6
175.8
171.9
176.6
155.7
126.8
Weminuche (W)
50TH
-.0168*
.0305
29.0
30.7
29 3
29.8
29.0
27.7
28.6
23.0
Yellowstone NP
50TH
-.0364
.0543
27.8
29.5
31.5
31.7
28.2
26.7
26.1
21.9
Yosemite NP
50TH
-.0003
.5476
35.9
36.4
40.2
40.6
42.1
36 6
33.0
36.1
Acadia NP
90TH
0.0053
.5476
145.7
156.1
131.9
133.7
152.2
153.9
155.8
122.9
Badlands (W)
90TH
0.0081
.4524
68.0
65.3
65.3
67.6
86.8
69 3
74.6
64.8
Bandelier (W)
90TH
-.0119
.4524
41.9
52.2
36.2
40.6
44.9
42.4
43.2
38.2
Big Bend NP
90TH
-.0015
.3598
67.3
70.1
63.5
67.0
61.3
63 9
69.0
66.6
Bryce Canyon NP
90TH
-.0091
.1375
41.1
44.8
38.7
40.1
40.2
41.3
40.0
36.8
Bridger (W)
90TH
-.0170
.0543
37.8
37.5
38.0
36.4
40.3
31.6
35.2
30.7
Canyonlands NP
90TH
-.0394*
.0071
43.1
45.4
45.3
42.9
37.1
39.0
38.3
32.4
Chiricahua (W)
90TH
-.0050
.1994
51.0
45.7
45.9
45.5
45.1
48.0
48.7
44.5
Crater Lake NP
90TH
0.0006
.5476
47.4
52.7
51.0
49.2
48.0
53.6
53.5
41.6
Denali NP
90TH
-.0254
.1994
35.0
34.6
44.1
39.4
30.3
34.8
36.4
29.5
Glacier NP
90TH
-.0089
.3598
73.1
89.6
88.1
90.0
92.9
86.2
85.3
80.6
Grand Canyon NP
90TH
-.0142
.1375
40.0
44.2
44.9
38 3
38.8
39 6
39 6
36 3
Great Sand Dunes (W)
90TH
-.0353
.0894
43.2
48.1
42.7
42.2
36.0
37.4
52.7
34.6
Great Smoky Mtns NP
90TH
0.0113
.3598
154.0
175.9
219.0
194.6
188.5
172.9
185.8
188.6
Guadalupe Mtns NP
90TH
-.0209
.0894
62.8
69.1
58.7
55.2
53.7
55.6
61.9
54.7
Lassen N/blcanic NP
90TH
-.0116
.3598
48.5
54.3
43.6
37.2
45.7
46.5
49.1
41.9
Mesa Verde NP
90TH
-.0078
.2742
37.5
41.3
43.7
36 2
34.4
42.9
39.4
36.0
Mt. Rainier NP
90TH
-.0310
.2742
107.1
130.6
165.1
131.0
132.4
113.4
120.9
100.7
Petrified Forest NP
90TH
-.0323*
.0156
48.8
51.4
54.0
47.7
46.3
43.4
41.0
44.2
Pinnacles (W)
90TH
-.0393*
.0305
78.7
97.5
96.5
86.0
87.9
77.3
74.8
74.9
Pt. Reyes NS
90TH
-.0319
.2742
94.8
167.2
126.7
108.1
120.0
159.8
109.4
90.3
Redwood NP
90TH
-.0235
.0894
92.4
98.7
99 6
95.6
98.0
82.4
76.3
86.8
Rocky Mtns NP
90TH
-.0175
.0543
43.7
50.1
46.9
44.0
43.0
44.6
43.6
42.4
San Gorgonio (W)
90TH
-.0334
.0543
128.7
136.0
144.0
129.7
141.8
119.9
116.7
98.5
Shenandoah NP
90TH
0.0091
.3598
227.2
232.3
249.8
263.7
255.2
219.7
240.7
244.7
Tonto NM
90TH
-.0113
.1994
52.8
62.1
48.8
51.6
51.7
54.7
43.9
49.7
Washington, DC
90TH
0.0005
.5476
246.2
235.6
229.1
296.0
307.4
298.6
263.2
225.2
Weminuche (W)
90TH
-.0257*
.0156
39.8
46.2
40.4
40.5
37.4
38.4
36.7
35.7
Yellowstone NP
90TH
-.0358*
.0305
50.7
49.3
47.5
42.7
46.8
38.7
50.1
37.2
Yosemite NP
90TH
-.0088
.3598
73.1
66.0
73.4
63.0
73.4
60.1
65.8
69 6
*	Denotes that the slope is significant at the .05 significance level.
NP	= National Park
W	= Wilderness
NS	= National Seashore
NM	= National Monument
APPENDIX A: DATA TABLES 105

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-12. Trends From IMPROVE Monitoring Sites, 1988-1995
LIGHT EXTINCTION DUE TO SULFATE (Mm1)
OBSERVED
SIGNIFICANCE
SITE PERCENTILE SLOPE LEVEL
1988
1989
1990
1991
1992
1993
1994
1995
Acadia NP
10TH
-.0353
. 1375
12.5
16.1
17.0
14.7
12.0
13.8
11.0
12.9
Badlands (W)
10TH
0.0187
.3598
4.9
5.5
6.0
6.0
7.8
6.5
5.8
5.2
Bandelier (W)
10TH
-.0200
.3598
2.8
3.7
4.7
4.3
4.7
4.1
3.5
2.5
Big Bend NP
10TH
-.0130
.4524
5.7
6.4
7.0
5.2
5.0
6.5
5.2
6.0
Bryce Canyon NP
10TH
-.0362
.4524
3.0
1.9
2.7
3.2
3 9
3.0
2.3
2.1
Bridger (W)
10TH
0.0000
.5476
1.7
1.8
2.7
2.0
2.9
2.0
2.0
1.6
Canyonlands NP
10TH
-.0629
.3598
3.0
3.1
5.1
3.8
3 9
3.5
3.1
2.0
Chiricahua (W)
10TH
0.0000
.5476
3.4
3.6
4.5
4.2
4.0
4.2
3.4
3.7
Crater Lake NP
10TH
-.0138
.4524
1.7
2.1
2.5
2.0
3.5
2.3
2.0
1.5
Denali NP
10TH
0.0123
.4524
1.6
1.6
2.7
2.1
2.2
1.9
2.1
1.9
Glacier NP
10TH
-.0105
.5476
5.7
8.5
9.6
9.4
11.5
9.0
7.0
7.0
Grand Canyon NP
10TH
0.0000
.5476
2.0
1.9
2.8
2.8
3 6
2.6
1.9
2.3
Great Sand Dunes (W)
10TH
-.0489
.2742
2.9
2.4
4.1
3.5
4.1
3.2
2.8
2.0
Great Smoky Mtns NP
10TH
-.0129
.1994
17.2
21.0
20.7
20.3
18.2
19.2
16.9
19.6
Guadalupe Mtns NP
10TH
0.0060
.5476
5.3
7.1
6.5
4.5
5.7
6.0
5.3
6 9
Lassen Vblcanic NP
10TH
0.0000
.4524
1.3
1.6
1.3
0.9
2.5
1.6
1.3
1.4
Mesa Verde NP
10TH
-.0281
.3598
2.6
2.7
5.2
3.5
4.0
3 3
3.1
2.3
Mt. Rainier NP
10TH
-.0353
.2742
5.7
6.3
7.8
7.5
11.7
7.1
4.8
4.0
Petrified Forest NP
10TH
-.0573
.2742
2.7
3 9
4.9
5.1
4.3
3.7
3.2
2.9
Pinnacles (W)
10TH
-.0542
.0543
5.9
5.6
7.3
5.1
4.7
5.9
4.2
4.6
Pt. Reyes NS
10TH
0.0264
.4524
7.1
8.7
15.7
12.8
10.1
12.0
10.9
9.5
Redwood NP
10TH
-.0164
.3598
7.5
5.8
8.5
7.0
9.0
6.3
5.6
7.0
Rocky Mtns NP
10TH
-.0458
.1375
2.1
2.4
2.4
2.2
2.8
2.2
1.8
1.5
San Gorgonio (W)
10TH
0.0205
.3598
1.9
2.0
2.8
2.0
2.3
2.2
1.6
2.4
Shenandoah NP
10TH
-.0058
.3598
26.1
24.7
25.4
26.3
22.6
26.1
19.9
25.5
Tonto NM
10TH
-.0164
.2742
3 3
3.8
5.2
3 6
4.6
3.7
3.2
3.4
Washington, DC
10TH
-.0133
.3598
35.5
34.1
32.9
36.0
39.8
45.7
32.3
29.9
Weminuche (W)
10TH
0.0746
.1994
1.3
1.9
2.4
2.4
3.4
2.4
3.1
1.7
Yellowstone NP
10TH
-.0592*
.0305
3.1
2.5
3.0
2.8
3.0
2.0
2.3
2.0
Yosemite NP
10TH
0.0000
.4524
1.4
1.5
2.7
1.5
2.9
1.8
1.4
1.5
Acadia NP
50TH
-.0491*
.0305
29.5
39 6
35 3
33 3
29.3
30.3
29.4
25.6
Badlands (W)
50TH
0.0092
.2742
11.8
14.1
14.3
14.0
14.7
12.6
14.0
14.3
Bandelier (W)
50TH
0.0000
.5476
6.7
6.6
6.3
6.6
7.3
7.3
6.7
5.0
Big Bend NP
50TH
0.0069
.2742
13.0
12.9
12.9
10.6
12.2
12.9
13.5
13.6
Bryce Canyon NP
50TH
-.0095
.4524
7.8
7.4
6.7
7.6
8.4
7.1
8.8
6.0
Bridger (W)
50TH
0.0000
.5476
3.8
5.0
5.0
4.8
6.0
4.6
5.0
4.6
Canyonlands NP
50TH
-.0432
.1994
6.5
5.7
8.0
7.8
7.0
6.2
6.5
4.6
Chiricahua (W)
50TH
0.0099
.3598
8.5
8.0
8.7
7.2
8.0
10.0
9.5
8.2
Crater Lake NP
50TH
0.0684
.1375
3.7
4.2
4.9
7.0
7.5
5.7
6.1
4.7
Denali NP
50TH
0.0366
.3598
3.2
5.6
7.7
3.8
4.2
4.5
4.7
4.3
Glacier NP
50TH
0.0169
.0543
13.1
14.2
16.0
14.9
18.1
15.1
15.5
15.6
Grand Canyon NP
50TH
-.0021
.5476
5.4
6.1
7.1
6.7
7.1
6.0
6.6
5.7
Great Sand Dunes (W)
50TH
-.0052
.4524
5.9
6.9
6.1
5.9
7.0
6.0
6.7
5.7
Great Smoky Mtns NP
50TH
0.0222
.3598
40.8
50.0
49.7
45.7
57.0
60.5
41.4
49.1
Guadalupe Mtns NP
50TH
0.0107
.3598
10.7
10.6
12.0
10.6
10.8
10.2
13.5
11.9
Lassen Vblcanic NP
50TH
0.0217
.1994
4.2
3.8
3.4
2.8
4.6
5.0
4.7
4.3
Mesa Verde NP
50TH
0.0146
.3598
6.1
5.7
6.5
7.4
6.6
6.4
8.4
5.6
Mt. Rainier NP
50TH
0.0183
.3598
24.1
21.1
19.6
32.0
34.0
33 6
25.5
22.7
106 APPENDIX A: DATA TABLES

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-12. Trends From IMPROVE Monitoring Sites, 1988-1995 (continued)
LIGHT EXTINCTION DUE TO SULFATE (Mm1)
SITE
PERCENTILE
SLOPE
OBSERVED
SIGNIFICANCE
LEVEL 1988
1989
1990
1991
1992
1993
1994
1995
Petrified Forest NP
50TH
-.0258
.2742
6.9
7.7
9.4
9.2
8.5
6.9
8.1
6.0
Pinnacles (W)
50TH
-.0050
.5476
8.3
12.5
14.3
12.5
11.7
11.4
9.1
13.6
Pt. Reyes NS
50TH
-.0101
.2742
18.9
23.3
21.9
22.9
19.6
18.8
22.0
19.1
Redwood NP
50TH
0.0099
.4524
18.2
22.1
24.1
20.8
20.8
15.5
21.4
23.5
Rocky Mtns NP
50TH
-.0100
.3598
6.0
5.9
7.1
6.1
7.1
5.9
6.5
4.8
San Gorgonio (W)
50TH
0.0164
.3598
8.5
7.2
7.2
11.8
9.4
11.5
8.9
8.8
Shenandoah NP
50TH
-.0062
.2742
71.0
58.6
63.1
70.0
73.2
72.7
57.4
56.7
Tonto NM
50TH
0.0021
.5476
6.7
8.2
6.7
8.7
7.8
7.5
8.0
6.9
Washington, DC
50TH
0.0231
.2742
51.3
61.3
54.9
83.0
75.8
79.7
64.7
55.9
Weminuche (W)
50TH
-.0039
.5476
5.9
7.2
6.9
6.2
7.6
6.6
7.4
5.1
Yellowstone NP
50TH
-.0022
.4524
4.4
4.5
4.6
4.9
5.2
4.6
4.4
3 9
Yosemite NP
50TH
0.0390
.0894
5.3
6.1
7.1
7.7
8.5
7.2
6.4
7.6
Acadia NP
90TH
-.0097
.3598
88.6
101.5
79.8
78.2
102.1
97.5
100.2
73.3
Badlands (W)
90TH
0.0166
.3598
19.7
26.2
22.7
24.7
37.4
27.2
22.5
24.0
Bandelier (W)
90TH
0.0337
.1375
9.2
15.2
6.1
8.7
10.9
10.0
11.3
11.6
Big Bend NP
90TH
0.0019
.5476
22.6
21.9
24.2
20.6
24.7
19.9
27.6
21.3
Bryce Canyon NP
90TH
0.0086
.4524
11.0
11.9
10.5
9 3
11.6
9 9
11.0
12.3
Bridger (W)
90TH
-.0155
.1375
7.1
8.6
7.3
7.2
9.5
6.8
6.4
6.9
Canyonlands NP
90TH
-.0229
.0894
9.8
8.8
10.8
7.6
9.4
8.7
8.0
8.4
Chiricahua (W)
90TH
-.0034
.4524
16.0
13.5
12.9
10.4
13.3
14.6
12.5
15.8
Crater Lake NP
90TH
0.0145
.3598
9.2
13.8
10.4
9.6
13.7
13.4
10.7
11.2
Denali NP
90TH
-.0088
.4524
10.8
10.4
13.5
6.5
10.1
6.4
11.6
11.4
Glacier NP
90TH
-.0159
.4524
16.2
23.1
20.0
19.7
25.7
20.9
18.1
18.4
Grand Canyon NP
90TH
-.0061
.4524
9.7
9.4
9.8
8.6
10.1
8.4
10.0
9.0
Great Sand Dunes (W)
90TH
0.0040
.5476
10.6
9.2
7.6
7.0
9.5
9.5
8.2
9 9
Great Smoky Mtns NP
90TH
0.0189
.1994
84.7
120.5
153.0
127.4
129.9
110.7
125.1
134.5
Guadalupe Mtns NP
90TH
-.0155
.3598
20.7
25.0
15.2
18.0
19.5
18.9
19.5
18.3
Lassen N/blcanic NP
90TH
0.0227
.3598
8.1
11.0
7.7
4.9
11.1
9.0
10.2
9.6
Mesa Verde NP
90TH
-.0016
.5476
10.1
11.6
10.3
8.3
11.0
10.2
10.1
10.6
Mt. Rainier NP
90TH
-.0201
.2742
45.2
65.9
93.1
65.4
66.6
55.4
63.0
51.2
Petrified Forest NP
90TH
-.0049
.5476
11.5
11.1
11.9
10.2
13.6
10.3
10.2
13.2
Pinnacles (W)
90TH
0.0029
.5476
16.2
18.6
21.3
19.0
20.4
16.1
19.4
18.3
Pt. Reyes NS
90TH
0.0419
.0894
23.5
29.8
29.1
30.9
41.5
28.9
30.3
36.1
Redwood NP
90TH
-.0200
.2742
31.8
42.4
44.3
43.5
42.0
30.9
34.0
37.2
Rocky Mtns NP
90TH
-.0098
.4524
9.2
11.8
9.4
9.5
9.0
10.8
8.0
10.5
San Gorgonio (W)
90TH
-.0300
.0543
17.7
17.1
16.7
16.7
21.1
17.1
14.4
14.2
Shenandoah NP
90TH
0.0170
.1994
151.3
171.3
183.9
200.8
190.9
163.3
180.9
184.9
Tonto NM
90TH
-.0208
.1994
12.3
10.6
11.7
11.7
10.7
9 3
9 9
11.7
Washington, DC
90TH
0.0286
.3598
103.4
107.5
85.4
171.9
170.8
141.8
133.5
117.6
Weminuche (W)
90TH
0.0078
.4524
8.4
12.2
9.8
8.1
10.4
10.8
8.9
10.1
Yellowstone NP
90TH
-.0054
.5476
4.5
6.7
5.7
5.8
6.1
5.0
5.8
5.4
Yosemite NP
90TH
-.0046
.4524
14.2
14.7
12.8
12.8
16.7
14.9
12.6
13.0
*	Denotes that the slope is significant at the .05 significance level.
NP	= National Park
W	= Wilderness
NS	= National Seashore
NM	= National Monument
APPENDIX A: DATA TABLES 107

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-12. Trends From IMPROVE Monitoring Sites, 1988-1995
LIGHT EXTINCTION DUE TO ORGANIC CARBON (Mm1)
SITE
PERCENTILE
OBSERVED
SIGNIFICANCE
SLOPE LEVEL
1988
1989
1990
1991
1992
1993
1994
1995
Acadia NP
10TH
-.1079*
.0156
4.6
4.4
4.9
4.4
2.6
3.4
2.8
2.3
Badlands (W)
10TH
-.1399*
.0009
5.2
4.1
4.3
2.9
2.3
2.3
2.2
2.0
Bandelier (W)
10TH
-.0995*
.0156
4.0
4.2
4.6
3.8
2.7
3.2
2.7
2.0
Big Bend NP
10TH
-.0786*
.0305
4.5
3.7
4.6
2.9
1.9
2.7
2.7
2.6
Bryce Canyon NP
10TH
-.1209*
.0156
2.6
2.7
3.2
2.1
1.5
1.4
1.5
1.3
Bridger (W)
10TH
-.1263
.0894
2.6
2.6
3.5
1.4
0.9
1.1
1.4
1.2
Canyonlands NP
10TH
-.0908*
.0305
2.7
2.8
3.8
2.5
1.4
1.9
1.8
1.6
Chiricahua (W)
10TH
-.1156*
.0305
4.2
3.1
3.4
2.3
1.8
1.8
1.8
2.1
Crater Lake NP
10TH
-.1479*
.0071
2.9
3.5
3.7
1.6
1.6
1.3
1.2
1.1
Denali NP
10TH
-.2124*
.0071
3 3
2.3
3.2
2.5
0.9
1.0
0.9
0.8
Glacier NP
10TH
-.0875*
.0156
6.1
5.2
6.2
5.6
4.0
4.7
3 6
3 6
Grand Canyon NP
10TH
-.1196*
.0305
2.2
2.8
3.7
2.6
1.8
1.6
1.4
1.6
Great Sand Dunes (W)
10TH
-.1621*
.0028
4.3
4.1
5.4
3.7
2.4
2.0
2.1
1.5
Great Smoky Mtns NP
10TH
-.0756*
.0002
7.4
6.7
6.7
5.9
5.0
4.9
4.7
4.4
Guadalupe Mtns NP
10TH
-.1035*
.0071
4.5
4.6
4.2
2.5
2.6
2.7
2.4
2.3
Lassen Vblcanic NP
10TH
-.1024*
.0156
3 3
3.4
4.5
2.7
2.2
2.3
2.2
1.6
Mesa Verde NP
10TH
-.1209*
.0071
3.5
2.8
3.4
2.6
1.9
1.4
2.1
1.6
Mt. Rainier NP
10TH
-.0974*
.0305
3 9
3 3
4.1
3 9
3.5
2.9
2.0
2.4
Petrified Forest NP
10TH
-.1108*
.0156
3.5
4.3
4.7
4.2
3.1
2.4
2.8
2.0
Pinnacles (W)
10TH
-.0865*
.0071
4.6
4.6
6.0
3 9
3.0
3.5
3.0
2.7
Pt. Reyes NS
10TH
-.0904*
.0028
3.7
3.5
3.2
3.0
2.4
2.0
2.0
2.1
Redwood NP
10TH
-.1567*
.0028
4.1
3.5
4.5
3.1
2.3
1.8
1.6
1.7
Rocky Mtns NP
10TH
-.1441*
.0071
4.2
2.6
4.0
1.7
2.1
1.5
1.7
1.4
San Gorgonio (W)
10TH
-.1042*
.0305
3 9
2.5
4.9
2.1
1.8
2.3
1.5
1.9
Shenandoah NP
10TH
-.1024*
.0156
8.0
5.1
5.9
4.3
3.1
4.2
3.2
3.8
Tonto NM
10TH
-.0988*
.0028
6.4
4.4
5.0
3.2
3 3
3.1
2.8
2.9
Washington, DC
10TH
-.0403
.0543
10.1
11.4
10.4
9.7
9 3
11.1
9.4
6.0
Weminuche (W)
10TH
-.1479*
.0071
3.6
3.0
3.1
2.1
1.5
1.6
1.7
1.3
Yellowstone NP
10TH
-.1696*
.0071
5.4
3.6
5.6
4.0
2.5
1.9
1.9
1.7
Yosemite NP
10TH
-.1100
.0894
3.4
2.7
5.0
2.2
1.6
2.2
1.5
2.3
Acadia NP
50TH
-.0487*
.0305
6.8
6.8
6.0
6.8
5.5
5.6
5.8
4.7
Badlands (W)
50TH
-.0940*
.0028
6.0
6.2
6.2
5.6
4.1
3 9
3 9
3.4
Bandelier (W)
50TH
-.0955*
.0156
6.6
5.9
6.6
6.9
4.5
4.1
3 6
3 5
Big Bend NP
50TH
-.0719*
.0009
7.2
6.5
6.2
6.0
4.4
4.9
4.8
4.3
Bryce Canyon NP
50TH
-.0916*
.0071
4.9
4.8
4.6
4.4
2.6
2.9
2.8
2.8
Bridger (W)
50TH
-.1305*
.0028
4.9
4.3
5.4
4.2
3.4
2.4
2.8
2.3
Canyonlands NP
50TH
-.1174*
.0305
5.3
4.6
6.0
4.6
2.8
3.2
3.6
2.3
Chiricahua (W)
50TH
-.1162*
.0028
6.6
5.0
5.2
4.7
3.2
3.2
2.6
3.0
Crater Lake NP
50TH
-.1082
.0894
4.8
6.0
7.1
4.9
3 9
2.7
5.6
2.6
Denali NP
50TH
-.1926*
.0028
3.5
3 3
3 6
2.8
1.8
1.2
1.5
1.1
Glacier NP
50TH
-.0597*
.0009
12.7
11.4
11.7
10.8
10.2
9 3
9.7
6.8
Grand Canyon NP
50TH
-.0750*
.0071
4.3
4.1
5.2
4.3
3.0
3.0
2.8
2.6
Great Sand Dunes (W)
50TH
-.1072*
.0028
5.8
5.1
5.7
5.5
3 9
3.0
3.4
2.8
Great Smoky Mtns NP
50TH
-.0445*
.0305
10.8
11.9
12.9
10.4
9 9
10.7
8.1
9 3
Guadalupe Mtns NP
50TH
-.0738*
.0028
6.7
6.0
5.9
5.0
3 3
4.7
4.3
4.0
Lassen Vblcanic NP
50TH
-.0978*
.0305
5.0
6.5
7.3
5.5
5.0
3.8
4.0
3 6
Mesa Verde NP
50TH
-.1156*
.0156
7.0
4.1
4.5
4.5
3.0
2.9
3.2
2.5
Mt. Rainier NP
50TH
-.0678*
.0028
9.4
9.4
11.7
9.0
9.0
8.6
7.0
5.5
108 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-12. Trends From IMPROVE Monitoring Sites, 1988-1995 (continued)
LIGHT EXTINCTION DUE TO ORGANIC CARBON (Mm1)
SITE
PERCENTILE
SLOPE
OBSERVED
SIGNIFICANCE
LEVEL
1988
1989
1990
1991
1992
1993
1994
1995
Petrified Forest NP
50TH
-.0893*
.0028
6.8
5.3
6.2
6.0
4.5
3.8
4.2
3.5
Pinnacles (W)
50TH
-.0824*
.0071
9.6
9.5
10.1
7.8
7.0
7.8
6.1
5.6
Pt. Reyes NS
50TH
-.1719*
.0156
5.3
6.8
8.1
6.2
4.0
3.0
3.4
2.4
Redwood NP
50TH
-.1247*
.0156
5.6
5.6
7.3
6.0
5.1
4.6
4.0
2.6
Rocky Mtns NP
50TH
-.1371*
.0002
6.1
5.9
5.5
4.8
3 9
3.1
3.7
2.2
San Gorgonio (W)
50TH
-.0527
.1375
10.1
10.0
9 3
11.4
7.0
11.5
7.6
6.1
Shenandoah NP
50TH
-.0524*
.0071
11.1
9 3
11.6
9.7
8.8
7.9
8.1
7.7
Tonto NM
50TH
-.0604*
.0028
7.2
6.5
7.0
5.5
5.8
5.4
4.1
5.1
Washington, DC
50TH
0.0031
.5476
15.8
18.0
16.9
18.5
16.2
19.2
18.0
12.1
Weminuche (W)
50TH
-.1176*
.0009
5.2
4.7
4.5
4.6
3.0
2.7
2.8
2.3
Yellowstone NP
50TH
-.0996*
.0305
5.0
6 3
6.6
5.9
4.4
3.5
4.4
3.1
Yosemite NP
50TH
-.0181
.3598
6.7
7.7
8.2
7.8
7.1
6.4
5.6
7.9
Acadia NP
90TH
-.0291
.1375
17.6
17.2
13.2
16.6
12.1
14.3
14.2
14.4
Badlands (W)
90TH
-.0456
.2742
12.1
8.7
9.8
11.0
6.7
5.6
12.7
8.2
Bandelier (W)
90TH
-.0550*
.0156
9 3
8.8
8.1
8.0
8.9
8.1
6.7
6.0
Big Bend NP
90TH
-.0321
.1375
11.3
13.0
8.2
10.6
6.8
9 9
8.9
9.4
Bryce Canyon NP
90TH
-.0589
.0543
6.8
7.0
6.5
5.7
5.3
7.1
5.5
4.5
Bridger (W)
90TH
-.0674
.0894
9 6
7.0
7.8
6.9
6.9
4.7
8.2
5.4
Canyonlands NP
90TH
-.1195*
.0028
8.7
8.0
7.1
6.3
4.4
4.7
4.1
4.4
Chiricahua (W)
90TH
-.0327
.2742
9 3
6.7
8.0
6.9
7.1
7.3
7.5
6.0
Crater Lake NP
90TH
-.0568
.3598
12.7
11.4
13.6
11.5
6.9
7.9
15.4
8.3
Denali NP
90TH
-.0643
.3598
5.0
4.9
6.6
12.6
2.6
9.1
5.6
2.0
Glacier NP
90TH
-.0034
.4524
19.3
25.2
27.4
23.0
18.9
23.4
25.0
20.0
Grand Canyon NP
90TH
-.0631*
.0028
7.9
7.7
7.8
5.6
5.3
6.9
4.9
4.8
Great Sand Dunes (W)
90TH
-.0951*
.0071
9.2
7.8
6.9
6.5
4.3
4.9
6.1
4.6
Great Smoky Mtns NP
90TH
-.0375
.1994
28.0
17.3
22.1
21.5
15.5
19.7
18.6
19.8
Guadalupe Mtns NP
90TH
-.0752*
.0071
9.2
9.1
7.4
7.8
5.9
6.7
6.8
5.1
Lassen N/blcanic NP
90TH
-.0306
.0894
11.1
12.4
10.1
9.4
9.2
10.1
10.6
8.7
Mesa Verde NP
90TH
-.0760
.0543
7.9
7.2
8.0
5.8
3 9
5.6
5.8
4.6
Mt. Rainier NP
90TH
-.0532*
.0305
21.4
23.3
26.0
21.4
22.0
19.4
18.1
15.7
Petrified Forest NP
90TH
-.0958*
.0028
10.4
8.6
8.2
7.3
6.3
6.7
4.9
6.5
Pinnacles (W)
90TH
-.0584*
.0156
13.9
18.6
16.0
14.3
12.3
12.9
11.0
11.8
Pt. Reyes NS
90TH
-.1305
.0543
11.2
19.0
15.4
12.9
9.0
12.9
7.1
7.3
Redwood NP
90TH
-.0590*
.0071
16.7
15.0
13.9
11.4
13.3
12.3
6.7
11.9
Rocky Mtns NP
90TH
-.0751*
.0156
9.5
10.9
9.6
7.6
6.9
6.5
8.7
6.1
San Gorgonio (W)
90TH
-.0594*
.0071
20.5
19.2
17.9
17.1
19.4
15.2
15.6
10.3
Shenandoah NP
90TH
-.0215
.1375
26.9
18.0
20.2
19.8
16.8
11.4
18.9
19.4
Tonto NM
90TH
-.0236
.4524
10.3
15.0
7.7
8.5
9.2
13.9
6.0
10.3
Washington, DC
90TH
-.0032
.5476
31.7
22.8
29.2
28.5
24.8
35.7
30.5
24.8
Weminuche (W)
90TH
-.1003*
.0071
9.0
8.4
7.9
5.7
4.7
4.7
4.8
4.7
Yellowstone NP
90TH
-.0718
.0894
12.7
10.2
10.7
9 3
9.5
7.5
15.6
7.0
Yosemite NP
90TH
0.0534
.3598
22.2
14.5
16.6
16.5
18.4
12.3
21.0
21.9
*	Denotes that the slope is significant at the .05 significance level.
NP	= National Park
W	= Wilderness
NS	= National Seashore
NM	= National Monument
APPENDIX A: DATA TABLES 109

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-12. Trends From IMPROVE Monitoring Sites, 1988-1995
DECIVIEW
SITE
PERCENTILE
SLOPE
OBSERVED
SIGNIFICANCE
LEVEL
1988
1989
1990
1991
1992
1993
1994
1995
Acadia NP
10TH
-.0294*
.0305
13.0
14.1
14.2
13.4
11.7
12.6
11.3
11.3
Badlands (W)
10TH
-.0229*
.0305
10.3
9.5
9.7
9.7
10.0
9.5
8.9
7.8
Bandelier (W)
10TH
-.0404
.0894
8.1
9.7
10.4
9 3
8.5
8.9
8.3
6.0
Big Bend NP
10TH
-.0237
.0894
10.1
10.3
10.7
9.5
8.2
9.6
8.6
9.1
Bryce Canyon NP
10TH
-.0592
.0894
6.6
5.8
6.8
7.2
6.7
6.2
5.2
4.2
Bridger (W)
10TH
-.0481
.0543
5.0
5.4
6.6
5.0
5.3
4.3
4.9
3.2
Canyonlands NP
10TH
-.0552
.0543
7.1
7.9
9.0
8.3
6.9
7.4
6.6
4.9
Chiricahua (W)
10TH
-.0210*
.0305
8.2
7.9
8.3
8.0
7.2
7.8
7.1
7.3
Crater Lake NP
10TH
-.0395
.0543
5.8
6.5
6.6
6.5
6 3
5.1
5.5
3.8
Denali NP
10TH
-.0587*
.0071
5.4
5.0
7.6
5.3
4.5
4.2
4.2
3.7
Glacier NP
10TH
-.0163
.2742
10.9
11.4
12.2
12.7
12.5
11.7
10.3
9.7
Grand Canyon NP
10TH
-.0145
.3598
5.8
6.1
8.1
7.2
7.1
5.9
5.3
6.1
Great Sand Dunes (W)
10TH
-.0908*
.0071
8.6
8.0
9.7
9.1
7.5
6 9
6.2
4.6
Great Smoky Mtns NP
10TH
-.0120*
.0305
15.9
16.4
16.1
16.2
15.4
15.6
15.0
15.2
Guadalupe Mtns NP
10TH
-.0168
.1375
10.0
11.1
10.3
8.4
9 3
9 9
8.6
9.6
Lassen Volcanic NP
10TH
-.0585
.0543
5.6
6.3
7.1
4.7
6.1
4.9
4.7
4.0
Mesa Verde NP
10TH
-.0686
.0894
7.7
6.8
9.2
8.1
7.0
6.5
7.0
4.5
Mt. Rainier NP
10TH
-.0400
.2742
9.0
8.5
10.1
10.3
11.9
9 3
7.4
6.4
Petrified Forest NP
10TH
-.0575*
.0305
8.4
10.3
10.4
10.2
8.8
8.0
8.1
6.7
Pinnacles (W)
10TH
-.0405*
.0156
11.6
11.9
14.1
10.8
10.2
11.5
9.4
9.2
Pt. Reyes NS
10TH
-.0221
.1375
11.6
12.2
14.5
12.7
11.9
12.6
11.3
10.2
Redwood NP
10TH
-.0357*
.0156
10.6
9.6
11.4
9.6
10.1
8.6
8.4
8.3
Rocky Mtns NP
10TH
-.0241
.1375
6.8
5.8
6.6
5.9
6.2
6.0
6.1
4.0
San Gorgonio (W)
10TH
-.0373
.1994
8.4
7.9
11.3
7.8
6.8
7.9
6.0
8.1
Shenandoah NP
10TH
-.0085
.1994
18.4
17.0
17.6
18.0
15.8
17.9
15.8
17.2
Tonto NM
10TH
-.0302*
.0156
10.2
10.0
10.9
9 3
9.5
8.8
8.1
8.9
Washington, DC
10TH
-.0004
.4524
21.7
22.3
22.6
22.2
22.3
23.7
22.2
19.3
Weminuche (W)
10TH
0.0051
.5476
5.7
6.1
6.8
7.4
7.2
6.0
7.2
4.3
Yellowstone NP
10TH
-.0848*
.0071
8.3
7.7
8.9
8.0
6.6
5.2
5.4
5.0
Yosemite NP
10TH
-.0115
.2742
5.9
5.4
8.9
5.8
6.3
5.9
4.9
5.7
Acadia NP
50TH
-.0169
.1375
18.1
20.3
18.7
18.9
17.8
18.1
18.2
16.7
Badlands (W)
50TH
-.0130
.0543
14.8
15.3
14.7
15.1
14.9
13.4
13.9
13.8
Bandelier (W)
50TH
-.0386*
.0071
11.9
12.4
12.7
12.2
11.6
11.3
10.6
9.1
Big Bend NP
50TH
-.0049
.1375
14.4
15.0
14.4
14.1
14.1
14.2
14.5
13.9
Bryce Canyon NP
50TH
-.0183
.0543
11.5
11.5
10.6
11.5
10.5
10.6
11.1
8.8
Bridger (W)
50TH
-.0285
.1375
9.0
9.1
10.2
9.6
9 9
8.1
8.6
7.4
Canyonlands NP
50TH
-.0257
.0543
10.9
10.7
12.4
12.0
10.8
10.7
10.7
8.4
Chiricahua (W)
50TH
-.0190*
.0156
12.4
11.9
12.4
11.6
11.0
11.9
11.4
10.7
Crater Lake NP
50TH
0.0033
.5476
8.8
10.3
11.1
11.7
11.1
9 3
11.4
8.1
Denali NP
50TH
-.0517*
.0156
8.1
8.9
10.1
7.5
6.7
6.6
7.4
5.9
Glacier NP
50TH
-.0095
.1994
16.6
16.3
16.9
17.0
17.0
15.8
16.3
14.8
Grand Canyon NP
50TH
-.0269
.0543
10.2
10.8
11.9
11.2
10.7
10.1
10.1
9 3
Great Sand Dunes (W)
50TH
-.0366*
.0156
11.1
12.1
12.0
11.6
11.2
9.7
10.0
8.7
Great Smoky Mtns NP
50TH
0.0051
.4524
21.6
22.3
22.5
21.5
23.0
23.5
20.3
22.1
Guadalupe Mtns NP
50TH
-.0071
.3598
13.8
14.4
15.2
13.2
12.3
13.2
14.1
13.3
Lassen Volcanic NP
50TH
-.0204*
.0305
10.9
10.6
10.8
9.4
10.1
9.8
10.1
9.0
Mesa Verde NP
50TH
-.0169
.1994
10.8
10.0
10.4
11.2
9.8
10.0
10.6
8.6
Mt. Rainier NP
50TH
0.0020
.5476
17.6
16.9
17.0
18.8
19.4
19.1
17.4
15.8
110 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-12. Trends From IMPROVE Monitoring Sites, 1988-1995 (continued)
DECIVIEW
SITE
PERCENTILE
SLOPE
OBSERVED
SIGNIFICANCE
LEVEL
1988
1989
1990
1991
1992
1993
1994
1995
Petrified Forest NP
50TH
-.0338*
.0305
12.8
13.1
14.0
13.7
12.6
11.4
11.8
10.2
Pinnacles (W)
50TH
-.0194
.0543
17.1
17.6
18.5
17.1
16.5
17.1
15.3
15.6
Pt. Reyes NS
50TH
-.0225
.0543
17.4
18.3
19.3
17.9
16.4
16.7
17.1
14.9
Redwood NP
50TH
-.0123
.0894
15.8
16.5
17.7
16.4
16.2
14.7
15.8
15.4
Rocky Mtns NP
50TH
-.0183
.0894
11.2
11.4
11.6
11.0
11.6
10.2
11.0
8.6
San Gorgonio (W)
50TH
-.0089
.1994
18.7
19.6
19.5
20.0
17.5
19.8
18.3
17.2
Shenandoah NP
50TH
-.0050
.1994
25.3
23.6
24.7
25.2
25.3
25.1
23.9
23.4
Tonto NM
50TH
-.0195*
.0305
13.4
14.4
13.7
13.5
13.6
13.2
12.4
12.4
Washington, DC
50TH
0.0023
.3598
24.9
27.4
27.3
28.7
28.4
28.7
27.5
25.4
Weminuche (W)
50TH
-.0160*
.0305
10.6
11.2
10.8
10.9
10.6
10.2
10.5
8.3
Yellowstone NP
50TH
-.0383
.0543
10.2
10.8
11.5
11.6
10.4
9.8
9.6
7.9
Yosemite NP
50TH
0.0006
.5476
12.8
12.9
13.9
14.0
14.4
13.0
11.9
12.9
Acadia NP
90TH
0.0018
.5476
26.8
27.5
25.8
25.9
27.2
27.3
27.5
25.1
Badlands (W)
90TH
0.0049
.4524
19.2
18.8
18.8
19.1
21.6
19.4
20.1
18.7
Bandelier (W)
90TH
-.0082
.4524
14.3
16.5
12.9
14.0
15.0
14.5
14.6
13.4
Big Bend NP
90TH
-.0012
.3598
19.1
19.5
18.5
19.0
18.1
18.5
19.3
19.0
Bryce Canyon NP
90TH
-.0062
.1994
14.1
15.0
13.5
13.9
13.9
14.2
13.9
13.0
Bridger (W)
90TH
-.0134
.0543
13.3
13.2
13.3
12.9
13.9
11.5
12.6
11.2
Canyonlands NP
90TH
-.0292*
.0156
14.6
15.1
15.1
14.6
13.1
13.6
13.4
11.7
Chiricahua (W)
90TH
-.0033
.1994
16.3
15.2
15.2
15.1
15.1
15.7
15.8
14.9
Crater Lake NP
90TH
0.0008
.5476
15.6
16.6
16.3
15.9
15.7
16.8
16.8
14.2
Denali NP
90TH
-.0205
.2742
12.5
12.4
14.8
13.7
11.1
12.5
12.9
10.8
Glacier NP
90TH
-.0046
.3598
19.9
21.9
21.8
22.0
22.3
21.5
21.4
20.9
Grand Canyon NP
90TH
-.0114
.1375
13.9
14.9
15.0
13.4
13.6
13.8
13.8
12.9
Great Sand Dunes (W)
90TH
-.0273
.0894
14.6
15.7
14.5
14.4
12.8
13.2
16.6
12.4
Great Smoky Mtns NP
90TH
0.0037
.4524
27.3
28.7
30.9
29.7
29.4
28.5
29.2
29.4
Guadalupe Mtns NP
90TH
-.0115
.0894
18.4
19.3
17.7
17.1
16.8
17.2
18.2
17.0
Lassen N/blcanic NP
90TH
-.0076
.3598
15.8
16.9
14.7
13.1
15.2
15.4
15.9
14.3
Mesa Verde NP
90TH
-.0058
.2742
13.2
14.2
14.7
12.9
12.4
14.6
13.7
12.8
Mt. Rainier NP
90TH
-.0123
.2742
23.7
25.7
28.0
25.7
25.8
24.3
24.9
23.1
Petrified Forest NP
90TH
-.0213*
.0156
15.8
16.4
16.9
15.6
15.3
14.7
14.1
14.9
Pinnacles (W)
90TH
-.0204*
.0305
20.6
22.8
22.7
21.5
21.7
20.5
20.1
20.1
Pt. Reyes NS
90TH
-.0126
.2742
22.5
28.2
25.4
23.8
24.9
27.7
23.9
22.0
Redwood NP
90TH
-.0107
.0894
22.2
22.9
23.0
22.6
22.8
21.1
20.3
21.6
Rocky Mtns NP
90TH
-.0132
.0543
14.8
16.1
15.5
14.8
14.6
14.9
14.7
14.4
San Gorgonio (W)
90TH
-.0130
.0543
25.6
26.1
26.7
25.6
26.5
24.8
24.6
22.9
Shenandoah NP
90TH
0.0029
.3598
31.2
31.5
32.2
32.7
32.4
30.9
31.8
32.0
Tonto NM
90TH
-.0072
.1994
16.6
18.3
15.8
16.4
16.4
17.0
14.8
16.0
Washington, DC
90TH
0.0001
.5476
32.0
31.6
31.3
33 9
34.3
34.0
32.7
31.1
Weminuche (W)
90TH
-.0190*
.0156
13.8
15.3
14.0
14.0
13.2
13.5
13.0
12.7
Yellowstone NP
90TH
-.0254*
.0305
16.2
16.0
15.6
14.5
15.4
13.5
16.1
13.1
Yosemite NP
90TH
-.0044
.2742
19.9
18.9
19.9
18.4
19.9
17.9
18.8
19.4
*	Denotes that the slope is significant at the .05 significance level.
NP	= National Park
W	= Wilderness
NS	= National Seashore
NM	= National Monument
APPENDIX A: DATA TABLES 111

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-13. Condensed Nonattainment Areas List(a)

State
Area Name(b)
Pollutant(c)
03 CO S02 PM10 Pb N02
03
CO
Population(d)
S02 PM10
Pb
All
1
AK
Anchorage
. 1

1

222

170

222
2
AK
Fairbanks
. 1



30



30
3
AK
Juneau


1



12

12
4
AL
Birmingham
1


751




751
5
AZ
Ajo

1
1


6
6

6
6
AZ
Bullhead City


1



5

5
7
AZ
Douglas

1
1


13
13

13
8
AZ
Miami-Hayden

2
1


3
3

3
9
AZ
Morenci

1



8


8
10
AZ
Nogales


1



19

19
11
AZ
Paul Spur


1



1

1
12
AZ
Payson


1



8

8
13
AZ
Phoenix
1 1

1
2092
2006

2122

2122
14
AZ
Rillito


1



0

0
15
AZ
San Manuel

1



5


5
16
AZ
Yuma


1



54

54
17
CA
Chico
. 1



72



72
18
CA
Imperial Valley


1



92

92
19
CA
Lake Tahoe South Shore
. 1



30



30
20
CA
Los Angeles-South Coast Air Basin
1 1

1 ¦ 1(e)
13000
13000

13000

13000
21
CA
Mono Basin (in Mono Co.)


1



0

0
22
CA
Owens Valley


1



18

18
23
CA
Sacramento Metro
1 1

1
1639
1097

1041

1639
24
CA
San Diego
1 1


2498
2348



2498
25
CA
San Francisco-Oakland-San Jose
¦ 1(f)



3630



3630
26
CA
San Joaquin Valley
1 3

1
2742
946

2742

2742
27
CA
Santa Barbara-Santa Maria-Lompoc
1


370




370
28
CA
Searles Valley


1



30

30
29
CA
Southeast Desert Modified AQMA
1


384


349

384
30
CA
Ventura Co.
1


669




669
31
CO
Aspen


1



5

5
32
CO
Canon City


1



12

12
33
CO
Colorado Springs
. 1



353



353
34
CO
Denver-Boulder
. 1

1

1800

1836

1836
35
CO
Fort Collins
. 1



106



106
36
CO
Lamar


1



8

8
37
CO
Longmont
. 1



52



52
38
CO
Pagosa Springs


1



1

1
39
CO
Steamboat Springs


1



6

6
40
CO
Telluride


1



1

1
41
CT
Greater Connecticut
1

1
2470


126

2470
42
DC-MD-VA
Washington
1


3923




3923
43
DE
Sussex Co
1


113




113
44
GA
Atlanta
1


2653




2653
45
GA
Muscogee Co. (Columbus)


. 1




179
179
46
GU
Piti Power Plant

1



0


Q
47
GU
Tanguisson Power Plant

1



Q


0
48
IA
Muscatine Co.

1



23


23
49
ID
Boise


1



125

125
50
ID
Bonner Co.(Sandpoint)


1



26

26
51
ID
Pocatello


1



46

46
52
ID
Shoshone Co.


2



13

13
53
IL-IN
Chicago-Gary-Lake County
1
1
3
7887

475
625

7887
54
IN
Evansville
1


165




165
112 APPENDIX A: DATA TABLES

-------
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-13. Condensed Nonattainment Areas List(a) (continued)
Pollutant(c)	Population(d)
State Area Name(b)	03 CO S02 PIUI10 Pb N0 2 03 CO S02 PM10 Pb All
N
Marion Co. (Indianapolis)



Kg) ¦




16
16
N
Vermillion Co. (Terre Haute)


1




17

17
KY
Boyd Co. (Ashland)

1(h)




51


51
KY
Muhlenberg Co.

1




31


31
KY-IN
Louisville
1



834




834
LA
Baton Rouge
1



559




559
MA
Springfield (W. Mass)
1



812




812
MA-NH
Boston-Lawrence-Worcester
1



5507




5507
MD
Baltimore
1



2348




2348
MD
Kent and Queen Anne Cos.
1



52




52
ME
Knox and Lincoln Cos.
1



67




67
ME
Lewiston-Auburn
1



221




221
ME
Portland
1



441




441
Ml
Muskegon
1



159




159
MN
Minneapolis-St. Paul
. 1

1


2310

272

2310
MN
Olmsted Co. (Rochester)

1




71


71
MO
Dent



1




2
2
MO
Liberty-Arcadia



1




2
2
MO-IL
St. Louis
1

1(i)
1® ¦
2390


32
2
2390
MT
Butte


1




33

33
MT
Columbia Falls


1




2

2
MT
Kalispell


1




11

11
MT
Lame Deer


1




0

Q
MT
Lewis & Clark (E. Helena)

1

i(k) .


2

2
2
MT
Libby


1




2

2
MT
Missoula
. 1

1


43

43

43
MT
Poison


1




3

3
MT
Ronan


1




1

1
MT
Thompson Falls


1




1

1
MT
Whitefish


1




3

3
MT
Yellowstone Co. (Laurel)

1




5


5
NE
Douglas Co. (Omaha)



1




1
1
NH
Manchester
1



222




222
NH
Portsmouth-Dover-Rochester
1



183




183
NJ
Atlantic City
1



319




319
NM
Anthony


1




1

1
NM
Grant Co.

1




27


27
NM
Sunland Park
1(1) ¦



8




8
NV
Central Steptoe Valley

1




2


2
NV
Las Vegas
. 1

1


258

741

741
NV
Reno
1 1

1

255
134

254

255
NY
Albany-Schenectady-Troy
1



874




874
NY
Buffalo-Niagara Falls
1



1189




1189
NY
Essex Co. (Whiteface Mtn.)
1



1




1
NY
Jefferson Co.
1



111




111
NY
Poughkeepsie
1



259




259
NY-NJ-CT
New York-N. New Jersey-Long Island
1 1

1

17943
13155

1487

17943
OH
Cleveland-Akron-Lorain

3
1



1898
1412

1898
OH
Coshocton Co.

1




35


35
OH
Gallia Co.

1




30


30
OH
Jefferson Co. (Steubenville)

1
1



80
4

80
OH
Lucas Co. (Toledo)

1




462


462
OH-KY
Cincinnati-Hamilton
1



1705




1705
OH-PA
Youngstown-Warren-Sharon
1 (m) .



121




121
OR
Grants Pass
. 1

1


17

17

17
OR
Klamath Falls
. 1

1


18

17

18
APPENDIX A: DATA TABLES 113

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-13. Condensed Nonattainment Areas List(a) (continued)
Pollutant(c)	Population(d)

State
Area Name(b)
o3
CO
SO 2
PM,o
Pb N02
03
CO
so2
PM,o
Pb
All
111
OR
LaGrande



1




11

11
112
OR
Lakeview



1




2

2
113
OR
Medford

1

1


62

63

63
114
OR
Oakridge



1




3

3
115
OR
Springfield-Eugene



1




157

157
116
OR-WA
Portland-Vancouver

1




948



948
117
PA
Altoona
1




131




131
118
PA
Erie
1




276




276
119
PA
Harrisburg-Leba non-Car lisle
1




588




588
120
PA
Johnstown
1




241




241
121
PA
Lancaster
1




423




423
122
PA
Pittsburgh-Beaver Valley
1

2
1

2468

446
75

2468
123
PA
Scranton-Wilkes-Barre
1




734




734
124
PA
Warren Co


2




22


22
125
PA
York
1




418




418
126
PA-DE-NJ-MD Philadelphia-Wilmington-Trenton
1





6010



6010
127
PA-NJ
Allentown-Bethlehem-Easton
1

1


687

91


687
128
PR
Guaynabo Co.



1




85

85
129
Rl
Providence (all of Rl)
1




1003




1003
130
TN
Benton Co.


1




14


14
131
TN
Humphreys Co.


1




15


15
132
TN
Shelby Co. (Memphis)




1 (n) ¦




826
826
133
TN
Nashville




1(o) ¦




81
81
134
TN
Polk Co.


1




13


13
135
TX
Beaumont-Port Arthur
1




361




361
136
TX
Dallas-Fort Worth
1



1(P) ¦
3561



264
3561
137
TX
El Paso
1
1

1

592
54

515

592
138
TX
Houston-Galveston-Brazo ria
1




3731




3731
139
UT
Ogden

1

1


63

63

63
140
UT
Salt Lake City


1
1



725
725

725
141
UT
Tooele Co.


1




26


26
142
UT
Utah Co. (Provo)

1

1


85

263

263
143
VA
Richmond
1




738




738
144
VA
Smyth Co. (White Top Mtn.)
1




0




0
145
WA
Olympia-Tumwater-Lacey



1




63

63
146
WA
Seattle-Tacoma



3




730

730
147
WA
Spokane

1

1


279

177

279
148
WA
Wallula



1




47

47
149
WA
Yakima



1




54

54
150
Wl
Door Co.
1




26




26
151
Wl
Manitowoc Co.
1




80




80
152
Wl
Marathon Co. (V\fausau)


1




115


115
153
Wl
Milwaukee-Racine
1




1735




1735
154
Wl
Oneida Co. (Rhinelander)


1




31


31
155
WV
Follansbee



1




3

3
156
WV
New Manchester Gr. (in Hancock Co)


1




10


10
157
WV
Wier.-Butler-Clay (in Hancock Co)


1
1



25
22

25
158
WY
Sheridan



1




13

13


Total
59
29
38
79
10 1
101,739
43,118
4,760
29,939
1,375
119,424
114 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-13. Condensed Nonattainment Areas List(a) (continued)
Notes:
(a)	This is a simplified listing of Classified Nonattainment areas. Unclassified and section 185a nonattainment areas are not included. In
certain cases, footnotes are used to clarify the areas involved. For example, the lead nonattainment area listed within the Dallas-Fort V\forth
ozone nonattainment area is in Frisco, Texas, which is not in Dallas county, but is within the designated boundaries of the ozone nonattain-
ment area. Readers interested in more detailed information should use the official Federal Register citation (40 CFR 81).
(b)	Names of nonattainment areas are listed alphabetically within each state. The largest city determines which state is listed first in the case
of multiple-city nonattainment areas. When a larger nonattainment area, such as ozone, contains one or more smaller nonattainment
areas, such as PM10 or lead, the common name for the larger nonattainment area is used. Note that several smaller nonattainment areas
may be inside one larger nonattainment area, as is the case in Figure 1. For the purpose of this table, these are considered one nonattain-
ment area and are listed on one line. Occasionally, two nonattainment areas may only partially overlap, as in Figure 2. These are counted
as two distinct nonattainment areas and are listed on separate lines.
(c)	The number of nonattainment areas for each of the criteria pollutants is listed.
(d)	Population figures (in 1000s) were obtained from 1990 census data. For nonattainment areas defined as only partial counties, population
figures for just the nonattainment area were used when these were available. Otherwise, whole county population figures were used. When
a larger nonattainment area encompasses a smaller one, double-counting the population in the "AH" column is avoided by only counting the
population of the larger nonattainment area.
(e)	NO, population same as 03 and CO.
(f)	Carbon monoxide nonattainment area includes San Francisco county, and parts of Alameda, Contra Costa, Marin, Napa, San Mateo Santa
Clara, Solano, Sonoma counties.
(g)	Lead nonattainment area is a portion of Franklin township, Marion county, Indiana.
(h)	Sulfur dioxide nonattainment area is a portion of Boyd county.
(i)	PM10 nonattainment area is Granite City, Illinois, in Madison county.
(j) Lead nonattainment area is Herculaneum, Missouri in Jefferson county.
(k) Lead nonattainment area is a portion of Lewis and Clark county, Montana.
(I) Ozone nonattainment area is a portion of Dona Ana county, New Mexico.
(m)Youngstown has been redesignated for ozone but not the rest of the MSA and the population has been adjusted accordingly.
(n) Lead nonattainment area is a portion of Shelby county, Tennessee.
(o) Lead nonattainment area is a portion of Williamson county, Tennessee.
(p) Lead nonattainment area is Frisco, Texas, in Collin county.
NAfur 03
NA for PM-llJ
Figure A-1. (Multiple NA areas within a larger NA area)
Two SO, areas inside the Pittsburgh-Beaver Valley
ozone NA. Counted as one NA area.
Figure A-2. (Overlapping NA areas) Searles Valley
PM10 NA partially overlaps the San Joaquin Valley
ozone NA. Counted as two NA areas.
APPENDIX A: DATA TABLES 115

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-14. Maximum Air Quality Concentrations by Metropolitan Statistical Area, 1996
Metropolitan Statistical Area
CO
1990 8-hr
Population (ppm)
Pb
QMAX
(pgm)
no2
AM
(ppm)
03
2nd MAX
(ppm)
PM
rin-IO
WTDAM
(pgm)
PM10 S02
2nd MAX AM
(pgm) (ppm)
so2
24-hr
(ppm)
ABILENE, TX
119,655
ND
ND
ND
ND
ND
ND
ND
ND
AGUADILLA, PR
128,172
ND
ND
ND
ND
ND
ND
ND
ND
AKRON, OH
657,575
3
0.04
ND
0.11
25
73
0.010
0.042
ALBANY, GA
112,561
ND
ND
ND
ND
IN
21
ND
ND
ALBANY-SCHENECTADY-TROY NY
861,424
4
0.03
0.015
0.11
21
48
0.005
0.025
ALBUQUERQUE,NM
589,131
7
ND
0.022
0.10
38
94
ND
ND
ALEXANDRIA, LA
131,556
ND
ND
ND
ND
19
42
ND
ND
ALLENTOWN-BETHLEHEM-EASTON, PA
595,081
3
0.08
0.024
0.11
IN
65
0.010
0.035
ALTOONA, PA
130,542
2
ND
0.013
0.10
22
60
0.008
0.033
AMARILLO, TX
187,547
ND
ND
ND
ND
IN
38
ND
ND
ANCHORAGE, AK
226,338
11
ND
ND
ND
34
133
ND
ND
ANN ARBOR, Ml
490,058
ND
ND
ND
0.10
ND
ND
ND
ND
ANNISTON, AL
116,034
ND
ND
ND
ND
IN
31
ND
ND
APPLETON-OSHKOSH-NEENAH, Wl
315,121
ND
ND
ND
0.09
ND
ND
ND
ND
ARECIBO, PR
155,005
ND
ND
ND
ND
ND
ND
ND
ND
ASHEVILLE, NC
191,774
ND
ND
ND
0.08
25
76
ND
ND
ATHENS, GA
126,262
ND
ND
ND
ND
ND
ND
ND
ND
ATLANTA, GA
2,959,950
4
0.03
0.027
0.14
31
60
0.005
0.022
ATLANTIC-CAPE MAY, NJ
319,416
4
0.01
ND
0.11
IN
40
0.003
0.014
AUGUSTA-AIKEN, GA-SC
415,184
ND
0.00
ND
0.11
19
44
ND
ND
AURORA-ELGIN, IL
356,884
ND
ND
ND
ND
ND
ND
ND
ND
AUSTIN-SAN MARCOS, TX
846,227
3
ND
0.018
0.10
20
32
ND
ND
BAKERSFIELD, CA
543,477
6
0.00
0.029
0.16
54
110
0.003
0.009
BALTIMOREvMD
2,3821,72
4
0.03
0.027
0.13
29
75
0.008
0.028
BANGOR, ME
91,629
ND
ND
ND
0.08
19
34
ND
ND
BARNSTABLE-YARMOUTH, MA
134,954
ND
ND
ND
ND
ND
ND
ND
ND
BATON ROUGE, LA
528,264
5
0.15
0.021
0.12
26
51
0.006
0.024
BEAUMONT-PORT ARTHUR, TX
361,226
2
0.02
0.011
0.12
15
34
0.006
0.044
BELLINGHAM, WA
127,780
ND
ND
ND
0.08
15
37
0.005
0.013
BENTON HARBOR, Ml
161,378
ND
ND
ND
0.13
ND
ND
ND
ND
BERGEN-PASSAIC, NJ
1,278,440
4
0.00
0.028
0.11
37
61
0.007
0.026
BILLINGS, MT
113,419
7
ND
ND
ND
28
75
0.014
0.099
BILOXI-GULFPORT-PASCAGOU LA, MS
312,368
ND
ND
ND
0.10
18
33
0.003
0.043
BINGHAMTON, NY
264,497
ND
ND
ND
ND
IN
34
ND
ND
BIRMINGHAM, AL
840,140
6
0.13
0.010
0.14
34
100
0.004
0.015
BISMARCK, ND
83,831
ND
ND
ND
ND
12
27
0.007
0.056
BLOOMINGTON, IN
108,978
ND
ND
ND
ND
ND
ND
ND
ND
BLOOMINGTON-NORMAL, IL
129,180
ND
ND
ND
ND
ND
ND
ND
ND
BOISE CITY, ID
295,851
5
ND
IN
ND
36
90
ND
ND
BOSTON, MA-NH
3,227,707
5
ND
0.031
0.11
27
80
0.008
0.037
BOULDER-LONGMONT, CO
225,339
6
ND
ND
0.09
19
59
ND
ND
BRAZORIA, TX
191,707
ND
ND
ND
0.11
ND
ND
ND
ND
BREMERTON, WA
189,731
4
ND
ND
ND
14
41
ND
ND
BRIDGEPORT, CT
443,722
3
0.02
0.024
0.13
27
63
0.006
0.023
BROCKTON, MA
236,409
ND
ND
0.008
0.10
ND
ND
ND
ND
BROWNSVILLE-HAR LING EN-SAN BENITO, TX
260,120
2
0.02
ND
0.08
21
40
0.001
0.004
BRYAN-COLLEGE STATION, TX
121,862
ND
ND
ND
ND
ND
ND
ND
ND
BUFFALO-NIAGARA FALLS, NY
1,189,288
4
0.03
0.022
0.10
22
78
0.008
0.048
BURLINGTON, VT
151,506
3
ND
0.017
ND
20
37
0.002
0.014
CAGUAS, PR
279,501
ND
ND
ND
ND
ND
ND
ND
ND
CANTON-MASSILLON, OH
394,106
3
ND
ND
0.10
28
68
0.006
0.032
CASPER, WY
61226
ND
ND
ND
ND
19
36
ND
ND
116 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-14. Maximum Air Quality Concentrations by Metropolitan Statistical Area, 1996 (continued)


CO
Pb
no2
03
DM
rm10
PM
rm10
so2
so2

1990
8-hr
QMAX
AM
2nd MAX
WTD AM
2nd MAX
AM
24-hr
Metropolitan Statistical Area
Population
(ppm)
(pgm)
(ppm)
(ppm)
(pgm)
(pgm)
(ppm)
(ppm)
CEDAR RAPIDS, IA
168,767
8
ND
ND
0.07
26
65
0.011
0.2000
CHAMPAIGN-URBAN A, IL
173,025
ND
ND
ND
0.09
19
39
0.003
0.013
CHARLESTON-NORTH CHARLESTON,SC
506,875
5
0.02
0.010
0.10
22
54
0.003
0.021
CHARLESTON, WV
250,454
2
0.02
0.020
0.10
25
50
0.010
0.039
CHARLOTTE-GASTONIA-ROCK HILL, NC-SC
1,162,093
5
0.01
0.016
0.13
28
53
0.005
0.015
CHARLOTTESVILLE, VA
131,107
ND
ND
ND
ND
21
39
ND
ND
CHATTANOOGA, TN-GA
424,347
ND
ND
ND
0.11
33
65
ND
ND
CHEYENNE, WY
73,142
ND
ND
ND
ND
15
31
ND
ND
CHICAGO, IL
7,410,858
5
0.54(a)
0.032
0.13
40
122
0.008
0.032
CHICO-PARADISE, CA
182,120
5
0.00
0.013
0.10
25
62
ND
ND
CINCINNATIvOH-KY-IN
1,526,092
3
0.22
0.029
0.12
32
72
0.011
0.045
CLARKSVILLE-HOPKINSVILLE, TN-KY
169,439
ND
ND
ND
0.10
26
56
0.006
0.023
CLEVELAND-LORAIN-ELYRIA, OH
2,202,069
9
1.06(b)
0.026
0.12
41
123
0.011
0.049
COLORADO SPRINGS, CO
397,014
5
0.01
ND
0.08
26
76
ND
ND
COLUMBIA, MO
112,379
ND
ND
ND
ND
ND
ND
ND
ND
COLUMBIA, SC
453,331
3
0.02
0.013
0.10
42
117
0.004
0.020
COLUMBUS, GA-AL
260,860
ND
0.65(c)
ND
0.10
22
58
ND
ND
COLUMBUS, OH
1,345,450
3
0.07
ND
0.11
28
66
0.004
0.021
CORPUS CHRISTI, TX
349,894
ND
ND
ND
0.10
25
45
0.003
0.015
CUMBERLAND, MD-VW
101,643
ND
ND
ND
ND
27
47
0.003
0.019
DALLAS, TX
2,676,248
6
0.70(d)
0.019
0.14
51
102
0.005
0.046
DAN BURY, CT
193,597
ND
ND
ND
0.11
IN
45
0.005
0.020
DANVILLE, VA
108,711
ND
ND
ND
ND
ND
ND
ND
ND
DAVENPORT-MOLINE-ROCK ISLAND, IA-IL
350,861
ND
0.02
ND
0.09
43
153
0.004
0.024
DAYTON-SPRINGFIELD, OH
951,270
3
0.05
ND
0.12
25
66
0.005
0.031
DAYTON A BEACH, FL
399,413
ND
ND
ND
0.09
21
63
ND
ND
DECATUR, AL
131,556
ND
ND
ND
0.11
21
45
IN
0.001
DECATUR, IL
117,206
ND
0.02
ND
0.10
28
53
0.005
0.022
DENVER, CO
1,622,980
7
0.05
0.033
0.11
34
96
0.006
0.024
DES MOINES, IA
392,928
4
ND
ND
0.08
IN
130
ND
ND
DETROIT, Ml
4,266,654
6
0.04
0.021
0.11
40
106
0.011
0.079
DOTH AN, AL
130,964
ND
ND
ND
ND
IN
54
ND
ND
DOVER, DE
110,993
ND
ND
ND
0.11
ND
ND
ND
ND
DUBUQUE, IA
86,403
ND
ND
ND
ND
ND
ND
0.003
0.022
DULUTH-SUPERIOR, MN-WI
239,971
5
ND
ND
0.07
21
58
ND
ND
DUTCHESS COUNTY NY
259,462
ND
ND
ND
0.11
ND
ND
ND
ND
EAU CLAIRE, Wl
137,543
ND
ND
ND
ND
ND
ND
ND
ND
EL PASO, TX
591,610
10
0.40
0.035
0.12
45
158
0.009
0.046
ELKHART-GOSHEN, IN
156,198
ND
ND
ND
0.12
ND
ND
ND
ND
ELMIRA, NY
95,195
ND
ND
ND
0.09
IN
24
0.004
0.016
ENID, OK
56,735
ND
ND
0.009
ND
ND
ND
ND
ND
ERIE, PA
275,572
ND
ND
0.015
0.10
IN
56
0.011
0.066
EUGENE-SPRINGFIELD, OR
282,912
6
0.02
ND
0.11
19
78
ND
ND
EVANSVILLE-HENDERSON, IN-KY
278,990
4
ND
0.017
0.12
26
59
0.018
0.097
FARGO-MOORHEAD, ND-MN
153,296
ND
ND
0.008
0.08
17
54
0.002
0.008
FAYETTEVILLE, NC
274,566
4
ND
ND
0.11
26
53
0.004
0.012
FAYETTEVILLE-S PR ING DALE-ROGERS, AR
259,462
ND
ND
ND
ND
23
48
ND
ND
FITCHBURG-LEOMINSTER, MA
138,165
ND
ND
ND
ND
ND
ND
ND
ND
FLAGSTAFF, AZ-UT
101,760
ND
ND
ND
0.08
IN
31
ND
ND
FLINT, Ml
430,459
ND
0.01
ND
0.11
20
45
0.002
0.012
FLORENCE, AL
131,327
ND
ND
ND
ND
18
46
0.003
0.019
FLORENCE, SC
114,344
ND
0.01
ND
ND
ND
ND
ND
ND
APPENDIX A: DATA TABLES 117

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-14. Maximum Air Quality Concentrations by Metropolitan Statistical Area, 1996 (continued)
Metropolitan Statistical Area
CO
1990 8-hr
Population (ppm)
Pb
QMAX
(pgm)
no2
AM
(ppm)
03
2nd MAX
(ppm)
PM
rin-IO
WTDAM
(pgm)
PM
rin-io
2nd MAX
(pgm)
so2
AM
(ppm)
so2
24-hr
(ppm)
FORT COLLINS-LOVE LAND, CO
186,136
5
ND
ND
0.09
IN
52
ND
ND
FORT LAUDERDALE, FL
1,255,488
4
0.05
0.010
0.10
20
48
0.002
0.008
FORT MYERS-CAPE CORAL, FL
335,113
ND
ND
ND
0.08
17
38
ND
ND
FORT PIERCE-PORT ST. LUCIE, FL
251,071
ND
ND
ND
0.07
IN
42
ND
ND
FORT SMITH, AR-OK
175,911
ND
ND
ND
ND
25
47
ND
ND
FORT WALTON BEACH, FL
143,776
ND
ND
ND
ND
ND
ND
ND
ND
FORT WAYNE, IN
456,281
3
0.02
0.007
0.11
35
80
0.003
0.010
FORT WORTH-ARLINGTON, TX
1,361,034
3
0.02
0.021
0.13
24
56
0.001
0.011
FRESNO, CA
755,580
7
0.00
0.021
0.15
39
101
0.002
0.008
GADSDEN, AL
99,840
ND
0.26
ND
ND
23
50
ND
ND
GAINESVILLE, FL
181,596
ND
ND
ND
ND
19
44
ND
ND
GALVESTON-TEXAS CITY TX
217,399
ND
0.02
IN
0.11
22
52
0.014
0.067
GARY, IN
604,526
4
0.21(e)
0.021
0.13
28
208
0.007
0.031
GLENS FALLS, NY
118,539
ND
ND
ND
ND
IN
40
0.002
0.013
GOLDSBORO, NC
104,666
ND
ND
ND
ND
23
43
ND
ND
GRAND FORKS, ND-MN
103,181
ND
ND
ND
ND
IN
53
ND
ND
GRAND JUNCTION, CO
93,145
6
ND
ND
ND
21
63
ND
ND
GRAND RAPIDS-MUSKEGON-HOLLAND, Ml
937,891
3
0.01
0.009
0.13
22
71
0.002
0.011
GREAT FALLS, MT
77,691
5
ND
ND
ND
19
59
0.004
0.020
GREELEY, CO
131,821
7
ND
ND
0.10
18
56
ND
ND
GREEN BAY Wl
194,594
ND
ND
ND
0.11
ND
ND
0.003
0.011
GREENSBORO—WINSTON-SALEM—HIGH POINT, NC1,050,304 4
ND
0.016
0.12
28
58
0.007
0.026
GREENVILLE, NC
107,924
ND
ND
ND
0.10
20
36
ND
ND
GREENVILLE-SPARTANBURG-ANDERSON, SC
830,563
5
0.01
0.016
0.11
39
77
0.002
0.012
HAGERSTOWN, MD
121,393
ND
ND
ND
ND
ND
ND
ND
ND
HAMILTON-MIDDLETOWN, OH
291,479
ND
0.05
ND
0.12
32
78
0.007
0.026
HARRISBURG-LEBANON-CARLISLE, PA
587,986
2
0.04
0.021
0.10
23
63
0.006
0.022
HARTFORD, CT
1,157,585
5
0.03
0.016
0.10
21
49
0.006
0.022
HATTIESBURG, MS
98,738
ND
ND
ND
ND
ND
ND
ND
ND
HICKORY-MORGANTON-LENOIR, NC
292,409
ND
ND
ND
0.09
24
60
0.004
0.012
HONOLULU, HI
836,231
3
0.03
0.003
0.05
19
29
0.002
0.009
HOUMA, LA
182,842
ND
ND
ND
0.09
ND
ND
ND
ND
HOUSTON, TX
3,322,025
7
0.02
0.023
0.18
40
68
0.006
0.046
HUNTINGTON-ASHLAND, WV-KY-OH
312,529
4
0.05
0.013
0.12
37
86
0.012
0.057
HUNTSVILLE, AL
293,047
3
ND
ND
0.10
22
54
ND
ND
INDIANAPOLIS, IN
1,380,491
3
0.16(f)
0.018
0.12
29
71
0.006
0.041
IOWA CITY, IA
96,119
ND
ND
ND
ND
ND
ND
ND
ND
JACKSON, Ml
149,756
ND
ND
ND
ND
ND
ND
ND
ND
JACKSON, MS
395,396
5
ND
ND
0.10
22
55
0.002
0.008
JACKSON, TN
90,801
ND
0.02
ND
ND
22
45
ND
ND
JACKSONVILLE, FL
906,727
4
0.02
0.015
0.10
26
61
0.006
0.030
JACKSONVILLE, NC
149,838
ND
ND
ND
ND
22
37
ND
ND
JAMESTOWN, NY
141,895
ND
ND
ND
0.10
15
33
0.008
0.039
JANESVILLE-BELOIT, Wl
139,510
ND
ND
ND
0.10
ND
ND
ND
ND
JERSEY CITY, NJ
553,099
7
0.03
0.027
0.12
43
83
0.009
0.030
JOHNSON CITY-KINGS PORT-BRISTOL, TN-VA
436,047
3
0.13
0.018
0.10
28
67
0.012
0.052
JOHNSTOWN, PA
241,247
5
0.05
0.018
0.10
IN
63
0.011
0.034
JONESBORO, AR
68,956
ND
ND
ND
ND
26
53
ND
ND
JOPLIN, MO
134,910
ND
ND
ND
ND
ND
ND
ND
ND
KALAMAZOO-BATTLE CREEK, Ml
429,453
2
0.01
0.011
0.10
22
57
0.003
0.011
KANKAKEE, IL
96,255
ND
ND
ND
ND
ND
ND
ND
ND
KANSAS CITY, MO-KS
1,582,875
4
0.07
0.022
0.11
45
120
0.006
0.057
118 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-14. Maximum Air Quality Concentrations by Metropolitan Statistical Area, 1996 (continued)
Metropolitan Statistical Area
CO
1990 8-hr
Population (ppm)
Pb
QMAX
(pgm)
no2
AM
(ppm)
03
2nd MAX
(ppm)
PM
WTDAM
(pgm)
PM10 S02
2nd MAX AM
(pgm) (ppm)
so2
24-hr
(ppm)
KENOSHA, Wl
128,181
ND
ND
ND
0.14
ND
ND
ND
ND
KILLEEN-TEMPLE, TX
255,301
ND
ND
ND
ND
IN
41
ND
ND
KNOXVILLE, TN
585,960
3
ND
0.014
0.11
36
78
0.009
0.058
KOKOMO, IN
96,946
ND
ND
ND
ND
ND
ND
ND
ND
LACROSSE, WI-MN
116,401
ND
ND
ND
ND
ND
ND
ND
ND
LAFAYETTE, LA
344,853
ND
ND
ND
0.10
16
25
ND
ND
LAFAYETTE, IN
161,572
1
ND
IN
ND
IN
34
IN
0.020
LAKE CHARLES, LA
168,134
ND
ND
0.006
0.10
IN
33
0.003
0.018
LAKELAND-WINTER HAVEN, FL
405,382
ND
ND
ND
0.09
22
45
0.006
0.021
LANCASTER, PA
422,822
3
0.04
0.017
0.10
31
69
0.005
0.021
LANSING-EAST LANSING, Ml
432,674
ND
ND
ND
0.10
ND
ND
ND
ND
LAREDO, TX
133,239
6
ND
ND
0.07
42
103
ND
ND
LAS CRUCES, NM
135,510
4
0.07
0.009
0.12
56
143
0.006
0.056
LAS VEGAS, NV-AZ
852,737
10
ND
0.027
0.10
IN
328
ND
ND
LAWRENCE, KS
81,798
ND
ND
ND
ND
ND
ND
ND
ND
LAWRENCE, MA-NH
353,232
ND
ND
ND
0.09
IN
34
0.005
0.023
LAWTON, OK
111,486
2
ND
IN
0.08
IN
56
ND
ND
LEWISTON-AUBURN, ME
93,679
ND
ND
ND
ND
20
37
0.004
0.018
LEXINGTON, KY
405,936
3
0.04
0.014
0.10
26
60
0.006
0.020
LIMA, OH
154,340
ND
ND
ND
0.11
IN
44
0.003
0.015
LINCOLN, NE
213,641
5
ND
ND
0.06
28
63
ND
ND
LITTLE ROCK-NORTH LITTLE ROCK, AR
513,117
4
ND
0.011
0.10
29
52
0.002
0.009
LONGVIEW-MARSHALL, TX
193,801
ND
ND
ND
0.11
ND
ND
ND
ND
LOS ANGELES-LONG BEACH, CA
8,863,164
15
0.06
0.045
0.20
45
109
0.004
0.011
LOUISVILLE, KY-IN
948,829
6
0.02
0.020
0.12
28
61
0.009
0.038
LOWELL, MA-NH
280,578
5
ND
ND
ND
ND
ND
ND
ND
LUBBOCK, TX
222,636
ND
ND
ND
ND
22
85
ND
ND
LYNCHBURG, VA
193,928
ND
ND
ND
ND
23
41
ND
ND
MACON, GA
290,909
ND
ND
ND
ND
IN
34
ND
ND
MADISON, Wl
367,085
4
ND
ND
0.09
21
44
0.002
0.010
MANCHESTER, NH
50,000
ND
ND
ND
ND
ND
ND
ND
ND
MANSFIELD, OH
174,007
ND
ND
ND
ND
24
68
ND
ND
MAYAGUEZ, PR
237,143
ND
ND
ND
ND
ND
ND
ND
ND
MCALLEN-EDINBURG-MISSION, TX
383,545
ND
ND
ND
0.06
28
111
ND
ND
MEDFORD-ASHLAND, OR
146,389
7
0.02
ND
0.10
29
82
ND
ND
MELBOURNE-TITUSVILLE-PALM BAY, FL
398,978
ND
ND
ND
0.09
18
44
ND
ND
MEMPHIS, TN-AR-MS
1,007,306
7
2.81(g)
0.024
0.15
29
60
0.004
0.017
MERCED, CA
178,403
ND
ND
0.012
0.12
IN
57
ND
ND
MIAMI, FL
1,937,094
5
0.01
0.016
0.10
28
62
0.002
0.005
MIDDLESEX-SOMERSET-HUNTERDON, NJ
1,019,835
3
0.06
0.020
0.13
IN
46
0.005
0.024
MILWAUKEE-WAUKESHA, Wl
1,432,149
3
0.03
0.021
0.12
28
69
0.004
0.028
MINNEAPOLIS-ST. PAUL, MN-WI
2,538,834
7
0.55(h)
0.027
0.09
30
91
0.004
0.041
MOBILE, AL
476,923
ND
ND
ND
0.10
28
91
0.009
0.070
MODESTO, CA
370,522
6
0.00
0.022
0.13
32
83
ND
ND
MONMOUTH-OCEAN, NJ
986,327
5
ND
ND
0.12
ND
ND
ND
ND
MONROE, LA
142,191
ND
ND
ND
0.09
IN
76
0.003
0.007
MONTGOMERY AL
292,517
2
ND
0.010
0.10
23
39
0.003
0.022
MUNCIE, IN
119,659
ND
0.94(i)
ND
ND
ND
ND
ND
ND
MYRTLE BEACH,SC
144,053
ND
ND
ND
ND
ND
ND
ND
ND
NAPLES, FL
152,099
ND
ND
ND
ND
16
45
ND
ND
NASHUA, NH
168,233
8
ND
0.019
0.10
17
44
0.007
0.026
NASHVILLE, TN
985,026
5
0.90©
0.012
0.12
32
66
0.007
0.076
APPENDIX A: DATA TABLES 119

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-14. Maximum Air Quality Concentrations by Metropolitan Statistical Area, 1996 (continued)
Metropolitan Statistical Area
CO
1990 8-hr
Population (ppm)
Pb
QMAX
(pgm)
no2
AM
(ppm)
03
2nd MAX
(ppm)
PM
rin-IO
WTDAM
(pgm)
PM10 S02
2nd MAX AM
(pgm) (ppm)
so2
24-hr
(ppm)
NASSAU-SUFFOLK, NY
2,609,212
5
ND
0.026
0.12
21
55
0.008
0.031
NEW BEDFORD, MA
175,641
ND
ND
ND
0.12
16
44
ND
ND
NEW HAVEN-MERIDEN, CT
530,180
3
0.05
0.026
0.12
28
109
0.008
0.031
NEW LONDON-NORWICH, CT-RI
290,734
ND
ND
ND
0.12
19
56
0.005
0.016
NEW ORLEANS, LA
1,285,270
4
0.09
0.018
0.11
31
64
0.006
0.035
NEW YORK, NY
8,546,846
6
0.16
0.042
0.12
41
87
0.015
0.055
NEWARK, NJ
1,915,928
6
0.07
0.041
0.12
34
67
0.007
0.030
NEWBURGH, NY-PA
335,613
ND
0.06
ND
0.12
ND
ND
ND
ND
NORFOLK-VIRGINIA BEACH-NEWPORT, VA
1,443,244
6
0.03
0.018
0.10
21
50
0.007
0.025
OAKLAND, CA
2,082,914
4
0.02
0.022
0.14
23
45
0.003
0.011
OCALA, FL
194,833
ND
ND
ND
ND
ND
ND
ND
ND
ODESSA-MIDLAND, TX
255,545
ND
ND
ND
ND
26
59
ND
ND
OKLAHOMA CITY, OK
958,839
8
0.01
0.014
0.10
28
56
IN
0.005
OLYMPIA, WA
161,238
4
ND
ND
ND
IN
53
ND
ND
OMAHA, NE-IA
639,580
7
5.06(k)
ND
0.07
42
145
0.004
0.051
ORANGE COUNTY, CA
2,410,556
7
ND
0.035
0.14
35
77
0.001
0.004
ORLANDO, FL
1,224,852
4
0.00
0.013
0.10
25
67
0.002
0.008
OWENSBORO, KY
87,189
3
ND
0.011
0.11
23
59
0.007
0.020
PANAMA CITY FL
126,994
ND
ND
ND
ND
22
50
ND
ND
PARKERSBURG-MARIETTA, WV-OH
149,169
ND
0.02
ND
0.11
23
78
0.010
0.046
PENSACOLA, FL
344,406
ND
ND
ND
0.10
21
37
0.005
0.033
PEORIA-PEKIN, IL
339,172
5
0.02
ND
0.09
24
44
0.008
0.047
PHILADELPHIA, PA-NJ
4,922,175
6
9.23(1)
0.034
0.13
70
356
0.010
0.063
PHOENIX-MESA, AZ
2,238,480
10
0.05
0.032
0.12
IN
130
0.003
0.020
PINE BLUFF, AR
85,487
ND
ND
ND
ND
23
51
ND
ND
PITTSBURGH, PA
2,384,811
4
0.07
0.030
0.11
41
123
0.015
0.070
PITTSFIELD, MA
88,695
ND
ND
ND
0.11
ND
ND
ND
ND
POCATELLO, ID
66,026
ND
ND
0.014
ND
31
89
0.006
0.030
PONCE, PR
3,442,660
ND
ND
ND
ND
IN
53
ND
ND
PORTLAND, ME
221,095
ND
ND
ND
0.10
27
61
0.005
0.021
PORTLAND-VANCOUVER, OR-WA
1,515,452
7
0.11
IN
0.13
27
70
ND
ND
PORTSMOUTH-ROCHESTER, NH-ME
223,271
ND
ND
0.013
0.11
18
42
0.004
0.015
PROVIDENCE-FALL RIVER-WARWICK, RI-MA
1,134,350
4
ND
0.025
0.11
38
83
0.009
0.043
PROVO-OREM,UT
263,590
9
ND
0.024
0.11
37
141
ND
ND
PUEBLO, CO
123,051
ND
ND
ND
ND
IN
49
ND
ND
PUNTA GORDA, FL
110,975
ND
ND
ND
ND
ND
ND
ND
ND
RACINE, Wl
175,034
3
ND
ND
0.13
ND
ND
ND
ND
RALEIGH-DURHAM-CHAPEL HILL, NC
855,545
6
ND
ND
0.11
26
49
0.003
0.010
RAPID CITY, SD
81,343
ND
ND
ND
ND
37
137
ND
ND
READING, PA
336,523
3
0.82(m)
0.022
0.11
30
66
0.010
0.037
REDDING, CA
147,036
ND
ND
ND
0.11
IN
50
ND
ND
RENO, NV
254,667
8
ND
ND
0.10
45
131
ND
ND
RICH LAN D-KENNEWICK-FASCO, WA
150,033
ND
ND
ND
ND
IN
82
ND
ND
RICHMOND-PETERSBURG, VA
865,640
3
0.01
0.022
0.11
26
69
0.006
0.027
RIVERSIDE-SAN BERNARDINO, CA
2,588,793
7
0.04
0.038
0.22
63
155
0.002
0.005
ROANOKE, VA
224,477
6
ND
0.013
0.08
IN
78
0.003
0.014
ROCHESTER, MN
106,470
ND
ND
ND
ND
19
44
0.002
0.016
ROCHESTER, NY
1,062,470
4
0.04
ND
0.09
25
54
0.010
0.041
ROCKFORD, IL
329,676
3
0.05
ND
0.09
18
36
ND
ND
ROCKY MOUNT, NC
133,235
ND
ND
ND
0.09
23
39
0.003
0.010
SACRAMENTO, CA
1,340,010
7
0.01
0.022
0.14
27
80
0.002
0.005
SAGINAW-BAY CITY-MIDLAND, Ml
399,320
ND
ND
ND
ND
ND
ND
ND
ND
120 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-14. Maximum Air Quality Concentrations by Metropolitan Statistical Area, 1996 (continued)
Metropolitan Statistical Area
CO
1990 8-hr
Population (ppm)
Pb
QMAX
(pgm)
no2
AM
(ppm)
03
2nd MAX
(ppm)
PM
WTDAM
(pgm)
PM10 S02
2nd MAX AM
(pgm) (ppm)
so2
24-hr
(ppm)
ST. CLOUD, MN
190,921
4
ND
ND
ND
ND
ND
ND
ND
ST. JOSEPH, MO
83,083
ND
ND
ND
ND
32
126
0.008
0.079
ST. LOUIS, MO-IL
1,836,302
6
5.74(n)
0.025
0.13
40
107
0.012
0.102
SALEM, OR
278,024
7
ND
ND
0.12
ND
ND
ND
ND
SALINAS, CA
355,660
2
ND
0.011
0.09
20
40
ND
ND
SALT LAKE CITY-OGDEN, UT
1,072,227
7
0.03
0.026
0.12
47
157
0.004
0.021
SAN ANGELO, TX
98,458
ND
ND
ND
ND
ND
ND
ND
ND
SAN ANTONIO, TX
1,324,749
5
0.02
0.009
0.13
20
38
ND
ND
SAN DIEGO, CA
2,498,016
6
0.02
0.022
0.13
30
92
0.005
0.017
SAN FRANCISCO, CA
1,603,678
5
0.01
0.022
0.10
24
59
0.002
0.007
SAN JOSE, CA
1,497,577
6
0.01
0.025
0.12
25
68
ND
ND
SAN JUAN-BAYAMON, PR
1,836,302
7
ND
ND
ND
34
95
0.006
0.022
SAN LUIS OBISPO-ATASCADERO-PASO ROBLE, CA217.162
2
ND
0.013
0.11
21
96
0.006
0.029
SANTA BARBARA-SANTA MARIA-LOMPOC, CA
369,608
5
0.00
0.019
0.13
29
63
0.001
0.006
SANTA CRUZ-WATSONVILLE, CA
229,734
1
ND
0.005
0.10
33
69
0.002
0.003
SANTA FE, NM
117,043
2
ND
ND
ND
14
33
ND
ND
SANTA ROSA, CA
388,222
3
ND
0.014
0.09
17
39
ND
ND
SARASOTA-BRADENTON, FL
489,483
5
ND
ND
0.09
27
73
0.002
0.018
SAVANNAH, GA
258,060
ND
ND
ND
0.09
ND
ND
0.005
0.030
SCRANTON—WILKES-BARRE—HAZLETON, PA
638,466
4
ND
0.018
0.11
24
61
0.007
0.033
SEATTLE-BELLEVUE-EVERETT, WA
2,033,156
7
0.66(o)
0.020
0.12
24
93
0.006
0.019
SHARON, PA
121,003
ND
0.07
ND
0.10
IN
52
0.007
0.029
SHEBOYGAN, Wl
103,877
ND
ND
ND
0.11
ND
ND
ND
ND
SHERMAN-DENISON, TX
95,021
ND
ND
ND
ND
ND
ND
ND
ND
SHREVEPORT-BOSSIER CITY, LA
376,330
ND
ND
ND
0.10
22
47
0.002
0.004
SIOUX CITY, IA-NE
115,018
ND
ND
ND
ND
IN
95
ND
ND
SIOUX FALLS, SD
139,236
ND
ND
ND
ND
19
53
ND
ND
SOUTH BEND, IN
247,052
3
ND
0.011
0.11
20
45
ND
ND
SPOKANE, WA
361,364
9
ND
ND
0.08
32
110
ND
ND
SPRINGFIELD, IL
189,550
3
ND
ND
0.10
IN
26
0.006
0.061
SPRINGFIELD, MO
264,346
3
ND
0.011
0.10
41
148
0.008
0.089
SPRINGFIELD, MA
587,884
8
ND
0.024
0.11
30
67
0.007
0.028
STAMFORD-NORWALK, CT
329,935
4
ND
ND
0.12
32
65
0.005
0.026
STATE COLLEGE, FA
123,786
ND
ND
ND
0.09
ND
ND
ND
ND
STEUBENVILLE-WEIRTON, OH-WV
142,523
6
0.04
0.020
0.10
37
170
0.014
0.066
STOCKTON-LODI, CA
480,628
7
0.00
0.023
0.13
27
61
ND
ND
SUMTER, SC
102,637
ND
0.01
ND
ND
ND
ND
ND
ND
SYRACUSE, NY
742,177
4
ND
ND
0.09
24
61
0.003
0.015
TACOMA, WA
586,203
6
ND
ND
0.10
22
74
0.006
0.028
TALLAHASSEE, FL
233,598
ND
ND
ND
0.09
IN
33
ND
ND
TAMPA-ST. PETERSBURG-CLEARWATER, FL
2,067,959
4
2-81(p)
0.011
0.11
35
81
0.007
0.087
TERRE HAUTE, IN
147,585
3
ND
ND
0.11
27
53
0.012
0.039
TEXARKANA, TX-TEXARKANA, AR
120,132
ND
ND
ND
ND
23
50
ND
ND
TOLEDO, OH
614,128
3
0.44(q)
ND
0.11
23
69
0.005
0.049
TOPEKA, KS
160,976
ND
0.01
ND
ND
21
58
ND
ND
TRENTON,NJ
325,824
ND
ND
0.017
0.12
27
59
ND
ND
TUSCON, AZ
666,880
5
0.05
0.019
0.09
38
81
0.001
0.004
TULSA, OK
708,954
7
0.11
0.015
0.12
IN
76
0.008
0.042
TUSCALOOSA, AL
150,522
ND
ND
ND
ND
IN
58
ND
ND
TYLER, TX
151,309
ND
ND
ND
0.10
IN
30
ND
ND
UTICA-ROME, NY
316,633
ND
ND
ND
0.08
20
43
0.002
0.009
VALLEJO-FAIRFIELD-NAPA, CA
451,186
5
ND
0.015
0.12
20
43
0.002
0.006
VENTURA,CA
669,016
3
0.00
0.022
0.14
30
79
0.001
0.003
APPENDIX A: DATA TABLES 121

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-14. Maximum Air Quality Concentrations by Metropolitan Statistical Area, 1996 (continued)
Metropolitan Statistical Area
1990
Population
CO
8-hr
(ppm)
Pb
QMAX
(pgm)
no2
AM
(ppm)
03
2nd MAX
(ppm)
PM
rin-IO
WTD AM
(pgm)
PM10 S02
2nd MAX AM
(pgm) (ppm)
so2
24-hr
(PPm)
VICTORIA, TX
74,361
ND
ND
ND
0.09
ND
ND
ND
ND
VINELAND-MILLVILLE-BRIDGETON, NJ
138,053
ND
ND
ND
0.11
ND
ND
0.005
0.016
VISALIA-TULARE-PORTERVILLE, CA
311,921
4
ND
0.018
0.14
45
87
ND
ND
WACO, TX
189,123
ND
ND
ND
ND
ND
ND
ND
ND
WASHINGTON, DC-MD-VA-WV
4,223,485
5
0.02
0.026
0.12
23
57
0.009
0.048
WATERBURY, CT
221,629
ND
0.04
ND
ND
27
69
0.005
0.022
WATERLOO-CEDAR FALLS, IA
123,798
ND
ND
ND
ND
32
59
ND
ND
WAUSAU, Wl
115,400
ND
ND
ND
0.08
25
50
0.003
0.015
WEST PALM BEACH-BOCA RATON, FL
863,518
4
0.00
0.012
0.09
23
56
0.002
0.014
WHEELING, WV-OH
159,301
4
ND
ND
0.11
28
86
0.015
0.072
WICHITA, KS
485,270
6
0.02
ND
0.10
26
119
0.005
0.007
WICHITA FALLS, TX
130,351
ND
ND
ND
ND
19
50
ND
ND
WILLIAMSPORT, PA
118,710
ND
ND
ND
0.08
25
46
0.006
0.028
WILMINGTON-NEWARK, DE-MD
513,293
4
ND
0.019
0.12
32
81
0.011
0.067
WILMINGTON, NC
171,269
ND
ND
ND
0.09
IN
46
0.006
0.036
WORCESTER, MA-CT
478,384
5
ND
0.019
0.09
IN
46
0.005
0.021
YAKIMA, WA
188,823
7
ND
ND
ND
31
112
ND
ND
YOLO, CA
141,092
1
ND
0.011
0.11
28
65
ND
ND
YORK, PA
339,574
3
0.07
0.021
0.10
28
53
0.007
0.022
YOUNGSTOWN-WARREN, OH
600,859
ND
0.04
0.019
0.11
33
86
0.012
0.057
YUBA CITY, CA
122,643
4
ND
0.012
0.11
29
69
ND
ND
YUMA, AZ
106,895
ND
ND
ND
0.10
IN
59
ND
ND"
CO = Highest second maximum non-overlapping 8-hour concentration (Applicable NAAQS is 9 ppm)
Pb = Highest quarterly maximum concentration (Applicable NAAQS is 1.5 ug/m3)
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)
PM10 = Highest weighted annual mean concentration (Applicable NAAQS is 50 ug/m3)
Data from exceptional events not included.
= Highest second maximum 24-hour concentration (Applicable NAAQS is 150 ug/m3)
SO, = Highest annual mean concentration (Applicable NAAQS is 0.03 ppm)
= Highest second maximum 24-hour concentration (Applicable NAAQS is 0.14 ppm)
ND = Indicates data not available
IN = Indicates insufficient data to calculate summary statistic
WTD = Weighted
AM = Annual mean
UGM = Units are micrograms per cubic meter
PPM = Units are parts per million
* - Localized impact from electric utility and switching to low sulfur coal per SIP
(a)	- Localized impact from an industrial source in Chicago, IL. Highest population-oriented site in Chicago, IL is 0.06 (jg/m3.
(b)	- Localized impact from an industrial source in Cleveland, OH. This facility has been shut down. Highest population-oriented site in
mbus, GA. Highest population-oriented site in Columbus, GA is 0.11 (jg/m3.
n Co., TX. Highest population-oriented site in Dallas, TX is 0.17 (jg/m3.
imond, IN. Highest population-oriented site in Hammond is 0.04 (jg/m3.
tnapolis, IN. Highest population-oriented site in Indianapolis, IN is 0.07 (jg/m3.
lphis, TN. Highest population-oriented site in Memphis, TN is 0.03 (jg/m3.


Cleveland, OH is
0.04
(jg/m3.


(c)
-
Localized impact
from
an
industrial
source
in
(d)
-
Localized impact
from
an
industrial
source
in
(e)
-
Localized impact
from
an
industrial
source
in
(f)
-
Localized impact
from
an
industrial
source
in
(g)
-
Localized impact
from
an
industrial
source
in
(h)
-
Localized impact
from
an
industrial
source
in
(i)
-
Localized impact
from
an
industrial
source
in
(j)
-
Localized impact
from
an
industrial
source
in
(k)
-
Localized impact
from
an
industrial
source
in
(i)
-
Localized impact
from
an
industrial
source
in
(m)
-
Localized impact
from
an
industrial
source
in
(n)
-
Localized impact
from
an
industrial
source
in
(0)
-
Localized impact
from
an
industrial
source
in
(P)
-
Localized impact
from
an
industrial
source
in
(q)
-
Localized impact
from
an
industrial
source
in
IN.
NE
JO., TN. Highest population-oriented site in Nashville, TN is 0.07 (jg/m3.
Highest population-oriented site in Omaha, NE is 0.02 (jg/m3.
slphia, PA. Highest population-oriented site in Philadelphia, PA is 0.76 (jg/m3.
Jale, PA.
aneum, MO. Highest population-oriented site in St. Louis, MO is 0.03 (jg/m3.
!.
, FL.
OH.
Note: The reader is cautioned that this summary is not adequate in itself to numerically rank MSAs according to their air quality. The monitor-
ing data represent the quality of air in the vicinity of the monitoring site but may not necessarily represent urban-wide air quality.
122 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
AKRON,OH













CO
SECOND MAX 8-HOUR
NS
1
5.1
4.6
5.2
5.7
3.3
4.1
3.1
5.3
3.3
3.4
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.13
0.07
0.10
0.04
0.06
0.05
0.06
0.06
0.03
0.04
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
2
0.13
0.16
0.13
0.11
0.12
0.11
0.11
0.10
0.12
0.11
PM,0
SECOND MAX 24-HOUR
NS
1
—
72
72
61
59
57
62
62
63
47
WEIGHTED ANNUAL MEAN
DOWN
1
—
34
34
26
28
27
25
28
26
25
S02
ARITHMETIC MEAN
DOWN
1
0.014
0.015
0.015
0.015
0.015
0.013
0.015
0.012
0.009
0.010

SECOND MAX 24-HOUR
NS
1
0.045
0.056
0.053
0.061
0.051
0.064
0.056
0.042
0.046
0.042
ALBANY-SCHENECTADY-TROY, NY












CO
SECOND MAX 8-HOUR
DOWN
1
7.5
6.2
5.7
6.2
5.4
4.7
3.8
5.2
4.3
3.7
LEAD
MAX QUARTERLY MEAN
NS
1
0.08
0.05
0.04
0.13
0.04
0.03
0.03
0.04
0.04
0.03
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.11
0.12
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.09
PM,0
SECOND MAX 24-HOUR
NS
2
—
46
46
46
51
54
51
57
49
43
WEIGHTED ANNUAL MEAN
NS
2
—
22
22
22
22
21
20
22
19
19
S02
ARITHMETIC MEAN
DOWN
1
0.007
0.006
0.005
0.006
0.007
0.006
0.006
0.006
0.005
0.005

SECOND MAX 24-HOUR
NS
1
0.027
0.039
0.022
0.028
0.030
0.022
0.026
0.027
0.016
0.021
ALBUQUERQUE, NM












CO
SECOND MAX 8-HOUR
DOWN
5
8.6
6.6
6.6
6.2
5.6
5.1
5.4
5.0
5.2
4.5
N02
ARITHMETIC MEAN
NS
1
0.018
0.018
0.019
0.018
0.004
0.021
0.024
0.023
0.018
0.022
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
7
0.09
0.09
0.09
0.09
0.08
0.09
0.08
0.08
0.08
0.08
PM,0
SECOND MAX 24-HOUR
NS
9
—
79
75
58
52
46
52
53
58
52
WEIGHTED ANNUAL MEAN
NS
9
—
37
35
26
23
24
25
24
25
25
ALEXANDRIA,
LA












PM,o
SECOND MAX 24-HOUR
NS
1
—
43
43
43
44
48
43
49
45
42
WEIGHTED ANNUAL MEAN
NS
1
—
23
23
23
22
25
21
23
21
19
ALLENTOWN-BETHLEHEM-EASTON, PA












CO
SECOND MAX 8-HOUR
NS
2
4.7
6.8
4.8
5.3
5.3
3.8
3.6
6.6
4.7
3.2
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.43
0.84
0.44
0.24
0.27
0.18
0.12
0.11
0.06
0.06
N02
ARITHMETIC MEAN
NS
1
0.019
0.020
0.020
0.017
0.018
0.018
0.020
0.021
0.018
0.018
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.12
0.15
0.10
0.11
0.12
0.10
0.11
0.11
0.11
0.11
PM,o
SECOND MAX 24-HOUR
NS
3
—
65
63
74
62
38
60
64
57
57
WEIGHTED ANNUAL MEAN
DOWN
3
—
28
28
27
27
20
23
25
24
24
S02
ARITHMETIC MEAN
NS
1
0.012
0.012
0.010
0.010
0.008
0.008
0.009
0.010
0.010
0.010

SECOND MAX 24-HOUR
DOWN
1
0.035
0.049
0.047
0.044
0.033
0.030
0.027
0.042
0.027
0.033
ALTOONA, PA













OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.13
0.14
0.10
0.10
0.11
0.10
0.10
0.11
0.11
0.10
PM10
SECOND MAX 24-HOUR
NS
1
—
75
60
53
65
38
62
74
57
57
WEIGHTED ANNUAL MEAN
NS
1
—
31
25
21
26
21
23
26
25
25
S02
ARITHMETIC MEAN
DOWN
1
0.010
0.011
0.011
0.011
0.011
0.009
0.009
0.010
0.008
0.008

SECOND MAX 24-HOUR
NS
1
0.051
0.051
0.059
0.062
0.044
0.046
0.052
0.058
0.037
0.033
ANCHORAGE, AK












PM,o
SECOND MAX 24-HOUR
NS
3
—
97
79
107
104
130
102
95
115
89
WEIGHTED ANNUAL MEAN
NS
3
—
28
26
31
30
31
28
27
26
25
ANN ARBOR, Ml












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.13
0.13
0.10
0.09
0.11
0.10
0.10
0.09
0.11
0.10
ANNISTON, AL













PM,o
SECOND MAX 24-HOUR
NS
1
—
64
64
64
78
45
69
44
62
31
WEIGHTED ANNUAL MEAN
DOWN
1
—
28
28
28
29
25
25
24
23
19
APPLETON-OSHKOSH-NEENAH, Wl












OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.10
0.11
0.09
0.08
0.09
0.09
0.07
0.08
0.08
0.08
ASHEVILLE, NC












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.08
0.08
0.08
0.09
0.08
0.08
0.08
0.08
0.09
0.08
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
75
53
49
53
41
53
33
38
37
WEIGHTED ANNUAL MEAN
DOWN
1
—
29
29
25
24
23
22
19
18
19
ATLANTA, GA













CO
SECOND MAX 8-HOUR
DOWN
1
5.9
5.3
6.2
5.4
6.5
5.1
4.9
5.3
4.5
3.7
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.07
0.05
0.04
0.03
0.04
0.03
0.02
0.03
0.05
0.03
N02
ARITHMETIC MEAN
DOWN
2
0.024
0.024
0.023
0.021
0.020
0.020
0.020
0.018
0.017
0.021
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.16
0.16
0.12
0.14
0.12
0.12
0.15
0.12
0.14
0.13
PM,o
SECOND MAX 24-HOUR
DOWN
2
—
87
73
96
78
61
72
61
55
58
WEIGHTED ANNUAL MEAN
DOWN
2
—
41
37
46
36
31
31
30
31
29
S02
ARITHMETIC MEAN
DOWN
2
0.006
0.007
0.007
0.007
0.006
0.006
0.006
0.004
0.004
0.004

SECOND MAX 24-HOUR
DOWN
2
0.035
0.041
0.043
0.026
0.032
0.028
0.036
0.023
0.018
0.018
ATLANTIC-CAPE MAY, NJ












LEAD
MAX QUARTERLY MEAN
NS
1
0.06
0.04
0.07
0.02
0.03
0.02
0.03
0.04
0.03
0.03
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.14
0.15
0.12
0.16
0.14
0.12
0.12
0.10
0.12
0.11
PM,o
SECOND MAX 24-HOUR
NS
1
—
82
69
59
71
51
58
56
66
66
WEIGHTED ANNUAL MEAN
DOWN
1
—
41
37
34
34
31
30
33
32
32
S02
ARITHMETIC MEAN
DOWN
1
0.004
0.006
0.005
0.004
0.004
0.003
0.003
0.003
0.003
0.003

SECOND MAX 24-HOUR
NS
1
0.016
0.025
0.029
0.012
0.011
0.016
0.014
0.019
0.011
0.014
AUGUSTA-AIKEN, GA-SC












LEAD
MAX QUARTERLY MEAN
DOWN
1
0.03
0.02
0.03
0.02
0.01
0.01
0.01
0.01
0.01
0.00
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.10
0.11
0.09
0.10
0.10
0.09
0.10
0.09
0.11
0.10
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 123

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
PM10
SECOND MAX 24-HOUR
DOWN
1
	
67
49
53
50
42
51
45
40
41
WEIGHTED ANNUAL MEAN
DOWN
1
—
27
21
22
23
22
22
21
19
19
AUSTIN-SAN MARCOS,TX












CO
SECOND MAX 8-HOUR
NS
1
4,2
4,2
4,2
5,9
3,4
3.7
3,0
5,8
3,5
3.2
N02
ARITHMETIC MEAN
NS
1
0.017
0.017
0.017
0.017
0.016
0.017
0.017
0,018
0.021
0,018
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.10
0.11
0.11
0.11
0.10
0,09
0,09
0.10
0.11
0.10
PM,o
SECOND MAX 24-HOUR
NS
2
—
56
44
43
40
48
51
45
41
31
WEIGHTED ANNUAL MEAN
DOWN
2
—
26
25
21
24
23
19
20
22
19
BAKERSFIELD, CA












N02
ARITHMETIC MEAN
DOWN
3
0.017
0,018
0.017
0.016
0.016
0,015
0.014
0.014
0.012
0.012
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0,15
0,15
0.14
0.14
0.14
0.13
0.13
0.13
0.14
0.14
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
199
158
165
169
104
96
131
111
64
WEIGHTED ANNUAL MEAN
DOWN
1
—
74
65
69
70
55
44
40
46
36
S02
ARITHMETIC MEAN
DOWN
1
0,006
0,006
0,004
0,004
0,002
0,003
0,002
0,003
0,003
0,003

SECOND MAX 24-HOUR
DOWN
1
0.016
0.016
0.014
0.011
0.010
0.010
0.010
0.007
0,008
0,009
BALTIMORE, MD












CO
SECOND MAX 8-HOUR
DOWN
4
7.3
7.7
6,7
6,9
6.1
5,4
5,2
5,5
4,3
3,5
LEAD
MAX QUARTERLY MEAN
DOWN
3
0,09
0,08
0.07
0,05
0,04
0,04
0,03
0,03
0,03
0,03
N02
ARITHMETIC MEAN
DOWN
2
0.031
0,030
0,030
0,029
0,029
0,026
0.027
0,028
0,025
0,025
OZONE
SECOND DAILY MAX 1-HOUR
NS
6
0,15
0.17
0.12
0.12
0.13
0.12
0.13
0.13
0.14
0.12
PM,0
SECOND MAX 24-HOUR
DOWN
3
—
82
73
69
74
59
63
70
65
57
WEIGHTED ANNUAL MEAN
DOWN
3
—
36
36
30
35
30
29
30
28
27
S02
ARITHMETIC MEAN
DOWN
2
0.011
0.012
0.012
0,008
0,009
0,009
0,008
0,009
0,006
0,007

SECOND MAX 24-HOUR
DOWN
2
0.037
0,038
0,042
0,030
0,030
0.027
0,026
0,030
0,022
0,026
BANGOR, ME













PM,o
SECOND MAX 24-HOUR
NS
1
—
58
54
37
48
70
52
59
51
34
WEIGHTED ANNUAL MEAN
DOWN
1
—
31
26
21
25
22
22
22
20
19
BATON ROUGE, LA












LEAD
MAX QUARTERLY MEAN
DOWN
2
0.21
0.10
0,09
0,06
0,03
0,03
0,02
0,02
0,04
0,03
N02
ARITHMETIC MEAN
NS
1
0,019
0.017
0,015
0,014
0,015
0.016
0.012
0.016
0.016
0,015
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.14
0,15
0.14
0,15
0.13
0.11
0.11
0.12
0.12
0.11
PM,o
SECOND MAX 24-HOUR
NS
2
—
54
57
56
62
57
47
54
49
43
WEIGHTED ANNUAL MEAN
DOWN
2
—
28
28
28
28
27
22
26
24
24
S02
ARITHMETIC MEAN
NS
1
0,007
0,007
0,007
0,005
0,009
0,008
0,006
0,008
0,006
0,006

SECOND MAX 24-HOUR
NS
1
0,030
0,029
0,056
0,022
0,036
0,033
0.021
0,025
0,034
0,024
BEAUMONT-PORT ARTHUR.TX












CO
SECOND MAX 8-HOUR
NS
1
4,0
3,0
2,0
2.3
2.3
2,4
3,3
2,0
1.7
2.1
LEAD
MAX QUARTERLY MEAN
NS
1
0,04
0,03
0,02
0,02
0,03
0,02
0,02
0,02
0,02
0,02
N02
ARITHMETIC MEAN
UP
1
0,007
0,007
0,007
0,005
0,008
0,009
0.010
0.012
0.010
0,008
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.13
0,15
0.14
0.12
0.13
0.13
0.12
0.11
0.14
0.12
PM,o
SECOND MAX 24-HOUR
NS
1
—
48
48
48
58
53
56
45
56
34
WEIGHTED ANNUAL MEAN
DOWN
1
—
23
23
23
26
26
22
20
20
15
S02
ARITHMETIC MEAN
DOWN
2
0,009
0,008
0,008
0,009
0,008
0,006
0,006
0,006
0,005
0,005

SECOND MAX 24-HOUR
DOWN
2
0,053
0,046
0,088
0,042
0,059
0,044
0,047
0,039
0,025
0,041
BELLINGHAM.WA












S02
ARITHMETIC MEAN
NS
1
0,008
0,005
0,006
0,007
0,006
0,007
0,006
0.007
0,006
0,005

SECOND MAX 24-HOUR
DOWN
1
0,025
0,026
0,018
0,028
0.021
0,022
0.017
0,019
0,018
0.013
BERGEN-PASSAIC, NJ












CO
SECOND MAX 8-HOUR
DOWN
2
7,5
6,8
7,5
6,8
6,6
4,5
5,2
6,2
4,9
3,8
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.13
0,09
0,05
0,04
0,03
0,02
0,03
0,08
0,03
0,03
N02
ARITHMETIC MEAN
DOWN
1
0,036
0,036
0,035
0.031
0.031
0,030
0,029
0.031
0,029
0,028
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.17
0,19
0.12
0.13
0.14
0.10
0.11
0.11
0.12
0.11
PM,0
SECOND MAX 24-HOUR
NS
3
—
83
70
83
79
60
71
91
72
53
WEIGHTED ANNUAL MEAN
DOWN
3
—
38
35
37
39
33
31
35
31
31
S02
ARITHMETIC MEAN
DOWN
2
0.010
0.012
0.011
0.010
0.010
0,009
0,008
0.007
0,005
0,006

SECOND MAX 24-HOUR
DOWN
2
0.037
0,053
0,045
0,041
0,035
0,040
0,026
0.037
0.027
0,022
BILLINGS, MT













S02
ARITHMETIC MEAN
DOWN
3
0,022
0.021
0,019
0.016
0.016
0.021
0,022
0.016
0.014
0.010

SECOND MAX 24-HOUR
DOWN
3
0.107
0,108
0,086
0.070
0.070
0.081
0,104
0.072
0,066
0,065
BILOXI-GULFPORT-PASCAGOULA, MS












S02
ARITHMETIC MEAN
DOWN
1
0,006
0,006
0,006
0,007
0,006
0,006
0,004
0,003
0,003
0,003

SECOND MAX 24-HOUR
NS
1
0,022
0,022
0,029
0.037
0,034
0,020
0,029
0,022
0,024
0,043
BIRMINGHAM, AL












CO
SECOND MAX 8-HOUR
DOWN
4
7,6
7,4
7,4
6,9
7.0
6,6
6,6
6,6
6,2
5,4
LEAD
MAX QUARTERLY MEAN
DOWN
2
1,59
2,51
1.23
0,91
1,34
0,62
0,19
0,09
0,08
0.10
OZONE
SECOND DAILY MAX 1-HOUR
NS
6
0.12
0.12
0.10
0.12
0.10
0.11
0.11
0.10
0.12
0.13
PM,o
SECOND MAX 24-HOUR
DOWN
6
—
76
62
69
75
54
62
49
54
46
WEIGHTED ANNUAL MEAN
DOWN
6
—
37
31
35
32
29
27
25
26
25
BISMARCK, ND












PM,o
SECOND MAX 24-HOUR
DOWN
1
—
43
51
84
51
45
45
40
36
36
WEIGHTED ANNUAL MEAN
NS
1
—
19
21
24
21
21
19
18
20
20
BOISE CITY, ID













PM,„
SECOND MAX 24-HOUR
NS
3
—
92
107
67
129
79
80
90
74
74
WEIGHTED ANNUAL MEAN
DOWN
3
—
40
42
29
35
34
37
35
30
28
Note: NS = Not Significant (no significant upward or downward trend).
124 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
BOSTON, MA-NH












CO
SECOND MAX 8-HOUR
DOWN
3
6.2
5.3
5.2
5.9
4.0
4.5
3.6
4.5
3.5
3.2
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.11
0.16
0.07
0.04
0.03
0.03
0.02
0.01
0.01
0.01
N02
ARITHMETIC MEAN
DOWN
6
0.029
0.029
0.028
0.027
0.027
0.026
0.027
0.027
0.024
0.025
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
4
0.12
0.15
0.12
0.10
0.13
0.11
0.11
0.11
0.11
0.09
PM,o
SECOND MAX 24-HOUR
NS
8
—
54
52
53
51
51
51
48
42
54
WEIGHTED ANNUAL MEAN
DOWN
8
—
27
27
25
24
22
22
22
21
22
S02
ARITHMETIC MEAN
DOWN
10
0.011
0.012
0.011
0.010
0.009
0.009
0.009
0.008
0.006
0.006

SECOND MAX 24-HOUR
DOWN
10
0.044
0.050
0.044
0.039
0.031
0.038
0.033
0.033
0.024
0.026
BOULDER-LONGMONT, CO












CO
SECOND MAX 8-HOUR
DOWN
1
8.7
6.0
6.5
4.8
4.2
5.1
4.1
2.7
3.7
2.5
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.12
0.12
0.11
0.10
0.10
0.09
0.10
0.09
0.10
0.09
PM,0
SECOND MAX 24-HOUR
DOWN
2
—
78
85
70
71
61
73
47
45
45
WEIGHTED ANNUAL MEAN
DOWN
2
—
28
29
23
23
23
24
19
16
17
BRAZORIA,TX













OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.14
0.14
0.15
0.15
0.13
0.13
0.13
0.11
0.15
0.11
BRIDGEPORT,
CT












CO
SECOND MAX 8-HOUR
DOWN
1
5.3
6.5
5.2
5.0
5.5
4.7
3.7
5.8
4.9
3.0
N02
ARITHMETIC MEAN
DOWN
1
0.027
0.027
0.026
0.026
0.025
0.024
0.024
0.026
0.024
0.024
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
2
0.20
0.22
0.16
0.15
0.15
0.12
0.16
0.15
0.13
0.11
PM10
SECOND MAX 24-HOUR
NS
2
—
54
48
52
55
45
45
54
51
40
WEIGHTED ANNUAL MEAN
DOWN
2
—
26
25
23
25
20
19
22
19
19
S02
ARITHMETIC MEAN
DOWN
2
0.012
0.012
0.012
0.011
0.010
0.010
0.009
0.009
0.006
0.006

SECOND MAX 24-HOUR
DOWN
2
0.051
0.060
0.047
0.048
0.042
0.037
0.033
0.051
0.031
0.029
BROCKTON, MA












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.12
0.13
0.13
0.12
0.15
0.11
0.11
0.12
0.13
0.10
BROWNSVILLE-HARLINGEN-SAN BENITO,TX












PM,o
SECOND MAX 24-HOUR
NS
2
—
49
49
49
68
59
67
51
48
39
WEIGHTED ANNUAL MEAN
NS
2
—
24
24
24
26
27
25
24
23
20
BUFFALO-NIAGARA FALLS, NY












CO
SECOND MAX 8-HOUR
DOWN
3
4.7
4.1
4.4
3.4
3.1
4.6
3.4
3.2
2.6
2.9
LEAD
MAX QUARTERLY MEAN
NS
2
0.08
0.07
0.04
0.04
0.03
0.03
0.04
0.05
0.04
0.04
N02
ARITHMETIC MEAN
NS
2
0.022
0.021
0.022
0.020
0.018
0.018
0.017
0.019
0.019
0.019
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.13
0.14
0.10
0.11
0.11
0.11
0.09
0.09
0.10
0.10
PM,o
SECOND MAX 24-HOUR
NS
12
—
59
57
49
61
52
63
40
44
40
WEIGHTED ANNUAL MEAN
DOWN
12
—
26
25
20
25
22
19
19
19
20
S02
ARITHMETIC MEAN
DOWN
4
0.012
0.013
0.012
0.011
0.012
0.011
0.010
0.010
0.008
0.007

SECOND MAX 24-HOUR
DOWN
4
0.056
0.062
0.051
0.054
0.062
0.058
0.042
0.039
0.040
0.034
BURLINGTON,VT












CO
SECOND MAX 8-HOUR
NS
1
4.7
3.7
3.7
4.6
3.8
3.9
3.9
3.9
2.5
3.3
N02
ARITHMETIC MEAN
DOWN
1
0.019
0.019
0.019
0.018
0.017
0.016
0.017
0.017
0.017
0.017
PM,0
SECOND MAX 24-HOUR
NS
2
—
38
45
62
53
50
45
47
45
36
WEIGHTED ANNUAL MEAN
DOWN
2
—
23
25
24
23
23
21
21
20
20
S02
ARITHMETIC MEAN
DOWN
1
0.006
0.007
0.007
0.008
0.008
0.003
0.003
0.003
0.002
0.002

SECOND MAX 24-HOUR
DOWN
1
0.018
0.027
0.031
0.021
0.022
0.013
0.011
0.013
0.006
0.014
CANTON-MASSILLON, OH












OZONE
SECOND DAILY MAX 1-HOUR
DOWN
2
0.12
0.14
0.11
0.10
0.11
0.09
0.10
0.10
0.10
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
2
—
79
77
65
61
59
63
60
60
57
WEIGHTED ANNUAL MEAN
DOWN
2
—
34
35
30
31
28
26
28
29
25
S02
ARITHMETIC MEAN
DOWN
1
0.010
0.011
0.012
0.011
0.010
0.010
0.010
0.009
0.006
0.006

SECOND MAX 24-HOUR
NS
1
0.045
0.039
0.041
0.036
0.037
0.040
0.046
0.052
0.033
0.032
CEDAR RAPIDS, IA












CO
SECOND MAX 8-HOUR
NS
1
3.3
4.2
2.9
4.8
4.5
4.2
4.1
3.4
2.5
2.5
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
2
0.09
0.08
0.08
0.07
0.08
0.08
0.07
0.07
0.07
0.07
PM,o
SECOND MAX 24-HOUR
DOWN
3
—
67
73
71
62
60
47
46
56
63
WEIGHTED ANNUAL MEAN
DOWN
3
—
35
33
28
29
27
22
23
23
23
S02
ARITHMETIC MEAN
DOWN
5
0.007
0.006
0.007
0.006
0.006
0.005
0.004
0.004
0.004
0.003

SECOND MAX 24-HOUR
DOWN
5
0.052
0.047
0.049
0.048
0.040
0.036
0.037
0.029
0.028
0.023
CHAMPAIGN-URBANA, IL












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.10
0.10
0.09
0.09
0.08
0.09
0.07
0.09
0.10
0.09
PM,0
SECOND MAX 24-HOUR
DOWN
1
—
70
70
66
61
71
50
50
50
39
WEIGHTED ANNUAL MEAN
DOWN
1
—
32
32
28
30
31
22
25
22
19
S02
ARITHMETIC MEAN
DOWN
1
0.005
0.005
0.005
0.004
0.005
0.004
0.004
0.004
0.003
0.003

SECOND MAX 24-HOUR
NS
1
0.021
0.025
0.025
0.030
0.038
0.018
0.015
0.024
0.011
0.013
CHARLESTON-NORTH CHARLESTON, SC












CO
SECOND MAX 8-HOUR
NS
1
5.4
7.5
5.9
4.7
4.9
5.2
5.8
4.0
6.4
4.7
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.05
0.03
0.02
0.03
0.04
0.01
0.01
0.01
0.01
0.01
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.10
0.11
0.09
0.09
0.09
0.09
0.10
0.09
0.09
0.10
PM,0
SECOND MAX 24-HOUR
DOWN
4
—
63
55
59
46
46
40
48
40
40
WEIGHTED ANNUAL MEAN
DOWN
4
—
29
29
27
25
23
22
21
20
20
S02
ARITHMETIC MEAN
DOWN
1
0.005
0.005
0.005
0.003
0.005
0.005
0.004
0.004
0.003
0.003

SECOND MAX 24-HOUR
DOWN
1
0.042
0.063
0.044
0.027
0.030
0.035
0.025
0.038
0.019
0.021
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 125

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
CHARLESTON, WV












CO
SECOND MAX 8-HOUR
NS
1
4.7
2.8
2.9
2.8
3.1
3.3
2.2
3.5
2.4
2.3
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.04
0.02
0.02
0.04
0.02
0.02
0.02
0.02
0.02
0.02
N02
ARITHMETIC MEAN
DOWN
1
0.025
0.024
0.021
0.020
0.020
0.017
0.018
0.019
0.020
0.020
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.11
0.16
0.10
0.12
0.12
0.07
0.08
0.10
0.11
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
83
88
72
59
50
59
57
53
50
WEIGHTED ANNUAL MEAN
DOWN
1
—
37
35
36
29
28
29
28
26
24
S02
ARITHMETIC MEAN
DOWN
2
0.011
0.013
0.014
0.012
0.009
0.009
0.009
0.010
0.007
0.008

SECOND MAX 24-HOUR
DOWN
2
0.045
0.049
0.062
0.056
0.036
0.031
0.034
0.037
0.023
0.031
CHARLOTTE-GASTONIA-ROCK HILL, NC-SC












CO
SECOND MAX 8-HOUR
DOWN
5
6.7
6.7
7.0
7.1
6.3
6.0
5.6
5.8
4.7
4.4
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.07
0.07
0.03
0.04
0.01
0.08
0.02
0.03
0.01
0.01
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.13
0.16
0.12
0.12
0.12
0.10
0.13
0.11
0.11
0.13
PM,o
SECOND MAX 24-HOUR
DOWN
2
—
68
55
57
57
54
52
47
48
51
WEIGHTED ANNUAL MEAN
DOWN
2
—
35
34
33
30
30
29
29
26
28
CHARLOTTESVILLE, VA












PM,o
SECOND MAX 24-HOUR
DOWN
1
—
72
64
53
57
37
54
40
53
39
WEIGHTED ANNUAL MEAN
DOWN
1
—
40
30
27
28
22
24
22
23
21
CHATTANOOGA,TN-GA












OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.12
0.10
0.12
0.10
0.09
0.10
0.11
0.11
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
2
—
76
67
72
75
72
61
63
58
63
WEIGHTED ANNUAL MEAN
DOWN
2
—
39
36
38
38
34
32
33
32
32
CHICAGO.IL













CO
SECOND MAX 8-HOUR
NS
6
4.6
5.0
4.8
5.3
4.3
4.8
4.7
6.5
3.7
3.2
LEAD
MAX QUARTERLY MEAN
DOWN
8
0.10
0.15
0.10
0.08
0.06
0.07
0.06
0.06
0.05
0.04
N02
ARITHMETIC MEAN
NS
5
0.029
0.030
0.030
0.026
0.025
0.027
0.028
0.031
0.031
0.031
OZONE
SECOND DAILY MAX 1-HOUR
NS
16
0.14
0.14
0.11
0.09
0.11
0.10
0.09
0.10
0.12
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
13
—
91
84
99
78
79
78
92
75
65
WEIGHTED ANNUAL MEAN
DOWN
13
—
39
39
37
35
34
33
37
34
31
S02
ARITHMETIC MEAN
DOWN
9
0.008
0.008
0.007
0.006
0.007
0.006
0.006
0.006
0.005
0.005

SECOND MAX 24-HOUR
DOWN
9
0.036
0.031
0.028
0.024
0.029
0.026
0.028
0.030
0.023
0.022
CHICO-PARADISE, CA












CO
SECOND MAX 8-HOUR
DOWN
2
5.6
7.2
6.4
6.2
7.4
5.9
4.7
4.6
4.1
4.4
N02
ARITHMETIC MEAN
DOWN
1
0.017
0.016
0.016
0.015
0.016
0.016
0.016
0.015
0.014
0.013
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.10
0.10
0.10
0.12
0.09
0.09
0.09
0.10
0.09
0.10
CINCINNATI, OH-KY-IN












CO
SECOND MAX 8-HOUR
NS
3
5.0
3.8
4.9
4.2
4.2
4.5
4.7
4.3
3.4
2.9
LEAD
MAX QUARTERLY MEAN
NS
2
0.09
0.13
0.09
0.11
0.06
0.05
0.05
0.04
0.05
0.13
N02
ARITHMETIC MEAN
DOWN
3
0.027
0.025
0.026
0.024
0.024
0.022
0.023
0.024
0.023
0.023
OZONE
SECOND DAILY MAX 1-HOUR
NS
6
0.13
0.14
0.11
0.12
0.12
0.09
0.10
0.12
0.12
0.11
PM,„
SECOND MAX 24-HOUR
DOWN
7
—
94
94
91
66
60
70
68
69
61
WEIGHTED ANNUAL MEAN
DOWN
7
—
40
41
36
32
30
31
30
31
28
S02
ARITHMETIC MEAN
DOWN
6
0.012
0.011
0.012
0.012
0.011
0.010
0.011
0.008
0.007
0.008

SECOND MAX 24-HOUR
DOWN
6
0.055
0.049
0.052
0.058
0.044
0.044
0.041
0.042
0.029
0.035
CLARKSVILLE-HOPKINSVILLE.TN-KY












S02
ARITHMETIC MEAN
NS
1
0.005
0.010
0.007
0.007
0.006
0.009
0.010
0.007
0.006
0.006

SECOND MAX 24-HOUR
DOWN
1
0.040
0.066
0.042
0.038
0.029
0.036
0.058
0.037
0.019
0.023
CLEVELAND-LORAIN-ELYRIA.OH












CO
SECOND MAX 8-HOUR
NS
2
6.0
5.7
5.9
4.7
4.7
5.1
4.3
5.3
5.7
3.7
LEAD
MAX QUARTERLY MEAN
DOWN
4
0.31
0.26
0.19
0.32
0.18
0.21
0.21
0.14
0.11
0.06
N02
ARITHMETIC MEAN
DOWN
1
0.022
0.023
0.025
0.022
0.022
0.021
0.022
0.021
0.021
0.020
OZONE
SECOND DAILY MAX 1-HOUR
NS
6
0.12
0.14
0.10
0.11
0.11
0.10
0.11
0.11
0.11
0.11
PM,o
SECOND MAX 24-HOUR
NS
7
—
85
93
87
82
79
77
93
97
74
WEIGHTED ANNUAL MEAN
NS
7
—
42
41
36
38
33
32
39
36
33
S02
ARITHMETIC MEAN
DOWN
9
0.011
0.011
0.012
0.010
0.010
0.009
0.008
0.008
0.006
0.006

SECOND MAX 24-HOUR
DOWN
9
0.045
0.044
0.042
0.041
0.039
0.038
0.039
0.040
0.023
0.030
COLORADO SPRINGS, CO












CO
SECOND MAX 8-HOUR
DOWN
2
8.3
11.5
7.7
6.8
6.5
6.0
5.4
4.6
5.1
4.4
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.08
0.08
0.08
0.07
0.08
0.07
0.06
0.07
0.07
0.07
PM,o
SECOND MAX 24-HOUR
DOWN
4
—
73
74
68
75
65
71
63
53
51
WEIGHTED ANNUAL MEAN
DOWN
4
—
30
30
25
27
24
27
25
23
23
COLUMBIA, SC













CO
SECOND MAX 8-HOUR
DOWN
1
7.0
7.4
6.5
5.8
6.0
6.3
5.6
4.7
4.0
3.4
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.09
0.06
0.03
0.03
0.05
0.04
0.02
0.02
0.01
0.01
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.12
0.13
0.10
0.11
0.10
0.10
0.11
0.10
0.11
0.09
PM,o
SECOND MAX 24-HOUR
DOWN
5
—
66
57
59
49
54
48
40
41
44
WEIGHTED ANNUAL MEAN
DOWN
5
—
31
30
29
25
26
25
24
20
23
S02
ARITHMETIC MEAN
DOWN
1
0.003
0.003
0.003
0.003
0.002
0.002
0.003
0.002
0.001
0.002

SECOND MAX 24-HOUR
DOWN
1
0.017
0.017
0.012
0.009
0.013
0.013
0.012
0.010
0.005
0.011
COLUMBUS, GA-AL












OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.10
0.09
0.10
0.09
0.09
0.10
0.10
0.11
0.09
PM,„
SECOND MAX 24-HOUR
NS
1
—
43
43
63
75
51
50
49
54
38
WEIGHTED ANNUAL MEAN
NS
1
—
26
26
29
27
26
25
27
28
22
Note: NS = Not Significant (no significant upward or downward trend).
126 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
COLUMBUS, OH












CO
SECOND MAX 8-HOUR
DOWN
3
5.4
6.0
5.7
4.1
4.8
4.9
3.9
4.5
3.8
2.5
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.09
0.08
0.08
0.06
0.06
0.06
0.04
0.04
0.04
0.03
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.14
0.11
0.11
0.12
0.09
0.10
0.10
0.11
0.11
PM,0
SECOND MAX 24-HOUR
NS
3
—
69
80
84
64
64
66
64
67
60
WEIGHTED ANNUAL MEAN
DOWN
3
—
31
34
32
31
27
27
27
29
26
S02
ARITHMETIC MEAN
DOWN
1
0.009
0.008
0.008
0.008
0.007
0.006
0.007
0.007
0.004
0.004

SECOND MAX 24-HOUR
NS
1
0.032
0.035
0.038
0.038
0.033
0.030
0.034
0.041
0.019
0.021
CORPUS CHRISTLTX












OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.13
0.10
0.10
0.10
0.11
0.09
0.12
0.11
0.12
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
2
—
76
74
63
70
59
74
53
54
40
WEIGHTED ANNUAL MEAN
NS
2
—
28
30
27
31
29
29
28
28
23
S02
ARITHMETIC MEAN
NS
2
0.003
0.003
0.003
0.002
0.003
0.003
0.003
0.002
0.002
0.002

SECOND MAX 24-HOUR
NS
2
0.017
0.025
0.019
0.013
0.027
0.018
0.024
0.012
0.016
0.013
CUMBERLAND, MD-WV












S02
ARITHMETIC MEAN
DOWN
1
0.012
0.013
0.011
0.010
0.009
0.006
0.008
0.010
0.005
0.003

SECOND MAX 24-HOUR
DOWN
1
0.044
0.055
0.049
0.031
0.028
0.024
0.027
0.037
0.015
0.019
DALLAS,TX













CO
SECOND MAX 8-HOUR
NS
1
4.7
8.0
4.5
4.7
3.8
5.6
5.4
5.3
5.9
5.5
LEAD
MAX QUARTERLY MEAN
DOWN
11
0.25
0.23
0.24
0.21
0.16
0.16
0.16
0.10
0.11
0.07
N02
ARITHMETIC MEAN
UP
1
0.014
0.014
0.012
0.012
0.013
0.015
0.014
0.016
0.019
0.019
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.13
0.13
0.13
0.14
0.10
0.12
0.13
0.12
0.14
0.12
PM,o
SECOND MAX 24-HOUR
NS
5
—
57
58
60
57
54
62
51
66
72
WEIGHTED ANNUAL MEAN
NS
5
—
29
29
28
26
26
27
26
30
30
DANBURY, CT













OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.15
0.20
0.13
0.15
0.14
0.12
0.14
0.13
0.13
0.11
PM,o
SECOND MAX 24-HOUR
NS
1
—
60
48
44
53
57
46
48
52
45
WEIGHTED ANNUAL MEAN
NS
1
—
26
25
22
26
22
19
26
22
22
S02
ARITHMETIC MEAN
DOWN
1
0.008
0.009
0.008
0.007
0.008
0.007
0.006
0.006
0.004
0.005

SECOND MAX 24-HOUR
DOWN
1
0.035
0.051
0.036
0.033
0.032
0.027
0.024
0.037
0.020
0.020
DAVENPORT-MOLINE-ROCK ISLAND, IA-IL












LEAD
MAX QUARTERLY MEAN
NS
1
0.03
0.01
0.02
0.03
0.01
0.02
0.02
0.02
0.01
0.02
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.10
0.11
0.10
0.08
0.09
0.10
0.08
0.09
0.09
0.09
PM,0
SECOND MAX 24-HOUR
NS
3
—
72
75
71
57
59
62
74
78
84
WEIGHTED ANNUAL MEAN
NS
3
—
33
32
31
30
29
28
32
34
31
S02
ARITHMETIC MEAN
NS
3
0.004
0.004
0.005
0.005
0.004
0.004
0.004
0.004
0.004
0.003

SECOND MAX 24-HOUR
DOWN
3
0.018
0.023
0.025
0.022
0.020
0.019
0.018
0.023
0.017
0.016
DAYTON-SPRINGFIELD, OH












CO
SECOND MAX 8-HOUR
DOWN
2
5.0
4.0
4.8
3.2
3.5
3.6
3.6
3.4
3.0
2.4
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.09
0.08
0.06
0.05
0.04
0.04
0.06
0.04
0.05
0.04
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.12
0.13
0.12
0.11
0.11
0.10
0.11
0.11
0.12
0.11
PM,0
SECOND MAX 24-HOUR
DOWN
4
—
74
70
64
53
52
58
56
56
54
WEIGHTED ANNUAL MEAN
DOWN
4
—
31
30
25
28
25
24
24
25
23
S02
ARITHMETIC MEAN
DOWN
2
0.006
0.006
0.006
0.006
0.005
0.005
0.006
0.006
0.004
0.005

SECOND MAX 24-HOUR
NS
2
0.030
0.026
0.031
0.023
0.022
0.020
0.031
0.032
0.016
0.027
DECATUR, AL













PM,o
SECOND MAX 24-HOUR
NS
1
—
57
57
57
68
48
60
45
52
44
WEIGHTED ANNUAL MEAN
NS
1
—
25
25
25
28
25
25
22
25
21
DECATUR, IL













LEAD
MAX QUARTERLY MEAN
DOWN
1
0.09
0.10
0.07
0.03
0.03
0.03
0.03
0.05
0.03
0.02
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.10
0.11
0.09
0.09
0.10
0.09
0.08
0.10
0.10
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
99
110
101
85
75
64
66
58
53
WEIGHTED ANNUAL MEAN
DOWN
1
—
40
40
34
36
38
28
29
30
28
S02
ARITHMETIC MEAN
DOWN
1
0.013
0.015
0.012
0.008
0.007
0.005
0.006
0.007
0.005
0.005

SECOND MAX 24-HOUR
DOWN
1
0.081
0.162
0.108
0.060
0.039
0.023
0.025
0.030
0.024
0.022
DENVER, CO













CO
SECOND MAX 8-HOUR
DOWN
6
12.1
9.9
7.8
7.2
7.0
8.3
6.6
6.1
5.6
4.8
LEAD
MAX QUARTERLY MEAN
DOWN
3
0.09
0.07
0.05
0.06
0.05
0.06
0.06
0.04
0.05
0.03
N02
ARITHMETIC MEAN
DOWN
2
0.034
0.033
0.033
0.032
0.032
0.032
0.027
0.032
0.029
0.027
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
5
0.11
0.11
0.10
0.10
0.09
0.09
0.09
0.09
0.09
0.09
PM,0
SECOND MAX 24-HOUR
NS
10
—
66
79
67
75
71
92
66
54
52
WEIGHTED ANNUAL MEAN
DOWN
10
—
30
30
28
28
29
32
27
24
24
S02
ARITHMETIC MEAN
DOWN
2
0.007
0.007
0.006
0.006
0.006
0.007
0.006
0.006
0.004
0.005

SECOND MAX 24-HOUR
NS
2
0.021
0.022
0.023
0.020
0.026
0.038
0.025
0.025
0.016
0.020
DES MOINES, IA












CO
SECOND MAX 8-HOUR
NS
3
4.7
3.9
4.4
4.6
4.6
3.9
4.5
3.9
4.0
3.2
OZONE
SECOND DAILY MAX 1-HOUR
UP
2
0.05
0.06
0.06
0.07
0.06
0.08
0.08
0.07
0.08
0.08
PM,o
SECOND MAX 24-HOUR
NS
3
—
83
87
89
66
81
77
90
78
89
WEIGHTED ANNUAL MEAN
NS
3
—
35
33
32
29
28
29
30
30
31
DETROIT, Ml













CO
SECOND MAX 8-HOUR
NS
6
6.6
5.4
6.0
4.5
5.1
4.2
4.5
6.6
4.5
3.9
LEAD
MAX QUARTERLY MEAN
DOWN
4
0.07
0.06
0.06
0.04
0.04
0.03
0.03
0.03
0.03
0.03
N02
ARITHMETIC MEAN
NS
1
0.023
0.023
0.025
0.024
0.022
0.021
0.022
0.025
0.022
0.020
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 127

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
OZONE
SECOND DAILY MAX 1-HOUR
NS
7
0.11
0.14
0.12
0.10
0.12
0.10
0.11
0.12
0.11
0.10
PM,o
SECOND MAX 24-HOUR
NS
6
—
92
81
78
73
69
82
90
88
65
WEIGHTED ANNUAL MEAN
NS
6
—
38
39
36
33
28
33
38
35
31
S02
ARITHMETIC MEAN
DOWN
9
0.010
0.010
0.010
0.010
0.008
0.007
0.007
0.007
0.006
0.006

SECOND MAX 24-HOUR
DOWN
9
0.040
0.040
0.037
0.038
0.033
0.030
0.030
0.031
0.029
0.035
DOTHAN, AL













PM,o
SECOND MAX 24-HOUR
NS
1
—
47
47
70
62
63
59
63
56
54
WEIGHTED ANNUAL MEAN
NS
1
—
26
26
31
28
25
26
28
28
22
DOVER, DE













OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.15
0.17
0.12
0.10
0.10
0.08
0.11
0.10
0.10
0.10
DUBUQUE, IA













S02
ARITHMETIC MEAN
NS
1
0.005
0.005
0.005
0.005
0.004
0.004
0.003
0.005
0.006
0.003

SECOND MAX 24-HOUR
NS
1
0.028
0.052
0.030
0.037
0.028
0.029
0.014
0.037
0.027
0.022
DULUTH-SUPERIOR, MN-WI












CO
SECOND MAX 8-HOUR
NS
1
8.5
5.1
9.9
4.4
5.2
4.0
4.1
4.3
4.5
4.5
PM,o
SECOND MAX 24-HOUR
DOWN
6
—
68
52
55
51
48
37
41
46
46
WEIGHTED ANNUAL MEAN
DOWN
6
—
27
26
22
23
20
19
19
19
19
EL PASO, TX













CO
SECOND MAX 8-HOUR
DOWN
5
10.0
9.1
9.8
10.9
9.1
8.1
8.0
6.6
6.8
8.4
LEAD
MAX QUARTERLY MEAN
DOWN
4
0.32
0.26
0.30
0.27
0.27
0.19
0.18
0.12
0.13
0.20
N02
ARITHMETIC MEAN
NS
1
0.023
0.021
0.022
0.017
0.019
0.021
0.021
0.023
0.023
0.023
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
3
0.16
0.14
0.13
0.12
0.12
0.12
0.11
0.13
0.11
0.12
PM,o
SECOND MAX 24-HOUR
NS
6
—
116
109
104
71
85
58
82
88
84
WEIGHTED ANNUAL MEAN
DOWN
6
—
47
42
36
30
30
27
28
31
30
S02
ARITHMETIC MEAN
DOWN
3
0.015
0.014
0.013
0.010
0.010
0.012
0.009
0.007
0.008
0.008

SECOND MAX 24-HOUR
DOWN
3
0.066
0.059
0.055
0.055
0.047
0.053
0.049
0.029
0.038
0.036
ELMIRA, NY













OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.10
0.12
0.09
0.10
0.10
0.09
0.09
0.08
0.09
0.09
S02
ARITHMETIC MEAN
DOWN
1
0.006
0.007
0.005
0.005
0.005
0.005
0.005
0.004
0.004
0.004

SECOND MAX 24-HOUR
DOWN
1
0.029
0.027
0.026
0.021
0.022
0.021
0.019
0.023
0.014
0.016
ERIE, PA













CO
SECOND MAX 8-HOUR
DOWN
1
5.3
4.9
4.4
5.1
3.8
3.6
4.4
3.7
3.2
3.2
N02
ARITHMETIC MEAN
NS
1
0.016
0.016
0.015
0.015
0.013
0.014
0.014
0.015
0.015
0.015
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.15
0.15
0.12
0.10
0.11
0.10
0.11
0.10
0.11
0.10
PM,„
SECOND MAX 24-HOUR
NS
1
—
87
73
71
68
56
59
54
94
94
WEIGHTED ANNUAL MEAN
NS
1
—
35
27
27
29
22
26
29
29
29
S02
ARITHMETIC MEAN
DOWN
1
0.014
0.014
0.014
0.014
0.010
0.011
0.011
0.010
0.009
0.011

SECOND MAX 24-HOUR
NS
1
0.050
0.050
0.074
0.057
0.044
0.056
0.072
0.076
0.050
0.066
EUGENE-SPRINGFIELD, OR












CO
SECOND MAX 8-HOUR
DOWN
1
6.9
7.1
6.0
4.8
5.4
6.0
4.7
5.3
4.7
4.6
LEAD
MAX QUARTERLY MEAN
NS
1
0.08
0.03
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.12
0.08
0.09
0.09
0.10
0.08
0.09
0.08
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
4
—
102
104
87
117
92
91
85
75
61
WEIGHTED ANNUAL MEAN
DOWN
4
—
35
31
28
33
29
29
25
23
20
EVANSVILLE-HENDERSON, IN-KY












CO
SECOND MAX 8-HOUR
NS
1
2.5
3.1
2.3
2.5
2.0
2.3
2.6
2.7
2.7
2.0
N02
ARITHMETIC MEAN
DOWN
1
0.021
0.022
0.020
0.018
0.021
0.018
0.017
0.018
0.017
0.017
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0.11
0.12
0.10
0.10
0.10
0.09
0.10
0.11
0.11
0.10
PM,0
SECOND MAX 24-HOUR
DOWN
3
—
82
81
79
63
54
68
76
70
46
WEIGHTED ANNUAL MEAN
DOWN
3
—
38
36
32
34
30
30
33
32
26
S02
ARITHMETIC MEAN
DOWN
8
0.011
0.012
0.014
0.013
0.013
0.012
0.012
0.012
0.010
0.010

SECOND MAX 24-HOUR
NS
8
0.060
0.062
0.060
0.062
0.065
0.069
0.051
0.048
0.042
0.047
FARGO-MOORHEAD, ND-MN












PM,o
SECOND MAX 24-HOUR
NS
1
—
45
46
63
45
54
39
39
40
40
WEIGHTED ANNUAL MEAN
NS
1
—
21
21
21
19
21
18
18
20
20
FAYETTEVILLE-SPRINGDALE-ROGERS, AR












PM,„
SECOND MAX 24-HOUR
NS
1
—
58
58
59
46
53
58
49
46
48
WEIGHTED ANNUAL MEAN
NS
1
—
26
26
23
24
22
24
25
24
23
FAYETTEVILLE, NC












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.10
0.10
0.10
0.09
0.09
0.09
0.10
0.10
0.10
0.11
PM,0
SECOND MAX 24-HOUR
NS
1
—
73
52
56
52
44
55
44
38
53
WEIGHTED ANNUAL MEAN
DOWN
1
—
33
29
31
27
26
27
25
23
26
FLINT, Ml













OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.12
0.13
0.10
0.10
0.10
0.09
0.10
0.09
0.09
0.10
FLORENCE, AL












PM,o
SECOND MAX 24-HOUR
NS
1
—
56
56
56
57
40
52
39
49
46
WEIGHTED ANNUAL MEAN
DOWN
1
—
24
24
24
24
21
23
20
22
18
S02
ARITHMETIC MEAN
DOWN
1
0.007
0.007
0.005
0.005
0.004
0.004
0.004
0.003
0.003
0.003

SECOND MAX 24-HOUR
DOWN
1
0.071
0.050
0.036
0.027
0.025
0.019
0.022
0.022
0.018
0.019
FORT COLLINS-LOVELAND, CO












CO
SECOND MAX 8-HOUR
DOWN
1
12.8
11.3
8.3
7.0
9.8
6.9
6.6
6.0
5.2
5.1
OZONE
SECOND DAILY MAX 1-HOUR
NS

0.09
0.10
0.09
0.08
0.09
0.09
0.09
0.10
0.09
0.09
PM,o
SECOND MAX 24-HOUR
NS
1
—
83
59
45
58
39
54
45
47
52
WEIGHTED ANNUAL MEAN
DOWN
1
—
28
29
23
25
23
22
22
22
20
Note: NS = Not Significant (no significant upward or downward trend).
128 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
FORT LAUDERDALE, FL












CO
SECOND MAX 8-HOUR
NS
4
4.3
3.5
4.4
3.4
3.6
4.0
3.6
3.5
3.5
3.0
LEAD
MAX QUARTERLY MEAN
NS
2
0.04
0.04
0.04
0.03
0.02
0.06
0.03
0.03
0.02
0.04
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
2
0.12
0.12
0.11
0.10
0.09
0.09
0.10
0.09
0.09
0.09
PM,0
SECOND MAX 24-HOUR
UP
1
—
42
36
29
42
42
66
50
50
50
WEIGHTED ANNUAL MEAN
NS
1
—
22
21
17
18
18
19
24
24
24
FORT MYERS-CAPE CORAL, FL












OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.10
0.10
0.10
0.08
0.08
0.08
0.08
0.09
0.09
0.07
FORT SMITH, AR-OK












PM,o
SECOND MAX 24-HOUR
NS
1
—
46
46
55
47
51
60
44
56
47
WEIGHTED ANNUAL MEAN
NS
1
—
28
28
26
25
24
25
24
26
25
FORTWAYNE, IN












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.11
0.12
0.12
0.09
0.10
0.09
0.10
0.11
0.11
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
64
64
64
55
45
61
47
53
34
WEIGHTED ANNUAL MEAN
DOWN
1
—
29
29
27
27
23
23
24
24
17
FORTWORTH-ARLINGTON, TX












CO
SECOND MAX 8-HOUR
DOWN
2
5.1
5.1
4.8
4.2
3.7
4.0
3.4
3.2
3.2
3.0
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.08
0.05
0.03
0.03
0.02
0.03
0.03
0.03
0.03
0.02
N02
ARITHMETIC MEAN
NS
1
0.015
0.014
0.013
0.012
0.014
0.015
0.013
0.017
0.017
0.015
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.13
0.14
0.13
0.14
0.15
0.12
0.11
0.13
0.14
0.13
PM,0
SECOND MAX 24-HOUR
NS
3
—
54
50
49
45
51
58
40
52
49
WEIGHTED ANNUAL MEAN
NS
3
—
25
24
24
23
21
21
20
24
25
S02
ARITHMETIC MEAN
NS
1
0.002
0.002
0.001
0.002
0.002
0.003
0.001
0.002
0.001
0.001

SECOND MAX 24-HOUR
NS
1
0.010
0.010
0.007
0.008
0.006
0.013
0.005
0.006
0.004
0.011
FRESNO, CA













CO
SECOND MAX 8-HOUR
DOWN
2
4.0
5.0
4.8
4.9
5.4
3.9
3.4
4.3
3.5
3.2
N02
ARITHMETIC MEAN
NS
2
0.017
0.021
0.022
0.021
0.021
0.020
0.020
0.020
0.019
0.019
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.16
0.16
0.14
0.14
0.15
0.14
0.14
0.12
0.13
0.14
PM,0
SECOND MAX 24-HOUR
DOWN
6
—
153
153
153
120
87
114
100
104
72
WEIGHTED ANNUAL MEAN
DOWN
6
—
53
53
53
52
43
43
39
39
34
GADSDEN, AL













PM,o
SECOND MAX 24-HOUR
NS
2
—
70
52
61
80
59
76
54
62
49
WEIGHTED ANNUAL MEAN
DOWN
2
—
36
28
33
32
31
33
30
30
23
GALVESTON-TEXAS CITY, TX












LEAD
MAX QUARTERLY MEAN
DOWN
1
0.04
0.04
0.03
0.02
0.02
0.02
0.03
0.02
0.03
0.02
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.13
0.14
0.14
0.15
0.15
0.10
0.18
0.13
0.20
0.11
PM,0
SECOND MAX 24-HOUR
NS
3
—
54
59
49
43
52
62
47
62
47
WEIGHTED ANNUAL MEAN
DOWN
3
—
27
28
24
22
24
24
23
25
19
S02
ARITHMETIC MEAN
NS
1
0.006
0.007
0.008
0.007
0.007
0.005
0.005
0.006
0.006
0.014

SECOND MAX 24-HOUR
NS
1
0.053
0.049
0.045
0.063
0.050
0.039
0.056
0.052
0.089
0.067
GARY, IN













CO
SECOND MAX 8-HOUR
NS
1
4.5
4.2
4.0
3.8
4.6
4.2
5.0
4.6
3.7
2.8
LEAD
MAX QUARTERLY MEAN
DOWN
4
0.91
0.47
0.23
0.21
0.11
0.11
0.08
0.17
0.12
0.13
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0.13
0.15
0.10
0.10
0.11
0.11
0.09
0.11
0.12
0.11
PM,0
SECOND MAX 24-HOUR
DOWN
8
—
91
74
82
68
59
56
57
53
45
WEIGHTED ANNUAL MEAN
DOWN
8
—
35
33
33
29
26
24
26
25
21
S02
ARITHMETIC MEAN
DOWN
5
0.011
0.010
0.011
0.010
0.008
0.007
0.007
0.006
0.005
0.005

SECOND MAX 24-HOUR
DOWN
5
0.041
0.052
0.047
0.048
0.028
0.028
0.032
0.032
0.022
0.023
GLENS FALLS, NY












S02
ARITHMETIC MEAN
DOWN
1
0.006
0.005
0.004
0.005
0.004
0.004
0.004
0.004
0.003
0.002

SECOND MAX 24-HOUR
DOWN
1
0.029
0.040
0.023
0.040
0.020
0.017
0.018
0.027
0.011
0.013
GRAND FORKS, ND-MN












PM,0
SECOND MAX 24-HOUR
DOWN
1
—
53
53
104
57
57
38
36
40
28
WEIGHTED ANNUAL MEAN
DOWN
1
—
24
24
25
20
18
17
16
18
15
GRAND RAPIDS-MUSKEGON-HOLLAND, Ml












CO
SECOND MAX 8-HOUR
NS
1
4.9
4.1
4.5
3.5
4.0
3.2
3.2
4.0
4.6
3.3
LEAD
MAX QUARTERLY MEAN
DOWN
3
0.09
0.04
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.13
0.14
0.12
0.12
0.12
0.10
0.09
0.10
0.12
0.13
PM,o
SECOND MAX 24-HOUR
NS
2
—
64
60
69
62
122
65
68
52
43
WEIGHTED ANNUAL MEAN
DOWN
2
—
28
29
30
26
35
22
27
21
20
S02
ARITHMETIC MEAN
DOWN
1
0.004
0.004
0.004
0.004
0.004
0.003
0.003
0.003
0.002
0.002

SECOND MAX 24-HOUR
DOWN
1
0.017
0.016
0.016
0.012
0.014
0.015
0.012
0.013
0.011
0.011
GREAT FALLS,
MT












PM,o
SECOND MAX 24-HOUR
DOWN
1
—
65
65
61
72
53
61
48
52
59
WEIGHTED ANNUAL MEAN
NS
1
—
20
20
24
21
21
21
21
18
19
GREELEY, CO













CO
SECOND MAX 8-HOUR
DOWN
1
10.5
9.2
7.3
7.1
7.8
7.5
5.8
5.2
5.3
7.0
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.09
0.10
0.10
0.11
0.10
0.08
0.09
0.09
0.09
0.10
PM,0
SECOND MAX 24-HOUR
DOWN
1
—
83
73
66
80
60
99
57
59
56
WEIGHTED ANNUAL MEAN
DOWN
1
—
40
30
25
26
25
23
23
20
18
GREEN BAY, Wl












S02
ARITHMETIC MEAN
DOWN
1
0.006
0.007
0.006
0.005
0.005
0.004
0.003
0.003
0.004
0.003

SECOND MAX 24-HOUR
DOWN
1
0.045
0.039
0.024
0.020
0.042
0.021
0.018
0.015
0.017
0.011
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 129

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
GREENSBORO—WINSTON-SALEM—HIGH POINT, N












CO
SECOND MAX 8-HOUR
DOWN
1
9.7
9.7
9.7
6.8
6.6
5.7
5.5
6.0
6.2
4.3
N02
ARITHMETIC MEAN
NS
1
0.018
0.018
0.016
0.017
0.016
0.015
0.017
0.017
0.016
0.016
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.12
0.14
0.10
0.12
0.10
0.10
0.11
0.11
0.11
0.11
PM,0
SECOND MAX 24-HOUR
DOWN
5
—
69
66
60
61
51
57
43
57
46
WEIGHTED ANNUAL MEAN
DOWN
5
—
34
33
32
31
27
28
25
26
25
S02
ARITHMETIC MEAN
NS
1
0.007
0.007
0.007
0.008
0.007
0.006
0.006
0.007
0.007
0.007

SECOND MAX 24-HOUR
NS
1
0.028
0.031
0.024
0.023
0.027
0.019
0.022
0.021
0.025
0.026
GREEN VILLE-SRftRTANBURG-ANDERSON, SC












LEAD
MAX QUARTERLY MEAN
DOWN
3
0.06
0.06
0.04
0.04
0.04
0.02
0.02
0.02
0.02
0.01
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.12
0.13
0.10
0.09
0.10
0.10
0.11
0.10
0.11
0.11
GREENVILLE, NC












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.12
0.12
0.10
0.10
0.09
0.10
0.11
0.09
0.10
0.10
HAMILTON-MIDDLETOWN.OH












OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.13
0.11
0.12
0.11
0.10
0.12
0.11
0.13
0.11
PM,o
SECOND MAX 24-HOUR
NS
1
—
76
76
76
53
50
73
55
77
53
WEIGHTED ANNUAL MEAN
NS
1
—
27
27
27
33
27
29
27
29
26
S02
ARITHMETIC MEAN
DOWN
2
0.010
0.010
0.010
0.010
0.009
0.007
0.008
0.008
0.005
0.007

SECOND MAX 24-HOUR
DOWN
2
0.041
0.041
0.040
0.037
0.040
0.033
0.035
0.038
0.019
0.025
HARRISBURG-LEBANON-CARLISLE, PA












N02
ARITHMETIC MEAN
NS
2
0.014
0.014
0.014
0.013
0.014
0.013
0.011
0.015
0.014
0.015
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.12
0.14
0.10
0.11
0.11
0.09
0.11
0.12
0.11
0.10
PM,o
SECOND MAX 24-HOUR
NS
2
—
74
61
52
52
36
62
68
60
50
WEIGHTED ANNUAL MEAN
NS
2
—
27
25
23
25
21
24
27
25
24
S02
ARITHMETIC MEAN
NS
2
0.006
0.006
0.006
0.005
0.006
0.005
0.006
0.007
0.005
0.005

SECOND MAX 24-HOUR
NS
2
0.026
0.024
0.029
0.021
0.021
0.022
0.021
0.035
0.017
0.021
HARTFORD, CT












CO
SECOND MAX 8-HOUR
DOWN
2
7.5
8.3
6.7
6.7
6.1
6.1
5.6
6.4
5.8
5.3
N02
ARITHMETIC MEAN
DOWN
1
0.020
0.020
0.020
0.019
0.020
0.017
0.018
0.020
0.017
0.016
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.14
0.17
0.15
0.15
0.16
0.12
0.15
0.13
0.13
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
7
—
51
47
47
52
51
41
50
39
39
WEIGHTED ANNUAL MEAN
DOWN
7
—
23
23
20
23
20
18
20
16
17
S02
ARITHMETIC MEAN
DOWN
2
0.008
0.009
0.009
0.008
0.007
0.006
0.005
0.006
0.005
0.005

SECOND MAX 24-HOUR
DOWN
2
0.040
0.044
0.042
0.034
0.032
0.027
0.020
0.029
0.019
0.019
HONOLULU, HI













CO
SECOND MAX 8-HOUR
DOWN
2
3.7
3.3
3.4
2.9
2.6
2.8
3.1
3.1
2.5
2.4
LEAD
MAX QUARTERLY MEAN
NS
2
0.02
0.01
0.03
0.01
0.01
0.01
0.01
0.00
0.00
0.01
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.04
0.03
0.05
0.05
0.05
0.06
0.06
0.06
0.06
0.05
PM,o
SECOND MAX 24-HOUR
NS
1
—
26
26
34
35
25
23
28
25
26
WEIGHTED ANNUAL MEAN
NS
1
—
16
16
16
17
17
16
19
15
16
HOUMA, LA













OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.11
0.11
0.11
0.12
0.10
0.09
0.10
0.10
0.14
0.09
HOUSTON, TX













CO
SECOND MAX 8-HOUR
DOWN
4
6.7
6.5
5.8
6.8
6.0
6.8
5.6
4.9
4.0
5.3
LEAD
MAX QUARTERLY MEAN
DOWN
3
0.06
0.06
0.03
0.02
0.02
0.01
0.01
0.01
0.01
0.00
N02
ARITHMETIC MEAN
DOWN
4
0.024
0.023
0.022
0.023
0.022
0.022
0.019
0.021
0.021
0.020
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
10
0.17
0.18
0.18
0.19
0.17
0.16
0.16
0.15
0.17
0.16
PM,o
SECOND MAX 24-HOUR
NS
7
—
63
63
65
64
70
68
61
64
49
WEIGHTED ANNUAL MEAN
DOWN
7
—
33
33
33
32
31
30
31
30
26
S02
ARITHMETIC MEAN
DOWN
7
0.005
0.005
0.005
0.005
0.005
0.005
0.005
0.004
0.004
0.004

SECOND MAX 24-HOUR
NS
7
0.022
0.027
0.026
0.025
0.025
0.022
0.020
0.018
0.026
0.022
HUNTINGTON-ASHLAND, WV-KY-OH












CO
SECOND MAX 8-HOUR
NS
1
4.5
3.9
5.5
4.7
4.4
4.1
3.8
5.2
3.8
3.7
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.09
0.13
0.06
0.04
0.04
0.04
0.04
0.03
0.04
0.03
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.12
0.14
0.12
0.11
0.12
0.09
0.11
0.13
0.12
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
4
—
87
85
70
59
62
59
61
61
61
WEIGHTED ANNUAL MEAN
DOWN
4
—
37
35
35
33
30
29
32
31
28
S02
ARITHMETIC MEAN
DOWN
7
0.017
0.016
0.014
0.013
0.012
0.010
0.011
0.010
0.009
0.008

SECOND MAX 24-HOUR
DOWN
7
0.087
0.091
0.080
0.075
0.051
0.044
0.053
0.048
0.036
0.029
HUNTSVILLE, AL












CO
SECOND MAX 8-HOUR
DOWN
1
5.0
5.0
5.2
4.2
4.1
4.2
4.0
3.5
3.6
3.0
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.11
0.13
0.09
0.09
0.11
0.11
0.11
0.11
0.10
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
58
58
65
65
50
56
46
49
43
WEIGHTED ANNUAL MEAN
DOWN
1
—
31
31
30
28
30
23
21
22
21
INDIANAPOLIS
, IN












LEAD
MAX QUARTERLY MEAN
DOWN
4
0.56
0.68
0.53
0.68
0.30
0.26
0.11
0.20
0.06
0.04
OZONE
SECOND DAILY MAX 1-HOUR
NS
5
0.11
0.13
0.11
0.10
0.10
0.09
0.10
0.11
0.11
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
14
—
72
73
76
63
56
63
63
60
50
WEIGHTED ANNUAL MEAN
DOWN
14
—
34
36
33
31
28
28
28
28
23
S02
ARITHMETIC MEAN
DOWN
8
0.011
0.011
0.011
0.009
0.008
0.008
0.009
0.007
0.006
0.005

SECOND MAX 24-HOUR
DOWN
8
0.046
0.048
0.041
0.036
0.029
0.029
0.038
0.038
0.026
0.026
JACKSON, MS













LEAD
MAX QUARTERLY MEAN
NS
1
0.12
0.07
0.08
0.07
0.05
0.02
0.02
0.00
0.09
0.09
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.09
0.09
0.08
0.10
0.09
0.08
0.09
0.09
0.09
0.09
Note: NS = Not Significant (no significant upward or downward trend).
130 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
JACKSON, TN













PM,o
SECOND MAX 24-HOUR
DOWN
2
—
65
56
60
46
53
56
44
51
43
WEIGHTED ANNUAL MEAN
DOWN
2
—
32
31
28
27
27
23
23
25
22
JACKSONVILLE, FL












CO
SECOND MAX 8-HOUR
DOWN
4
5.7
5.6
5.9
4.3
3.8
3.9
4.2
3.7
3.6
3.1
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.12
0.06
0.04
0.04
0.03
0.02
0.05
0.02
0.03
0.02
N02
ARITHMETIC MEAN
NS
1
0.018
0.019
0.015
0.015
0.014
0.014
0.015
0.014
0.016
0.015
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.11
0.11
0.11
0.09
0.10
0.11
0.10
0.11
0.09
PM,„
SECOND MAX 24-HOUR
NS
3
—
59
59
59
54
47
60
49
53
53
WEIGHTED ANNUAL MEAN
DOWN
3
—
34
36
34
32
26
27
26
27
24
S02
ARITHMETIC MEAN
DOWN
5
0.004
0.005
0.004
0.004
0.003
0.003
0.003
0.003
0.003
0.003

SECOND MAX 24-HOUR
DOWN
5
0.038
0.041
0.035
0.037
0.023
0.023
0.025
0.030
0.019
0.020
JAMESTOWN,
NY












S02
ARITHMETIC MEAN
DOWN
1
0.013
0.014
0.014
0.012
0.013
0.011
0.011
0.010
0.009
0.008

SECOND MAX 24-HOUR
NS
1
0.066
0.054
0.072
0.065
0.048
0.050
0.049
0.072
0.056
0.039
JERSEY CITY,
NJ












CO
SECOND MAX 8-HOUR
DOWN
1
8.0
7.8
7.3
7.2
7.5
6.0
5.6
5.9
6.2
4.9
LEAD
MAX QUARTERLY MEAN
DOWN

0.10
0.11
0.07
0.05
0.06
0.04
0.04
0.03
0.04
0.04
N02
ARITHMETIC MEAN
DOWN
1
0.031
0.033
0.031
0.030
0.028
0.028
0.027
0.026
0.026
0.027
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.16
0.20
0.12
0.18
0.14
0.11
0.13
0.12
0.13
0.12
PM,0
SECOND MAX 24-HOUR
NS
4
—
71
73
74
68
58
67
90
64
56
WEIGHTED ANNUAL MEAN
NS
4
—
31
32
31
32
26
27
31
25
26
S02
ARITHMETIC MEAN
DOWN
2
0.012
0.015
0.014
0.013
0.012
0.010
0.009
0.009
0.007
0.008

SECOND MAX 24-HOUR
DOWN
2
0.041
0.059
0.047
0.043
0.035
0.041
0.030
0.036
0.026
0.027
JOHNSON CITY-KINGSPORT-BRISTOL.TN-VA












CO
SECOND MAX 8-HOUR
DOWN
1
4.8
4.3
3.7
3.4
3.3
3.0
6.5
3.4
3.0
3.0
N02
ARITHMETIC MEAN
DOWN
1
0.020
0.019
0.019
0.019
0.019
0.018
0.017
0.017
0.018
0.018
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.09
0.12
0.11
0.12
0.12
0.10
0.13
0.10
0.11
0.10
PM,0
SECOND MAX 24-HOUR
DOWN
3
—
68
68
59
67
57
73
53
58
53
WEIGHTED ANNUAL MEAN
DOWN
3
—
31
31
32
32
29
29
28
27
26
S02
ARITHMETIC MEAN
DOWN
3
0.010
0.011
0.010
0.009
0.009
0.009
0.008
0.009
0.008
0.009

SECOND MAX 24-HOUR
NS
3
0.046
0.049
0.053
0.044
0.044
0.039
0.042
0.045
0.039
0.044
JOHNSTOWN,
PA












CO
SECOND MAX 8-HOUR
NS
1
5.6
4.3
4.1
3.7
4.8
4.4
4.2
4.1
3.5
4.8
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.52
0.30
0.31
0.16
0.19
0.14
0.06
0.05
0.06
0.06
N02
ARITHMETIC MEAN
DOWN
1
0.020
0.019
0.019
0.018
0.019
0.018
0.017
0.018
0.015
0.018
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.12
0.14
0.10
0.10
0.11
0.09
0.10
0.09
0.10
0.10
PM,0
SECOND MAX 24-HOUR
NS
1
—
70
70
58
70
56
63
69
61
61
WEIGHTED ANNUAL MEAN
DOWN
1
—
33
33
28
33
28
27
29
27
27
S02
ARITHMETIC MEAN
DOWN
1
0.016
0.017
0.017
0.014
0.015
0.013
0.015
0.014
0.012
0.011

SECOND MAX 24-HOUR
DOWN
1
0.065
0.054
0.089
0.046
0.043
0.052
0.049
0.080
0.042
0.034
KALAMAZOO-BATTLE CREEK, Ml












PM,o
SECOND MAX 24-HOUR
DOWN
1
—
108
73
69
72
57
59
57
55
57
WEIGHTED ANNUAL MEAN
DOWN
1
—
38
34
28
29
27
24
26
26
22
KANSAS CITY, MO-KS












CO
SECOND MAX 8-HOUR
DOWN
5
5.4
4.4
4.6
4.4
3.8
3.5
4.1
4.3
3.4
3.3
LEAD
MAX QUARTERLY MEAN
DOWN
5
0.16
0.17
0.06
0.03
0.03
0.02
0.02
0.02
0.02
0.03
N02
ARITHMETIC MEAN
NS
3
0.013
0.010
0.011
0.011
0.010
0.010
0.009
0.010
0.010
0.012
OZONE
SECOND DAILY MAX 1-HOUR
NS
6
0.11
0.13
0.10
0.10
0.10
0.09
0.10
0.10
0.12
0.10
PM,0
SECOND MAX 24-HOUR
NS
8
—
65
71
67
60
60
61
59
60
72
WEIGHTED ANNUAL MEAN
NS
8
—
32
33
30
30
29
29
29
24
31
S02
ARITHMETIC MEAN
NS
5
0.006
0.005
0.004
0.003
0.003
0.003
0.003
0.003
0.003
0.004

SECOND MAX 24-HOUR
NS
5
0.026
0.022
0.016
0.022
0.017
0.016
0.020
0.025
0.018
0.024
KENOSHA,Wl













OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.19
0.19
0.13
0.11
0.14
0.11
0.11
0.12
0.12
0.13
KNOXVILLE.TN












CO
SECOND MAX 8-HOUR
DOWN
1
6.1
6.1
6.7
5.1
4.5
4.5
4.6
4.3
4.1
3.3
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0.10
0.12
0.09
0.11
0.10
0.10
0.11
0.11
0.12
0.11
PM,o
SECOND MAX 24-HOUR
NS
8
—
64
61
64
63
54
61
56
58
62
WEIGHTED ANNUAL MEAN
DOWN
8
—
33
32
32
34
30
30
32
31
31
S02
ARITHMETIC MEAN
UP
2
0.006
0.007
0.007
0.007
0.007
0.007
0.007
0.007
0.007
0.007

SECOND MAX 24-HOUR
UP
2
0.029
0.032
0.031
0.033
0.039
0.035
0.041
0.042
0.038
0.047
LAKE CHARLES, LA












OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.13
0.13
0.12
0.11
0.12
0.11
0.10
0.10
0.11
0.09
PM,0
SECOND MAX 24-HOUR
NS
1
—
44
44
44
52
75
51
46
54
33
WEIGHTED ANNUAL MEAN
NS
1
—
21
21
21
23
25
22
23
23
18
LAKELAND-WINTER HAVEN, FL












S02
ARITHMETIC MEAN
NS
1
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.005
0.006

SECOND MAX 24-HOUR
NS
1
0.019
0.018
0.016
0.022
0.016
0.018
0.019
0.016
0.014
0.021
LANCASTER, PA












CO
SECOND MAX 8-HOUR
NS
1
3.3
3.4
4.1
3.4
2.6
2.6
3.0
3.8
2.4
2.6
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.09
0.07
0.05
0.06
0.04
0.04
0.04
0.04
0.04
0.04
N02
ARITHMETIC MEAN
NS
1
0.019
0.020
0.018
0.017
0.018
0.015
0.015
0.019
0.016
0.017
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.12
0.13
0.10
0.10
0.12
0.11
0.12
0.11
0.12
0.10
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 131

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
PM10
SECOND MAX 24-HOUR
NS
1
	
59
59
59
51
45
68
117
73
63
WEIGHTED ANNUAL MEAN
NS
1
—
31
31
31
30
27
31
38
33
31
S02
ARITHMETIC MEAN
DOWN
1
0.007
0.007
0.007
0.006
0.006
0.006
0.007
0.006
0.006
0.005

SECOND MAX 24-HOUR
NS
1
0.027
0.028
0.037
0.028
0.023
0.023
0.026
0.030
0.018
0.021
LANSING-EAST LANSING, Ml












OZONE
SECOND DAILY MAX 1-HOUR
DOWN
2
0.10
0.12
0.10
0.10
0.11
0.09
0.10
0.09
0.10
0.09
LAS CRUCES, NM












CO
SECOND MAX 8-HOUR
DOWN
2
5.8
5.0
4.5
4.6
5.0
3.8
6.0
4.1
3.7
3.7
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.20
0.18
0.16
0.17
0.15
0.13
0.12
0.05
0.09
0.07
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.10
0.10
0.10
0.09
0.09
0.09
0.09
0.09
0.09
0.09
PM,o
SECOND MAX 24-HOUR
DOWN
3
—
140
123
93
86
88
77
91
75
78
WEIGHTED ANNUAL MEAN
NS
3
—
44
45
35
31
31
30
33
34
33
S02
ARITHMETIC MEAN
DOWN
2
0.011
0.010
0.010
0.011
0.010
0.009
0.006
0.004
0.004
0.004

SECOND MAX 24-HOUR
DOWN
2
0.063
0.068
0.061
0.056
0.055
0.052
0.055
0.023
0.021
0.030
LAS VEGAS,
NV-AZ












CO
SECOND MAX 8-HOUR
DOWN
2
9.7
11.1
10.0
10.9
9.5
7.9
8.6
8.8
7.8
8.4
N02
ARITHMETIC MEAN
DOWN
1
0.028
0.031
0.034
0.037
0.030
0.028
0.029
0.027
0.027
0.027
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
3
0.11
0.11
0.10
0.10
0.09
0.09
0.10
0.09
0.09
0.09
PM,„
SECOND MAX 24-HOUR
NS
2
—
106
155
159
111
89
106
112
102
104
WEIGHTED ANNUAL MEAN
NS
2
—
50
65
67
60
47
44
47
47
50
LAWRENCE,
MA-NH












OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.12
0.14
0.11
0.10
0.13
0.10
0.11
0.11
0.10
0.10
PM,o
SECOND MAX 24-HOUR
NS
1
—
39
39
39
35
48
46
35
28
34
WEIGHTED ANNUAL MEAN
DOWN
1
—
21
21
21
18
19
18
16
13
14
S02
ARITHMETIC MEAN
DOWN
2
0.010
0.008
0.009
0.008
0.007
0.008
0.008
0.006
0.006
0.005

SECOND MAX 24-HOUR
DOWN
2
0.043
0.031
0.036
0.029
0.026
0.027
0.026
0.027
0.025
0.019
LAWTON, OK













PM,o
SECOND MAX 24-HOUR
DOWN
1
—
82
74
73
54
52
55
51
52
56
WEIGHTED ANNUAL MEAN
DOWN
1
—
32
32
30
27
26
27
28
25
28
LEWISTON-AUBURN, ME












PM,o
SECOND MAX 24-HOUR
NS
1
—
55
55
55
66
58
68
46
46
37
WEIGHTED ANNUAL MEAN
DOWN
1
—
25
25
25
29
24
24
20
20
20
S02
ARITHMETIC MEAN
DOWN
1
0.009
0.007
0.008
0.007
0.006
0.005
0.007
0.006
0.004
0.004

SECOND MAX 24-HOUR
DOWN
1
0.034
0.044
0.035
0.027
0.023
0.020
0.025
0.025
0.020
0.018
LEXINGTON, KY












CO
SECOND MAX 8-HOUR
DOWN
1
5.8
5.4
5.6
3.7
4.9
3.8
6.5
4.2
3.0
3.1
N02
ARITHMETIC MEAN
NS
1
0.017
0.018
0.019
0.017
0.016
0.016
0.017
0.016
0.017
0.014
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.12
0.11
0.10
0.09
0.08
0.10
0.10
0.11
0.09
PM,o
SECOND MAX 24-HOUR
NS
2
—
76
76
61
52
52
61
66
65
57
WEIGHTED ANNUAL MEAN
DOWN
2
—
30
30
28
28
24
25
27
26
24
S02
ARITHMETIC MEAN
NS
1
0.007
0.007
0.006
0.006
0.008
0.007
0.007
0.008
0.006
0.006

SECOND MAX 24-HOUR
NS
1
0.031
0.027
0.034
0.020
0.025
0.030
0.026
0.037
0.016
0.020
LIMA, OH













OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.10
0.11
0.10
0.10
0.10
0.10
0.10
0.10
0.11
0.11
S02
ARITHMETIC MEAN
DOWN
1
0.006
0.006
0.006
0.005
0.006
0.004
0.005
0.004
0.003
0.003

SECOND MAX 24-HOUR
NS
1
0.030
0.024
0.033
0.026
0.021
0.020
0.023
0.036
0.015
0.015
LINCOLN, NE













CO
SECOND MAX 8-HOUR
DOWN
2
6.1
6.4
6.1
6.2
7.4
4.5
4.3
4.0
4.9
3.4
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.06
0.08
0.06
0.07
0.07
0.07
0.06
0.08
0.07
0.06
PM,0
SECOND MAX 24-HOUR
NS
2
—
57
61
58
66
50
51
49
54
61
WEIGHTED ANNUAL MEAN
NS
2
—
29
33
29
30
25
26
28
25
28
LITTLE ROCK-NORTH LITTLE ROCK, AR












N02
ARITHMETIC MEAN
NS
1
0.009
0.010
0.009
0.009
0.009
0.012
0.009
0.011
0.011
0.011
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.11
0.09
0.10
0.10
0.09
0.10
0.09
0.11
0.10
PM,o
SECOND MAX 24-HOUR
NS
4
—
63
59
60
53
63
55
57
59
50
WEIGHTED ANNUAL MEAN
NS
4
—
30
29
29
25
28
27
27
29
26
S02
ARITHMETIC MEAN
NS
1
0.002
0.002
0.002
0.003
0.003
0.005
0.006
0.003
0.002
0.002

SECOND MAX 24-HOUR
NS
1
0.006
0.016
0.010
0.014
0.012
0.012
0.017
0.009
0.008
0.009
LONGVIEW-MARSHALL.TX












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.12
0.12
0.10
0.13
0.11
0.10
0.11
0.10
0.15
0.11
LOS ANGELES-LONG BEACH, CA












CO
SECOND MAX 8-HOUR
DOWN
12
9.4
10.5
9.9
9.1
9.0
8.0
6.9
8.3
7.7
7.0
LEAD
MAX QUARTERLY MEAN
DOWN
6
0.15
0.15
0.09
0.09
0.10
0.08
0.06
0.06
0.05
0.05
N02
ARITHMETIC MEAN
DOWN
12
0.045
0.048
0.046
0.042
0.043
0.040
0.038
0.041
0.039
0.037
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
13
0.22
0.23
0.22
0.19
0.20
0.20
0.18
0.17
0.15
0.14
PM,0
SECOND MAX 24-HOUR
DOWN
9
—
121
124
115
120
92
83
82
106
77
WEIGHTED ANNUAL MEAN
DOWN
9
—
57
57
49
53
41
40
39
39
38
S02
ARITHMETIC MEAN
DOWN
4
0.005
0.005
0.004
0.003
0.003
0.004
0.003
0.003
0.003
0.003

SECOND MAX 24-HOUR
DOWN
4
0.015
0.019
0.015
0.012
0.013
0.015
0.011
0.008
0.008
0.008
LOUISVILLE,
KY-IN












CO
SECOND MAX 8-HOUR
DOWN
3
6.8
5.9
6.0
5.9
5.9
4.2
4.6
5.1
3.8
3.3
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.10
0.09
0.05
0.03
0.04
0.04
0.05
0.02
0.06
0.01
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0.11
0.16
0.11
0.11
0.12
0.09
0.13
0.12
0.12
0.11
PM,0
SECOND MAX 24-HOUR
DOWN
6
—
84
71
66
61
53
65
63
62
57
Note: NS = Not Significant (no significant upward or downward trend).
132 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996

WEIGHTED ANNUAL MEAN
DOWN
6
	
38
35
34
33
30
29
30
29
26
S02
ARITHMETIC MEAN
NS
4
0.009
0.010
0.010
0.010
0.010
0.009
0.010
0.010
0.008
0.007

SECOND MAX 24-HOUR
DOWN
4
0.045
0.044
0.055
0.041
0.037
0.034
0.035
0.040
0.028
0.031
LOWELL, MA-NH












CO
SECOND MAX 8-HOUR
NS
1
6.4
6.4
5.3
7.3
5.8
5.9
5.1
6.5
7.8
4.5
LUBBOCK,TX













PM,o
SECOND MAX 24-HOUR
NS
1
—
100
94
61
79
58
56
81
76
85
WEIGHTED ANNUAL MEAN
DOWN
1
—
36
34
24
26
22
20
23
21
22
LYNCHBURG,VA












PM,o
SECOND MAX 24-HOUR
NS
1
—
64
54
51
53
45
63
40
54
41
WEIGHTED ANNUAL MEAN
DOWN
1
—
31
30
24
28
24
26
23
24
23
MADISON,Wl













PM,0
SECOND MAX 24-HOUR
DOWN
1
—
90
90
54
55
39
43
50
55
34
WEIGHTED ANNUAL MEAN
DOWN
1
—
34
34
24
25
22
21
22
23
20
MANSFIELD, OH












PM,o
SECOND MAX 24-HOUR
UP
1
—
56
56
56
62
68
66
58
61
68
WEIGHTED ANNUAL MEAN
NS
1
—
27
27
27
27
26
28
29
25
24
MEDFORD-ASHLAND, OR












CO
SECOND MAX 8-HOUR
DOWN
1
8.8
11.3
11.0
8.2
8.1
6.4
6.9
6.2
5.3
6.4
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.07
0.05
0.04
0.02
0.03
0.02
0.02
0.02
0.02
0.02
PM,0
SECOND MAX 24-HOUR
DOWN
3
—
174
199
123
148
99
91
80
60
65
WEIGHTED ANNUAL MEAN
DOWN
3
—
54
54
42
40
36
35
33
26
24
MELBOURNE-TITUSVILLE-PALM BAY, FL












OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.10
0.10
0.10
0.08
0.09
0.08
0.09
0.09
0.08
0.09
MEMPHIS,TN-AR-MS












CO
SECOND MAX 8-HOUR
DOWN
5
8.8
6.4
8.2
7.5
6.1
7.7
7.6
7.3
6.0
5.3
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.18
0.13
0.17
0.10
0.05
0.24
0.11
0.10
0.04
0.03
N02
ARITHMETIC MEAN
NS
1
0.034
0.032
0.026
0.023
0.024
0.026
0.026
0.027
0.027
0.024
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.12
0.13
0.11
0.12
0.11
0.11
0.11
0.11
0.12
0.13
PM,0
SECOND MAX 24-HOUR
NS
2
—
63
65
65
51
57
62
60
59
55
WEIGHTED ANNUAL MEAN
DOWN
2
—
31
31
31
27
28
29
27
27
27
S02
ARITHMETIC MEAN
DOWN
2
0.007
0.006
0.007
0.007
0.007
0.007
0.006
0.005
0.004
0.003

SECOND MAX 24-HOUR
DOWN
2
0.031
0.029
0.029
0.027
0.025
0.031
0.029
0.025
0.019
0.011
MERCED, CA













PM,o
SECOND MAX 24-HOUR
DOWN
1
—
106
137
153
122
82
119
109
89
57
WEIGHTED ANNUAL MEAN
DOWN
1
—
52
52
53
52
46
43
39
39
31
MIAMI, FL













CO
SECOND MAX 8-HOUR
NS
2
5.9
4.8
7.3
6.0
7.2
6.2
5.3
4.4
4.9
4.5
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.12
0.05
0.05
0.02
0.02
0.01
0.01
0.01
0.01
0.01
N02
ARITHMETIC MEAN
DOWN
2
0.014
0.012
0.013
0.011
0.011
0.011
0.012
0.010
0.011
0.011
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
4
0.12
0.11
0.11
0.10
0.09
0.10
0.10
0.09
0.09
0.09
PM,0
SECOND MAX 24-HOUR
NS
3
—
50
48
48
54
53
87
67
47
58
WEIGHTED ANNUAL MEAN
DOWN
3
—
28
27
28
26
27
27
26
24
25
S02
ARITHMETIC MEAN
UP
1
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.002
0.002

SECOND MAX 24-HOUR
UP
1
0.002
0.002
0.003
0.003
0.003
0.005
0.004
0.004
0.004
0.005
MIDDLESEX-SOMERSET-HUNTERDON, NJ












CO
SECOND MAX 8-HOUR
DOWN
1
5.4
5.3
5.4
5.4
4.2
3.9
3.7
4.3
5.3
3.3
LEAD
MAX QUARTERLY MEAN
NS
1
0.17
0.38
0.38
0.30
1.15
1.22
0.33
0.12
0.07
0.06
OZONE
SECOND DAILY MAX 1-HOUR
DOWN

0.16
0.19
0.13
0.14
0.13
0.12
0.11
0.12
0.13
0.12
PM,0
SECOND MAX 24-HOUR
DOWN
1
—
67
67
60
65
54
60
56
43
46
WEIGHTED ANNUAL MEAN
DOWN
1
—
34
34
29
30
25
25
27
22
25
S02
ARITHMETIC MEAN
DOWN
1
0.011
0.012
0.010
0.007
0.007
0.006
0.005
0.005
0.004
0.005

SECOND MAX 24-HOUR
DOWN
1
0.035
0.043
0.037
0.032
0.025
0.026
0.018
0.028
0.018
0.024
MILWAUKEE-WAUKESHA,Wl












CO
SECOND MAX 8-HOUR
NS
5
4.5
4.2
3.9
4.5
3.8
3.3
4.3
4.6
3.0
2.0
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.13
0.12
0.07
0.08
0.06
0.05
0.04
0.03
0.04
0.03
N02
ARITHMETIC MEAN
DOWN
2
0.023
0.023
0.024
0.022
0.021
0.021
0.020
0.021
0.021
0.020
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
6
0.17
0.15
0.13
0.11
0.14
0.10
0.10
0.12
0.12
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
4
—
91
84
78
64
53
61
63
63
53
WEIGHTED ANNUAL MEAN
DOWN
4
—
32
35
33
29
26
26
28
27
25
S02
ARITHMETIC MEAN
DOWN
2
0.005
0.006
0.006
0.006
0.006
0.005
0.003
0.004
0.003
0.004

SECOND MAX 24-HOUR
NS
2
0.025
0.035
0.030
0.039
0.034
0.026
0.024
0.027
0.023
0.025
MINNEAPOLIS-ST. PAUL, MN-WI












CO
SECOND MAX 8-HOUR
DOWN
3
9.5
7.8
10.0
6.0
6.9
5.6
5.3
5.7
6.0
5.3
LEAD
MAX QUARTERLY MEAN
DOWN
3
0.55
0.55
0.38
0.77
0.31
0.25
0.12
0.07
0.23
0.12
N02
ARITHMETIC MEAN
NS
1
0.009
0.009
0.009
0.009
0.008
0.008
0.009
0.009
0.010
0.008
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.10
0.11
0.09
0.09
0.08
0.09
0.08
0.08
0.11
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
10
—
66
76
68
60
55
49
56
54
59
WEIGHTED ANNUAL MEAN
DOWN
10
—
29
29
27
24
21
21
21
22
22
S02
ARITHMETIC MEAN
DOWN
7
0.003
0.003
0.003
0.003
0.003
0.003
0.003
0.002
0.002
0.002

SECOND MAX 24-HOUR
DOWN
7
0.017
0.016
0.016
0.015
0.017
0.018
0.014
0.011
0.011
0.012
MOBILE, AL













OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.10
0.10
0.09
0.10
0.07
0.10
0.09
0.09
0.11
0.10
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 133

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
PM,0
SECOND MAX 24-HOUR
DOWN
4
	
72
62
57
59
69
68
60
53
49
WEIGHTED ANNUAL MEAN
NS
4
—
35
31
31
32
34
32
31
29
25
S02
ARITHMETIC MEAN
NS
1
0.009
0.008
0.008
0.008
0.009
0.010
0.010
0.011
0.009
0.009

SECOND MAX 24-HOUR
NS
1
0.052
0.054
0.064
0.038
0.050
0.054
0.066
0.052
0.053
0.070
MODESTO, CA













CO
SECOND MAX 8-HOUR
DOWN
1
8.6
9.7
11.8
10.5
9.4
5.9
6.6
6.3
5.4
5.6
N02
ARITHMETIC MEAN
DOWN
1
0.024
0.027
0.027
0.026
0.024
0.022
0.024
0.023
0.022
0.022
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.14
0.12
0.11
0.12
0.11
0.11
0.11
0.12
0.13
0.13
PM,„
SECOND MAX 24-HOUR
DOWN
2
—
129
129
135
133
81
118
101
90
66
WEIGHTED ANNUAL MEAN
DOWN
2
—
46
46
44
48
39
40
37
34
28
MONMOUTH-OCEAN, NJ












CO
SECOND MAX 8-HOUR
DOWN
2
6.1
6.6
6.1
5.7
5.5
4.7
5.3
4.9
3.8
4.4
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.14
0.14
0.14
0.14
0.15
0.14
0.13
0.11
0.15
0.12
MONROE, LA













PM,o
SECOND MAX 24-HOUR
UP
1
—
72
72
72
58
79
81
99
111
76
WEIGHTED ANNUAL MEAN
NS
1
—
30
30
30
25
28
27
34
36
31
MONTGOMERY, AL












PM10
SECOND MAX 24-HOUR
NS
1
—
40
40
58
60
48
48
45
55
39
WEIGHTED ANNUAL MEAN
NS
1
—
23
23
27
26
24
23
25
26
23
NASHUA, NH













CO
SECOND MAX 8-HOUR
NS
2
7.0
5.7
6.2
7.1
6.9
6.8
5.2
7.5
6.8
6.5
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.03
0.02
0.02
0.01
0.01
0.02
0.01
0.01
0.01
0.01
N02
ARITHMETIC MEAN
DOWN
1
0.020
0.024
0.022
0.019
0.016
0.015
0.016
0.015
0.014
0.019
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.09
0.14
0.09
0.10
0.10
0.10
0.11
0.10
0.10
0.10
PM,,,
SECOND MAX 24-HOUR
DOWN
5
—
52
44
41
50
49
39
38
31
39
WEIGHTED ANNUAL MEAN
DOWN
5
—
22
22
18
19
17
17
15
14
16
S02
ARITHMETIC MEAN
DOWN
3
0.008
0.008
0.008
0.007
0.005
0.006
0.006
0.006
0.005
0.005

SECOND MAX 24-HOUR
DOWN
3
0.041
0.044
0.040
0.036
0.024
0.025
0.022
0.028
0.023
0.021
NASHVILLE,TN












CO
SECOND MAX 8-HOUR
DOWN
3
6.9
6.5
7.4
5.9
5.0
5.5
6.4
5.4
4.8
3.9
LEAD
MAX QUARTERLY MEAN
NS
4
1.16
1.29
0.66
1.45
1.21
1.05
0.91
0.98
1.93
0.62
N02
ARITHMETIC MEAN
NS
1
0.012
0.012
0.012
0.012
0.010
0.014
0.012
0.020
0.014
0.012
OZONE
SECOND DAILY MAX 1-HOUR
NS
7
0.11
0.12
0.10
0.11
0.10
0.10
0.10
0.10
0.10
0.11
PM,0
SECOND MAX 24-HOUR
DOWN
5
—
76
76
75
71
60
79
65
66
59
WEIGHTED ANNUAL MEAN
DOWN
5
—
38
37
36
35
31
31
30
31
28
S02
ARITHMETIC MEAN
DOWN
5
0.007
0.008
0.008
0.008
0.008
0.006
0.007
0.005
0.004
0.005

SECOND MAX 24-HOUR
NS
6
0.033
0.049
0.057
0.050
0.055
0.030
0.045
0.041
0.030
0.037
NASSAU-SUFFOLK, NY












CO
SECOND MAX 8-HOUR
DOWN
1
9.9
9.1
6.5
7.2
6.6
5.6
5.6
5.4
5.0
4.9
N02
ARITHMETIC MEAN
DOWN
1
0.032
0.033
0.029
0.028
0.029
0.026
0.026
0.028
0.025
0.026
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.17
0.16
0.15
0.14
0.18
0.13
0.13
0.13
0.15
0.12
S02
ARITHMETIC MEAN
DOWN
2
0.009
0.008
0.010
0.009
0.009
0.008
0.008
0.007
0.005
0.007

SECOND MAX 24-HOUR
DOWN
2
0.038
0.056
0.045
0.045
0.039
0.039
0.033
0.037
0.030
0.028
NEW BEDFORD, MA












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.12
0.16
0.12
0.13
0.13
0.11
0.09
0.10
0.14
0.12
PM,,
SECOND MAX 24-HOUR
NS
1
—
39
39
39
51
42
44
49
28
44
WEIGHTED ANNUAL MEAN
DOWN
1
—
23
23
23
20
17
17
19
14
16
NEW HAVEN-MERIDEN, CT












N02
ARITHMETIC MEAN
NS
1
0.028
0.029
0.028
0.027
0.028
0.025
0.027
0.030
0.025
0.026
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.15
0.17
0.15
0.13
0.16
0.12
0.14
0.14
0.14
0.11
PM,o
SECOND MAX 24-HOUR
NS
8
—
67
62
71
76
70
69
68
56
55
WEIGHTED ANNUAL MEAN
DOWN
8
—
30
30
28
32
25
26
27
23
21
S02
ARITHMETIC MEAN
DOWN
2
0.012
0.015
0.012
0.010
0.010
0.009
0.008
0.008
0.006
0.006

SECOND MAX 24-HOUR
DOWN
2
0.055
0.071
0.071
0.045
0.055
0.042
0.038
0.049
0.031
0.027
NEW LONDON-NORWICH, CT-RI












OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.16
0.15
0.14
0.16
0.14
0.12
0.13
0.12
0.14
0.12
PM,o
SECOND MAX 24-HOUR
NS
3
—
42
42
48
52
52
40
49
43
50
WEIGHTED ANNUAL MEAN
DOWN
3
—
22
22
20
23
19
18
22
17
18
S02
ARITHMETIC MEAN
DOWN
1
0.007
0.009
0.008
0.008
0.007
0.006
0.006
0.005
0.005
0.005

SECOND MAX 24-HOUR
DOWN
1
0.028
0.047
0.027
0.029
0.027
0.025
0.019
0.029
0.017
0.016
NEW ORLEANS, LA












CO
SECOND MAX 8-HOUR
DOWN
2
6.7
6.1
6.1
4.9
4.2
5.4
5.1
4.6
3.6
4.0
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.10
0.10
0.09
0.05
0.03
0.03
0.02
0.02
0.03
0.02
N02
ARITHMETIC MEAN
DOWN
2
0.021
0.019
0.017
0.016
0.015
0.017
0.016
0.015
0.016
0.015
OZONE
SECOND DAILY MAX 1-HOUR
NS
5
0.11
0.11
0.10
0.10
0.10
0.10
0.10
0.11
0.11
0.10
PM,0
SECOND MAX 24-HOUR
NS
1
—
47
58
54
52
52
54
50
50
44
WEIGHTED ANNUAL MEAN
DOWN
1
—
26
31
27
26
27
25
25
24
22
S02
ARITHMETIC MEAN
UP
2
0.004
0.004
0.003
0.003
0.004
0.005
0.005
0.005
0.005
0.005

SECOND MAX 24-HOUR
UP
2
0.016
0.017
0.017
0.013
0.023
0.018
0.019
0.021
0.019
0.025
NEW YORK, NY













CO
SECOND MAX 8-HOUR
DOWN
4
7.7
8.3
7.9
7.1
6.6
6.0
5.1
5.8
6.5
4.5
LEAD
MAX QUARTERLY MEAN
NS
3
0.11
0.14
0.08
0.09
0.08
0.06
0.09
0.08
0.07
0.08
N02
ARITHMETIC MEAN
DOWN
1
0.049
0.049
0.049
0.046
0.047
0.036
0.043
0.046
0.042
0.042
Note: NS = Not Significant (no significant upward or downward trend).
134 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0.15
0.18
0.12
0.14
0.15
0.12
0.12
0.12
0.13
0.12
PM,o
SECOND MAX 24-HOUR
NS
12
—
68
69
66
61
55
55
69
65
51
WEIGHTED ANNUAL MEAN
DOWN
12
—
33
34
31
30
27
26
28
26
27
S02
ARITHMETIC MEAN
DOWN
6
0.015
0.016
0.015
0.014
0.013
0.012
0.011
0.012
0.009
0.009

SECOND MAX 24-HOUR
DOWN
6
0.054
0.062
0.062
0.055
0.045
0.048
0.038
0.051
0.035
0.037
NEWARK, NJ













CO
SECOND MAX 8-HOUR
NS
3
7.4
7.3
7.6
7.1
8.3
5.6
4.9
7.7
6.0
5.1
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.55
0.83
0.41
0.39
1.04
0.44
0.23
0.30
0.23
0.23
N02
ARITHMETIC MEAN
NS
5
0.031
0.031
0.028
0.028
0.027
0.029
0.027
0.029
0.027
0.028
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
3
0.17
0.18
0.12
0.12
0.12
0.11
0.11
0.12
0.12
0.12
PM,o
SECOND MAX 24-HOUR
NS
3
—
80
74
68
62
55
67
95
69
61
WEIGHTED ANNUAL MEAN
NS
3
—
35
35
31
30
29
30
35
28
31
S02
ARITHMETIC MEAN
DOWN
4
0.011
0.012
0.012
0.010
0.010
0.009
0.007
0.008
0.006
0.006

SECOND MAX 24-HOUR
DOWN
4
0.041
0.050
0.047
0.040
0.035
0.040
0.025
0.033
0.025
0.027
NEWBURGH, NY-PA












LEAD
MAX QUARTERLY MEAN
DOWN
1
2.46
1.18
1.36
0.54
0.28
0.22
0.28
0.06
0.05
0.06
NORFOLK-VIRGINIA BEACH-NEWPORT NEWS.VA-N












CO
SECOND MAX 8-HOUR
DOWN
3
6.0
5.5
5.2
4.5
5.1
4.3
5.0
5.4
4.3
4.3
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.10
0.10
0.12
0.18
0.03
0.03
0.03
0.02
0.03
0.03
N02
ARITHMETIC MEAN
NS
1
0.020
0.020
0.020
0.019
0.020
0.020
0.021
0.019
0.018
0.018
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.12
0.13
0.10
0.11
0.10
0.13
0.13
0.10
0.10
0.10
PM,0
SECOND MAX 24-HOUR
DOWN
4
—
53
60
58
56
46
54
41
40
43
WEIGHTED ANNUAL MEAN
DOWN
4
—
28
27
26
26
23
23
20
21
22
S02
ARITHMETIC MEAN
DOWN
2
0.007
0.008
0.007
0.007
0.007
0.006
0.007
0.007
0.006
0.006

SECOND MAX 24-HOUR
DOWN
2
0.032
0.032
0.033
0.025
0.022
0.024
0.026
0.024
0.022
0.022
OAKLAND, CA













CO
SECOND MAX 8-HOUR
DOWN
6
4.3
4.8
4.9
4.8
4.8
4.0
3.4
3.6
2.7
2.9
LEAD
MAX QUARTERLY MEAN
DOWN
4
0.09
0.15
0.13
0.08
0.10
0.02
0.02
0.02
0.02
0.01
N02
ARITHMETIC MEAN
DOWN
2
0.022
0.023
0.022
0.021
0.022
0.020
0.020
0.020
0.019
0.018
OZONE
SECOND DAILY MAX 1-HOUR
NS
7
0.12
0.11
0.10
0.09
0.09
0.09
0.10
0.10
0.13
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
3
—
73
82
81
89
58
66
72
47
41
WEIGHTED ANNUAL MEAN
DOWN
3
—
30
31
30
33
27
25
25
22
22
S02
ARITHMETIC MEAN
NS
3
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002

SECOND MAX 24-HOUR
DOWN
3
0.009
0.009
0.013
0.011
0.010
0.009
0.010
0.007
0.007
0.007
OKLAHOMA CITY, OK












CO
SECOND MAX 8-HOUR
NS
3
7.5
5.2
6.4
5.4
4.7
4.8
6.1
5.2
5.0
5.1
LEAD
MAX QUARTERLY MEAN
DOWN
3
0.06
0.07
0.05
0.02
0.02
0.01
0.01
0.01
0.01
0.01
N02
ARITHMETIC MEAN
NS
3
0.014
0.018
0.013
0.012
0.011
0.011
0.011
0.012
0.012
0.012
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0.10
0.10
0.10
0.10
0.10
0.09
0.09
0.09
0.11
0.09
PM,o
SECOND MAX 24-HOUR
NS
5
—
54
53
47
45
55
45
42
51
50
WEIGHTED ANNUAL MEAN
NS
5
—
25
24
23
23
22
21
21
21
24
S02
ARITHMETIC MEAN
NS
1
0.005
0.010
0.007
0.004
0.002
0.002
0.003
0.004
0.002
0.002

SECOND MAX 24-HOUR
DOWN
1
0.012
0.041
0.015
0.019
0.005
0.009
0.008
0.007
0.006
0.006
OLYMPIA, WA













PM,0
SECOND MAX 24-HOUR
DOWN
1
—
117
118
86
99
78
78
63
65
53
WEIGHTED ANNUAL MEAN
DOWN
1
—
35
28
24
25
24
24
17
17
16
OMAHA, NE-IA













CO
SECOND MAX 8-HOUR
NS
2
5.4
5.5
4.8
5.2
5.8
5.9
5.3
4.0
5.5
4.9
LEAD
MAX QUARTERLY MEAN
NS
5
0.55
0.79
0.67
0.54
0.44
0.69
0.55
0.73
0.49
0.40
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
3
0.08
0.09
0.08
0.07
0.08
0.08
0.06
0.07
0.08
0.07
PM,o
SECOND MAX 24-HOUR
DOWN
7
—
96
95
92
78
89
70
81
77
78
WEIGHTED ANNUAL MEAN
DOWN
7
—
42
42
37
36
36
31
33
30
33
ORANGE COUNTY, CA












CO
SECOND MAX 8-HOUR
DOWN
3
7.8
8.4
8.7
7.7
6.9
7.2
5.5
7.2
5.9
5.5
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.09
0.09
0.08
0.06
0.06
0.03
0.05
0.04
0.04
0.04
N02
ARITHMETIC MEAN
DOWN
2
0.040
0.044
0.045
0.046
0.044
0.039
0.037
0.040
0.038
0.033
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
3
0.21
0.22
0.23
0.19
0.19
0.18
0.16
0.17
0.13
0.13
PM,0
SECOND MAX 24-HOUR
NS
2
—
96
96
95
97
79
78
83
124
75
WEIGHTED ANNUAL MEAN
DOWN
2
—
45
45
45
41
37
36
36
41
33
S02
ARITHMETIC MEAN
NS
1
0.005
0.004
0.003
0.002
0.002
0.002
0.002
0.002
0.003
0.003

SECOND MAX 24-HOUR
DOWN
1
0.015
0.014
0.009
0.006
0.012
0.007
0.008
0.007
0.005
0.005
ORLANDO, FL













CO
SECOND MAX 8-HOUR
DOWN
2
4.7
4.5
4.3
4.5
3.6
3.9
3.8
3.6
3.3
3.3
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.05
0.05
0.02
0.01
0.00
0.00
0.00
0.00
0.00
0.00
N02
ARITHMETIC MEAN
DOWN
1
0.013
0.013
0.013
0.012
0.012
0.011
0.012
0.011
0.010
0.013
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
3
0.11
0.10
0.11
0.11
0.09
0.10
0.10
0.10
0.10
0.10
PM,o
SECOND MAX 24-HOUR
NS
3
—
45
44
46
42
49
39
37
37
55
WEIGHTED ANNUAL MEAN
DOWN
3
—
28
27
27
27
24
24
23
22
23
S02
ARITHMETIC MEAN
NS
1
0.002
0.003
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002

SECOND MAX 24-HOUR
NS
1
0.008
0.010
0.006
0.011
0.007
0.007
0.011
0.012
0.006
0.008
OWENSBORO, KY












CO
SECOND MAX 8-HOUR
NS
1
4.1
6.4
5.9
5.4
3.8
4.5
5.5
3.9
4.2
4.2
N02
ARITHMETIC MEAN
NS
1
0.015
0.015
0.014
0.011
0.011
0.012
0.012
0.012
0.013
0.011
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 135

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.11
0.14
0.10
0.11
0.09
0.09
0.11
0.11
0.11
0.11
PM,o
SECOND MAX 24-HOUR
NS
1
—
80
80
69
55
52
56
90
70
47
WEIGHTED ANNUAL MEAN
DOWN
1
—
33
33
29
29
27
25
30
29
24
S02
ARITHMETIC MEAN
NS
1
0.008
0.010
0.010
0.009
0.009
0.009
0.009
0.009
0.007
0.007

SECOND MAX 24-HOUR
NS
1
0.033
0.040
0.053
0.038
0.044
0.053
0.050
0.035
0.028
0.020
PARKERSBURG-MARIETTA, WV-OH












LEAD
MAX QUARTERLY MEAN
DOWN
1
0.08
0.04
0.04
0.02
0.02
0.02
0.02
0.01
0.02
0.02
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.15
0.15
0.12
0.11
0.12
0.10
0.10
0.11
0.12
0.11
S02
ARITHMETIC MEAN
DOWN
1
0.017
0.015
0.016
0.014
0.014
0.014
0.014
0.017
0.010
0.010

SECOND MAX 24-HOUR
NS
1
0.070
0.076
0.076
0.064
0.060
0.059
0.065
0.084
0.041
0.046
PENSACOLA
, FL












OZONE
SECOND DAILY MAX 1-HOUR
NS

0.11
0.10
0.09
0.11
0.10
0.10
0.10
0.11
0.12
0.10
S02
ARITHMETIC MEAN
DOWN
1
0.006
0.006
0.007
0.008
0.006
0.007
0.005
0.004
0.003
0.003

SECOND MAX 24-HOUR
DOWN
1
0.086
0.071
0.057
0.078
0.056
0.057
0.032
0.039
0.019
0.015
PEORIA-PEKIN, IL












CO
SECOND MAX 8-HOUR
DOWN
1
7.4
7.9
7.7
7.4
6.3
7.2
7.3
5.7
5.6
4.6
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.08
0.04
0.04
0.04
0.02
0.02
0.03
0.02
0.03
0.02
OZONE
SECOND DAILY MAX 1-HOUR
DOWN

0.11
0.11
0.10
0.08
0.10
0.09
0.08
0.09
0.09
0.09
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
57
70
72
48
54
39
45
42
43
WEIGHTED ANNUAL MEAN
NS
1
—
23
28
27
24
25
20
21
20
21
S02
ARITHMETIC MEAN
NS
2
0.008
0.009
0.007
0.007
0.008
0.007
0.007
0.007
0.007
0.007

SECOND MAX 24-HOUR
NS
2
0.058
0.062
0.046
0.055
0.065
0.043
0.039
0.049
0.084
0.045
PHILADELPHIA, PA-NJ












CO
SECOND MAX 8-HOUR
DOWN
9
6.3
5.4
7.1
4.9
4.6
4.7
4.7
5.2
4.1
4.2
LEAD
MAX QUARTERLY MEAN
NS
10
0.77
0.50
0.38
0.54
0.35
0.56
0.86
0.54
0.69
0.93
N02
ARITHMETIC MEAN
DOWN
5
0.033
0.031
0.030
0.028
0.028
0.028
0.026
0.028
0.027
0.028
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
8
0.16
0.18
0.13
0.13
0.14
0.11
0.13
0.12
0.13
0.12
PM,o
SECOND MAX 24-HOUR
DOWN
10
—
75
73
68
73
55
69
71
65
63
WEIGHTED ANNUAL MEAN
NS
10
—
34
34
31
33
27
29
32
31
30
S02
ARITHMETIC MEAN
DOWN
10
0.011
0.012
0.011
0.010
0.009
0.008
0.008
0.009
0.006
0.006

SECOND MAX 24-HOUR
DOWN
10
0.046
0.052
0.045
0.040
0.034
0.034
0.031
0.040
0.026
0.026
PHOENIX-MESA, AZ












CO
SECOND MAX 8-HOUR
DOWN
9
8.0
7.6
7.4
6.2
5.9
6.0
5.7
5.9
5.8
5.4
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.19
0.16
0.09
0.09
0.11
0.06
0.05
0.05
0.06
0.04
OZONE
SECOND DAILY MAX 1-HOUR
NS
9
0.11
0.11
0.10
0.11
0.10
0.11
0.11
0.11
0.12
0.11
PM,o
SECOND MAX 24-HOUR
NS
6
—
96
113
85
84
97
79
83
88
81
WEIGHTED ANNUAL MEAN
DOWN
6
—
48
51
43
44
43
43
42
43
42
S02
ARITHMETIC MEAN
NS
1
0.001
0.001
0.002
0.003
0.005
0.004
0.003
0.003
0.002
0.003

SECOND MAX 24-HOUR
NS
1
0.010
0.001
0.006
0.011
0.013
0.010
0.009
0.009
0.008
0.017
PINE BLUFF, AR












PM,„
SECOND MAX 24-HOUR
NS
1
—
60
60
47
42
51
55
56
62
51
WEIGHTED ANNUAL MEAN
NS
1
—
27
27
21
19
22
23
25
26
23
PITTSBURGH, PA












CO
SECOND MAX 8-HOUR
DOWN
5
5.6
5.1
5.3
5.6
4.3
4.8
3.8
4.3
3.8
3.3
LEAD
MAX QUARTERLY MEAN
DOWN
4
0.12
0.13
0.12
0.09
0.09
0.07
0.07
0.08
0.06
0.04
N02
ARITHMETIC MEAN
DOWN
5
0.025
0.023
0.023
0.023
0.023
0.022
0.022
0.023
0.021
0.021
OZONE
SECOND DAILY MAX 1-HOUR
NS
6
0.12
0.13
0.11
0.10
0.11
0.09
0.11
0.11
0.12
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
14
—
96
89
80
80
75
77
83
72
61
WEIGHTED ANNUAL MEAN
DOWN
14
—
35
34
32
33
29
29
32
29
28
S02
ARITHMETIC MEAN
DOWN
12
0.017
0.018
0.018
0.017
0.015
0.015
0.015
0.015
0.011
0.011

SECOND MAX 24-HOUR
DOWN
12
0.077
0.078
0.075
0.074
0.056
0.068
0.062
0.072
0.047
0.044
PITTSFIELD,
MA












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.09
0.09
0.09
0.11
0.10
0.11
0.11
0.09
0.09
0.11
PONCE, PR













PM,o
SECOND MAX 24-HOUR
DOWN
1
—
96
96
77
58
64
66
64
57
53
WEIGHTED ANNUAL MEAN
DOWN
1
—
46
46
38
30
29
30
27
24
24
PORTLAND-VANCOUVER, OR-WA












CO
SECOND MAX 8-HOUR
DOWN
2
10.7
8.9
8.2
8.5
9.1
7.0
6.3
7.0
5.7
6.1
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.17
0.12
0.07
0.06
0.06
0.05
0.06
0.04
0.03
0.02
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.10
0.11
0.08
0.12
0.09
0.10
0.09
0.09
0.09
0.12
PM,0
SECOND MAX 24-HOUR
DOWN
6
—
75
72
61
85
59
66
50
41
48
WEIGHTED ANNUAL MEAN
DOWN
6
—
28
25
25
26
23
25
23
20
20
S02
ARITHMETIC MEAN
NS
1
0.006
0.006
0.007
0.006
0.006
0.007
0.006
0.005
0.005
0.005

SECOND MAX 24-HOUR
NS
1
0.018
0.018
0.023
0.019
0.024
0.017
0.025
0.013
0.013
0.013
PORTLAND,
ME












OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.14
0.17
0.13
0.13
0.14
0.12
0.11
0.12
0.12
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
58
56
42
54
57
48
51
49
37
WEIGHTED ANNUAL MEAN
DOWN
1
—
24
26
23
25
23
21
21
21
20
S02
ARITHMETIC MEAN
DOWN
1
0.011
0.010
0.010
0.010
0.009
0.008
0.009
0.008
0.006
0.005

SECOND MAX 24-HOUR
DOWN
1
0.042
0.044
0.039
0.034
0.032
0.029
0.032
0.043
0.022
0.021
PORTSMOUTH-ROCHESTER, NH-ME












OZONE
SECOND DAILY MAX 1-HOUR
DOWN
2
0.14
0.17
0.12
0.11
0.14
0.11
0.11
0.11
0.12
0.10
PM,„
SECOND MAX 24-HOUR
NS
2
—
51
44
44
49
57
39
37
37
40
Note: NS = Not Significant (no significant upward or downward trend).
136 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996

WEIGHTED ANNUAL MEAN
DOWN
2
	
21
21
20
19
19
18
14
15
16
S02
ARITHMETIC MEAN
DOWN
1
0.006
0.006
0.008
0.007
0.007
0.006
0.006
0.006
0.004
0.004

SECOND MAX 24-HOUR
DOWN
1
0.034
0.034
0.029
0.025
0.021
0.027
0.019
0.022
0.017
0.015
PROVIDENCE-FALL RIVER-WARWICK, RI-MA












CO
SECOND MAX 8-HOUR
NS
1
8.1
7.3
6.2
7.3
7.4
6.3
5.4
6.7
7.0
4.4
N02
ARITHMETIC MEAN
NS
1
0.024
0.024
0.024
0.024
0.025
0.023
0.022
0.022
0.022
0.025
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
2
0.15
0.15
0.12
0.13
0.14
0.11
0.11
0.12
0.13
0.10
PM,o
SECOND MAX 24-HOUR
NS
3
—
61
60
58
68
52
56
60
63
59
WEIGHTED ANNUAL MEAN
DOWN
3
—
31
31
29
30
24
26
29
24
27
S02
ARITHMETIC MEAN
DOWN
5
0.011
0.011
0.010
0.009
0.008
0.009
0.008
0.007
0.005
0.006

SECOND MAX 24-HOUR
DOWN
5
0.049
0.050
0.043
0.039
0.039
0.044
0.036
0.035
0.022
0.030
PROVO-OREM,
UT












CO
SECOND MAX 8-HOUR
DOWN
1
13.3
11.0
15.8
16.2
11.6
10.0
9.6
9.3
7.1
7.1
N02
ARITHMETIC MEAN
NS
1
0.024
0.028
0.028
0.025
0.022
0.019
0.026
0.024
0.023
0.024
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.10
0.11
0.11
0.09
0.08
0.09
0.08
0.08
0.08
0.10
PM,o
SECOND MAX 24-HOUR
NS
3
—
184
222
115
220
202
194
106
94
125
WEIGHTED ANNUAL MEAN
DOWN
3
—
50
49
32
42
37
38
34
29
34
PUEBLO, CO













PM,o
SECOND MAX 24-HOUR
NS
1
—
70
75
52
57
54
51
54
86
49
WEIGHTED ANNUAL MEAN
DOWN
1
—
35
33
26
30
26
26
30
26
26
RACINE,Wl













CO
SECOND MAX 8-HOUR
DOWN
1
6.7
7.4
6.4
5.5
5.7
4.9
4.1
4.3
4.3
3.0
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.18
0.18
0.14
0.11
0.14
0.10
0.10
0.11
0.11
0.13
RALEIGH-DURHAM-CHAPEL HILL, NC












CO
SECOND MAX 8-HOUR
DOWN
1
10.9
10.9
10.9
8.7
8.8
7.3
7.2
6.9
6.6
5.6
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.11
0.11
0.11
0.12
0.11
0.10
0.11
0.11
0.10
0.09
PM,o
SECOND MAX 24-HOUR
NS
2
—
73
60
50
51
46
47
37
48
50
WEIGHTED ANNUAL MEAN
DOWN
2
—
34
29
29
26
24
25
22
23
25
RAPID CITY, SD












PM,o
SECOND MAX 24-HOUR
NS
2
—
74
68
76
138
80
88
79
75
62
WEIGHTED ANNUAL MEAN
NS
2
—
29
26
27
28
25
23
29
24
23
READING, PA













CO
SECOND MAX 8-HOUR
DOWN
1
5.3
5.2
5.0
6.4
4.6
4.6
3.8
5.4
3.9
3.4
LEAD
MAX QUARTERLY MEAN
DOWN
9
0.59
0.49
0.59
0.50
0.53
0.42
0.39
0.33
0.26
0.25
N02
ARITHMETIC MEAN
DOWN
1
0.025
0.024
0.023
0.022
0.022
0.020
0.021
0.023
0.021
0.022
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.12
0.15
0.11
0.11
0.12
0.10
0.11
0.10
0.11
0.11
PM,0
SECOND MAX 24-HOUR
NS
1
—
52
52
61
67
47
55
80
54
54
WEIGHTED ANNUAL MEAN
NS
1
—
31
31
26
28
23
25
29
26
26
S02
ARITHMETIC MEAN
DOWN
2
0.012
0.013
0.012
0.010
0.010
0.009
0.009
0.011
0.009
0.009

SECOND MAX 24-HOUR
DOWN
2
0.043
0.053
0.048
0.038
0.034
0.033
0.033
0.040
0.033
0.036
REDDING, CA













OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.08
0.08
0.09
0.09
0.08
0.08
0.07
0.09
0.09
0.08
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
66
66
59
74
58
50
54
47
34
WEIGHTED ANNUAL MEAN
DOWN
1
—
26
26
25
29
25
20
24
20
19
RENO, NV













CO
SECOND MAX 8-HOUR
DOWN
2
8.6
8.6
9.1
8.3
9.2
7.4
5.8
6.9
5.3
5.9
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
2
0.10
0.10
0.10
0.11
0.09
0.08
0.09
0.09
0.08
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
6
—
127
123
135
106
86
92
86
65
72
WEIGHTED ANNUAL MEAN
DOWN
6
—
44
42
44
36
36
40
36
32
29
RICHLAND-KENNEWICK-PASCO, WA












PM,o
SECOND MAX 24-HOUR
NS
1
—
90
175
382
281
85
136
103
103
103
WEIGHTED ANNUAL MEAN
DOWN
1
—
33
29
40
31
24
28
27
27
27
RICHMOND-PETERSBURG, VA












CO
SECOND MAX 8-HOUR
DOWN
2
6.0
4.1
4.0
4.4
3.7
2.5
3.9
3.4
2.6
2.9
N02
ARITHMETIC MEAN
DOWN
1
0.026
0.026
0.025
0.023
0.024
0.023
0.024
0.024
0.022
0.022
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0.13
0.14
0.11
0.11
0.11
0.12
0.12
0.11
0.11
0.10
PM,o
SECOND MAX 24-HOUR
NS
3
—
59
54
59
59
44
55
37
53
63
WEIGHTED ANNUAL MEAN
DOWN
3
—
28
28
25
26
22
23
21
23
24
S02
ARITHMETIC MEAN
DOWN
1
0.007
0.009
0.009
0.006
0.006
0.005
0.007
0.006
0.005
0.005

SECOND MAX 24-HOUR
DOWN
1
0.031
0.042
0.032
0.034
0.027
0.024
0.023
0.022
0.016
0.027
RIVERSIDE-SAN BERNARDINO, CA












CO
SECOND MAX 8-HOUR
DOWN
7
4.5
4.7
5.1
4.4
5.1
3.6
3.5
3.5
3.4
2.9
LEAD
MAX QUARTERLY MEAN
DOWN
4
0.08
0.08
0.06
0.05
0.06
0.03
0.04
0.04
0.04
0.04
N02
ARITHMETIC MEAN
NS
7
0.028
0.030
0.030
0.029
0.029
0.027
0.028
0.028
0.029
0.027
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
16
0.21
0.22
0.22
0.21
0.21
0.19
0.18
0.19
0.18
0.17
PM,0
SECOND MAX 24-HOUR
DOWN
10
—
134
208
160
133
100
107
99
115
95
WEIGHTED ANNUAL MEAN
DOWN
10
—
66
69
62
58
50
49
47
47
45
S02
ARITHMETIC MEAN
DOWN
4
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.001

SECOND MAX 24-HOUR
DOWN
4
0.007
0.012
0.013
0.006
0.008
0.009
0.006
0.004
0.005
0.004
ROANOKE, VA













N02
ARITHMETIC MEAN
DOWN
1
0.016
0.016
0.014
0.013
0.014
0.013
0.014
0.013
0.013
0.013
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.11
0.13
0.10
0.09
0.10
0.09
0.10
0.10
0.09
0.08
PM,„
SECOND MAX 24-HOUR
NS
2
—
65
65
68
63
64
72
68
74
70
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 137

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996

WEIGHTED ANNUAL MEAN
NS
2
	
37
35
36
33
32
35
36
34
33
S02
ARITHMETIC MEAN
DOWN
1
0.004
0.004
0.005
0.004
0.004
0.004
0.004
0.004
0.003
0.003

SECOND MAX 24-HOUR
NS
1
0.014
0.018
0.022
0.018
0.019
0.016
0.018
0.011
0.010
0.014
ROCHESTER, MN












CO
SECOND MAX 8-HOUR
DOWN
1
9.0
7.1
6.3
6.1
6.3
5.1
4.9
5.0
4.0
4.0
PM,o
SECOND MAX 24-HOUR
NS
1
—
54
64
89
43
44
38
43
49
44
WEIGHTED ANNUAL MEAN
DOWN
1
—
29
30
28
23
21
20
21
20
19
ROCHESTER, NY












CO
SECOND MAX 8-HOUR
NS
2
3.8
4.0
3.6
3.5
3.3
3.5
3.2
4.5
3.2
3.7
LEAD
MAX QUARTERLY MEAN
NS
1
0.10
0.09
0.04
0.03
0.03
0.04
0.04
0.04
0.04
0.04
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.13
0.10
0.11
0.11
0.09
0.09
0.09
0.11
0.08
PM,o
SECOND MAX 24-HOUR
NS
2
—
81
60
47
61
49
64
42
47
45
WEIGHTED ANNUAL MEAN
DOWN
2
—
30
24
21
26
22
23
20
21
21
S02
ARITHMETIC MEAN
DOWN
2
0.011
0.012
0.013
0.012
0.011
0.011
0.010
0.011
0.010
0.009

SECOND MAX 24-HOUR
NS
2
0.045
0.038
0.054
0.040
0.043
0.039
0.041
0.043
0.038
0.033
ROCKFORD.IL













CO
SECOND MAX 8-HOUR
DOWN
1
8.0
8.1
6.6
6.5
5.1
4.6
4.3
4.0
4.5
3.2
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.05
0.13
0.07
0.09
0.04
0.06
0.03
0.04
0.03
0.05
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.09
0.11
0.09
0.09
0.09
0.09
0.08
0.10
0.10
0.09
PM,o
SECOND MAX 24-HOUR
NS
1
—
37
58
54
55
49
42
44
45
36
WEIGHTED ANNUAL MEAN
NS
1
—
17
25
25
22
21
16
19
19
18
SACRAMENTO
CA












CO
SECOND MAX 8-HOUR
DOWN
5
9.5
10.4
9.8
9.6
8.4
6.7
7.2
6.9
5.4
5.4
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.11
0.08
0.07
0.10
0.04
0.02
0.05
0.02
0.02
0.01
N02
ARITHMETIC MEAN
DOWN
4
0.019
0.019
0.019
0.019
0.017
0.017
0.018
0.015
0.016
0.016
OZONE
SECOND DAILY MAX 1-HOUR
NS
6
0.13
0.14
0.11
0.13
0.14
0.12
0.12
0.11
0.13
0.12
S02
ARITHMETIC MEAN
DOWN
1
0.010
0.010
0.006
0.006
0.003
0.002
0.001
0.001
0.001
0.001

SECOND MAX 24-HOUR
DOWN
1
0.020
0.020
0.020
0.010
0.010
0.010
0.003
0.004
0.004
0.003
SAGINAW-BAY CITY-MIDLAND, Ml












PM,„
SECOND MAX 24-HOUR
DOWN
1
—
100
124
71
86
115
51
45
45
45
WEIGHTED ANNUAL MEAN
DOWN
1
—
31
30
26
30
29
22
22
22
22
SALINAS, CA













CO
SECOND MAX 8-HOUR
NS
1
2.3
2.3
2.3
2.5
2.1
2.3
2.1
2.0
1.7
2.4
N02
ARITHMETIC MEAN
DOWN
1
0.013
0.014
0.014
0.012
0.012
0.012
0.012
0.012
0.011
0.011
OZONE
SECOND DAILY MAX 1-HOUR
NS

0.08
0.08
0.10
0.08
0.08
0.07
0.08
0.08
0.07
0.08
PM,o
SECOND MAX 24-HOUR
NS
1
—
49
49
49
43
38
55
33
47
40
WEIGHTED ANNUAL MEAN
DOWN
1
—
25
25
23
23
22
22
20
21
20
SALT LAKE CITY-OGDEN, UT












CO
SECOND MAX 8-HOUR
DOWN
2
8.7
7.7
7.3
6.9
7.8
7.6
6.5
6.4
5.7
6.5
LEAD
MAX QUARTERLY MEAN
DOWN
3
0.16
0.16
0.13
0.08
0.08
0.05
0.06
0.05
0.05
0.03
N02
ARITHMETIC MEAN
NS
1
0.024
0.026
0.027
0.019
0.020
0.022
0.025
0.026
0.024
0.026
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0.11
0.12
0.13
0.11
0.10
0.09
0.10
0.11
0.11
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
8
—
136
129
96
151
133
114
94
81
105
WEIGHTED ANNUAL MEAN
DOWN
8
—
42
43
32
39
35
35
30
28
31
S02
ARITHMETIC MEAN
DOWN
4
0.008
0.010
0.010
0.008
0.009
0.008
0.007
0.004
0.003
0.003

SECOND MAX 24-HOUR
NS
4
0.039
0.051
0.079
0.036
0.048
0.051
0.041
0.012
0.012
0.012
SAN ANTONIO,TX












CO
SECOND MAX 8-HOUR
DOWN
2
6.2
5.7
6.3
5.4
4.6
4.7
5.1
3.5
3.8
4.8
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.11
0.06
0.04
0.07
0.03
0.03
0.03
0.03
0.03
0.02
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.12
0.12
0.11
0.10
0.11
0.10
0.11
0.11
0.12
0.12
PM,o
SECOND MAX 24-HOUR
DOWN
3
—
63
57
49
48
48
54
47
41
37
WEIGHTED ANNUAL MEAN
DOWN
3
—
28
28
25
25
25
23
23
21
19
SAN DIEGO, CA












CO
SECOND MAX 8-HOUR
DOWN
7
5.8
6.1
6.6
5.8
5.4
5.0
4.5
4.8
4.2
4.2
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.09
0.06
0.04
0.08
0.05
0.03
0.04
0.01
0.02
0.01
N02
ARITHMETIC MEAN
DOWN
6
0.025
0.028
0.027
0.024
0.024
0.023
0.020
0.021
0.021
0.019
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
8
0.16
0.17
0.16
0.16
0.15
0.14
0.13
0.11
0.12
0.10
PM,0
SECOND MAX 24-HOUR
NS
3
—
67
75
67
74
52
62
62
72
50
WEIGHTED ANNUAL MEAN
DOWN
3
—
36
39
34
37
32
30
31
32
28
S02
ARITHMETIC MEAN
DOWN
2
0.004
0.005
0.005
0.004
0.003
0.004
0.003
0.003
0.003
0.004

SECOND MAX 24-HOUR
NS
2
0.012
0.014
0.016
0.015
0.018
0.019
0.010
0.014
0.012
0.014
SAN FRANCISCO, CA












CO
SECOND MAX 8-HOUR
DOWN
4
6.1
6.4
5.9
5.7
6.2
4.8
4.6
4.3
3.7
3.9
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.09
0.10
0.08
0.04
0.04
0.02
0.03
0.02
0.03
0.01
N02
ARITHMETIC MEAN
DOWN
1
0.024
0.026
0.026
0.021
0.024
0.022
0.024
0.022
0.021
0.022
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.09
0.09
0.08
0.06
0.06
0.06
0.08
0.07
0.09
0.08
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
84
84
93
84
75
72
65
42
45
WEIGHTED ANNUAL MEAN
DOWN
1
—
33
33
28
32
29
27
25
21
21
S02
ARITHMETIC MEAN
NS
1
0.002
0.002
0.003
0.002
0.002
0.003
0.002
0.001
0.002
0.002

SECOND MAX 24-HOUR
NS
1
0.010
0.012
0.015
0.010
0.013
0.012
0.010
0.005
0.005
0.007
SAN JOSE, CA













CO
SECOND MAX 8-HOUR
DOWN
2
7.2
10.4
11.9
10.8
10.2
7.3
6.4
7.4
5.6
5.7
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.19
0.12
0.12
0.08
0.04
0.03
0.02
0.02
0.02
0.01
Note: NS = Not Significant (no significant upward or downward trend).
138 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0.13
0.12
0.11
0.11
0.11
0.11
0.11
0.10
0.12
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
4
—
115
122
117
102
85
72
76
47
47
WEIGHTED ANNUAL MEAN
DOWN
4
—
38
39
36
34
30
25
26
22
21
SAN JUAN-BAYAMON, PR












CO
SECOND MAX 8-HOUR
DOWN
2
5.5
5.4
5.5
5.3
5.3
5.3
4.5
4.8
4.9
4.0
PM,o
SECOND MAX 24-HOUR
DOWN
6
—
79
82
80
70
71
75
70
59
63
WEIGHTED ANNUAL MEAN
DOWN
6
—
33
34
35
30
28
32
30
26
27
S02
ARITHMETIC MEAN
UP
2
0.002
0.002
0.002
0.002
0.002
0.003
0.003
0.003
0.004
0.003

SECOND MAX 24-HOUR
NS
2
0.016
0.023
0.014
0.016
0.015
0.022
0.013
0.015
0.019
0.015
SAN LUIS OBISPO-ATASCADERO-PASO ROBLES.C












CO
SECOND MAX 8-HOUR
DOWN
1
3.6
4.0
4.7
3.9
3.3
3.0
3.1
3.1
2.4
2.3
N02
ARITHMETIC MEAN
DOWN
2
0.012
0.012
0.013
0.012
0.012
0.011
0.011
0.011
0.010
0.010
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
5
0.09
0.09
0.09
0.09
0.08
0.08
0.08
0.08
0.08
0.08
PM,„
SECOND MAX 24-HOUR
DOWN
3
—
58
58
54
47
41
54
38
49
40
WEIGHTED ANNUAL MEAN
DOWN
3
—
27
27
25
25
23
23
21
21
19
S02
ARITHMETIC MEAN
NS
4
0.001
0.001
0.001
0.002
0.001
0.001
0.001
0.002
0.001
0.001

SECOND MAX 24-HOUR
NS
4
0.004
0.006
0.006
0.006
0.007
0.004
0.004
0.005
0.003
0.003
SANTA BARBARA-SANTA MARIA-LOMPOC, CA












CO
SECOND MAX 8-HOUR
DOWN
4
2.6
2.6
2.8
2.4
2.3
2.3
2.2
2.5
2.1
1.9
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.05
0.05
0.05
0.03
0.03
0.01
0.02
0.01
0.01
0.01
N02
ARITHMETIC MEAN
DOWN
19
0.008
0.008
0.008
0.007
0.007
0.006
0.006
0.006
0.006
0.006
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
20
0.11
0.11
0.15
0.10
0.10
0.10
0.10
0.09
0.10
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
14
—
53
54
49
45
45
51
43
45
42
WEIGHTED ANNUAL MEAN
DOWN
14
—
26
25
23
22
22
24
23
23
22
S02
ARITHMETIC MEAN
NS
12
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001

SECOND MAX 24-HOUR
NS
12
0.004
0.004
0.003
0.003
0.003
0.003
0.004
0.003
0.003
0.003
SANTA CRUZ-WATSONVILLE, CA












CO
SECOND MAX 8-HOUR
NS
1
1.0
1.0
1.1
1.0
1.0
1.0
1.0
1.2
0.8
0.7
N02
ARITHMETIC MEAN
DOWN
1
0.006
0.008
0.009
0.008
0.010
0.007
0.006
0.006
0.005
0.005
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.09
0.08
0.08
0.08
0.09
0.07
0.08
0.07
0.07
0.08
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
56
50
47
43
35
49
37
36
39
WEIGHTED ANNUAL MEAN
DOWN
1
—
30
31
24
24
22
22
22
19
19
S02
ARITHMETIC MEAN
NS
1
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.002
0.001
0.002

SECOND MAX 24-HOUR
NS
1
0.007
0.007
0.004
0.003
0.002
0.006
0.006
0.006
0.008
0.003
SANTA FE, NM













CO
SECOND MAX 8-HOUR
DOWN
1
4.3
3.8
3.5
3.5
3.9
3.7
3.4
2.7
2.3
2.2
PM,0
SECOND MAX 24-HOUR
DOWN
2
—
34
40
43
32
36
32
28
28
29
WEIGHTED ANNUAL MEAN
DOWN
2
—
17
16
17
14
16
15
14
13
14
SANTA ROSA, CA












CO
SECOND MAX 8-HOUR
DOWN
1
4.1
4.9
5.0
4.3
3.8
3.5
3.8
3.2
2.4
3.0
N02
ARITHMETIC MEAN
NS
1
0.016
0.016
0.015
0.015
0.015
0.016
0.016
0.015
0.015
0.014
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.10
0.10
0.09
0.08
0.09
0.08
0.08
0.08
0.08
0.08
PM,o
SECOND MAX 24-HOUR
DOWN
3
—
52
52
51
69
44
45
41
37
34
WEIGHTED ANNUAL MEAN
DOWN
3
—
23
23
20
23
18
19
18
16
16
SARASOTA-BRADENTON, FL












CO
SECOND MAX 8-HOUR
NS
1
6.3
6.3
6.3
6.2
6.9
5.6
6.5
5.3
5.9
5.1
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.08
0.10
0.10
0.10
0.10
0.09
0.09
0.10
0.09
0.09
PM,o
SECOND MAX 24-HOUR
NS
2
—
43
43
43
53
72
66
48
37
38
WEIGHTED ANNUAL MEAN
NS
2
—
24
24
24
24
26
25
22
20
19
S02
ARITHMETIC MEAN
NS
1
0.002
0.002
0.003
0.002
0.003
0.003
0.003
0.003
0.002
0.002

SECOND MAX 24-HOUR
NS
1
0.008
0.012
0.017
0.016
0.035
0.021
0.018
0.017
0.010
0.018
SAVANNAH, GA












S02
ARITHMETIC MEAN
NS
1
0.002
0.007
0.003
0.002
0.002
0.002
0.003
0.003
0.004
0.004

SECOND MAX 24-HOUR
NS
1
0.010
0.046
0.013
0.008
0.009
0.008
0.011
0.015
0.013
0.019
SCRANTON—WILKES-BARRE—HAZLETON, PA












CO
SECOND MAX 8-HOUR
DOWN
2
4.8
4.8
4.1
4.5
4.2
3.8
2.9
3.6
2.8
3.8
N02
ARITHMETIC MEAN
DOWN
2
0.020
0.018
0.019
0.018
0.017
0.016
0.018
0.018
0.016
0.018
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.11
0.13
0.10
0.10
0.12
0.10
0.11
0.10
0.10
0.10
PM,o
SECOND MAX 24-HOUR
NS
3
—
66
58
61
65
45
69
61
64
50
WEIGHTED ANNUAL MEAN
DOWN
3
—
29
29
25
29
25
26
28
25
24
S02
ARITHMETIC MEAN
DOWN
2
0.011
0.010
0.009
0.010
0.009
0.008
0.007
0.007
0.005
0.006

SECOND MAX 24-HOUR
DOWN
2
0.048
0.051
0.047
0.049
0.039
0.033
0.026
0.035
0.036
0.028
SEATTLE-BELLEVUE-EVERETT.WA












CO
SECOND MAX 8-HOUR
DOWN
5
9.3
9.1
8.5
7.3
7.4
7.5
5.6
5.4
5.4
5.0
LEAD
MAX QUARTERLY MEAN
NS
2
0.29
0.47
0.21
0.35
0.30
0.22
0.20
0.32
0.27
0.34
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.09
0.11
0.08
0.12
0.10
0.09
0.10
0.11
0.09
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
7
—
81
96
83
93
74
75
59
61
56
WEIGHTED ANNUAL MEAN
DOWN
7
—
31
32
29
30
29
28
23
22
20
S02
ARITHMETIC MEAN
NS
1
0.007
0.007
0.006
0.009
0.010
0.010
0.009
0.007
0.006
0.006

SECOND MAX 24-HOUR
DOWN
1
0.022
0.028
0.022
0.026
0.028
0.024
0.022
0.017
0.020
0.019
SHARON, PA













OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.12
0.14
0.11
0.10
0.11
0.10
0.11
0.11
0.11
0.10
PM,„
SECOND MAX 24-HOUR
DOWN
1
—
84
88
68
73
58
56
68
72
52
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 139

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996

WEIGHTED ANNUAL MEAN
DOWN
1
	
37
35
30
36
27
28
30
28
29
S02
ARITHMETIC MEAN
DOWN
1
0.009
0.011
0.011
0.010
0.009
0.008
0.008
0.008
0.008
0.007

SECOND MAX 24-HOUR
DOWN
1
0.037
0.054
0.043
0.036
0.032
0.030
0.029
0.047
0.032
0.029
SHREVEPORT-BOSSIER CITY, LA












OZONE
SECOND DAILY MAX 1-HOUR
NS

0.11
0.11
0.12
0.11
0.10
0.10
0.11
0.09
0.10
0.10
PM,o
SECOND MAX 24-HOUR
NS
1
—
47
47
47
100
44
52
51
52
44
WEIGHTED ANNUAL MEAN
NS
1
—
23
23
23
28
24
22
24
24
22
S02
ARITHMETIC MEAN
NS
1
0.003
0.003
0.004
0.002
0.002
0.004
0.004
0.002
0.001
0.002

SECOND MAX 24-HOUR
NS
1
0.010
0.009
0.023
0.006
0.009
0.013
0.011
0.008
0.004
0.004
SIOUX CITY, IA-NE












PM,o
SECOND MAX 24-HOUR
NS
1
—
77
75
69
66
87
44
69
62
95
WEIGHTED ANNUAL MEAN
NS
1
—
31
28
28
28
25
23
23
26
33
SIOUX FALLS, SD












PM,o
SECOND MAX 24-HOUR
NS
1
—
52
54
46
44
43
48
43
50
43
WEIGHTED ANNUAL MEAN
NS
1
—
22
22
20
19
19
15
22
20
19
SOUTH BEND, IN












OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.10
0.12
0.08
0.09
0.10
0.10
0.09
0.10
0.11
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
2
—
78
71
89
63
64
59
61
51
44
WEIGHTED ANNUAL MEAN
DOWN
2
—
29
30
31
30
23
24
27
22
20
SPOKANE, WA













CO
SECOND MAX 8-HOUR
DOWN
1
19.0
13.8
12.3
11.5
11.0
9.9
9.8
8.1
8.4
9.0
PM,o
SECOND MAX 24-HOUR
DOWN
4
—
137
142
173
93
143
120
85
76
91
WEIGHTED ANNUAL MEAN
DOWN
4
—
50
46
45
40
40
40
37
31
32
SPRINGFIELD,
IL












CO
SECOND MAX 8-HOUR
DOWN
1
4.6
4.8
4.4
4.4
4.3
4.5
3.9
3.1
3.2
3.0
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.10
0.11
0.11
0.10
0.10
0.09
0.11
0.10
0.10
0.10
S02
ARITHMETIC MEAN
DOWN
1
0.008
0.007
0.007
0.007
0.008
0.006
0.006
0.006
0.006
0.006

SECOND MAX 24-HOUR
NS
1
0.039
0.074
0.047
0.054
0.048
0.043
0.040
0.050
0.062
0.061
SPRINGFIELD,
MA












CO
SECOND MAX 8-HOUR
NS
2
8.3
7.3
7.3
6.7
6.3
7.1
6.1
7.5
7.9
7.1
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.14
0.09
0.06
0.05
0.03
0.04
0.02
0.01
0.01
0.01
N02
ARITHMETIC MEAN
DOWN
2
0.018
0.019
0.018
0.018
0.017
0.016
0.016
0.019
0.015
0.016
OZONE
SECOND DAILY MAX 1-HOUR
NS
4
0.12
0.16
0.12
0.12
0.13
0.12
0.13
0.12
0.12
0.10
PM,0
SECOND MAX 24-HOUR
NS
4
—
56
49
52
50
56
50
56
43
47
WEIGHTED ANNUAL MEAN
DOWN
4
—
27
25
22
22
20
20
23
19
20
S02
ARITHMETIC MEAN
DOWN
6
0.010
0.010
0.009
0.009
0.008
0.007
0.006
0.006
0.006
0.006

SECOND MAX 24-HOUR
DOWN
6
0.039
0.050
0.033
0.034
0.030
0.030
0.022
0.037
0.025
0.026
SPRINGFIELD,
MO












CO
SECOND MAX 8-HOUR
DOWN
1
7.5
6.9
6.7
7.2
6.9
6.2
5.3
5.9
4.1
3.3
N02
ARITHMETIC MEAN
NS
1
0.010
0.010
0.010
0.008
0.008
0.010
0.011
0.013
0.012
0.011
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.09
0.09
0.07
0.08
0.07
0.08
0.08
0.09
0.10
0.09
PM,0
SECOND MAX 24-HOUR
NS
3
—
43
42
42
33
42
37
38
37
38
WEIGHTED ANNUAL MEAN
DOWN
3
—
22
22
22
18
19
17
17
17
18
S02
ARITHMETIC MEAN
NS
2
0.007
0.006
0.006
0.006
0.003
0.004
0.006
0.008
0.003
0.005

SECOND MAX 24-HOUR
NS
2
0.079
0.057
0.052
0.057
0.033
0.034
0.040
0.067
0.021
0.043
ST. JOSEPH, MO












PM,„
SECOND MAX 24-HOUR
NS
1
—
112
100
104
120
89
100
77
101
126
WEIGHTED ANNUAL MEAN
DOWN
1
—
46
45
40
44
39
32
34
33
32
ST. LOUIS, MO-IL












CO
SECOND MAX 8-HOUR
DOWN
7
6.2
4.6
4.8
4.0
4.1
3.3
3.3
3.5
3.3
3.3
LEAD
MAX QUARTERLY MEAN
DOWN
12
1.06
1.99
0.81
0.71
0.62
0.64
0.50
0.56
0.57
0.61
N02
ARITHMETIC MEAN
NS
8
0.021
0.020
0.019
0.018
0.018
0.019
0.018
0.019
0.019
0.018
OZONE
SECOND DAILY MAX 1-HOUR
NS
16
0.13
0.13
0.11
0.11
0.11
0.10
0.11
0.11
0.12
0.11
PM,0
SECOND MAX 24-HOUR
DOWN
15
—
84
84
78
62
67
62
67
64
56
WEIGHTED ANNUAL MEAN
DOWN
15
—
37
37
33
32
32
28
31
30
27
S02
ARITHMETIC MEAN
DOWN
15
0.012
0.012
0.012
0.011
0.010
0.009
0.009
0.009
0.008
0.008

SECOND MAX 24-HOUR
DOWN
15
0.054
0.054
0.056
0.042
0.042
0.039
0.041
0.041
0.037
0.039
STAMFORD-NORWALK, CT












CO
SECOND MAX 8-HOUR
DOWN
1
6.3
6.9
6.0
6.3
6.0
5.5
5.2
6.2
5.4
4.1
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.17
0.22
0.16
0.14
0.15
0.11
0.15
0.16
0.14
0.12
PM,0
SECOND MAX 24-HOUR
NS
4
—
62
59
62
59
48
48
64
51
47
WEIGHTED ANNUAL MEAN
NS
4
—
30
28
29
31
23
22
27
24
24
S02
ARITHMETIC MEAN
NS
1
0.005
0.006
0.006
0.005
0.006
0.005
0.005
0.006
0.004
0.005

SECOND MAX 24-HOUR
NS
1
0.022
0.031
0.029
0.024
0.025
0.022
0.020
0.028
0.023
0.019
STATE COLLEGE, PA












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.11
0.14
0.10
0.11
0.12
0.10
0.11
0.10
0.11
0.11
STEUBENVILLE-WEIRTON.OH-WV












CO
SECOND MAX 8-HOUR
DOWN
1
30.3
19.6
13.3
20.5
13.9
6.9
6.6
8.2
5.7
5.3
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.17
0.05
0.09
0.08
0.07
0.14
0.07
0.07
0.06
0.04
N02
ARITHMETIC MEAN
NS
1
0.020
0.021
0.023
0.020
0.021
0.019
0.017
0.020
0.020
0.020
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.12
0.10
0.09
0.11
0.09
0.10
0.10
0.11
0.10
PM,o
SECOND MAX 24-HOUR
NS
6
—
98
121
95
102
84
93
109
90
88
WEIGHTED ANNUAL MEAN
DOWN
6
—
41
42
37
40
36
34
35
34
32
Note: NS = Not Significant (no significant upward or downward trend).
140 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
S02
ARITHMETIC MEAN
DOWN
5
0.024
0.026
0.026
0.025
0.024
0.019
0.019
0.018
0.012
0.011

SECOND MAX 24-HOUR
DOWN
5
0.097
0.088
0.092
0.085
0.078
0.076
0.085
0.093
0.049
0.048
STOCKTON-LODI, CA












CO
SECOND MAX 8-HOUR
NS
2
8.4
9.4
9.0
10.9
9.7
5.9
5.8
7.0
4.8
6.0
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.06
0.06
0.05
0.04
0.04
0.02
0.03
0.02
0.02
0.02
N02
ARITHMETIC MEAN
DOWN
1
0.025
0.026
0.026
0.026
0.025
0.024
0.024
0.024
0.022
0.023
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.12
0.12
0.11
0.12
0.11
0.11
0.11
0.12
0.13
0.10
PM,o
SECOND MAX 24-HOUR
NS
2
—
97
113
118
127
77
100
95
91
55
WEIGHTED ANNUAL MEAN
DOWN
2
—
42
46
45
49
39
36
35
31
26
SYRACUSE, NY












CO
SECOND MAX 8-HOUR
DOWN
1
9.4
7.8
9.7
6.8
8.4
7.5
5.6
6.5
3.3
3.9
PM,o
SECOND MAX 24-HOUR
DOWN
3
—
66
66
62
74
62
67
59
51
53
WEIGHTED ANNUAL MEAN
DOWN
3
—
32
32
27
29
27
24
24
23
23
TACOMA, WA













CO
SECOND MAX 8-HOUR
DOWN
1
10.5
11.6
10.3
8.0
8.7
8.9
5.9
6.0
6.3
6.3
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.10
0.11
0.09
0.13
0.09
0.10
0.10
0.11
0.09
0.10
PM,0
SECOND MAX 24-HOUR
DOWN
4
—
90
106
91
94
89
78
66
67
60
WEIGHTED ANNUAL MEAN
DOWN
4
—
34
36
32
32
33
30
25
25
24
S02
ARITHMETIC MEAN
NS
2
0.007
0.007
0.007
0.008
0.008
0.009
0.009
0.007
0.006
0.006

SECOND MAX 24-HOUR
DOWN
2
0.029
0.029
0.027
0.026
0.023
0.030
0.025
0.021
0.020
0.024
TAMPA-ST. PETERSBURG-CLEARWATER, FL












CO
SECOND MAX 8-HOUR
DOWN
6
3.7
4.4
3.7
3.8
2.9
2.9
2.6
2.2
2.8
2.5
LEAD
MAX QUARTERLY MEAN
DOWN
2
0.03
0.03
0.03
0.01
0.00
0.00
0.00
0.00
0.00
0.00
N02
ARITHMETIC MEAN
DOWN
1
0.013
0.013
0.013
0.013
0.013
0.013
0.012
0.010
0.012
0.011
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
5
0.12
0.11
0.10
0.11
0.10
0.09
0.09
0.09
0.09
0.10
PM,0
SECOND MAX 24-HOUR
NS
3
—
52
50
46
48
55
55
59
52
47
WEIGHTED ANNUAL MEAN
DOWN
3
—
29
29
28
29
26
27
26
25
25
S02
ARITHMETIC MEAN
DOWN
6
0.006
0.006
0.007
0.006
0.004
0.004
0.004
0.004
0.004
0.004

SECOND MAX 24-HOUR
DOWN
6
0.028
0.028
0.027
0.026
0.022
0.023
0.023
0.024
0.020
0.022
TERRE HAUTE, IN












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.11
0.08
0.11
0.11
0.10
0.08
0.09
0.11
0.10
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
5
—
93
87
88
75
61
63
54
62
47
WEIGHTED ANNUAL MEAN
DOWN
5
—
34
33
33
30
26
25
25
27
22
S02
ARITHMETIC MEAN
NS
2
0.009
0.008
0.009
0.011
0.011
0.007
0.009
0.010
0.007
0.009

SECOND MAX 24-HOUR
NS
2
0.038
0.035
0.043
0.038
0.037
0.033
0.039
0.039
0.029
0.033
TEXARKANA.TX-TEXARKANA, AR












PM,0
SECOND MAX 24-HOUR
UP
1
—
40
40
48
45
50
44
52
55
50
WEIGHTED ANNUAL MEAN
NS
1
—
26
26
24
22
23
22
23
26
23
TOLEDO, OH













LEAD
MAX QUARTERLY MEAN
NS
1
0.65
0.54
0.48
0.79
0.48
0.57
0.63
0.70
0.43
0.44
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.11
0.13
0.10
0.10
0.11
0.09
0.11
0.11
0.11
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
64
64
59
60
53
63
58
50
42
WEIGHTED ANNUAL MEAN
DOWN
1
—
36
36
26
29
28
25
26
25
22
S02
ARITHMETIC MEAN
DOWN
2
0.009
0.009
0.007
0.006
0.006
0.006
0.007
0.007
0.004
0.004

SECOND MAX 24-HOUR
NS
2
0.043
0.041
0.040
0.033
0.022
0.029
0.028
0.047
0.025
0.031
TOPEKA, KS













LEAD
MAX QUARTERLY MEAN
DOWN
5
0.04
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.01
PM,o
SECOND MAX 24-HOUR
NS
1
—
66
66
66
56
58
48
49
65
58
WEIGHTED ANNUAL MEAN
NS
1
—
40
40
33
26
28
27
29
34
27
TRENTON, NJ













OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.16
0.20
0.14
0.14
0.15
0.15
0.14
0.14
0.13
0.12
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
79
66
68
58
49
66
64
45
59
WEIGHTED ANNUAL MEAN
DOWN
1
—
32
30
29
31
26
27
29
24
27
TULSA, OK













CO
SECOND MAX 8-HOUR
NS
2
6.3
4.2
5.6
4.7
4.6
5.1
3.9
3.9
3.4
5.3
LEAD
MAX QUARTERLY MEAN
NS
1
0.13
0.13
0.20
0.11
0.21
0.10
0.20
0.10
0.09
0.11
N02
ARITHMETIC MEAN
NS
2
0.012
0.013
0.014
0.011
0.013
0.013
0.013
0.013
0.010
0.012
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.11
0.12
0.11
0.12
0.11
0.10
0.11
0.11
0.12
0.11
PM,o
SECOND MAX 24-HOUR
NS
5
—
56
77
61
59
53
61
50
53
60
WEIGHTED ANNUAL MEAN
NS
5
—
28
28
24
25
24
26
26
26
26
S02
ARITHMETIC MEAN
NS
2
0.008
0.009
0.006
0.009
0.009
0.009
0.006
0.005
0.007
0.008

SECOND MAX 24-HOUR
NS
2
0.058
0.045
0.035
0.046
0.052
0.048
0.035
0.031
0.031
0.036
TUSCALOOSA, A L












PM,o
SECOND MAX 24-HOUR
NS
1
—
59
59
70
62
45
66
48
63
58
WEIGHTED ANNUAL MEAN
DOWN
1
—
29
29
32
28
26
26
26
27
26
TUSCON, AZ













CO
SECOND MAX 8-HOUR
DOWN
3
5.6
6.8
5.7
4.6
4.4
4.6
4.5
4.4
4.3
4.1
N02
ARITHMETIC MEAN
DOWN
1
0.023
0.023
0.023
0.022
0.024
0.023
0.022
0.021
0.020
0.019
OZONE
SECOND DAILY MAX 1-HOUR
NS
5
0.08
0.09
0.09
0.09
0.08
0.09
0.09
0.09
0.09
0.09
PM,„
SECOND MAX 24-HOUR
DOWN
10
—
90
90
87
55
53
44
40
54
47
WEIGHTED ANNUAL MEAN
DOWN
10
—
37
39
33
25
23
22
21
25
25
UTICA-ROME, NY












OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.11
0.12
0.09
0.10
0.10
0.09
0.09
0.09
0.10
0.08
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 141

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
VALLEJO-FAIRFIELD-NAPA, CA












CO
SECOND MAX 8-HOUR
DOWN
2
6.6
7.3
7.4
6.9
6.6
5.6
5.6
5.2
4.2
4.2
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.10
0.10
0.10
0.09
0.10
0.09
0.10
0.10
0.11
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
1
—
94
94
94
98
69
46
57
51
43
WEIGHTED ANNUAL MEAN
DOWN
1
—
27
27
27
41
24
23
21
19
17
VENTURA, CA













CO
SECOND MAX 8-HOUR
DOWN
2
3.9
3.3
3.0
3.3
3.1
2.3
2.5
2.8
3.2
2.4
LEAD
MAX QUARTERLY MEAN
DOWN
1
0.05
0.03
0.04
0.02
0.03
0.01
0.01
0.01
0.01
0.01
N02
ARITHMETIC MEAN
DOWN
4
0.015
0.016
0.017
0.016
0.015
0.014
0.014
0.014
0.014
0.013
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
6
0.15
0.14
0.15
0.13
0.14
0.13
0.12
0.13
0.13
0.13
PM,o
SECOND MAX 24-HOUR
DOWN
6
—
74
74
83
69
63
55
51
60
52
WEIGHTED ANNUAL MEAN
DOWN
6
—
38
38
34
35
30
27
29
27
26
VINELAND-MILLVILLE-BRIDGETON, NJ












OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.14
0.15
0.13
0.13
0.12
0.10
0.12
0.10
0.13
0.11
S02
ARITHMETIC MEAN
DOWN
1
0.007
0.009
0.008
0.007
0.007
0.006
0.006
0.005
0.004
0.005

SECOND MAX 24-HOUR
DOWN
1
0.038
0.034
0.049
0.024
0.023
0.021
0.019
0.032
0.016
0.016
VISALIA-TULARE-PORTERVILLE,CA












CO
SECOND MAX 8-HOUR
DOWN
1
5.5
5.6
5.9
5.0
5.3
4.3
3.5
4.0
4.2
3.9
N02
ARITHMETIC MEAN
NS
1
0.019
0.023
0.021
0.021
0.022
0.020
0.023
0.023
0.023
0.018
OZONE
SECOND DAILY MAX 1-HOUR
NS
3
0.13
0.12
0.13
0.12
0.12
0.12
0.13
0.13
0.12
0.13
PM,0
SECOND MAX 24-HOUR
DOWN
2
—
113
154
173
129
102
99
86
115
81
WEIGHTED ANNUAL MEAN
DOWN
2
—
60
61
69
61
51
49
42
47
40
WASHINGTON, DC-MD-VA-WV












CO
SECOND MAX 8-HOUR
DOWN
8
7.4
6.6
6.3
5.2
5.0
4.4
5.0
4.5
4.4
3.9
LEAD
MAX QUARTERLY MEAN
DOWN
5
0.07
0.05
0.05
0.05
0.03
0.02
0.02
0.02
0.02
0.01
N02
ARITHMETIC MEAN
NS
7
0.027
0.025
0.025
0.027
0.026
0.026
0.026
0.026
0.023
0.023
OZONE
SECOND DAILY MAX 1-HOUR
NS
13
0.13
0.15
0.11
0.11
0.12
0.11
0.12
0.12
0.12
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
9
—
61
65
54
53
42
53
47
50
45
WEIGHTED ANNUAL MEAN
DOWN
9
—
29
30
26
26
23
22
22
22
21
S02
ARITHMETIC MEAN
DOWN
4
0.008
0.009
0.010
0.008
0.008
0.008
0.008
0.008
0.007
0.007

SECOND MAX 24-HOUR
NS
4
0.030
0.030
0.038
0.030
0.029
0.033
0.027
0.031
0.020
0.028
WATERBURY, CT












PM,0
SECOND MAX 24-HOUR
NS
3
—
68
64
75
63
52
52
55
58
62
WEIGHTED ANNUAL MEAN
NS
3
—
30
31
31
29
23
23
25
24
25
S02
ARITHMETIC MEAN
DOWN
1
0.009
0.010
0.010
0.010
0.009
0.007
0.006
0.007
0.005
0.005

SECOND MAX 24-HOUR
DOWN
1
0.038
0.055
0.048
0.042
0.038
0.029
0.021
0.030
0.019
0.022
WEST PALM BEACH-BOCA RATON, FL












CO
SECOND MAX 8-HOUR
DOWN
1
3.8
4.0
3.7
2.7
3.1
3.7
3.1
2.8
2.8
2.5
N02
ARITHMETIC MEAN
NS
1
0.012
0.013
0.013
0.014
0.012
0.011
0.013
0.012
0.012
0.012
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.09
0.10
0.11
0.09
0.07
0.07
0.11
0.08
0.08
0.09
PM,0
SECOND MAX 24-HOUR
UP

—
33
33
33
33
47
43
56
36
52
WEIGHTED ANNUAL MEAN
NS

—
19
19
19
18
20
19
18
18
18
S02
ARITHMETIC MEAN
NS
1
0.001
0.001
0.003
0.002
0.002
0.003
0.004
0.003
0.002
0.002

SECOND MAX 24-HOUR
UP
1
0.004
0.004
0.009
0.007
0.012
0.010
0.028
0.016
0.019
0.014
WHEELING,WV-OH












CO
SECOND MAX 8-HOUR
NS
1
6.0
4.0
5.2
7.1
5.6
5.6
4.1
4.6
5.0
3.5
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.12
0.12
0.11
0.11
0.11
0.10
0.11
0.10
0.10
0.11
PM,o
SECOND MAX 24-HOUR
DOWN
2
—
83
81
77
67
66
73
63
65
58
WEIGHTED ANNUAL MEAN
DOWN
2
—
34
34
30
31
30
29
28
28
28
S02
ARITHMETIC MEAN
DOWN
3
0.019
0.021
0.021
0.020
0.020
0.018
0.018
0.015
0.010
0.011

SECOND MAX 24-HOUR
NS
3
0.069
0.072
0.065
0.064
0.074
0.077
0.075
0.065
0.055
0.058
WICHITA FALLS,TX












PM,0
SECOND MAX 24-HOUR
NS
1
—
56
56
56
55
52
62
73
57
50
WEIGHTED ANNUAL MEAN
DOWN
1
—
27
27
27
27
23
26
27
20
19
WICHITA, KS













CO
SECOND MAX 8-HOUR
DOWN
3
7.5
7.0
7.9
5.9
5.9
5.6
5.0
4.9
5.2
5.8
LEAD
MAX QUARTERLY MEAN
DOWN
5
0.04
0.03
0.03
0.02
0.02
0.01
0.01
0.01
0.01
0.01
OZONE
SECOND DAILY MAX 1-HOUR
NS
2
0.08
0.10
0.07
0.10
0.09
0.08
0.08
0.09
0.10
0.09
PM,o
SECOND MAX 24-HOUR
UP
4
—
62
61
63
68
65
83
64
69
72
WEIGHTED ANNUAL MEAN
NS
4
—
31
30
28
31
32
31
26
27
25
WILLIAMSPORT, PA












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.09
0.12
0.08
0.09
0.10
0.09
0.09
0.08
0.09
0.08
PM,o
SECOND MAX 24-HOUR
NS
1
—
62
62
60
67
42
58
61
59
46
WEIGHTED ANNUAL MEAN
NS
1
—
29
29
26
31
24
24
28
28
25
S02
ARITHMETIC MEAN
NS
1
0.006
0.009
0.007
0.006
0.007
0.007
0.006
0.006
0.006
0.006

SECOND MAX 24-HOUR
NS
1
0.026
0.035
0.042
0.025
0.025
0.029
0.025
0.042
0.027
0.028
WILMINGTON-NEWARK, DE-MD












CO
SECOND MAX 8-HOUR
NS
1
4.9
5.3
4.5
5.4
4.0
4.1
3.8
4.3
4.6
3.6
OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.14
0.19
0.12
0.14
0.14
0.12
0.14
0.12
0.14
0.11
PM10
SECOND MAX 24-HOUR
NS
1
—
60
84
91
65
52
67
82
73
66
WEIGHTED ANNUAL MEAN
NS
1
—
32
42
37
33
28
29
38
37
32
S02
ARITHMETIC MEAN
DOWN
2
0.014
0.016
0.016
0.013
0.012
0.013
0.013
0.012
0.010
0.009

SECOND MAX 24-HOUR
DOWN
2
0.047
0.054
0.048
0.043
0.033
0.046
0.041
0.044
0.036
0.035
Note: NS = Not Significant (no significant upward or downward trend).
142 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-15. Metropolitan Statistical Area Air Quality Trends, 1987-1996 (continued)
Metropolitan Statistical Area
Trend
#Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
WORCESTER, MA-CT












CO
SECOND MAX 8-HOUR
NS
1
7.1
5.6
7.9
6.0
7.2
8.0
6.1
5.9
4.2
5.3
N02
ARITHMETIC MEAN
DOWN
1
0.034
0.029
0.026
0.022
0.023
0.024
0.028
0.025
0.021
0.019
PM,o
SECOND MAX 24-HOUR
DOWN

—
62
55
48
47
41
43
43
39
42
WEIGHTED ANNUAL MEAN
DOWN

—
27
26
23
21
20
20
20
19
20
S02
ARITHMETIC MEAN
DOWN
1
0.009
0.009
0.011
0.008
0.009
0.007
0.007
0.008
0.006
0.005

SECOND MAX 24-HOUR
DOWN
1
0.038
0.042
0.040
0.034
0.029
0.033
0.025
0.024
0.023
0.021
YAKIMA,WA













CO
SECOND MAX 8-HOUR
DOWN
1
10.9
8.9
8.7
7.4
9.0
8.8
7.9
8.0
7.1
7.4
PM,o
SECOND MAX 24-HOUR
NS
1
—
77
77
77
173
67
90
86
50
99
WEIGHTED ANNUAL MEAN
NS
1
—
34
34
34
44
32
38
31
24
35
YORK, PA













CO
SECOND MAX 8-HOUR
DOWN
1
4.8
4.2
4.6
4.4
3.7
3.6
3.3
3.9
2.7
2.8
N02
ARITHMETIC MEAN
DOWN
1
0.025
0.023
0.022
0.022
0.021
0.020
0.022
0.024
0.021
0.021
OZONE
SECOND DAILY MAX 1-HOUR
DOWN
1
0.12
0.14
0.10
0.12
0.11
0.10
0.11
0.12
0.10
0.10
PM,o
SECOND MAX 24-HOUR
NS
1
—
81
57
63
69
47
77
80
66
51
WEIGHTED ANNUAL MEAN
NS
1
—
33
31
30
32
27
31
32
30
28
S02
ARITHMETIC MEAN
NS
1
0.008
0.007
0.008
0.007
0.008
0.007
0.008
0.009
0.006
0.007

SECOND MAX 24-HOUR
NS
1
0.032
0.029
0.035
0.023
0.020
0.034
0.032
0.041
0.020
0.022
YOUNGSTOWN-WARREN, OH












OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.11
0.12
0.11
0.10
0.12
0.10
0.10
0.10
0.11
0.10
PM,o
SECOND MAX 24-HOUR
DOWN
6
—
87
86
78
82
77
74
78
82
58
WEIGHTED ANNUAL MEAN
DOWN
6
—
37
36
31
34
31
30
31
30
28
S02
ARITHMETIC MEAN
DOWN
2
0.012
0.014
0.016
0.016
0.016
0.013
0.011
0.011
0.010
0.009

SECOND MAX 24-HOUR
NS
2
0.058
0.077
0.043
0.053
0.048
0.056
0.063
0.051
0.038
0.044
YUBA CITY, CA













OZONE
SECOND DAILY MAX 1-HOUR
NS
1
0.11
0.13
0.09
0.11
0.10
0.11
0.13
0.09
0.11
0.10
PM,o
SECOND MAX 24-HOUR
NS
1
—
88
88
88
95
75
69
81
114
69
WEIGHTED ANNUAL MEAN
DOWN
1
—
39
39
39
39
34
30
34
33
29
CO =	Highest second maximum non-overlapping 8-hour concentration (Applicable NAAQS is 9 ppm)
Pb =	Highest quarterly maximum concentration (Applicable NAAQS is 1.5 ug/m3)
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)
PM10 =	Highest weighted annual mean concentration (Applicable NAAQS is 50 ug/m3)
Data from exceptional events not included.
=	Highest second maximum 24-hour concentration (Applicable NAAQS is 150 ug/m3)
SO, =	Highest annual mean concentration (Applicable NAAQS is 0.03 ppm)
=	Highest second maximum 24-hour concentration (Applicable NAAQS is 0.14 ppm)
Note: NS = Not Significant (no significant upward or downward trend).
APPENDIX A: DATA TABLES 143

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-16. Number of Days with PSI Values Greater Than 100 at Trend Sites, 1987-1996,
and All Sites in 1996
Metropolitan Statistical Area
# of
Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
Total
#of
Sites
PSI
> IOC
1996
AKRON, OH
5
5
17
4
2
2
1
0
0
1
0
7
0
ALBANY-SCHENECTADY-TROY NY
7
Q
7
Q
0
1
0
0
1
0
0
12
0
ALBUQUERQUE,NM
21
26
8
10
7
5
0
1
1
2
0
26
0
ALLENTOWN-BETHLEHEM-EASTON, PA
9
5
16
0
0
3
0
0
1
0
0
11
0
ATLANTA, GA
8
27
21
3
17
6
5
17
4
19
6
16
12
AUSTIN-SAN MARCOS, TX
5
0
2
1
0
1
0
0
1
0
0
6
0
BAKERSFIELD, CA
6
67
87
76
60
65
32
56
47
49
56
20
59
BALTIMORE, MD
15
28
43
9
12
20
5
14
17
14
3
23
4
BATON ROUGE, LA
6
10
10
9
18
6
2
3
2
7
2
13
4
BERGEN-FRSSAIC, NJ
8
14
19
4
4
3
0
0
0
4
0
9
0
BIRMINGHAM, AL
16
10
16
1
7
0
2
5
0
15
5
17
5
BOSTON, MA-NH
24
5
15
4
1
4
1
3
1
1
0
28
0
BUFFALO-NIAGARA FALLS, NY
21
4
18
1
2
0
0
0
0
0
0
21
0
CHARLESTON-NORTH CHARLESTON,SC
9
0
0
0
0
1
1
0
0
0
0
9
0
CHARLOTTE-GASTONIA-ROCK HILL, NC-SC
: 10
10
21
3
6
2
0
4
0
1
3
28
6
CHICAGO, IL
44
17
23
4
3
8
7
1
8
4
3
65
4
CINCINNATI, OH-KY-IN
21
11
21
3
6
7
0
1
4
7
1
23
2
CLEVELAND-LORAIN-ELYRIA, OH
24
6
21
4
2
3
2
2
4
4
1
40
5
COLUMBUS, OH
9
1
4
Q
1
3
1
0
0
1
0
13
1
DALLAS, TX
8
10
14
7
8
1
3
5
1
13
2
24
6
DAYTON-SPRINGFIELD, OH
11
3
17
3
1
1
0
3
2
2
1
12
1
DENVER,CO
21
37
19
11
9
7
7
3
2
2
1
32
1
DETROIT, Ml
28
9
17
10
3
8
1
2
8
11
3
35
3
EL PASO, TX
17
32
16
33
27
13
17
10
10
4
9
21
10
FORT LAUDERDALE, FL
7
0
3
2
0
0
0
0
0
1
0
19
0
FORT WORTH-ARLINGTON, TX
8
4
11
8
5
9
2
1
8
6
3
8
3
FRESNO, CA
8
49
29
47
29
33
27
28
11
19
31
17
39
GARY, IN
18
8
13
1
3
3
2
0
1
4
3
23
3
GRAND RAPIDS-MUSKEGON-HOLLAND, Ml
6
5
10
3
2
2
0
1
1
1
3
9
4
GREENSBORO-WINSTON-SALEM-HIGH POINT, NC 10
0
19
5
2
0
0
2
1
0
2
22
2
GREENVILLE-SPARTANBURG-ANDERSON, SC 2
0
8
0
0
0
1
1
0
0
0
8
1
HARRISBURG-LEBANON-CARLISLE, PA
7
5
13
Q
2
0
0
1
2
0
0
7
0
HARTFORD, CT
14
20
27
11
7
14
9
9
10
9
1
15
1
HONOLULU, HI
4
Q
Q
Q
0
0
0
0
0
0
0
13
0
HOUSTON, TX
28
67
61
41
59
42
30
26
29
54
28
33
32
INDIANAPOLIS, IN
27
3
9
2
1
1
1
0
2
2
2
33
5
JACKSONVILLE, FL
14
2
2
0
0
0
0
1
0
2
0
19
0
JERSEY CITY, NJ
8
12
18
2
7
8
1
5
1
2
2
10
2
KANSAS CITY, MO-KS
24
6
4
2
2
2
1
2
0
6
3
28
3
KNOXVILLE, TN
13
0
8
0
5
0
0
2
1
4
1
24
1
LAS VEGAS, NV-AZ
7
7
31
46
22
12
5
8
12
7
3
19
13
LITTLE ROCK-NORTH LITTLE ROCK, AR
7
1
0
0
1
0
0
0
0
1
0
8
0
LOS ANGELES-LONG BEACH, CA
36
201
239
226
180
184
185
146
136
103
88
40
89
LOUISVILLE, KY-IN
17
2
20
3
4
4
0
6
4
4
3
27
4
MEMPHIS, TN-AR-MS
12
10
9
5
6
1
2
4
1
7
7
15
8
MIAMI, FL
10
4
5
4
1
2
0
0
0
0
1
12
1
MIDDLESEX-SOMERSET-HUNTERDON, NJ
5
10
24
8
12
8
3
1
5
1
0
7
3
MILWAUKEE-WAUKESHA, Wl
17
13
19
8
2
10
0
0
4
5
1
21
1
MINNEAPOLIS-ST. PAUL, MN-WI
23
14
3
7
3
2
1
0
5
3
1
41
1
144 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-16. Number of Days with PSI Values Greater Than 100 at Trend Sites, 1987-1996,
and All Sites in 1996 (continued)

# of
Total
PSI

Trend
#of
>100
Metropolitan Statistical Area
Sites 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996
Sites
1996
MONMOUTH-OCEAN, NJ
3
0
0
11
7
9
2
6
0
5
2
4
3
NASHVILLE, TN
20
4
23
4
9
1
1
2
3
2
2
27
2
NASSAU-SUFFOLK, NY
4
15
10
6
7
13
2
4
3
5
2
8
2
NEW HAVEN-MERIDEN, CT
11
20
16
7
10
22
3
11
8
8
2
10
2
NEW ORLEANS, LA
10
5
2
1
0
0
1
2
2
3
0
14
1
NEW YORK, NY
26
44
46
18
18
22
4
6
8
8
4
38
7
NEWARK, NJ
13
24
33
5
8
11
5
2
6
6
2
16
2
NORFOLK-VA BEACH-NEWPORT NEWS.VA-NC
11
5
8
0
0
1
2
4
2
0
0
12
0
OAKLAND, CA
19
14
10
3
5
6
2
3
3
12
11
29
11
OKLAHOMA CITY, OK
13
6
0
2
2
0
0
0
2
3
1
14
1
OMAHA, NE-IA
9
0
1
1
0
0
0
1
1
1
1
13
1
ORANGE COUNTY CA
9
58
63
66
47
40
43
25
14
6
6
11
6
ORLANDO, FL
9
0
0
1
2
0
1
0
0
0
0
16
0
PHILADELPHIA, PA-NJ
37
35
35
19
14
25
3
21
6
14
5
48
22
PHOENIX-MESA, AZ
25
42
27
30
9
4
10
7
9
13
5
29
10
PITTSBURGH, PA
37
10
20
9
8
4
1
3
2
7
0
55
1
PONCE, PR
1

Q
Q
0
0
0
0
0
0
0
1
0
PORTLAND-VANCOUVER, OR-WA
12
11
8
6
8
9
2
0
2
0
4
17
4
PROVIDENCE-FALL RIVER-WARWICK, RI-MA
11
10
9
2
7
11
2
1
2
5
0
20
0
RALEIGH-DURHAM-CHAPEL HILL, NC
4
3
4
4
2
1
1
0
1
0
0
23
0
RICHMOND-PETERSBURG, VA
10
8
20
1
3
4
3
9
1
4
0
11
0
RIVERSIDE-SAN BERNARDINO, CA
36
171
180
178
144
144
156
142
124
113
94
53
94
ROCHESTER, NY
8
1
5
0
1
0
0
0
0
0
0
9
0
SACRAMENTO, CA
12
52
72
57
41
46
21
11
11
16
12
37
17
ST. LOUIS, MO-IL
53
17
20
13
8
6
3
6
11
14
4
61
4
SALT LAKE CITY-OGDEN, UT
18
7
11
15
2
19
10
3
10
1
3
23
6
SAN ANTONIO, TX
7
2
2
0
1
0
0
0
1
3
2
7
2
SAN DIEGO, CA
20
61
84
91
61
40
37
17
16
14
4
27
4
SAN FRANCISCO, CA
9
1
2
1
0
0
0
0
0
1
0
11
0
SAN JOSE, CA
8
18
16
21
11
11
2
2
0
5
2
11
2
SAN JUAN-BAYAMON, PR
10
2
0
0
0
0
0
0
0
0
1
22
1
SCRANTON-WILKES-BARRE-HAZLETON, PA
10
1
12
1
0
2
0
0
0
0
0
11
0
SEATTLE-BELLEVUE-EVERETT, WA
14
14
20
8
5
2
1
0
0
0
0
21
1
SPRINGFIELD, MA
16
3
19
5
4
5
4
7
3
4
1
13
1
SYRACUSE, NY
4
3
1
2
1
2
0
0
0
0
0
10
0
TACOMA, WA
8
9
9
4
3
1
1
0
1
0
0
9
0
TAMPA-ST. PETERSBURG-CLEARWATER, FL
20
5
1
1
3
0
1
0
0
1
2
35
2
TOLEDO, OH
5
2
6
1
0
1
0
3
1
0
0
8
1
TUSCON, AZ
18
4
6
2
0
0
0
0
0
0
0
29
0
TULSA, OK
12
2
2
2
3
2
1
1
2
4
2
13
2
VENTURA, CA
13
54
83
59
36
49
25
16
24
30
25
18
28
WASHINGTON, DC-MD-VA-WV
34
26
37
8
5
16
2
13
7
8
2
52
2
WEST PALM BEACH-BOCA RATON, FL
5
0
0
0
0
0
0
0
0
0
0
9
0
WILMINGTON-NEWARK, DE-MD
5
16
22
3
4
6
2
3
1
6
0
12
1
YOUNGSTOWN-WARREN, OH
9
0
5
1
0
1
1
0
0
1
0
15
0
APPENDIX A: DATA TABLES 145

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-17. (Ozone only) Number of Days with PSI Values Greater Than 100 at Trend Sites, 1987-1996,
and All Sites in 1996

# of










Total
PSI

Trend










#of
>100
Metropolitan Statistical Area
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
Sites
1996
AKRON, OH
2
5
17
4
2
2
1
0
0
1
0
2
0
ALBANY-SCHENECTADY-TROY NY
3
Q
7
Q
0
1
0
0
1
0
0
3
0
ALBUQUERQUE,NM
7
1
Q
Q
0
0
0
0
1
0
0
9
0
ALLENTOWN-BETHLEHEM-EASTON, PA
3
5
15
Q
0
3
0
0
0
0
0
3
0
ATLANTA, GA
3
27
21
3
17
6
5
17
4
19
6
6
12
AUSTIN-SAN MARCOS, TX
2
0
2
1
0
1
0
0
1
0
0
2
0
BAKERSFIELD, CA
4
67
83
73
57
62
31
56
47
48
56
8
58
BALTIMORE, MD
6
26
40
8
11
20
5
14
16
14
3
8
4
BATON ROUGE, LA
3
10
10
9
18
6
2
3
2
7
2
7
4
BERGEN-FRSSAIC, NJ
1
13
18
2
3
3
0
0
0
4
0
1
0
BIRMINGHAM, AL
6
7
15
1
7
0
2
5
0
15
5
6
5
BOSTON, MA-NH
4
4
15
4
1
4
1
3
1
1
0
6
0
BUFFALO-NIAGARA FALLS, NY
2
4
18
1
1
0
0
0
0
0
0
2
0
CHARLESTON-NORTH CHARLESTON,SC
3
0
0
0
0
0
1
0
0
0
0
3
0
CHARLOTTE-GASTONIA-ROCK HILL, NC-SC
3
10
21
2
3
2
0
4
0
1
3
7
6
CHICAGO, IL
16
16
22
3
0
7
3
0
2
4
2
22
3
CINCINNATI, OH-KY-IN
6
11
21
3
6
7
0
1
4
7
1
8
2
CLEVELAND-LORAIN-ELYRIA, OH
6
6
21
1
2
3
1
1
2
1
1
8
2
COLUMBUS, OH
2
1
4
Q
1
3
0
0
0
1
0
4
1
DALLAS, TX
2
10
14
7
8
1
3
5
1
13
2
7
6
DAYTON-SPRINGFIELD, OH
3
2
17
3
1
1
0
3
2
2
1
4
1
DENVER,CO
5
5
4
0
2
0
0
0
0
0
0
9
0
DETROIT, Ml
7
6
16
10
3
8
0
2
6
9
2
8
2
EL PASO, TX
3
17
6
13
9
7
7
4
6
3
3
4
4
FORT LAUDERDALE, FL
2
0
3
2
0
0
0
0
0
1
0
3
0
FORT WORTH-ARLINGTON, TX
2
4
11
8
5
9
2
1
8
6
3
2
3
FRESNO, CA
3
49
28
45
22
32
27
27
11
19
31
7
39
GARY, IN
4
6
13
0
3
3
2
0
1
4
3
4
3
GRAND RAPIDS-MUSKEGON-HOLLAND, Ml
2
5
10
3
2
2
0
1
1
1
3
5
4
GREENSBORO—WINSTON-SALEM—HIGH POINT, NC 3
0
14
0
2
0
0
2
1
0
2
6
2
GREENVILLE-SPARTANBURG-ANDERSON, SC 2
0
8
0
0
0
1
1
0
0
0
4
1
HARRISBURG-LEBANON-CARLISLE, PA
3
5
13
0
2
0
0
1
2
0
0
3
0
HARTFORD, CT
3
10
24
9
7
12
8
9
10
7
1
3
1
HONOLULU, HI
1
Q
Q
Q
0
0
0
0
0
0
0
1
0
HOUSTON, TX
10
66
61
41
59
42
30
26
29
54
28
12
32
INDIANAPOLIS, IN
5
3
9
2
1
0
0
0
2
2
2
7
5
JACKSONVILLE, FL
2
2
2
0
0
0
0
1
0
2
0
3
0
JERSEY CITY, NJ
1
12
18
2
7
8
1
5
1
2
2
1
2
KANSAS CITY, MO-KS
6
5
4
1
2
2
1
1
0
6
2
7
2
KNOXVILLE, TN
4
0
8
0
5
0
0
2
1
4
1
8
1
LAS VEGAS, NV-AZ
3
0
3
1
1
0
0
0
0
0
0
4
0
LITTLE ROCK-NORTH LITTLE ROCK, AR
2
1
0
0
1
0
0
0
0
1
0
2
0
LOS ANGELES-LONG BEACH, CA
13
160
178
154
132
134
143
116
107
84
62
15
63
LOUISVILLE, KY-IN
4
2
20
1
4
4
0
6
4
4
3
7
4
MEMPHIS, TN-AR-MS
3
5
8
2
4
0
0
1
0
7
6
4
7
MIAMI, FL
4
4
5
3
1
2
0
0
0
0
1
4
1
MIDDLESEX-SOMERSET-HUNTERDON, NJ
2
10
24
8
12
8
3
1
5
1
0
2
3
MILWAUKEE-WAUKESHA, Wl
6
13
19
8
2
10
0
0
4
5
1
9
1
MINNEAPOLIS-ST. PAUL, MN-WI
3
1
1
0
0
0
0
0
0
0
0
5
0
146 APPENDIX A: DATA TABLES

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
Table A-17. (Ozone only) Number of Days with PSI Values Greater Than 100 at Trend Sites, 1987-1996,
and All Sites in 1996 (continued)

# of










Total
PSI

Trend










#of
> IOC
Metropolitan Statistical Area
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
Sites
1996
MONMOUTH-OCEAN, NJ
1
0
0
11
7
9
2
6
0
5
2
2
3
NASHVILLE, TN
7
3
23
2
9
1
1
2
3
2
2
9
2
NASSAU-SUFFOLK, NY
1
11
8
6
7
13
2
4
3
5
2
2
2
NEW HAVEN-MERIDEN, CT
2
17
16
7
8
20
3
7
6
8
2
2
2
NEW ORLEANS, LA
5
5
2
1
0
0
1
2
2
3
0
6
1
NEW YORK, NY
4
16
32
12
13
19
3
6
8
7
4
8
7
NEWARK, NJ
3
23
30
4
7
8
5
2
4
6
2
3
2
NORFOLK-VIRGINIA BEACH-NEWPORT NEWS.VA-NC 2
3
7
0
0
1
2
4
2
0
0
3
0
OAKLAND, CA
7
14
10
3
5
5
2
3
3
12
11
9
11
OKLAHOMA CITY, OK
4
1
0
0
2
0
0
0
0
3
0
4
0
OMAHA, NE-IA
3
0
0
0
0
0
0
0
0
0
0
3
0
ORANGE COUNTY CA
3
54
53
48
43
40
41
25
14
5
6
4
6
ORLANDO, FL
3
0
0
1
2
0
1
0
0
0
0
4
0
PHILADELPHIA, PA-NJ
8
34
35
17
14
25
3
21
5
14
5
10
5
PHOENIX-MESA, AZ
9
2
4
0
3
0
5
5
4
7
5
10
5
PITTSBURGH, PA
6
5
16
2
0
2
0
3
2
6
0
11
1
PONCE, PR


0
0
0
0
0
0
0
0
0

0
PORTLAND-VANCOUVER, OR-WA
3
2
2
Q
4
1
2
0
0
0
4
4
4
PROVIDENCE-FALL RIVER-WARWICK, RI-MA 2
10
8
2
7
11
2
1
2
5
0
3
0
RALEIGH-DURHAM-CHAPEL HILL, NC
1
Q
Q
Q
2
0
0
0
1
0
0
8
0
RICHMOND-PETERSBURG, VA
4
7
20
1
3
4
3
9
1
4
0
4
0
RIVERSIDE-SAN BERNARDINO, CA
16
168
179
169
138
141
154
141
123
107
91
20
91
ROCHESTER, NY
2
1
5
0
1
0
0
0
0
0
0
2
0
SACRAMENTO, CA
6
30
49
18
16
30
20
8
11
16
12
14
17
ST. LOUIS, MO-IL
16
14
20
7
8
6
3
6
11
14
4
17
4
SALT LAKE CITY-OGDEN, UT
4
2
8
7
2
1
0
0
1
1
0
6
3
SAN ANTONIO, TX
2
2
2
0
1
0
0
0
1
3
2
2
2
SAN DIEGO, CA
8
60
80
82
60
40
37
17
16
14
4
9
4
SAN FRANCISCO, CA
3
1
0
0
0
0
0
0
0
1
0
3
0
SAN JOSE, CA
4
18
11
6
2
3
2
2
0
5
2
6
2
SAN JUAN-BAYAMON, PR

0
0
0
0
0
0
0
0
0
0

0
SCRANTON—WILKES-BARRE—HAZLETON,
PA 3
1
12
1
0
2
0
0
0
0
0
4
0
SEATTLE-BELLEVUE-EVERETT, WA
1
Q
1
Q
2
0
0
0
0
0
0
3
1
SPRINGFIELD, MA
4
2
19
5
4
5
3
7
3
3
0
4
0
SYRACUSE, NY

Q
Q
Q
0
0
0
0
0
0
0
2
0
TACOMA, WA
1
Q
Q
Q
2
0
0
0
1
0
0
2
0
TAMPA-ST. PETERSBURG-CLEARWATER, FL 5
5
0
1
3
0
1
0
0
1
2
7
2
TOLEDO, OH
2
2
6
1
0
1
0
3
1
0
0
4
1
TUSCON, AZ
5
0
0
0
0
0
0
0
0
0
0
7
0
TULSA, OK
3
1
2
2
3
2
0
1
2
4
2
3
2
VENTURA, CA
6
54
83
59
36
49
25
16
24
30
25
8
28
WASHINGTON, DC-MD-VA-WV
13
21
35
5
5
16
2
13
7
8
2
18
2
WEST PALM BEACH-BOCA RATON, FL
1
0
0
0
0
0
0
0
0
0
0
2
0
WILMINGTON-NEWARK, DE-MD
1
16
22
3
4
6
2
3
1
6
0
4
1
YOUNGSTOWN-WARREN, OH
1
0
5
1
0
1
0
0
0
1
0
3
0
APPENDIX A: DATA TABLES 147

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
Table A-18. Total Number of Days with PSI Values Greater Than 100 at Trend Sites—Summary, 1987-1996
Metropolitan Statistical Area
# of
Trend
Sites
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
Total
#of
Sites
PSI
>100
1996
All Trend Sites
1,333
1,565
1,987
1,300
1,050
All Pollutants
1,043 712
705
635
725
480
1,921
582
LOS ANGELES-LONG BEACH, CA
36
201
239
226
180
184
185
146
136
103
88
40
89
RIVERSIDE-SAN BERNADINO, CA
36
171
180
178
144
144
156
142
124
113
94
53
94
All Except LA and Riverside
1,261
1,193
1,568
896
726
715
371
417
375
509
298
1,828
399






Ozone Only






All Trend Sites
380
1,221
1,696
922
849
877
607
636
545
666
429
534
495
LOS ANGELES-LONG BEACH, CA
13
160
178
154
132
134
143
116
107
84
62
15
63
RIVERSIDE-SAN BERNADINO, CA
16
168
179
169
138
141
154
141
123
107
91
20
91
All Except LA and Riverside
351
893
1,339
599
579
602
310
379
315
475
276
499
341
148 APPENDIX A: DATA TABLES

-------
Appendix B
Methodology
Air Quality Data Base
THE AMBIENT AIR quality data pre-
sented in Chapter 2 of this report are
based on data retrieved from AIRS on
July 3,1997. These are direct measure-
ments of pollutant concentrations at
monitoring stations operated by state
and local governments throughout the
nation. The monitoring stations are
generally located in larger urban areas.
EPA and other federal agencies also
operate some air quality monitoring
sites on a temporary basis as a part of
air pollution research studies. The na-
tional monitoring network conforms to
uniform criteria for monitor siting, in-
strumentation, and quality assur-
ance.1,2
In 1996, 4,858 monitoring sites re-
ported air quality data for one or more
of the six NAAQS pollutants to AIRS,
as seen in Table B-l. The geographic lo-
cations of these monitoring sites are
displayed in Figures B-l to B-6. The
sites are identified as NAMS, State and
Local Air Monitoring Stations (SLAMS),
or "other." NAMS were established to
ensure a long-term national network
for urban area-oriented ambient moni-
toring and to provide a systematic, con-
sistent data base for air quality
comparisons and trends analysis.
SLAMS allow state or local govern-
ments to develop networks tailored for
their immediate monitoring needs.
"Other" monitors may be Special Pur-
pose Monitors, industrial monitors,
tribal monitors, etc.
Table B-1. Number of Ambient Monitors
Reporting Data to AIRS
# of Sites
Reporting	# of
Data to Trend Sites
Pollutant AIRS in 1996 1987-1996
CO
554
345
Pb
428
208
no2
415
214
Os
1,037
600
PM,0
1,734
900
so2
690
479
Total
4,858
2,746
Air quality monitoring sites are se-
lected as national trends sites if they
have complete data for at least eight of
the 10 years between 1987 and 1996.
The annual data completeness criteria
are specific to each pollutant and mea-
surement methodology. Table B-l dis-
plays the number of sites meeting the
10-year trend completeness criteria.
For the PMi0 standard which was es-
tablished in 1987, the trend analyses are
based on sites with data in seven of the
nine years between 1988 and 1996.
Because of the annual turnover of
monitoring sites, the use of a moving
10-year window maximizes the num-
ber of sites available for trends and
yields a data base that is consistent
with the current monitoring network.
The air quality data are divided into
two major groupings: daily (24-hour)
measurements and continuous (1-hour)
measurements. The daily measurements
are obtained from monitoring instru-
ments that produce one measurement
per 24-hour period and typically oper-
ate on a systematic sampling schedule
of once every six days, or 61 samples
per year. Such instruments are used to
measure PMio and lead. More frequent
sampling of PMi0 (every other day or
every day) is also common. Only PMi0
weighted (for each quarter to account
for seasonality) annual arithmetic
means that meet the AIRS annual sum-
mary criteria are selected as valid
means for trends purposes.3 Only lead
sites with at least six samples per quar-
ter in three of the four calendar quar-
ters qualify as trends sites. Monthly
composite lead data are used if at least
two monthly samples are available for
at least three of the four calendar quar-
ters.
Monitoring instruments that oper-
ate continuously produce a measure-
ment every hour for a possible total of
8,760 hourly measurements in a year.
For hourly data, only annual averages
based on at least 4,380 hourly observa-
tions are considered as trends statistics.
The S02 standard-related daily statis-
tics require at least 183 daily values to
be included in the analysis. Ozone sites
meet the annual trends data complete-
APPENDIX B: METHODOLOGY 149

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
ness requirement if they have at least
50 percent of the daily data available
for the ozone season, which varies by
state, but typically runs from May
through September.4
Air Quality Trend
Statistics
The air quality statistics presented in
this report relate to the pollutant-spe-
cific NAAQS and comply with the rec-
ommendations of the Intra-Agency
Task Force on Air Quality Indicators.5
A composite average of each trend sta-
tistic is used in the graphical presenta-
tions throughout this report. 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 interpola-
tion from the surrounding years. Miss-
ing end points are replaced with the
nearest valid year of data. The result-
ing data sets are statistically balanced,
allowing simple statistical procedures
and graphics to be easily applied. This
procedure is conservative since endpoint
rates of change are dampened by the in-
terpolated estimates.
Emissions Estimates
Methodology
Trends are presented for annual nation-
wide emissions of CO, lead, NOx,
VOCs, PMio, and S02. These trends are
estimates of the amount and kinds of
pollution being emitted by automo-
biles, factories, and other sources based
upon best available engineering calcu-
lations. Because of recent changes in
the methodology used to obtain these
emissions estimates, the estimates have
been recomputed for each year. Thus,
comparisons of the estimates for a
given year in this report to the same
year in previous reports may not be ap-
propriate.
¦ NAMS
°SLAMS
<¦ Other
Figure B-1. Carbon monoxide monitoring network, 1996.
• NAMS
0 SLAMS
Other
Figure B-2. Lead monitoring network, 1996.
150 APPENDIX B: METHODOLOGY

-------
NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT 1996
• NAMS
° SLAMS
Other
Figure B-3. Nitrogen dioxide monitoring network, 1996.
• NAMS
° SLAMS
Other
Figure B-4. Ozone monitoring network, 1996.
The emissions estimates presented
in this report reflect several major
changes in methodologies. First, state-
derived emissions estimates were in-
cluded primarily for nonutility point
and area sources. Also, 1985-1994 NOx
emission rates derived from test data
from the Acid Rain Division, U.S. EPA,
were utilized. The MOBILE5b model
was run instead of MOBILE5a for 1995
and 1996, and state-derived VMT data
were applied. The Office of Mobile
Sources, U.S. EPA, provided new esti-
mates for non-road diesel, railroad, and
spark ignition marine engines, and
lead emission estimates from aircraft
gasoline consumption were added.
Finally, additional improvements were
made to the particulate matter fugitive
dust categories.
In addition to the changes in meth-
odology affecting most, if not all,
source categories and pollutants, other
changes were made to the emissions
for specific pollutants, source catego-
ries, and/or individual sources. Activ-
ity data and correction parameters for
agricultural crops, construction, and
paved roads were included. State-sup-
plied MOBILE model inputs for 1990,
1995, and 1996 were used, as well as
state-supplied VMT data for 1990.
Rule effectiveness from pre-1990
chemical and allied product emissions
was removed. Lead content of un-
leaded and leaded gasoline for the on-
road and non-road engine lead emission
estimates was revised, and Alaska and
Hawaii nonutility point and area
source emissions from several sources
were added. Also, this report incorpo-
rates data from CEMs collected be-
tween 1994 and 1996 for NOx and S02
emissions at major electric utilities.
All of these changes are part of a
broad effort to update and improve
emissions estimates. Additional emis-
APPENDIX B: METHODOLOGY 151

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NATIONAL AIR QUALITY AND EMISSIONS TRENDS REPORT, 1996
sions estimates and a more detailed
description of the estimation methodol-
ogy are available in a companion re-
port, National Air Pollutant Emission
Trends, 1900-1996,6
References
1.	Clean Air Act Ammendments of 1990,
U.S. Code, volume 42, section 7403
(c)(2), 1990.
2.	Ambient Air Quality Surveillance, 44
CFR 27558, May 10, 1979.
3.	Aerometric Information Retrieval Sys-
tem (AIRS), Volume 2, U.S. Environ-
mental Protection Agency, Office of
Air Quality Planning and Standards,
Research Triangle Park, NC, October,
1993.
4.	Ambient Air Quality Surveillance, 51
FR 9597, March 19, 1986.
5.	U.S. Environmental Protection Agency
Intra-Agency Task Force Report on Air
Quality Indicators, EPA-450/4-81-015,
U.S. Environmental Protection Agen-
cy, Office of Air Quality Planning
and Standards, Research Triangle
Park, NC, February 1981.
6.	National Air Pollutant Emission Trends,
1900-1996, EPA-454/R-97-011, U.S.
Environmental Protection Agency,
Office of Air Quality Planning and
Standards, Research Triangle Park,
NC, December 1997.
¦ NAMS
°SLAMS
Other
Figure B-5. PM10 monitoring network, 1996.
o
•	NAMS
° SLAMS
*	Other
Figure B-6. Sulfur dioxide monitoring network, 1996.
152 APPENDIX B: METHODOLOGY

-------