# The Health and Related Economic Benefits of Attaining Healthful Air in the San Joaquin Valley

Jane V. Hall, Ph.D. Victor Brajer, Ph.D.

California State University Fullerton, CA

Frederick W. Lurmann

Sonoma Technology, Inc

. Petaluma, CA

March 2006

Research funded by the William and Flora Hewlett Foundation1 

### The Health and Related Economic Benefits of Attaining Healthful Air in the San Joaquin Valley

Acknowledgements and Disclaimer 2 Acronyms 3

I. Executive Summary 4

II. Introduction 7

II.1 Background 7

II.2 Objectives of this Study 7 II.3 Overview of Approach 7

III. Population Exposure to Ozone and P articulate M atter 9

III.1 The Exposure Ass essment Approach 9

III.2 Population 10

III.3 Current Ambient Air Quality 13

III.4 Future Ambient Air Quality 15

III.5 Current and Future Population Exposure Estimates 16

IV

. Adverse Ozone and PM

- Related Health Eff ects 51

I V .1 Studies Used in Quantification of Effects 51

I V .2 Estimates of Reduced Adverse Effects with Attainment of the Federal AQS 58

V

. Economic Valuation 64

V.1 The Basis for Value

V.2 Concepts and Measures of Value 64 V.3 Spec ific Values for Premature Death 64 V.4 Specific Values for Health Endpoints 67

V.5 Estimated Economic Value from Reduced Adverse Health Effects with

Attainment of the Federal A ir Q uality S tandards 71

V I. Conclusions and Implications 74

VI I. References 76

Appendix A.1 The Benefits of Attaining the California Air Quality Standards 82 A.2 Sensitivity Analysis by Endpoint 842 ACKNOWLEDGMENTS

The authors thank the William and Flora Hewlett Fou ndation for funding this research. We also thank The California Endowment for supporting dissemination of the results. For their contributions to the research, we thank Siana Alcorn and Brian Penfold of Sonoma Technology, Inc., and Cheryl Paul of the Cent ral Valley Health Policy Institute at California State University, Fresno. We also thank Danielle Deane and Carole Chamberlain for their encouragement and

support.

All statements and conclusions in this study are solely those of the authors.3 ACRONYMS

ARB California Air Resources Board

CAAQS California Ambient Air Quality Standards

COI Cost of illness

C

- R Concentration response function

EPA Environmental Protection Agency

FRM Federal Reference Method

MRAD Minor restricted activity da y

NAAQS National Ambient Air Quality Standards

ppb Parts per billion

ppm Parts per million

REHEX Regional Human Exposure Model

SAB

- HEES Science Advisory Board Health and Ecological Effects

Subcommittee

SJVAB San Joaquin Valley Air Basin

SYMVA L Symptom Valuation Model

VSL Value of a statistical life

WLD Work loss day

WTP Willingness to pay4 I. EXECUTIVE SUMMARY

Overview

Only the Los Angeles and Houston regions have air pollution levels that rival those in the San Joaquin Valley (SJV). H istorical and current air quality levels for ozone and fine particles (PM 2.5 ) in the San Joaquin Valley (SJV) are unhealthful. The air basin is classified by the U. S. Environmental Protection Agency (EPA) as a serious nonattainment area for both ozone a nd

PM 2.5

.

Both the federal government and California have set health

- based air quality standards

for ozone and fine particles because there is wide concurrence that these pollutants pose a serious risk to health. Adverse effects clearly associated with ozone range from school absen ces and hospitalizations to symptoms that limit normal daily activity . PM 2.5 exposure is tied to a range of effects from premature death and the onset of chronic bronchitis to work loss days and respiratory symptoms.

Betw een 1990 and 2004 ambient ozone levels in the San Joaquin Valley exceeded the

health

- based 8

- h our Nat ional Ambient Air Quality Standard (NAAQS) on from more than 80 to nearly 135 days a year. Ozone levels are typically elevated in the summer months, so th is suggests that air is unhealthful on most summer days. Not only is the NAAQS frequently violated, but between 2001 and 2004 the maximum 8

- h ou r concentration was 65% above the

standard. In much of California ozone levels have fallen steadily over a perio d of years, but this is not the case in the SJV, which is a concern.

While the region has achieved reductions in coarser particle ( PM 10 ) levels, concentrations of the more dangerous fine particles

- PM 2.5 - remain unhealthful. To meet the maximum 24

- h o u r standard levels must fall by more than 10%, and annual average concentrations must fall by nearly 30%. Attaining the California standard (CAAQS) requires a drop of 50%. These health

based standards will be very difficult to achieve in the SJV.

The p rimary objective of this study is to assess the health and related economic benefits

that will result from attainment of the ozone and PM 2.5 standards , to the extent that they can be quantified.

Results

Valley

- wide, the economic benefits of meeting the federal PM 2.5 and ozone standards average nearly $ 1,000 per person per year , or a total of more than $3 billion . This gain represents the following:

**•** 460 fewer premature deaths among those age 30 and older

**•** 325 fewer new cases of chronic bronchitis

**•** 188, 400 fewer days of reduced activity in adults

**•** 260 fewer hospital admissions

**•** 23,300 fewer asthma attacks5 **•** 188,000 fewer days of school absence

**•** 3,230 fewer cases of acute bronchitis in children

**•** 3,000 fewer work loss days

**•** More than 17,000 fewer days of respira tory symptoms in children

To place the reduction in premature deaths in perspective, attaining the federal PM 2.5 standard would be the equivalent of reducing motor vehicle deaths by over 60% Valley

- wide, and by more than 70% in Fresno and Kern Counties.

Research Approach

A well

- es tablished three

- stage approach i s used to determine the benefits of attaining the

ozone and PM 2.5 air quality standards by identifying and quantifying the links between air quality and exposure, exposure and ill health, and av oiding ill health and the associated

economic loss.

The Regional Human Exposure Model (REHEX) was developed to estimate a population’s exposure to concentrations above the air quality standards. This model accounts for the spatial and temporal pollution patterns across a region, which is important because pollution patterns vary significantly across a large area. Exposure for the population in the SJV i s estimated by 5X5 kilometer grids relative to pollution levels averaged from 2002

- 2004. Averaging is n ecessary to reduce the influence of weather anomalies that do not accurately represent longer term trends in air quality. REHEX generates estimates of exposure by county, by age, and by ethnic group as defined by the U.S. Bureau of the Census. These expo sure estimates are then coupled with concentration

- response functions from the health science literature to calculate how many fewer adverse health effects and premature deaths would be expected if the 2004 population instantaneously experienced attainment of the NAAQS.

Finally, economic values a re applied to the avoided health effects and extended lives to

estimate in dollar terms the social value of more healthful air. These values are based on the cost of treating illness and the expressed value that p eople place on avoiding illness and premature

death.

Implications

Residents of the San Joaquin Valley face significant public health risks from the present unhealthful levels of ozone and fine particles. This is in addition to other he alth challenges, including a high rate of poverty, which exceeds 30% in Fresno County, compared to a statewide

rate below 20%. The region overall would experience substantial economic and health gains from effective policies to reduce pollution levels. For the more popu lous and more polluted areas in Kern and Fresno Counties, this is even more pronounced. Attaining the California air quality stand ards , which are more protective of health, would double the benefits listed above.

The adverse impacts of air pollution are not distributed equally. Both Hispanics and non

Hispanic blacks are exposed to more days when the health

- based standards are violated.6 Residents of Fresno and Kern Counties experience many more days than the Valley

- wide

average.

Because ozone is eleva ted during the summer months, and the PM 2.5 24

- hr standard is typically violated more frequently in the winter months, there is no “clean” season in this region.

As the population continues to increase, with associated increases in vehicle traffic and

e conomic activity, the gains from attaining the health

- based air quality standards will grow, but

also become more difficult to achieve. Identifying and acting on opportunities now would produce substantial gains to the people of the Valley

.7 II. I NTRODU CTION

II.1 Background

Only the Los Angeles and Houston regions have air pollution levels that rival those in the San Joaquin Valley (SJV). Historical and current air quality levels for ozone and fine particles (PM 2.5 ) in the SJV are unhealthful. The ai r basin is classified by the U. S. Environmental Protection Agency (EPA) as a serious nonattainment area for both ozone and PM 2.5

.

Both the federal government and California have set health

- based air quality standards for ozone and fine particles (PM 2.5 ) because there is wide concurrence that these pollutants pose a serious risk to health. Adverse effects clearly associated with ozone range from school absences and hospitalizations to symptoms that limit normal daily activity. PM 2.5 exposure is

tied to a range of effects from premature death and the onset of chronic bronchitis to work loss days and respiratory symptoms.

Between 1990 and 2004 ambient ozone levels in the San Joaquin Valley exceeded the

health

- based 8

- hour National Ambient Air Quality Standard (NAAQS) on from more than 80 to nearly 135 days a year. Ozone levels are typically elevated in the summer months, so this suggests that air is unhealthful on most summer days. Not only is the NAAQS frequently violated, but between 2001 and 2004 the maximum 8

- hour concentration was 65% above the standard. In much of California ozone levels have fallen steadily over a period of years, but this is not the case in the SJV, which is a concern.

While the region has achieved reductions in coarser part icle ( PM 10 ) levels, concentrations of the more dangerous fine particles

- PM 2.5 - remain unhealthful. To meet the maximum 24

- hour standard levels must fall by more than 10%, and annual average concentrations must fall by nearly 30%. Attaining the Calif ornia standard (CAAQS) requires a drop of 50%. These health

based standards will be very difficult to achieve in the SJV.

II.2 Objectives of this Study

The primary objective of this study is to assess the health and related economic benefits

that will result from attainment of the ozone and PM 2.5 standards, to the extent that they can be quantified with present knowledge. The gains from attaining both the federal and state standards are estimated, although it is generally recognized that attaining the state standards will be especially difficult in some parts of the SJV 1

.

II. 3 Overview of the Research Approach

A well

- established three

- stage approach i s used to determine the benefits of attaining the

ozone and PM 2.5 air quality standards by identif ying and quantifying the links between air quality and exposure, exposure and ill health, and avoiding ill health and the associated

economic loss.

1 Because attainment of the NAAQS is therefore the more policy

- relevant outcome over the next decade, the

California results a re included in the Appendix while the Federal results are discussed in the body of this report.8 The Regional Human Exposure Model (REHEX) was initially developed in 1989 to estimate a population’s expo sure to concentrations above the air quality standards. This model accounts for the spatial and temporal pollution patterns across a region, which is important because pollution patterns vary significantly across a large area. Here, exposure for the popul ation in the SJV i s estimated by 5X5 kilometer grids relative to pollution levels averaged

from 2002

- 2004. Averaging is necessary to reduce the influence of weather anomalies that do not accurately represent longer term trends in air quality. REHEX genera tes estimates of exposure by county, by age, and by ethnic group as defined by the U.S. Bureau of the Census. These exposure estimates are then coupled with concentration

- response functions from the health science literature to calculate how many fewer ad verse health effects and premature deaths would be expected if the 2004 population instantaneously experienced attainment of the NAAQS and the CAAQS.

Finally, economic values are applied to the avoided health effects and extended lives to

estimate in dol lar terms the social value of more healthful air. Specific values are derived from the economics literature and have all undergone peer

- review, both as part of that literature and as part of scientific and technical assessments of which values are most app ropriate for valuing health in relation to air pollution exposure.9 III. POPULATION EXPOSURE TO OZONE AND PARTICU LATE MATTER

III.1 The Exposure Assessment Approach

Accurate estimates of human exposure to inhaled air pollutants are necessary for appraisal of t he health risks these pollutants pose and for the design and implementation of strategies to control and limit those risks. Most exposure estimates are based on measured concentrations of outdoor (ambient) air concentrations obtained at fixed

- site air mon itoring stations. Ambient concentrations are used as surrogates for personal exposure. Personal exposure to air pollutants depends not only on ambient concentrations in locations or microenvironments (home, work, schools, vehicles, etc.) where individual s spend time, but also on the amount of time individuals spend in the microenvironments and on the concentrations in the microenvironments. Microenvironment concentrations are affected not only by infiltration of outdoor air, but also by indoor sources an d indoor pollutant deposition. Outdoor concentrations vary spatially and temporally and are affected by proximity to local outdoor sources, which may result in concentrations that deviate significantly from ambient concentrations at the nearest air

monito ring stations.

Despite the recognized discrepancies between personal exposure and exposures based on

ambient concentrations obtained from fixed

- site air monitoring stations, compliance with the National Ambient Air Quality Standards (NAAQS) depends exclu sively on outdoor measurements of pollutants. The NAAQS are intended to protect public health with an adequate margin of safety. Most epidemiologic studies of air pollution health effects use ambient concentrations as surrogates for actual population exp osures. In fact, virtually all concentration

response relationships from large population studies use ambient concentrations as the exposure input parameter. Several studies have argued that air pollution exposure should be separated into

ambient and non

- ambient components for health effects research because even though ambient concentrations are not highly correlated with personal exposures to non

- ambient concentrations or total concentrations, they are highly correlated with ambient

- generated concentrat ions (Wilson et al. 2000; Ebelt et al. 2003) . Therefore, ambient concentrations may be used in e pidemiologic studies as appropriate surrogates for exposure to ambient

- generated concentrations.

The exposure assessment approach for this study is constrained to rely on ambient concentrations not only because the ambient air quality database is the only database with sufficient spatial and temporal coverage to address the San Joaquin Valley Air Basin (SJVAB) population, but also because this study requires quantification of the benefits of attainment of the

ambient

- based NAAQS and must rely on the ambien t

- based concentration

- response relationships from the health science literature to quantify those benefits. The approach is also guided by the concern for spatial resolution of both the population and ambient concentrations.

The population exposure asse ssment approach used for this study involves representing the population and ambient concentrations on a spatial grid covering the SJVAB. Each grid square is 5 km x 5 km in size. Five

- kilometer resolution is sufficient to capture the urban

- and regional

- scale spatial gradients in between air quality monitoring stations, which are located from 10 to 50 km apart in the SJVAB. This resolution is insufficient to capture intra

- urban spatial variations associated with close proximity to major roadways or stati onary emission sources. Spatially and temporally resolved air quality and population data are used in the10 Regional Human Exposure (REHEX) model (Lurmann et al. 1989; Lurmann et al. 1994; Fruin et al. 2001) to quantify the frequency of population exposure to various levels of ambient ozone and particulate matter concentrations over multi

- year periods.

III.2 Population

We developed gridded popula tion data for use in the exposure assessment for eight age groups: < 1 year, 1 year, 2

- 4 years, 5

- 17 years, 18

- 21 years, 22

- 29 years, 30

- 64 years, and > 64 years, and four racial groups: white non

- Hispanic, black non

- Hispanic, other non

- Hispanic, and Hispa nic. The age groups were defined by the concentration

- response relationships chosen for

use in the benefits evaluation. Racial groups were defined by the U.S. Census. Not all the population data breakdowns by age and race were available at fine resolutio n in the 2000 U.S. Census database. County, census tract, and block

- group levels of population data were used in determining the disaggregated block

- group population data. County

- level age distribution data

were used to estimate the block

- group populatio n of children ages < 1, 1, and 2

- 4 years by racial group. Census

- tract level data were used to estimate the block

- group population of other age groups for black non

- Hispanic and other non

- Hispanic groups. Block

- group data were used directly for the other age groups for white non

- Hispanics and Hispanics. The block

- group population data for each age

- racial group were spatially allocated to 5 km x 5 km grid squares assuming uniform population density within each block group. The spatial allocation was perf ormed with STI’s GIS tools (ESRI ARCGIS Version 9.0). Grids on the boundaries between counties were assigned to the county with the most surface area within the grid.

The modeling grid and gridded 2000 total population data are shown in Figure III

- 1.

The se data show that high population densities (> 1,200 km - 2 ) occur in the major cities, such as Lodi, Stockton, Modesto, Turlock, Fresno, Visalia, and Bakersfield, as expected. A total of 1,708 grids located within the SJVAB were used for assessing exposure . Grid squares with extremely low population density (below 1 person per km - 2 or 25 persons per grid) were not included; they were large in number of grids but accounted for less than 1% of the total population in the aggregate.

The baseline period selec ted for exposure assessment was 2002 through 2004 (see

S ection III.3). Population data for 2000 were projected to 2004 to be consistent with the baseline period for air quality data. County

- specific growth rates based on the growth from 1990 to 2000 (as reported in the U.S. Census (www.censuscope.org ) ) were used to scale up the 2000 data to represent the 2004 population. Within each county, the population of all age and racial groups was scaled uniformly. The 2004 populations were estimated as 6.6, 7.8, 6.9, 14.3, 7.5, 10.2, 6.8, and 8.2% higher than the 2000 populations for San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare, and Kern Counties, respectively. The estimated total population in the region is 3.34 million persons in 2004. As sh own in Table III

- 1, about 25% of the residents live in Fresno County and another 35% lived in San Joaquin and Kern Counties. Adults, ages 30 to 64 years, are the largest age group (41%), followed by children ages 5 to 17 (23.5%). Likewise, as shown

in Ta ble III

- 2, whites and Hispanics are the largest racial/ethnic groups.

The SJVAB is experiencing high population growth; however, we have not included the likely population growth beyond 2004 in our estimates of the benefits of attaining air quality

standar ds in the future. This approach is conservative in that it results in underestimation of the11 likely benefits and avoids having to specify when the region will actually reach its air quality goals. Because the population is growing at about 2% per year, t he benefits are likely to be 16% to 20% greater than estimated if attainment is achieved in 8 to 10 years.

Estimates of the population of children attending school were also needed to determine the benefits of reduced school absences associated with air qu ality improvements. Public school

enrollment and schedules for the 2005

- 2006 school year were obtained from SJVAB school districts. They indicated that 83.5% and 16.5% of public school children attended schools on traditional and year

- round schedules, re spectively. The majority of traditional school schedules extended for 91⁄2 months, from mid

- August through May. Additional attendance data indicated that 4% of children, ages 5

- 17 years, attended private schools. We did not have private school

schedules o r information on summer school attendance for public or private schools. Because private school attendance was low, no distinction was made between the schedules of public and private school students. Ten percent of traditional

- schedule school children w ere assumed to attend summer school, which is a low estimate based on our analysis of data for Southern

California (Hall et al. 2003) . The population of children, ages 5

- 17 years, attending school in the

non

- summer period (mid

- August through May) was esti mated at 96.6% based on the sum of children in schools with traditional schedules (83.5%) and year

- round schedules (91⁄2 /12 x 16.5%=13.1%). The population of children, ages 5

- 17 years, attending school in the summer period (June through mid

- August) was est imated at 21.4% based on the sum of children in schools with year

- round schedules (13.1%) and children with traditional school schedules who were attending summer school (8.3%).12 Table III

- 1. 2004 SJVAB population by county and age group.

Region <1

Year 1 Year 2

- 4

Years 5

- 17

Years 18

- 21

Years 22

- 29

Years 30

- 64

Years >64

Years All Ages

San Joaquin County 8,531 8,711 27,796 130,408 35,154 59,283 242,360 61,762 574,005

Stanislaus County 6,888 7,174 22,569 107,166 27,466 49,096 196,460 49,545 466,364

Merce d County 3,695 3,766 12,084 56,898 13,956 23,726 87,393 21,109 222,627

Madera County 2,213 2,368 7,458 34,300 8,902 16,663 69,805 17,348 159,057

Fresno County 13,284 13,433 41,667 191,295 54,309 94,551 322,881 81,231 812,651

Kings County 2,136 2,155 6,5 25 28,336 8,921 19,533 59,417 10,211 137,234

Tulare County 6,706 6,538 20,750 95,226 24,841 42,301 150,254 37,576 384,192

Kern County 9,979 10,045 30,830 140,112 36,682 68,071 238,230 50,337 584,286

A ir Basin (Persons) 53,432 54,190 169,679 783,741 210, 231 373,224 1,366,800 329,119 3,340,416

Air Basin (Percent) 1.6% 1.6% 5.1% 23.5% 6.3% 11.2% 40.9% 9.9% 100%

Table III

- 2. 2004 SJVAB population by county and racial/ethnic groups.

Region White a Black a Hispanic Other a Total (Persons) Total (Percent)

San Joaquin County 279,855 38,694 182,293 73,163 574,005 17.2%

Stanislaus County 277,637 11,506 151,213 26,008 466,364 14%

Merced County 93,073 8,264 104,208 17,082 222,627 6.7%

Madera County 80,534 6,125 66,249 6,148 159,057 4.8%

Fresno County 324,342 42, 887 370,591 74,831 812,651 24.3%

Kings County 58,828 10,991 61,403 6,012 137,234 4.1%

Tulare County 163,320 5,459 199,331 16,082 384,192 11.5%

Kern County 265,643 35,044 256,831 26,769 584,286 17.5%

A ir Basin (persons) 1,543,201 158,968 1,392,180 246,0 66 3,340,416 100%

Air Basin (percent) 46.2% 4.8 % 41.7% 7.4 % 100%

a Non

- Hispanic whites, blacks and other

.13 III.3 Current Ambient Air Quality

III.3.1 Current Conditions Relative to the Air Quality Standards

Historical and current ambient air quality condi tions for ozone and particulate matter in

the SJVAB are unhealthful. Concentrations exceed the health

- based NAAQS and the more stringent California Ambient Air Quality Standards (CAAQS). The SJVAB is classified as a serious nonattainment area by the U.S. Environmental Protection Agency (EPA) for ozone and

PM 2.5 . The most relevant NAAQS for ozone is the 8

- hour daily maximum standard of 0.08 parts per million (ppm) or 80 parts per billion (ppb). It has essentially replaced the 1

- hour daily

maximum ozone s tandard of 0.12 ppm, which is less stringent 2

The frequency and severity of exceedances of the 8

- hour daily maximum ozone standard are illustrated in Figures III

- 2 and III

- 3. The SJVAB measurement data show that the ambient concentrations exceeded the level of the standard on 82 to 134 days per year between 1990 and 2004. This high frequency indicates that most days during the summe r were ozone exceedance days. Unlike other parts of California, the frequency of exceedances is not declining with time in the SJVAB, which is a concern for residents and government agencies. During the 2001

- 2004 time period, the maximum 8

- hour concentra tion was 132 ppb or 65% above the level of the standard. The highest 8

- hour concentrations occur most frequently southeast of Bakersfield at the Arvin air monitoring station. Similarly high concentrations can occur downwind of Fresno.

The 8

- hour NAAQS i s achieved when the three

- year average of the annual fourth

- highest

concentration is below the level of the standard. The three

- year average of the annual fourth

highest concentration was 116 ppb for 2002

- 2004 and 113 ppb for 2003

- 2005. This value is

ref erred to as the ozone design value for the baseline period. We chose to use 2002

- 2004 for our baseline period because we wanted to use the same period for ozone and PM 2.5 , and annual PM 2.5 data for 2005 were not available when we initiated this study. Th us, attainment of the 8

- hour NAAQS is expected when the annual fourth

- highest concentration is reduced from 116 ppb to 84.99 ppb. Note, 84.99 ppb is used instead of 80 ppb because of agency guidance on rounding concentrations for compliance with the “0.08 ppm” standard. Attainment of the ozone standard requires a 27% decrease in the design value. However, because there is a global background concentration of about 40 ppb, the required reduction in ozone in excess of the background level

is 41% to reach a ttainment. in the SJVAB. Federal standards

exist for maximum 24

- hour average and annual average PM 2.5 and PM 10 . The 65 μg/m 3 24

- hour

PM 2.5 standard and 15 μg/m 3 annual PM 2.5 standard are generally more stringent than th e 150 μg/m 3 24

- hour PM 10 standard and 50 μg/m 3 annual PM 10 standard. The SJVAB will reach federal attainment when the more stringent federal standards are reached. Thus, this study

focuses on the 8

- hour ozone standard and the 24

- hour and annual average P M 2.5 standards. Compliance with the California standards (a 70 ppb 8

- hour daily maximum ozone and a 12 μg/m 3 annual average PM 2.5 standard) is addressed in the appendix.

Even though the region achieved compliance with the PM 10 NAAQS in the 2003

- 2005 time period, PM 2.5 air quality conditions remain unhealthful. Figure III

- 4 shows the 98 th
percentile 24

- hour average and the annual average PM 2.5 concentration in 2002

- 2004 at key

2 Here, stringent means more limiting in terms of the difficulty of attainment.14 monitoring stations. The highest 24

- hour average PM 2.5 concentration in 2002 was 91 μg/m 3 at Corcoran, which is 40% above the level of the standard. The highest annual average concentration in 2002 was 24 μg/m 3 in Bakersfield at the Gol den State Highway air monitoring station, where the 24

- hour maximum was also high (85 μg/m 3 ). High PM 2.5 concentrations were also observed in the middle portion of the SJVAB as indicated by the data for Fresno, Visalia,

and Corcoran. High 24

- hour concent rations tend to occur in the fall and winter in this area. Like the ozone standard, the PM 2.5 standards are based on three

- year periods. The annual PM 2.5 NAAQS is achieved when the three

- year averaged annual mean PM 2.5 concentration is less than or equal to 15 μg/m 3 . The 24

- hour PM 2.5 standard is achieved when the three

- year average of the

annual 98 th percentile values at each PM 2.5 monitoring site is less than or equal to 65 μg/m 3 . The

PM 2.5 design values are 20.6 and 73.2 μg/m 3 for the annual average and 24

- hour standards, respectively. The design values are based on data from Bakersfield for the 2002

- 2004 baseline period. It should be noted that EPA’s PM 2.5 attainment document suggests a lower 24

- hour design value for this area, but we believe that 73.2 μg/m 3 is the correct value because it is based on the exact same data that were used to determine the 20.6 μg/m 3 annual average (also cited by EPA). The current design values indicate that maximum 24

- hour and annual averages need to decrease by 11% a nd 27% to achieve compliance with the federal standards. The San Joaquin Valley Air Pollution Control Agency is charged with developing an air quality management plan by 2008 that will result in attainment of the PM 2.5 NAAQS by 2013.

California has an ann ual average PM 2.5 standard of 12 μg/m 3 , never to be exceeded. Compliance with this standard would require the 2002 annual concentration of 24 μg/m 3 in Bakersfield be reduced by 50%. This health

- based standard will be very difficult to achieve in

the SJVA B.

III.3.2 Spatial Mapping

Ambient air quality data from California’s network of monitoring stations were used to spatially map concentrations to the exposure grids. Measured concentration data were spatially interpolated and extrapolated to provide est imates of concentrations at each grid shown in Figure III

- 1. The locations of air monitoring stations on the exposure grid are shown in Figure III

- 5. For the 2002

- 2004 baseline period, hourly ozone data were available for 27 stations

within the SJVAB and daily PM 2.5 data were available once every three days for 14 stations

within the SJVAB. Ozone and PM 2.5 data from stations within the grid and within 150 km of the grid boundaries were incorporated in the air quality database used for mapping. The ozone data were used to create maps of hourly concentrations for each day of the baseline period (1,096 days and 26,304 maps). Daily PM 2.5 data collected using the Federal Reference Method (FRM) were available on an every

- day basis at several sites and on an e very

- third

- day sampling schedule at many more sites. Spatial mapping was not feasible using data only from sites with

every

- day sampling. The spatial mapping of daily PM 2.5 concentrations was performed using the FRM data on days when the every

- third

- day data were available in addition to the every

- day data (~116 days per year). Annual average PM 2.5 concentrations were calculated from the FRM data using EPA’s methodology (i.e., annual average = average of quarterly averages) and mapped for each year.15 Th e spatial mapping method assigns exposure grid concentrations from the nearest station if the station is located within 3 km of the center of the exposure grid. If no stations with valid data are located with 3 km of the center of the exposure grid, the c oncentration is calculated by inverse

- distance squared weighting of the concentrations from the four stations closest to the center of the exposure grid, provided all stations are located within 100 km of the exposure grid center. In areas with sparse net work coverage, the algorithm may be applied with fewer than four stations (i.e., one to three stations). This method is very similar to the method used by EPA on its AIRNow web site ( www.epa.gov/airnow ) for mappi ng air quality indices. Examples of the maps created with this method are shown in Figure III

- 6. They show the spatially mapped annual average PM 2.5 concentrations for 2002, 2003, and 2004. The annual PM 2.5 concentrations are estimated to vary smoothly across the region, with higher concentrations in the southern regions and in the urban areas. The maps of daily PM 2.5 and hourly ozone maps often have more spatial variability than these examples because they reflect the day

- to

- day variations in

meteorolo gical conditions that greatly influence the spatial patterns. The ozone maps also reflect the greater spatial coverage of monitoring station data for ozone than for PM 2.5

.

III.4 Future Ambient Air Quality

For purposes of this exposure analysis, we are int erested in the spatial and temporal

distribution of ambient concentrations for a three

- year period in which the air quality standard is attained. Attainment of the standard means that the design value is reduced to the level of the

standard. Two methods are available to estimate future

- year air quality conditions. One method involved the application of detailed meteorological, emissions, and air quality models to estimate the distributions of future concentrations under specific emission scenarios. Such models are used to develop emission control strategies to reach attainment in the air quality plans. Typically, the detailed models are applied for relatively short periods (less than two weeks per episode) rather than multi

- year periods. The resources (time and budget) required to apply this

method for a three

- year period in the SJVAB are far greater than available for this study; hence, this method is not feasible for the present study.

The second method involves the application of the simple linear rollback model shown

below.



# ( **) **  ** **  ** **  ** **  ****

**− −** 

**− +**  **=**

Bkgrd Max Bkgrd Std
Bkgrd Base

xyt Bkgrd Future

xyt C C C C C C C C if Bkgrd Base

xyt C C **≥** (1)

Base

xyt Future

xyt C C **=** if Bkgrd Base

xyt C C **<** (2)

where Future

xyt C = the future concentration at location x,y , and time t

,

Base

xyt C = the baseline period concentration at location x,y , and time t

, C

Bkgrd = the background concentration,

C

Max = the design value concentration, and

C

Std = the air quality standard threshold concentration.16 This method assumes that future changes in concentrations in excess of the background concentration will linearly track changes in the current or baseline maximum concentration (minus the background concen tration). It assumes that concentrations in excess of the background concentration with attainment will be linearly reduced in proportion to the ratio of the standard (adjusted for background) to the design value (also adjusted for background).

Concentra tions at or below the background level are assumed to be unaffected by changes in emissions. The rollback model is a very simple air quality model that ignores much of the detailed knowledge of the atmospheric chemistry and physics that influence concentr ations, yet it is probably the most suitable model when the specific emission control measures needed to reach attainment in a region are not yet identified. The reason is that attainment can be achieved with different sets of control measures that will p roduce different spatial and temporal patterns of concentrations; and without knowledge of the specific path to attainment in the SJVAB, it is best to keep the projection method as simple as possible.

The parameters used to project the distributions of c oncentrations with attainment are

shown in Table III

- 3. They project that future ozone levels in excess of the background would be 59% of current levels. Similarly, the future 24

- hour and annual PM 2.5 concentrations in excess of the background are estima ted as 89% and 65% of current levels. These factors are applied to the spatially mapped baseline

- period concentrations to generate the future

- year spatial maps of concentrations for the same time period (three years).

Table III

- 3. Parameters used to e stimate ambient ozone and PM 2.5 concentrations with

attainment.

Pollutant/Parameter Design Value Attainment

Level Background

Concentration

Ozone 8

- hour daily Maximum NAAQS 116.7 ppb 84.99 ppb 40 ppb

Ozone 8

- hour daily Maximum CAAQS 132.5 ppb 74.99 ppb 4 0 ppb

PM 2.5 24

- hour Average NAAQS 73.2 μg/m 3 65.49 μg/m 3 6 μg/m 3

PM 2.5 Annual Average NAAQS 20.6 μg/m 3 15.49 μg/m 3 6 μg/m 3

PM 2.5 Annual Average CAAQS 24.1 μg/m 3 12.49 μg/m 3 6 μg/m 3

III.5 Current and Future Population Exposure Estimates

The REHEX mode l was applied using population and air quality data for the SJVAB to estimate the population exposure to ozone and PM 2.5 in the baseline period and the future with attainment. The population exposure to air pollution was quantified not only in terms of th e exposure metrics relevant to the air quality standards, but also in terms of the exposure metrics

used in the concentration

- response relationships reported in the health science literature. The exposure metrics for ozone include the 1

- hour daily maximum , the 2

- week average 1

- hour daily maximum, the 5

- hour daily maximum, the 8

- hour daily maximum, and the 24

- hour average

concentrations. Certain concentration

- response relationships use 8

- hour 10 a.m. to 6 p.m. ozone

rather than 8

- hour daily maximum ozone; the two metrics are almost indistinguishable in the17 SJVAB. The exposure metrics for PM 2.5 include the 24

- hour average concentration and the annual average concentrations.

Most of the concentration

- response relationships used in this study apply to all d ays of the year. The school

- absence concentration

- response relationship applies to exposures on the day preceding the school absence. For this analysis, exposures occurring on Fridays and Saturdays were excluded as well as the day preceding each holiday.

III.5.1 Exposure Frequency Distributions

The overall frequency distributions of daily exposure for the SJVAB population are shown in Figures III

- 7 through III

- 12. The total number of person

- days of exposure is large for this region and time period, 1.2 billion per year (3.34 million x 365 days), so the distributions are presented on a logarithmic scale. The figures show the number of person

- days of exposures per year to concentrations above various concentration thresholds. They illustrate a four to fi ve order of magnitude difference between the person

- days of exposure to the highest levels observed in the SJVAB and the person

- days of exposure to levels above the background concentrations. Figure III

- 13 shows the estimated number of persons exposed to annual average

PM 2.5 concentrations above various concentration thresholds in the SJVAB. The daily and annual distributions show large differences in the frequency of exposure between the baseline and NAAQS attainment scenario.

III.5.2 Spatial Distribut ions of Exposure

The estimated spatial distribution of exposure to ozone concentrations above 100, 85, and 70 ppb are shown in Figure III

- 14 through III

- 16. They show that the highest number of person

days of exposure occur in and around Bakersfield, Fres no, Visalia, Merced, and Turlock in the

2002

- 2004 period. The size of the region with more than 300,000 person

- days of exposure per year per grid greatly increases as the exposure concentration threshold increases from 70 to

85 ppb and from 85 to 100 ppb. The maps also show a dramatic decrease in estimated exposures above 85 ppb under the 8

- hour ozone NAAQS attainment scenario. No exposures above 85 ppb

are estimated for most o f the SJVAB with attainment; only residents in and around Fresno, and

downwind of Bakersfield are estimated to have about one day of exposure per year above the statistically based 8

- hour NAAQS threshold of 85 ppb with attainment.

Maps of the estimated population exposure to 24

- hour average PM 2.5 concentrations above 65 and 40 μg/m 3 are shown in Figures III

- 17 and III

- 18. The 40 μg/m 3 threshold is used here because it is the daily PM 2.5 threshold for sensitive groups. The maps show that the number of exposures above 40 and 65 μg/m 3 in Bakersfield, Fresno, Visalia, and Modesto are h igher than elsewhere. Residents in these urban areas are estimated to have one or two days per year of exposure to PM 2.5 concentrations above 65 μg/m 3 with attainment of the 24

- hour NAAQS.

The spatial distributions of population exposures to annual aver age PM 2.5 concentrations above 18, 15, and 12 μg/m 3 are shown in Figure III

- 19 through III

- 21, respectively. The number of residents estimated to be exposed to annual average PM 2.5 concentrations above 15 μg/m 3 is greater in Fresno, Visalia, and Bakersfie ld than elsewhere in the SJVAB. With attainment of the NAAQS, the area with residents exposed to concentrations above 15 μg/m 3 shrinks substantially18 from that in the baseline period. However, the number of exposures and size of areas where

residents are exposed to concentrations above 12 μg/m 3

— a level considered more protective of public health than 15 μg/m 3

— are quite similar in the baseline and NAAQS attainment cases.

III.5.3 Exposure Frequency by County, Age Group, and Racial/Ethnic Group

III.5.3.1 8

- hour Daily Maximum Ozone Exposures

The estimated number of exposures to 8

- hour daily maximum ozone concentrations above 70, 85, and 100 ppb are listed in Table III

- 4 for the individual counties and for the whole

air basin. The REHEX model estimates 10 mil lion, 69 million, and 235 million person

- days of exposures per year to 8

- hour concentrations above 100, 85, and 70 ppb, respectively, in the air basin in the baseline period. With NAAQS attainment, the estimated person

- days of exposures per year above 85 ppb decrease from 69 million to 293 thousand in the air basin. The estimated exposures above 70 ppb decrease from 235 million to 34 million with attainment. Zero exposures to 8

- hour ozone above 100 ppb are estimated with NAAQS attainment. The highest

nu mber of exposures to ozone above 85 ppb is estimated to occur in Fresno County where there are 25 million person

- days in the baseline period and 211 thousand person

- days with attainment. These changes represent large reductions in unhealthful ozone exposu res.

When these results are normalized by the population, they indicate the average number of days per year that residents are exposed to ambient concentrations above various thresholds.

Table III

- 5 shows that the number of days per year above 100, 85, and 70 ppb 8

- hour daily maximum ozone is estimated as 3, 21, and 70 days for the entire air basin population in 2002

- 2004. In Kern and Fresno Counties, residents are estimated to be exposed to more than 85 ppb

8

- hour daily maximum ozone concentrations on 31 and 34 days per year on average, respectively. In contrast, residents of San Joaquin and Stanislaus Counties are estimated to be exposed to more than 85 ppb 8

- hour ozone on 0 and 5 days per year, respectively, in the baseline period. The average numbe r of days per year with population exposure to 8

- hour ozone above 70 ppb in the baseline period is 10, 29, 67, 81, 94, 79, 100, and 106 days in San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare, and Kern Counties, respectively, and 70 in

the a ir basin, on average. With NAAQS attainment, the average number of days of population exposure above 85 and 70 ppb is estimated to be less than 1 and 10 days, respectively, for the air basin population.

Table III

- 6 and III

- 7 show the number of person

- days and days of exposure to the 8

- hour ozone concentration thresholds by age group. Because the age distributions are fairly similar across the region, the estimated number of days above 70 and 85 ppb is similar for the different age groups. Even without co nsideration of human time activity, the model results indicate children are exposed slightly more frequently than adults over age 30 in the SJVAB. For example, children under age 5 are exposed to ozone above 70 ppb on 72 days per year compared to 68 days per year for adults over age 64.

Table III

- 8 and III

- 9 show the number of person

- days and days of exposure to the 8

- hour ozone concentration thresholds by racial/ethnic group. The results show that Hispanics are exposed more frequently than other racial g roups to 8

- hour ozone levels above 70 and 85 ppb.19 For example, the estimated number of days above 85 ppb is 18, 19, 20, and 23 days per year for other races, blacks, whites, and Hispanics, respectively, in the air basin. Spatial differences in the popula tion racial/ethnic makeup for different counties and within counties are responsible the differences in exposure frequencies. Figure III

- 22 and III

- 23 illustrate the differences in estimated frequency of exposures by ethnic/racial group within the air bas in and by ethnic/racial group within each county. They show that the ranking of exposure frequencies by ethnic/racial group varies considerably by county. For example, in Merced and Madera Counties, black and

other non

- white racial groups have slightly h igher exposure frequencies than whites and Hispanics.

III.5.3.2 One

- hour, 5

- hour, and 24

- hour Ozone Exposures

Population exposure to ozone was also estimated for 1

- hour and 5

- hour daily maxima and

24

- hour average for use in the health benefits evaluation. Tables III

- 10 through III

- 13 summarize the exposure results for these metrics. The number of person

- days of exposure to

5

- hour daily maximum ozone concentrations above 90 and 100 ppb was 71 million and

23 million in the baseline period for the SJVAB. W ith NAAQS attainment, the estimated number of person

- days of exposure drops to 320 thousand and zero above 90 and 100 ppb, respectively. The number of person

- days of exposure to 1

- hour daily maximum concentrations above 100 and 120 ppb was 46 million and 6 million, respectively, in the baseline period and 250 thousand and zero with attainment, respectively. Results are also presented in Table III

- 12 for exposure to the 2

- week average 1

- hour daily maximum concentrations, which are similar to the

exposure r esults for the 5

- hour daily maximum concentrations. The results suggest residents of Fresno County have the highest number of person

- days of exposure to high 1

- hour and 5

- hour daily maximum concentrations in the SJVAB, which is consistent with the results for high 8

- hour daily maximum concentrations.

Many of the concentration

- response relationships rely on the 24

- hour average ozone values which are substantially lower than the 1

- hour and 8

- hour daily maxima, and do not receive much attention because they a re not the focus of the air quality standards. In the SJVAB, there are an estimated 97 million person

- days of exposure per year to 24

- hour average ozone concentrations above 50 ppb. There are also 17 million and 1.7 million person

- days of exposure

to 24

- hour average ozone concentrations above 60 and 70 ppb, respectively, in the 2002

- 2004 baseline period. With attainment, 19 million, 650 thousand, and zero person

- days of exposure to

24

- hour average ozone concentrations above 50, 60, and 70 ppb are estimat ed to occur in the air basin annually. Residents of Kern, Tulare, and Fresno Counties are estimated to have about the same number (4 million) of persons

- days of exposure to 24

- hour ozone above 60 ppb in the baseline period. With attainment, residents of Kern and Tulare Counties are estimated to have 387 thousand and 198 thousand person

- days above 60 ppb compared to 15 thousand person

- days for residents of Fresno County. The relative importance of 24

- hour exposures appears higher in the southern portion o f the SJVAB.

The results for alternate ozone exposure metrics suggest attainment of the NAAQS is likely to produce major reductions in all ozone metrics relevant to protection of public health, not just the 8

- hour daily maximum exposures which are the fo cus of the standard. Because the relationships between the metrics vary between counties and between the urban

- core, suburban,20 and rural areas within counties, the relative benefits of attainment are likely to vary with the metric selected for a particula r evaluation.

III.5.3.3 24

- hour Average PM 2.5 Exposures

The estimated number of exposures of the SJVAB population to 24

- hour average PM 2.5 concentrations above 40 and 65 μg/m 3 are shown in Tables III

- 14 through III

- 18. The results for the baseline period indicate about 88 million and 8.7 million person

- days of exposure to concentrations above 40 and 65 μg/m 3 occur annually in the SJVAB. The majority of the exposures occur in Fresno and Kern Counties. The average number of days of exposure to

concentrati ons above 40 μg/m 3 is 32 and 39 days per year in Fresno and Kern Counties, respectively, compared to 26 days per year on average in the SJVAB in 2002

- 2004. The estimated average number of days of exposure above the 65 μg/m 3 level of the NAAQS ranges

from zero in San Joaquin County to 4 per year in Fresno and Kern Counties.

With attainment of the 24

- hour NAAQS, which is much less stringent than the annual NAAQS, SJVAB population exposure to 24

- hour average PM 2.5 concentrations above 40 and

65 μg/m 3 is estim ated to be 61 million and 3.2 million person

- days per year above 40 and

65 μg/m 3 , respectively. This represents a 63% decrease in person

- days of exposure above the

level of the standard on average. On a county basis, the model estimates 36%, 38%, 73%, 86 %, 93%, 97%, 100%, and 100% fewer person

- days of PM 2.5 exposure above 65 μg/m 3 will occur

with attainment of the 24

- hour NAAQS in Kern, Stanislaus, Fresno, Tulare, Kings, San Joaquin, Merced, and Madera C ounties , respectively. On average, residents of Ker n and Stanislaus Counties are likely to experience two days per year with 24

- hour average PM 2.5 concentrations above 65 μg/m 3 after attainment of the 24

- hour NAAQS.

Table III

- 17 and III

- 18, and Figures III

- 24 and III

- 25 show the results for estimated daily

PM 2.5 exposures by racial/ethnic group. They suggest that blacks and Hispanics have slightly more frequent exposure to elevated PM 2.5 concentrations than whites and other races in the SJVAB. The largest difference in racial/ethnic group PM 2.5 exposure f requencies occurs in Madera County.

III.5.3.4 Annual Average PM 2.5 Exposures

The estimated annual average exposure of SJVAB residents to PM 2.5 in the 2002

- 2004

and with attainment is summarized in Tables III

- 19 through III

- 24. The exposure calculations indicate 98%, 74%, and 33% of the SJVAB population are exposed to annual average PM 2.5 concentrations above 12, 15, and 18 μg/m 3 . Approximately 31%, 33%, 67%, 74%, 85%, 95%, 97%, and 98% of the residents of San Joaquin, Stanislaus, Merced, Kern, Madera, Tulare, Fresno, and Kings counties are exposed to annual average PM 2.5 concentrations above 15 μg/m 3
in the baseline period, respectively. Similarly, 77% and 72% of residents, ages less than 1 year and greater than 64 years, are estimated to be exposed to annual average PM 2.5 concentrations above 15 μg/m 3 in the baseline period. Approximately 70%, 71%, 77%, and 79% of white, other race, black, and Hispanic residents are estimated to be exposed to annual PM 2.5 concentrations above the NAAQS threshold.21 Wi th attainment of the annu a l NAAQS, the model estimates that 0%, 16%, and 73% of the SJVAB population will be exposed to annual concentrations above 12, 15, and 18 μg/m 3

, respectively. No exposures to annual PM 2.5 concentrations above 15 μg/m 3 are estimate d to occur in the northern half of the SJVAB (i.e., in San Joaquin, Stanislaus, Merced, and Madera Counties) with attainment. However, approximately 16%, 22%, 27%, and 30% of residents in Kern, Fresno, Tulare, and Kings Counties, respectively, are estimat ed to be exposed to annual

PM 2.5 concentrations above 15 μg/m 3 under the NAAQS attainment scenario. Also, the majority (73% to 96%) of residents of Madera, Fresno, Kings, Tulare, and Kern Counties are estimated to be exposed to annual PM 2.5 concentrations above 12 μg/m 3 with annual NAAQS attainment. Nevertheless, the estimated reduction of population exposed to annual PM 2.5 greater than

15 μg/m 3 from 2.5 million people (74% of the population) in 2002

- 2004 to 520 thousand people (16% of the population) wit h NAAQS attainment represents a substantial improvement in air quality and a decrease in associated PM

- related health effects (including premature mortality) for

residents of the SJVAB.22 Table III

- 4. The estimated SJVAB population exposure to 8

- hour dai ly maximum ozone concentrations above 70, 85, and 100 ppb in the 2002

- 2004 baseline period and with NAAQS attainment by region.

Region Person

- days of Exposure Per Year in the

2002

– 2004 Baseline Period Person

- days of Exposure Per

Year With NAAQS Attai nment a

O 3 >70 ppb O 3 >85 ppb O 3 >100 ppb O 3 >70 ppb O 3 >85 ppb

SJV Air Basin 234,844,480 68,981,644 10,263,964 33,831,101 292,757

San Joaquin County 5,841,758 272,877 4,696 5,314 0

Stanislaus County 13,347,645 2,102,079 80,860 684,963 0

Merced County 14,889,810 4,626,388 577,332 2,480,696 362

Madera County 12,873,744 3,436,128 538,545 1,625,296 45,633

Fresno County 76,781,642 25,510,837 5,514,961 14,614,819 211,237

Kings County 10,824,809 2,567,352 301,929 1,030,735 0

Tulare County 38,564,534 10,7 67,642 1,071,872 4,520,114 62

Kern County 61,720,538 19,698,341 2,173,769 8,869,163 35,463

a Person

- days of exposure to ozone >100 ppb is estimated to be zero with attainment of the 8

- hour NAAQS.

Table III

- 5. The estimated average number of days per year that the SJVAB population is exposed to 8

- hour daily maximum ozone concentrations above 70, 85, and 100 ppb

in the 2002

- 2004 baseline period and with NAAQS attainment by region.

Region Average No. of Days of Exposure Per Year in

the 2002

– 2004 Basel ine Period Average No. of Days of Exposure Per Year With

NAAQS Attainment a

O 3 >70 ppb O 3 >85 ppb O 3 >100 ppb O 3 >70 ppb O 3 >85 ppb

SJV Air Basin 70 21 3 10 < 1

San Joaquin County 10 0 0 0 0

Stanislaus County 29 5 0 1 0

Merced County 67 21 3 11 0

Made ra County 81 22 3 10 < 1

Fresno County 94 31 7 18 < 1

Kings County 79 19 2 8 0

Tulare County 100 28 3 12 0

Kern County 106 34 4 15 < 1

a Days of exposure to ozone >100 ppb is estimated to be zero with attainment of the 8

- hour NAAQS

.23 Table III

- 6. The estimated SJVAB population exposure to 8

- hour daily maximum ozone concentrations above 70, 85, and 100 ppb in the 2002

- 2004 baseline period and with NAAQS attainment by age group.

Age Group Person

- days of Exposure Per Year in the

2002

– 2004 Baseline Period Person

- days of Exposure Per

Year With NAAQS Attainment a

O 3 >70 ppb O 3 >85 ppb O 3 >100 ppb O 3 >70 ppb O 3 >85 ppb

Children <1 Year 3,872,925 1,149,985 172,609 567,167 4,836

Children 1 Year 3,904,201 1,157,552 173,809 570,946 4,906

Children 2

- 4 Ye ars 12,166,958 3,604,316 540,086 1,776,968 15,228

Children 5

- 17 Years 55,807,112 16,494,003 2,450,812 8,112,525 68,028

Adults 18

- 21 Years 14,998,006 4,434,267 671,161 2,193,130 18,836

Adults 22

- 29 Years 26,760,371 7,873,702 1,181,929 3,870,832 34,088

A dults 30

- 64 Years 94,822,090 27,664,729 4,073,571 13,487,462 119,204

Adults >64 Years 22,512,583 6,603,022 999,976 3,252,038 27,631

a Person

- days of exposure to ozone >100 ppb is estimated to be zero with attainment of the 8

- hour NAAQS.

Table III

- 7. The estimated average number of days per year that the SJVAB population is exposed to 8

- hour daily maximum ozone concentrations above 70, 85, and 100 ppb

in the 2002

- 2004 baseline period and with NAAQS attainment by age groups.

Age Group Average No. of Da ys of Exposure Per Year in

the 2002

– 2004 Baseline Period Average No. of Days of Exposure Per Year With

NAAQS Attainment a

O 3 >70 ppb O 3 >85 ppb O 3 >100 ppb O 3 >70 ppb O 3 >85 ppb

Children <1 Year 72 22 3 11 <1

Children 1 Year 72 21 3 11 <1

Children 2

- 4 Years 72 21 3 10 <1

Children 5

- 17 Years 71 21 3 10 <1

Adults 18

- 21 Years 71 21 3 10 <1

Adults 22

- 29 Years 72 21 3 10 <1

Adults 30

- 64 Years 69 20 3 10 <1

Adults >64 Years 68 20 3 10 <1

a Days of exposure to ozone >100 ppb is estimated to be zero wit h attainment of the 8

- hour NAAQS.24 Table III

- 8. The estimated SJVAB population exposure to 8

- hour daily maximum ozone concentrations above 70, 85, and 100 ppb in the 2002

- 2004 baseline period and with NAAQS attainment by racial or ethnic group.

Group P erson

- days of Exposure Per Year in the

2002

– 2004 Baseline Period Person

- days of Exposure Per

Year With NAAQS Attainment a

O 3 >70 ppb O 3 >85 ppb O 3 >100 ppb O 3 >70 ppb O 3 >85 ppb

White 102,861,799 29,522,344 4,173,191 14,088,345 124,941

Black 10,879 ,697 3,206,169 472,590 1,589,282 15,431

Hispanic 106,115,459 31,818,857 4,882,668 15,876,654 128,487

Other 15,151,622 4,482,164 741,113 2,298,549 24,006

a Person

- days of exposure to ozone >100 ppb is estimated to be zero with attainment of the 8

- hour N AAQS.

Table III

- 9. The estimated average number of days per year the SJVAB population is exposed to

8

- hour daily maximum ozone concentrations above 70, 85, and 100 ppb in the

2002

- 2004 baseline period and with NAAQS attainment by racial or ethnic group.

Group Average No. of Days of Exposure Per Year in

the 2002

– 2004 Baseline Period Average No. of Days of Exposure Per Year With

NAAQS Attainment a

O 3 >70 ppb O 3 >85 ppb O 3 >100 ppb O 3 >70 ppb O 3 >85 ppb

White 67 19 3 9 <1

Black 68 20 3 10 <1

Hispanic 76 23 4 11 <1

Other 62 18 3 9 <1

a Days of exposure to ozone >100 ppb is estimated to be zero with attainment of the 8

- hour NAAQS.25 Figure III

- 1. Grid system used for assignment of population and air quality data in the SJVAB and gridd ed total population data for

2000.26 Figure III

- 2. The frequency of ozone NAAQS exceedance days in the SJVAB from 1990 to 2004. The figure shows the number of days per year with 8

- hour daily maximum ozone

concentrations at one or more stations above the NAAQS and the 7

- year average frequency (from SJVAPCD 2005)

.

Figure III

- 3. The frequency and severity of ozone NAAQS exceedances in the SJVAB from

2001 to 2004. Sev erity is indicated by the NAAQS exceedance percentage on the worst day of the year (from SJVAPCD 2005)

.27 0 10 20 30 40 50 60 70 80 90 100

Stockton Modesto Merced Clovis Fresno - 1st St. Fresno - Hamilton Visalia Corcoran Bakersfield - Golden St. Bakersfield - Calif. Ave Bakersfield - Planz

LocationConcentration (ug/m3)

2002

2003

2004 NAAQS

0 5 10 15 20 25

Stockton Modesto Merced Clovis Fresno - 1st St. Fresno - Hamilton Visalia Corcoran Bakersfield - Golden St. Bakersfield - Calif. Ave Bakersfield - Planz

LocationConcentration (ug/m3) .

2002

2003

2004 NAAQS

Figure III

- 4. Ninety

- eighth percentile 24

- hour average PM 2.5 c oncentrations (top) and annual average PM 2.5 concentrations (bottom) at key monitoring stations in the SJVAB in 2002

– 2004.28 Figure III

- 5. Locations of air monitoring stations for PM 2.5 (left) and ozone (right) in and around the SJVAB29 Figure III

- 6. Spatially mapped annual average PM 2.5 concentrations for 2002, 2003, and 2004 in the SJVAB.30 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 1.E+09

40 50 60 70 80 90 100 110 120 130 140

8-hr Daily Maximum Ozone Concentration Threshold (ppb)Person-days per year above threshold . 2002 - 2004 Baseline

Future 8-hr NAAQS Attainment

8-hr Ozone NAAQS

Figure III

- 7. The distribution of persons

- days per year of exposure to 8

- hour daily maximum

ozone concentrations above various co ncentration thresholds in 2002

- 2004 and with NAAQS attainment.

1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 1.E+09

30 40 50 60 70 80 90 100

24-hr Average Ozone Concentration Threshold (ppb)Person-days per year above threshold . 2002 - 2004 Baseline

Future 8-hr NAAQS Attainment

Figure III

- 8. The distribution of persons

- days per year of exposure to 24

- hour average ozone

concentrations above various concentration thresholds in 2002

- 2004 and with NAAQS attainment.31 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 1.E+09

60 70 80 90 100 110 120 130 140 150 160

1-hr Daily Maximum Ozone Concentration Threshold (ppb)Person-days per year above threshold . 2002 - 2004 Baseline

Future 8-hr NAAQS Attainment

1-hr Ozone NAAQ S

Figure III

- 9. The distribution of persons

- days per year of exposure to 1

- hour daily maximum

ozone concentrations above various concentration thresholds in 2002

- 2004 and with NAAQS attainment.

1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 1.E+09

60 70 80 90 100 110 120 130 140 150 160

2-Week Average 1-hr Daily Maximum Ozone Concentration Threshold (ppb)Person-days per year above threshold . 2002 - 2004 Baseline

Future 8-hr NAAQS Attainment

Figure III

- 10. The distribution of persons

- days per year of exposure to 2

- week average 1

- hour daily maximum ozone concentrations above various concentration thresholds in

2002

- 2004 and with NAAQS attainment.32 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 1.E+09

50 60 70 80 90 100 110 120 130 140 150

5-hr Daily Maximum Ozone Concentration Threshold (ppb)Person-days per year above threshold . 2002 - 2004 Baseline

Future 8-hr NAAQS Attainment

Figure III

- 11. The distribution of persons

- days per year of exposure to 5

- hour daily maximum

ozone conce ntrations above various concentration thresholds in 2002

- 2004 and with NAAQS attainment.33 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 1.E+09

10 20 30 40 50 60 70 80 90

24-hr Average PM2.5 Concentration Threshold (ug/m3)Person-days per year above threshold . 2002 - 2004 Baseline

Future 24-hr NAAQS Attainment

24-hr PM2.5 NAAQS

Figure III

- 12. The distribution of persons

- days per year of exposure to 24

- hour average PM 2.5 concentrations above various concentration thresholds in 2002

- 2004 an d with NAAQS attainment.

1.E+04 1.E+05 1.E+06 1.E+07

10 12 14 16 18 20 22 24 26

Annual Average PM2.5 Concentration Threshold (ug/m3)Persons Exposed per year above threshold . 2002 - 2004 Baseline

Future Annual NAAQS Attainment

Annual PM2.5 NAAQS

Figure III

- 13. The distribution of persons exposed per year to annual average PM 2.5 concentrations above various concentration thresholds in 2002

- 2004 and with the annual NAAQS attainment.34 Figure III

- 14. Spatial map of the number of person

- days per year of exposure to 8

- hour daily maximum ozone concentrations above 100 ppb in 2002

- 2004.35 Figure III

- 15. Spatial map of the number of person

- days per year of exposure to 8

- hour daily maximum ozone con centrations above 85 ppb in 2002

- 2004 (left) and with NAAQS attainment (right).36 Figure III

- 16. Spatial map of the number of person

- days per year of exposure to 8

- hour daily maximum ozone concentrations above 70 ppb in 2002

- 2004 ( left) and with NAAQS attainment (right).37 Figure III

- 17. Spatial map of the number of person

- days per year of exposure to 24

- hour average PM 2.5 concentrations above

65 μg/m 3 in 2002

- 2004 (left) and with 24

- hour NAAQS attai nment (right).38 Figure III

- 18. Spatial map of the number of person

- days per year of exposure to 24

- hour average PM 2.5 concentrations above

40 μg/m 3 in 2002

- 2004 (left) and with 24

- hour NAAQS attainment (right).39 Figure III

- 19. Spatial map of the number of persons exposed (per year) to annual average PM 2.5 concentrations above 18 μg/m 3 in 2002

- 2004.40 Figure III

- 20. Spatial map of the number of persons exposed to annual avera ge PM 2.5 concentrations above 15 μg/m 3 in 2002

- 2004 (left) and with attainment (right).41 Figure III

- 21. Spatial map of the number of persons exposed to annual average PM 2.5 concentrations above 12 μg/m 3 in 2002

- 2004 (left) and w ith attainment (right).42 - 10 20 30 40 50 60

>95 ppb >90 ppb >85 ppb >80 ppb >75 ppb

Concentration Thresholdy p White

Black

Other Hispanic Total Population

Figure III

- 22. The average number of days per year of exposure to 8

- hour daily maximum ozone

above various concentrations in the SJVAB in 2002

- 2004 by racial/ethnic group and county.

- 5 10 15 20 25 30 35 40

San Joaquin County Stanilaus County Merced County Madera County Fresno County Kings County Tulare County Kern County

CountyDays Per Year . White

Black

Other
Hispanic
Total Population

Figure III

- 23. The average number of days per year of exposure to 8

- hour daily maximum ozone above 85 ppb in the SJVAB in 2002

- 2004 by racial/ethnic group and county.43 Table III

- 10. The estimated SJVAB population exposure to 5

- hour daily maximum ozone concentrations above 80, 90 and 100 ppb in th e 2002

- 2004 baseline period and with NAAQS attainment by region.

Region Person

- days of Exposure Per Year in the

2002

– 2004 Baseline Period Person

- days of Exposure Per

Year With NAAQS Attainment a

O 3 >80 ppb O 3 >90 ppb O 3 >100 ppb O 3 >80 ppb O 3 >90 pp b

SJV Air Basin 160,612,236 70,992,203 23,036,909 8,774,819 323,671

San Joaquin County 3,485,314 507,787 5,099 4,796 184

Stanislaus County 9,227,736 3,122,399 546,788 87,867 0

Merced County 10,013,959 4,521,107 1,445,128 255,225 0

Madera County 8,425, 272 3,299,209 1,177,622 447,320 51,767

Fresno County 53,782,698 27,837,387 11,595,938 5,618,393 228,973

Kings County 6,594,764 2,795,412 792,613 259,751 0

Tulare County 27,267,903 11,699,739 3,085,285 1,027,820 6,769

Kern County 41,814,589 17,209,163 4 ,388,438 1,073,646 35,978

a SJVAB population exposure to 5

- hour daily maximum ozone >100 ppb is estimated to be 6,770 p erson

- days per year with

attainment of the 8

- hour NAAQS.

Table III

- 11. The estimated SJVAB population exposure to 1

- hour daily maxi mum ozone concentrations above 80, 100, and 120 ppb in the 2002

- 2004 baseline period and with NAAQS attainment by region.

Region Person

- days of Exposure Per Year in the

2002

– 2004 Baseline Period Person

- days of Exposure Per

Year With NAAQS Attainment a

O 3 >80 ppb O 3 >100 ppb O 3 >120 ppb O 3 >80 ppb O 3 >100 ppb

SJV Air Basin 213,217,847 45,904,168 6,063,003 20,176,110 254,935

San Joaquin County 8,395,004 488,874 4,888 10,681 4,728

Stanislaus County 15,166,787 2,353,467 48,987 534,337 0

Merced County 13,345,890 2,755,607 90,682 1,052,372 105

Madera County 10,842,116 2,088,746 293,815 1,008,657 34,359

Fresno County 69,222,219 20,903,413 4,408,225 11,620,506 185,340

Kings County 9,113,833 1,692,956 179,469 664,759 0

Tulare County 34,870,509 7,110,46 9 576,116 2,853,119 7,173

Kern County 52,261,490 8,510,636 460,819 2,431,680 23,230

a SJVAB population exposure to 1

- hour daily maximum ozone >120 ppb is estimated to be zero with attainment of the 8

- hour NAAQS.44 Table III

- 12. The estimated SJVAB popu lation exposure to 2

- week average 1

- hour daily maximum ozone concentrations above 80, 100, and 120 ppb in the 2002

- 2004 baseline period and with NAAQS attainment by region.

Region Person

- days of Exposure Per Year in the

2002

– 2004 Baseline Period With NAAQS

Attainment a

O 3 >80 ppb O 3 >100 ppb O 3 >120 ppb O 3 >80 ppb

SJV Air Basin 176,546,856 7,754,966 77,308 1,020,681

San Joaquin County 29,539 0 0 0

Stanislaus County 3,631,794 0 0 0

Merced County 10,437,480 148,280 0 0

Madera County 9,299,083 206,7 57 0 41,004

Fresno County 68,672,341 4,893,914 31,738 497,532

Kings County 6,769,397 48,949 0 126

Tulare County 33,531,673 1,056,492 403 110,562

Kern County 44,175,548 1,400,575 45,166 371,457

a SJVAB population exposure to 2

- week average 1

- hour dail y maximum ozone >100 ppb is estimated to

be zero with attainment of the 8

- hour NAAQS.

Table III

- 13. The estimated SJVAB population exposure to 24

- hour average ozone concentrations above 50, 60, and 70 ppb in the 2002

- 2004 baseline period and with NAAQS attainment by region.

Region Person

- days of Exposure Per Year in the

2002

– 2004 Baseline Period Person

- days of Exposure Per

Year With NAAQS Attainment a

O 3 >50 ppb O 3 >60 ppb O 3 >70 ppb O 3 >50 ppb O 3 >60 ppb

SJV Air Basin 97,277,322 16,992,036 1,741 ,620 19,462,969 653,916

San Joaquin County 319,971 787 0 6,418 0

Stanislaus County 1,867,299 44,491 79 59,409 0

Merced County 8,842,703 1,719,219 193,478 1,908,731 30,960

Madera County 7,058,729 1,478,549 137,148 1,790,058 23,539

Fresno County 35,382, 682 4,695,127 76,214 4,426,329 14,643

Kings County 3,023,231 110,651 0 112,848 0

Tulare County 18,298,749 4,094,132 502,563 5,376,160 197,971

Kern County 22,483,957 4,849,080 832,139 5,783,017 386,803

a SJVAB population exposure to 24

- hour average ozo ne >70 ppb is estimated to be 32,000 p erson

- days per year with attainment

of the 8

- hour NAAQS.45 Table III

- 14. The estimated SJVAB population exposure to 24

- hour average PM 2.5 concentrations above 40 and 65 μg/m 3 in the 2002

- 2004 baseline period and with NAAQS attainment by region.

Region Person

- days of Exposure Per Year in

the 2002

– 2004 Baseline Period Person

- days of Exposure Per Year With NAAQS Attainment

PM 2.5 >40 μg/m 3 PM 2.5 > 6 5 μg/m 3 PM 2.5 >40 μg/m 3 PM 2.5 > 6 5 μg/m 3

SJV Air Basin 88,444,759 8, 740,819 61,210,349 3,244,681

San Joaquin County 6,952,506 179,520 3,128,221 6,152

Stanislaus County 10,598,815 1,319,551 6,330,681 816,627

Merced County 4,517,016 337,293 2,602,691 1,509

Madera County 4,176,348 159,435 2,512,053 0

Fresno County 25,612 ,174 3,536,683 19,033,269 961,833

Kings County 3,704,890 415,924 2,909,207 27,889

Tulare County 9,857,985 724,773 7,308,016 102,482

Kern County 23,025,025 2,067,641 17,386,210 1,328,188

Table III

- 15 . The estimated average number of days per year th at the SJVAB population is exposed to 24

- hour PM 2.5 concentrations above 40 and 65 μg/m 3 in the 2002

- 2004 baseline period and with NAAQS attainment by region.

Region Average No. of Days of Exposure Per

Year in the 2002

– 2004 Baseline Period Average No. o f Days of Exposure

Per Year With NAAQS Attainment

PM 2.5 >40 μg/m 3 PM 2.5 >65 μg/m 3 PM 2.5 >40 μg/m 3 PM 2.5 >65 μg/m 3

SJV Air Basin 26 3 18 1

San Joaquin County 12 0 5 <1

Stanislaus County 23 3 14 2

Merced County 20 2 12 <1

Madera County 26 1 16 0

Fres no County 32 4 23 1

Kings County 27 3 21 <1

Tulare County 26 2 19 <1

Kern County 39 4 30 246 Table III

- 16. The estimated SJVAB population exposure to 24

- hour average PM 2.5 concentrations above 40 and 65 μg/m 3 in the 2002

- 2004 baseline period and with NAAQS attainment by age group.

Age Group Person

- days of Exposure Per Year in

the 2002

– 2004 Baseline Period Person

- days of Exposure Per Year With NAAQS Attainment

PM 2.5 >40 μg/m 3 PM 2.5 > 6 5 μg/m 3 PM 2.5 >40 μg/m 3 PM 2.5 > 6 5 μg/m 3

Children <1 Year 1,451, 170 145,336 1,014,127 53,513

Children 1 Year 1,469,069 146,894 1,024,404 54,377

Children 2

- 4 Years 4,573,955 457,019 3,184,968 168,053

Children 5

- 17 Years 20,902,138 2,073,829 14,525,114 761,301

Adults 18

- 21 Years 5,634,636 556,778 3,910,283 206,015

A dults 22

- 29 Years 10,110,743 1,002,256 7,031,299 373,369

Adults 30

- 64 Years 35,816,787 3,503,922 24,685,357 1,313,479

Adults >64 Years 8,486,261 854,785 5,834,797 314,575

Table III

- 17. The estimated SJVAB population exposure to 24

- hour average PM 2.5 concentrations above 40 and 65 μg/m 3 in the 2002

- 2004 baseline period and with NAAQS attainment by racial or ethnic group.

Group Person

- days of Exposure Per Year in

the 2002

– 2004 Baseline Period Person

- days of Exposure Per Year With NAAQS Attainment

P M 2.5 >40 μg/m 3 PM 2.5 >65 μg/m 3 PM 2.5 >40 μg/m 3 PM 2.5 >65 μg/m 3

White 39,421,625 3,842,572 26,815,582 1,558,292

Black 4,439,192 486,888 3,128,836 163,693

Other 38,467,115 3,771,060 27,133,707 1,300,489

Hispanic 6,158,795 643,435 4,160,633 223,028

Tab le III

- 18. The estimated average number of days per year that the SJVAB population is exposed to 24

- hour PM 2.5 concentrations above 40 and 65 μg/m 3 in the 2002

- 2004 baseline period and with NAAQS attainment by racial or ethnic group.

Group Average No. of Days of Exposure Per

Year in the 2002

– 2004 Baseline Period Average No. of Days of Exposure

Per Year With NAAQS Attainment a

PM 2.5 >40 μg/m 3 PM 2.5 >65 μg/m 3 PM 2.5 >40 μg/m 3 PM 2.5 >65 μg/m 3

White 26 2 17 1

Black 28 3 20 1

Hispanic 28 3 19 1

Other 25 3 17 147 0 10 20 30 40 50 60

65 ug/m3 50 ug/m3 40 ug/m3 30 ug/m3

Concentration ThresholdDays Per Year White

Black

Other

Hispanic

Total Population

Figure III

- 24. The average number of days per year of exposure to 24

- hour average PM 2.5 above

various concentrations in the SJVAB in 2002

- 2004 by racial/ethnic group.

0 5 10 15 20 25 30 35 40 45

San Joaquin County Stanilaus County Merced County Madera County Fresno County Kings County Tulare County Kern CountyDays Per Year White

Black

Other

Hispanic

Total Population

Figure III

- 25. The average number of days per year of exposure to 24

- hour average PM 2.5 above 40 μg/m 3 in the SJVAB in 2002

- 2004 by racial/ethnic group and county.48 Table III

- 19. The estimated SJVAB population exposure to annual average PM 2.5 concentrations above 12, 15, and 18 μg/m 3 in the 2002

- 2004 baseline period and with NA AQS attainment by region.

Region Person

- days of Exposure Per Year in the

2002

– 2004 Baseline Period Person

- days of Exposure Per

Year With NAAQS Attainment a

PM 2.5 >12

μg/m 3 PM 2.5 >15 μg/m 3 PM 2.5 >18 μg/m 3 PM 2.5 >12 μg/m 3 PM 2.5 >15 μg/m 3

SJV Air Basi n 3,266,891 2,485,816 1,110,165 2,429,546 520,575

San Joaquin County 548,259 180,226 733 179,474 0

Stanislaus County 465,500 155,140 140,181 155,101 0

Merced County 209,607 148,200 55,780 107,450 0

Madera County 139,758 135,335 44,189 134,303 0

Fresno County 802,163 784,847 214,722 783,162 182,782

Kings County 137,234 134,433 45,745 130,317 41,082

Tulare County 380,256 363,833 156,907 356,090 102,345

Kern County 584,114 583,802 451,908 583,649 194,366

a None of the SJVAB population is estimated to be exposed to annual average PM 2.5 concentrations above >18 μg/m 3 with

attainment of the annual PM 2.5 NAAQS.

Table III

- 20. The estimated percent of the SJVAB population exposed to annual average PM 2.5 concentrations above 12, 15, and 18 μg/m 3 in the 20 02

- 2004 baseline period and with NAAQS attainment by region.

Region Percent of the Population Exposed in the

2002

– 2004 Baseline Period Percent of the Population Exposed With NAAQS

Attainment a

PM 2.5 >12

μg/m 3 PM 2.5 >15 μg/m 3 PM 2.5 >18 μg/m 3 PM 2.5 >12 μg/m 3 PM 2.5 >15 μg/m 3

SJV Air Basin 98% 74% 33% 73% 16%

San Joaquin County 96% 31% 0% 31% 0%

Stanislaus County 100% 33% 30% 33% 0%

Merced County 94% 67% 25% 48% 0%

Madera County 88% 85% 28% 84% 0%

Fresno County 99% 97% 26% 96% 22%

Kings County 100% 98% 33% 95% 30%

Tulare County 99% 95% 41% 93% 27%

Kern County 98% 74% 33% 73% 16%

a None of the SJVAB population is estimated to be exposed to annual average PM 2.5 concentrations above >18 μg/m 3 with

attainment of the annual PM 2.5 NAAQS.49 Table III

- 21 . The estimated SJVAB population exposure to annual average PM 2.5 concentrations above 12, 15, and 18 μg/m 3 in the 2002

- 2004 baseline period and with NAAQS attainment by age group.

Age Group Person

- days of Exposure Per Year in the

2002

– 2004 Baseline Period Person

- days of Exposure Per

Year With NAAQS Attainment a

PM 2.5 >12

μg/m 3 PM 2.5 >15 μg/m 3 PM 2.5 >18 μg/m 3 PM 2.5 >12 μg/m 3 PM 2.5 >15 μg/m 3

Children <1 Year 52,518 40,905 18,534 40,018 8,969

Children 1 Year 53,244 41,327 18,703 40,421 8,959

Childr en 2

- 4 Years 166,507 128,722 58,015 125,823 27,787

Children 5

- 17 Years 767,767 588,313 264,331 574,640 125,186

Adults 18

- 21 Years 206,777 159,584 70,214 155,994 33,718

Adults 22

- 29 Years 367,444 285,834 127,762 279,426 61,316

Adults 30

- 64 Years 1,332,6 37 1,005,231 448,785 982,455 205,947

Adults >64 Years 319,994 235,898 103,822 230,767 48,692

a Zero percent of the SJVAB population is estimated to be exposed to annual average PM 2.5 concentrations above >18 μg/m 3

with attainment of the annual PM 2.5 NAA QS.

Table III

- 22. The percent of the SJVAB population exposed to annual average PM 2.5 concentrations above 12, 15, and 18 μg/m 3 in the 2002

- 2004 baseline period and with NAAQS attainment by age group.

Age Group Percent of the Population Exposed in the

2002

– 2004 Baseline Period Percent of the Population Exposed With NAAQS

Attainment a

PM 2.5 >12

μg/m 3 PM 2.5 >15 μg/m 3 PM 2.5 >18 μg/m 3 PM 2.5 >12 μg/m 3 PM 2.5 >15 μg/m 3

Children <1 Year 98% 77% 35% 75% 17%

Children 1 Year 98% 76% 35% 75% 17%

Children 2

- 4 Years 98% 76% 34% 74% 16%

Children 5

- 17 Years 98% 75% 34% 73% 16%

Adults 18

- 21 Years 98% 76% 33% 74% 16%

Adults 22

- 29 Years 98% 77% 34% 75% 16%

Adults 30

- 64 Years 98% 74% 33% 72% 15%

Adults >64 Years 97% 72% 32% 70% 15%

a Zero percent of the SJVA B population is estimated to be exposed to annual average PM 2.5 concentrations above >18 μg/m 3

with attainment of the annual PM 2.5 NAAQS.50 Table III

- 23. The estimated SJVAB population exposure to annual average PM 2.5 concentrations above 12, 15 and 18 μg/m 3 in the 2002

- 2004 baseline period and with NAAQS attainment by racial or ethnic group.

Group Person

- days of Exposure Per Year in the

2002

– 2004 Baseline Period Person

- days of Exposure Per

Year With NAAQS Attainment a

PM 2.5 >12

μg/m 3 PM 2.5 >15 μg/m 3 PM 2.5 >18 μg/m 3 PM 2.5 >12 μg/m 3 PM 2.5 >15 μg/m 3

White 1,495,318 1,085,149 496,585 1,062,947 208,770

Black 157,070 122,784 51,819 120,417 28,525

Hispanic 1,373,857 1,105,462 498,035 1,078,506 250,913

Other 242,304 173,721 64,248 168,918 32,672

a None of the SJVAB population is estimated to be exposed to annual average PM 2.5 concentrations above >18 μg/m 3 with

attainment of the annual PM 2.5 NAAQS.

Table III

- 24. The estimated percent of the SJVAB population exposed to annual average PM 2.5

conce ntrations above 12, 15, and 18 μg/m 3 in the 2002

- 2004 baseline period and with NAAQS attainment by racial or ethnic group.

Group Percent of the Population Exposed in the

2002

– 2004 Baseline Period Percent of the Population Exposed With NAAQS Attain ment a

PM 2.5 >12

μg/m 3 PM 2.5 >15 μg/m 3 PM 2.5 >18 μg/m 3 PM 2.5 >12 μg/m 3 PM 2.5 >15 μg/m 3

White 97% 70% 32% 69% 14%

Black 99% 77% 33% 76% 18%

Hispanic 99% 79% 36% 77% 18%

Other 98% 71% 26% 69% 13%

All Groups 98% 74% 33% 73% 16%

a None of the SJVAB po pulation is estimated to be exposed to annual average PM 2.5 concentrations above >18 μg/m 3 with

attainment of the annual PM 2.5 NAAQS.51 I V. A DVERSE OZONE AND PM

- RELATED HEALTH EFFECTS

Ozone and fine particles (PM 2.5 ) have long been associated with adver se health effects, and a growing body of health science literature enables us to quantify how changes in air quality translate into changes in the number of adverse health effects in a population. In order to select specific studies to estimate such chang es for the purposes of this study, we consider a number of factors. In particular, to be used a study:

**•** Must be peer

- reviewed.

**•** Must account for potential confounders such as other pollutants and weather.

**•** Must use reasonable measures of pollutants.

**•** Must be based on a population not significantly different from the population being

assessed.

**•** Must provide a basis to estimate changes in an effect that can be valued in economic

terms.

**•** Is preferred if it is more recent, using more advanced analytical methods and reflecting more recent demographics.

**•** Is preferred if it covers longer periods and larger populations.

**•** Is preferred if it meets other criteria and is also region

- specific.

**•** Is preferred if it meets other criteria and has been used in previous peer

- reviewed benefits

assessments.

Given this, we identified seven ozone

- related and 14 PM 2.5 - related effects that would be appropriate for inclusion in this study. 3 These effects are summarized in Table I V

- 1. Those that are quantified here are shaded in gray. Thos e that are not quantified occur in very small numbers, generally because the population at risk is small or because the concentration

- response relationship requires a large change in pollution levels to generate substantial reductions in the

effect in the exposed population. For example, we estimate that attaining the NAAQS for PM 2.5 would result in five fewer cardiovascular hospital admissions annually in the entire eight county region. Summing and including all of those small effects does not change the overall results.

IV. 1 Studies Used in Quantification of Effects

IV. 1.1 Developing Health (Concentration

- Response) Functions

To quantify the expected changes in health effects associated with reduced exposure to

ozone and PM 2.5 , we have used the basic exponential concentration

- response (C

- R) function developed in the Environmental Protection Agency’s Report to Congress ( EPA 1999), which evaluates the benefits and costs of emissions controls required by the Clean Air Act. 4

3 Some effects, such as individual respiratory symptoms or eye irritation are no t included here because they are at least in part captured by effects such as MRADs, work loss days, school absence days and upper and lower respiratory symptom days. Also, individually they carry relatively small economic values.

4 The one exception is t he case of ozone

- related emergency room visits, for which we use a linear concentration

response function.52 Specifically, the function al form used is as follows:

∆ C =

- C 0 (e - β ∆P

– 1)

where:

∆C = the change in the number of cases (of a particular health outcome)

C 0 = the number of baseline cases (of the health outcome)

∆P = the change in ambient pollution concentrations β = an expo nential “slope” factor derived from the health literature pertaining to that specific health outcome.

In most of the recent health literature, “relative risk” factors are reported which relate change in pollution levels to the increased odds of develop ing various health effects. These risk factors are related to the β in the EPA concentration

- response functions in the following manner:

β = (1 + Increased Odds)/(Change in Pollution)

The specific health studies used to develop these β values are des cribed in the following sections.

IV. 1.2 Ozone Morbidity

Minor Restricted Activity Days (MRADs)

Minor restricted activity days (MRADs) are days when various (often, respiratory) symptoms reduce normal activities, but do not prevent going to work or att ending school. The combination of symptoms that induces an MRAD is more restrictive than any individual symptom. The 1989 study by Ostro and Rothschild, which used a national sample of the adult (18

- 65) working population over six years (1976

- 1981) to de termine some of the health consequences of ozone and fine particles, is used here. They found an association between ozone and minor restrictions in activity, after controlling for fine particles, that can be used to derive an exponential ozone C

- R functi on. Using a weighted average of the coefficients reported in the analysis, the EPA (2003b) developed a best estimate β coefficient of 0.0022; an annual (baseline) number of 7.8 MRADs per person was also derived from the study. Further following

Ostro an d Rothschild, we apply this function to the nonelderly, or “working” adult portion of the population. The EPA (2003b) notes that this application is likely to produce a somewhat conservative health outcome estimate, since elderly adults are probably at le ast as susceptible to ozone pollution as are individuals under the age of 65.

Asthma Emergency Room Visits

Several studies have established a relationship between increases of ozone and a variety of asthmatic symptoms. In one of the more comprehensive w orks undertaken, Weisel et al. (1995) conducted a five

- year retrospective study of the relationship between summer ozone

concentrations and asthma

- induced emergency room (ER) visits. Specifically, they examined the relationship between ambient ozone level s and ER visits by asthmatics in central and northern New Jersey for five consecutive years (1986

- 1990). A similar study was undertaken by Cody et al. (1992) for the same geographic area and the summer months of 1988 and 1989.

While Weisel et al.’s res ults derive from a single pollutant equation, the Cody et al. study53 includes SO 2 as a co

- pollutant. In each case, though, multiple linear regression analyses were conducted for each year, generating positive and significant coefficients of daily ER visits with ozone concentrations. From these studies’ coefficients, the EPA (2003b) derives slope

coefficients for a linear concentration

- response function. For our analysis, we average these two linear coefficients, resulting in a β value of 0.0323. It is th is value that forms the basis for our

calculation of reductions in asthma

- related emergency room visits from improved ozone levels. The specific function thus developed is as follows:

Δ asthma

- related ER visits = (β/ Base Pop) ΔO3 pop,

where: β = ozone coefficient = 0.0323 Base Pop = original studies’ baseline population in NJ = 4,436,976

Δ O3 = change in daily 5

- hour average ozone concentration (ppb)

pop = the affected population (all ages).

School Absences

Ozone

- related school absences is a health o utcome that has been examined in two recently published health studies. The first, by Chen et al. (2000), considered the association between air pollution and daily elementary school absenteeism in Washoe County, Nevada, from

1996 to 1998. Student absent eeism was regressed on three air pollutants (ozone, PM 10 and carbon monoxide), weather variables, and other confounding factors, using autoregression analysis. The second study, by Gilliland et al. (2001), examined 1996 school absences for 12

southern Cal ifornia communities with differing concentrations of multiple pollutants (ozone,

NO 2 , and carbon monoxide). These researchers used a two

- stage time series regression model, controlling for day of the week and temperature, to assess whether there were any associations between pollution levels and absences. Both studies found ozone to be statistically associated with daily absenteeism. More specifically, Chen et al. predicted that for every 50 ppb increase in ozone the overall absence rate increased by 13. 01 percent. In contrast, Gilliland et al. found that a 20 ppb increase in 8

- hour average ozone concentrations was associated with a 16.3 percent

increase in the all

- absence rate. From these results, we can derive exponential β values of

0.002446 and 0.00 755, which we then average, resulting in an ozone

- related school absence

concentration

- response β value of 0.004998. Finally, EPA (2003b) reports a daily school

absence rate of 0.055 , obtained from the U. S. Department of Education

.

Asthma A ttacks

In an early, yet still widely cited, study, Whittemore and Korn (1980) examined daily asthma attack diaries from 16 panels of asthmatics living in six communities of southern California during the mid 1970s. They used multiple logistic regression analysis to t est for relationships between daily attack occurrences and daily levels of two types of pollutants (photochemical oxidants and total suspended particulates), plus a variety of weather variables. Results for the two pollutant models showed significant rela tionships between daily levels of both pollutants and reported asthma attacks. The EPA (2003b) adjusted the model’s oxidant results so that they could be used with ozone data. The resulting β value of 0.001843 can then be applied to the asthmatic portion of the Central Valley population, which we assume to be 3.86 percent of the all

- age population (as reported in American Lung Association 2002). Finally, a54 daily incidence rate of wheezing attacks for adult asthmatics of 0.055 is assumed as our baseline

r ate, based on an analysis of the 1999 National Health Interview Survey (EPA 2003b).

Respiratory Hospital Admissions

For non

- elderly (ages 0

– 64), ozone

- related respiratory hospital admissions, we turn to a report by Thurston and Ito (1999), which summa rized an extensive literature on hospital admissions that included ozone as one of the explanatory variables 5 . In this report, a statistical synthesis of three Canadian studies (Burnett et al. 1994, Thurston et al. 1994 and Burnett et al. 1997a) yielded a quantitative estimate of the respiratory hospital admission effect associated with ozone exposures for the non

- elderly general population. Specifically, they calculate a relative risk factor of 1.18 per 100 ppb increase in daily 1

- hour maximum ozone leve ls. From this, we

derive a concentration

- response β estimate of 0.001655. For respiratory hospital baseline admission rates, we turn to the Office of Statewide Health Planning and Development’s Inpatient Hospital Discharge Frequencies for California (200 3) and the U.S. National Hospital Discharge Survey (March 2005) to construct age

- specific hospital discharge numbers for each county.

To estimate ozone

- related avoided incidences of respiratory hospital admissions for patients 65 and older, we generated a pooled β value using several health studies referenced by the EPA (2003b). All of these studies found significant associations between ozone and various categories of respiratory hospital admissions. The studies include: Schwartz (1995), who analyzed th e relationship between ozone and all respiratory admissions for the cities of New Haven, Connecticut and Tacoma, Washington; and Moolgavkar et al. (1997), Schwartz (1994a), and Schwartz (1994b), who considered pneumonia and COPD admissions in Minneapolis a nd Detroit. Our pooled β estimate is equal to 0.004536. Finally, as described for the under

- 65 case,

our county

- specific baseline figures come from the California and U.S. Hospital Discharge

reports.

IV.1 .3 PM 2.5 Morbidity

Chronic Bronchitis

A case of chronic bronchitis is typically considered to be a recurring condition of mucus in the lungs and wet cough during at least 3 months per year for several years in a row. Abbey et al. (1995) studied the association between fine particles (including PM 2. 5 ) and new occurrences of these chronic respiratory symptoms in a survey group of nearly 1,900 Californian Seventh Day Adventists. The survey period extended from 1977 to 1987, and the study found a statistically significant relationship between PM 2.5 and the development of chronic bronchitis in adults aged 27 and over. From this work, the EPA calculated a concentration

- response β value of 0.0137 and from an earlier work by Abbey (1993), they obtained an annual bronchitis incidence rate per person of 0.0 0378. We apply these factors to the proportion of our adult population (27 years of age and older) without chronic bronchitis (which, according to the American Lung Association, is 95.57 percent of the population).

5 This is the same approach adopted by ARB (2005).55 Minor Restricted Activity Days (MRADs )

As noted above in the ozone morbidity section, minor restricted activity days (MRADs) are days when various (often, respiratory) symptoms reduce normal activities, but do not prevent going to work or attending school. The 1989 study by Ostro and Rothsc hild noted above used six years (1976

- 1981) of Health Interview Survey (HIS) data, a large cross

- sectional database collected by the National Center for Health Statistics, to determine some of the health consequences of particulate matter and ozone. They also found a statistical association between fine particles and minor restrictions in activity, after controlling for ozone, that can be used to derive an exponential PM 2.5 C

- R function. From the data included in the analysis, the EPA (2003b) developed a PM 2.5 β coefficient of 0.00741, which is again a weighted average of the coefficients reported in Ostro and Rothschild. As in the ozone case, an annual (baseline) number of 7.8 MRADs per person was derived. Finally, we again apply this function to the no n

- elderly, or “working” adult portion of the population. As we noted earlier, this application is likely to produce a somewhat conservative health outcome estimate, since elderly adults are probably at least as susceptible to fine particles as are individ uals under the age of 65.

Work Loss Days (WLDs)

In a 1987 study, Ostro examined the effect of fine particulate matter on work loss days (WLDs) using a national survey of working adults (aged 18

- 64) in 49 different metropolitan

areas in the United States. He found a significant link between PM 2.5 and missed days of work for each of the six years of the study (1976

- 1981), estimating separate coefficients for each year of the analysis. The β coefficient developed by the EPA (2003b) from this work (0.0046) is a weighted average of the coefficients estimated by Ostro, using the inverse of the variance as the weight . In addition, the EPA used a more recent data set (Adams et al. 1999) to determine a daily WLD incidence (baseline) rate of 0.00595, which we use in our analysis.

Acute Bronchitis

Dockery et al. (1996) examined the respiratory health effects of exposure to a number of pollutants, including fine particles, on a sample of over 13,000 children (8

- 12 years old) from 24

communities in the United S tates and Canada. Using a two

- stage logistic regression model, and adjusting for the potential confounding effects of sex, parental asthma and education, history of allergies, and current smoking in the home, they found PM 2.1 to be significantly related t o cases of bronchitis. From this work, the EPA developed a PM 2.5 concentration

- response function for acute bronchitis in children. The estimated β value of 0.0272 results from combining Dockery et al.’s odds ratio of 1.50 with the study’s observed change in particles of 14.9 μg/m 3 . In addition,

the EPA recommends usi ng a baseline incidence rate of 0.043 cases per child per year, as reported by the American Lung Association (2002). Finally, while the Dockery et al. sample

focused on children within a 5

- year age range, we extend their results to include all school

- aged children, based on the assumption that the response of all school

- aged children will be similar to those in the study’s more age group.

Lower Respiratory Symptoms

In an earlier health study, Schwartz et al. (1994) used logistic regression and found a

s tatistical association between lower respiratory symptoms (defined as cough, chest pain, phlegm56 and wheeze) in children and a number of pollutants, including PM 10 , acid aerosols, gaseous pollutants, and fine particles. The study was conducted in six citie s over a five

- year period (1984

- 1988) and considered a sample of over 1,800 students enrolled in grades two through five. More recently, Schwartz and Neas (2000) replicated the earlier analysis, focusing their efforts on

PM 2.5 . In a model that also inclu ded coarser particulate matter (PM 10

- 2.5 ), an odds ratio of 1.29 was associated with a 15 μg/m 3 change in PM 2.5 . From this work, we generate an exposure

response function, with an estimated β value of 0.01698 and a daily baseline rate of 0.0012. Finally, while the Schwartz and Neas work is suggestive of an age range from 7 to 14, we again

extend these results to include all school

- aged children because the response of older teenagers and younger children is likely to be similar to the children in the stud ied cohort.

Upper Respiratory Symptoms

In a study of Utah school children (ranging in age from 9 to 11), Pope et al. (1991) examined the association between daily occurrences of upper respiratory symptoms and daily

PM 10 concentrations. A day of upper re spiratory symptoms was defined as consisting of one or more of the following symptoms: runny or stuffy nose; wet cough; and burning, aching, or red eyes. Using logistic regression, the study found that PM 10 was significantly associated with upper respirat ory symptoms. The EPA (2003b) used this work to develop a concentration

response function with a β estimate of 0.0036. We convert this PM 10 - derived β value to its PM 2.5 counterpart (0.0072) and also rely on Pope et al. ’ s daily upper respiratory symptom i ncidence rate per child of 0.3419. Finally, we note that the sample size in the Pope et al. study was quite small, and is most representative of the asthmatic children’s population, not the total school

- aged population. We therefore apply this exposure

- response function only to asthmatic children, who are assumed to represent 11 percent of the total children’s population in the San Joaquin Valley.

IV. 1.4 PM 2.5 Mortality

The scientific literature that assesses associations between PM 2.5 and prema ture mortality in adults has expanded rapidly over the past decade, with several large scale multi

- city studies that extend or reanalyze earlier studies (for example, Pope et al. 1995; Krewski et al. 2000; Pope et al. 2002) as well as a California

- specific study that focuses on the Los Angles basin (Jerrett et al. 2005). To estimate PM 2.5 - related mortality for the SJV requires determining which of these studies is most appropriate for conditions in this region. In general, as noted above, studies are

p referred that: are peer reviewed, cover longer periods, are more recent (better reflecting current demographics and lifestyles), include larger samples, account for confounding factors, and were conducted in locations that have the greatest similarity to t he study population. There is also an increasing literature that measures (Woodruff et al. 1997) or indicates the probability of (Loomis

et al. 1999; Pereira et al. 1998; Wang et al. 1997; Chay and Greenstone 2003) an association

between PM 2.5 and mortal ity in children less than one year of age.

Both EPA and ARB have conducted recent benefit assessments for PM 2.5 reduction (EPA 2003; EPA 2004; EPA 2005; ARB 2005), and these assessments have also undergone peer

review of the analytical approaches used, including the choice of C

- R functions. The consensus is that for national studies Pope et al. (2002) is the preferred basis to estimate adult mortality. The EPA Science Advisory Board Health Effects Committee (SAB

- H E ES) (2004) further

recommends that neo natal mortality now be included in the base analysis using the C

- R function57 from Woodruff et al. (1997). For California, there is agreement that Pope et al. provides the best

C

- R function from the national literature, but there is also agreement that Jerr ett et al. (2005) likely better represents California (ARB 2005 and peer

- review comments thereon). Following the professional consensus, and based on the reasons discussed below, we rely on these three studies to estimate mortality effects. We use Pope e t al. for the primary analysis, Jerrett et al. as a sensitivity test for adult mortality, and Woodruff et al. as an indicator of neonatal mortality, but outside the primary analysis and aggregate results.

Pope et al. (2002)

This study meets all of the e ssential criteria noted above for the choice of a C

- R function. It is a large

- scale, longitudinal cohort study that follows a large nationally representative population (ages 30 and older) across 61 cities over a 16 year follow

- up period from a base of

19 79

- 1983. Extending the follow

- up period to 16 years increases the mortality data set by a factor of three compared to earlier studies. This study also includes PM 2.5 measurements from 1999 and the first three quarters of 2000, and controls more closely for a series of personal risk factors, including lifestyle and occupation. The increase for the all

- cause mortality associated with annual average PM 2.5 is 6% per 10 μg/m 3

.

Woodruff et al. (1997)

This is the first comprehensive national study to asses s the impact of fine particles (PM 10 ) on infant mortality in the United States. It includes a sample size of four million infants less than one year of age across 86 metropolitan areas for the interval 1989

- 1991. Overall, the study

estimates an increase of 4% for all

- cause infant mortality for every 10 μg/m 3 increase in PM 10

. The EPA SAB

- HEES (2004) now recommends that neonatal mortality be included in primary benefit analyses conducted by EPA, and that the Woodruff et al. C

- R be used. The Woodruff

st udy, however, did not include infants in a number of states, including California (because maternal education levels were not reported for California). While the study is likely representative of national conditions, it is impossible to determine whether the omission of California infants makes it less representative of the California population. Consequently, for the purposes of this study we do not include post neonatal deaths in the primary benefit analysis.

Jerrett et al. (2005)

This study is based on the Los Angeles area population subset from the national cohort included in Pope et al. (2002), accounts for the same confounders, and also assesses the association between average annual PM 2.5 and differences in mortality in the age 30 and older

popu lation. The authors find a substantially higher association between PM 2.5 and mortality,

with a 17% increase in all

- cause mortality for every 10 μg/m 3 increase in PM 2.5 . While this is quite a large difference, contrasted with the 6% increase found by Pope et al. for the overall national population, there are sound reasons to conclude that the results better represent the Los Angeles Basin population. A primary reason is that Jerrett et al. use a detailed intraurban exposure measure supported by 23 PM 2 .5 monitors across the region. This contrasts with the national cohort studies that compare interurban exposure and have much less spatial resolution.

Another is that traffic

- generated primary particles have a greater association with observed effects, a nd traffic in the Los Angeles basin accounts for nearly five times the proportion of total primary particles emitted as in the rest of the United States, at 3.7% compared to 0.75%.58 For purposes of assessing benefits in the SJV, the Jerrett et al. work is more appropriate than Pope et al. in that the exposure measure more closely fits the approach that we use in REHEX. However, because it is specific to the Los Angeles area population and the profile of

traffic

- related PM emissions in that region, we tak e the more conservative approach of relying on Pope et al. for our primary assessment and provide estimates based on Jerrett et al. as a sensitivity test. This is also the approach recommended by a peer

- review group recently asked by ARB to consider the u se of the Jerrett et al. result for a regulatory analysis (ARB 2005; Appendix A).

IV. 2 Estimates of Reduced Adverse Health Effects with Attainment of the NAAQS

Reductions in the numbers of adverse effects vary with the degree to which the baseline

per iod pollution levels exceed the standards, the size of the population at risk, and the size of the association between a change in pollution and triggering the effect. A further factor is the age of the population included in the underlying health science study. So, for example, while it is reasonable to think that chronic bronchitis might be caused by PM 2.5 exposure in the population under age 27, the study that we rely on only includes ages 27 and older, so the large population of those under that age i s treated as if this effect could not occur in that group. The same is true

for PM 2.5 - related mortality, where the population under age 30 is not included in the number of estimated annual deaths. Also, premature mortality, with a small risk factor, wil l not be as frequent an effect as one such as school absences, which carries a larger risk.

The number of pollution

- related effects that would be avoided if the NAAQS of ozone

and PM 2.5 were met are discussed and summarized below. The economic benefit and the aggregate value of reducing these effects are discussed in Section V.5 below.

IV. 2.1 Reductions in Ozone

- Related Effects

The reductions in effects that would be expected with attainment of the ozone NAAQS

are shown in Table I V

- 2. Typically, th ere are fewer of the more severe effects and fewer effects in smaller groups (for example, the population age 65 and older). However, while there are relatively few reductions in ozone

- related hospital admissions, at 260 per year, this is an effect

with considerable impacts on patients and their families. The relatively larger numbers of days of avoided school absences, 188,000, reflects the larger population and the sensitivity of children to ozone. For the age 5

- 17 population of 783,740 this suggests that on average one in four children experiences a day of absence each year due to elevated ozone levels.

IV. 2.2 Reductions in PM 2.5 - Related Effects

PM 2.5 - related effects are shown in Table I V

- 3. The most serious consequences of exposure to fine pa rticles over the health

- based standards are associated with PM 2.5, and this is reflected in the estimated gain of nearly 500 deaths averted each year. To put this in perspective, we estimate that 130 people die earlier than they would each year in Fresno County. In 2001

- 2003 an average of more than 180 people died in that county in motor vehicle accidents (DHS 2005). This means that reducing pollution can account for the equivalent of avoiding two thirds of the motor vehicle deaths there, similar to the proportions in Kern and Stanislaus Counties. This illustrates the real consequences of elevated fine particle levels, and the substantial gains59 from attaining the NAAQS. The contribution of PM 2.5 exposure to premature mortality, relative to reported moto r vehicle deaths, is shown by county in Table I V

- 4 below.

The avoidance of chronic bronchitis, an illness that can significantly limit activity, is also noteworthy at 325 cases a year. Asthmatic children also avoid more than 16,000 additional days

of u pper respiratory symptoms (in addition to ozone

- related school absences and asthma attacks). Children also experience fewer cases of acute bronchitis.

The economic value and aggregate benefits of avoiding these effects by attaining the NAAQS is discussed in Section V below.60 Table I V

- 1 Health endpoints

Ozone PM 2.5 School absences Ages 5

- 17 Acute bronchitis Ages 5

- 17 Emergency room visits All ages Lower respiratory symptoms in children Ages 5

- 17 Respiratory hospital admissions Under age 65 Upper respi ratory symptoms in children Ages 5

- 17 asthmatic population Respiratory hospital admissions Ages 65 and older Respiratory hospital admissions Ages 65 and older Asthma hospital admissions All ages of the asthmatic population Premature death (mortality Ages 18

- 64

Asthma attacks All ages of the asthmatic population Asthma ER visits Under age 18 Premature death (mortality ) All ages Minor restricted activity days All ages Minor restricted activity days Ages 18

- 64 Onset of chronic bronchitis Ages 27 and older

Non

- fatal heart attacks Ages 18 and older Cardiovascular hospital admissions Ages 18 and older

Neo

- natal mortality Under age 1 Asthma emergency room visits Under age 18 asthmatic population Work loss days Ages 18

- 64 Asthma hospital admissions Ages 64 and under61 Table I V

- 2 Ozone

- Related Effects

Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare Total

Respiratory Hospital

Admissions Ages 0

- 64 55 45 10 10 10 15 20 30 195

Respiratory Hospital

Admissions Ages 65+ 25 15 0 5 5 0 5 10 65

Respiratory Hospital

Admissions All ages 80 60 10 15 15 15 25 40 260

Asthma Attacks Asthmatic population all ages 5,900 4,700 900 1,100 1,300 1,500 1,900 3,000 23,300

Emergency Room

Visits All ages 20 15 5 5 5 5 5 10 70

School Absences Ages 5

- 17 34, 000 28,700 4,900 6,000 8,000 8,200 9,300 18,400 117,500

Days of School

Absences Ages 5

- 17 54,500 45,900 7,800 9,600 12,800 13,100 14,900 29,400 188,000

Minor Restricted Activity Days Ages 18

- 64 49,900 38,200 9,000 9,200 10,800 13,200 16,200 24,600 171,10 062 Table IV

- 3 PM 2.5 - Related Effects

Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare All

Counties

Minor Restricted Activity Days Ages 18

- 64 4,610 3,800 870 880 1,050 2,070 2,160 1,840 17,280

Premature Mor tality Ages 30 and older 130 100 15 15 20 65 65 50 460

Work Loss Days Ages 18

- 64 800 660 150 150 180 360 380 320 3,000

Lower Respiratory Symptoms Ages 5

- 17 240 195 35 40 60 100 105 100 875

Upper Respiratory Symptoms

Asthmatic Children 4,440 3,670 660 760 1,100 1,860 1,940 1,880 16,310

Acute Bronchitis Ages 5

- 17 860 750 130 140 210 390 360 390 3,230

Chronic Bronchitis Ages 27 and older 85 75 15 15 20 40 40 35 32563 Table IV

- 4 PM 2.5 - Related Deaths Compared to Motor Vehicle Deaths

County Annua l PM 2.5 - Related Deaths Annual Motor

Vehicle Deaths 6 PM 2.5 as % of MV

Kern 100 144 70% San Joaquin 65 111 59%

Stanislaus 65 97 67%

Merced 20 54 37%

Madera 15 37 41%

Fresno 130 181 72% Kings 15 34 45%

Tulare 50 89 56%

Total 460 747 62%

6 Annual average from 2001

- 2003.64 V. ECONOMIC VALUATION

V. 1 The Basis for Value

If we know how much illness and premature death might be avoided as a result of meeting the health

- based air quality standards, why assign monetary values at all, and what is the

basis for those values? First , there are more worthwhile things to do than either society or individuals can afford. As a result, we choose among the things that we do. The social choice to control emissions in order to improve air quality and health is one of these things, and one that is a high priority for Californians. It is therefore useful to have a sense in economic terms of the scale of gains from successfully implementing pollution control policies and programs. This study is designed to provide a measure of these gains that is transparent, uses the best available information, reflects social preferences and can readily be compared against the value of other

social choices.

The basis for each value begins with the premise that, within limits 7 , society accepts

individual ch oices as valid, and as reflecting the value that individuals place on their choices, whether it is which news channel to watch or which college is best for their child to attend. That is, what an individual chooses to do accurately represents what is bes t for him or her, and for society, which is simply the sum of the individuals that make up that society. Social value

– what we want to capture here

– is then simply the sum of value to individuals. To determine the value to individuals of reducing pollu tion

- related health risks we use prices or implied prices when available, along with survey (contingent valuation) results.

One objective of this study is to provide a monetary, or dollar, measure of the benefits that would accrue from avoiding some of t he adverse health effects that result from exposure to unhealthful air. A critical aspect of such a measure is determining the value that society places on avoiding specific adverse effects. These range from symptoms that are fairly minor, such as eye irritation, through hospitalization, emergency room visits, asthma attacks and the onset of chronic bronchitis, to premature death. Individuals value reducing these effects to avoid:

**•** Loss of time (work and school) and the direct medical costs that result f rom avoiding or responding to adverse health effects.

**•** The pain, inconvenience and anxiety that result from adverse effects, or efforts to avoid

or treat them.

**•** Loss of enjoyment and leisure time.

**•** Adverse effects on others resulting from their own adverse he alth effects.

V. 2 Concepts and Measures of Value

Ideally, measures of value would represent all of the losses to individuals and to society that result from adverse health effects. They would also accurately reflect actual preferences and

decision

- maki ng processes similar to those we use daily to make basic choices. Our decisions

7 Most people readily accept limits on individual choices that ar e necessary to protect others. This includes things such as criminal statutes, speed laws, and a variety of environmental protections ranging from vehicular exhaust standards to protection of endangered species.65 about which goods or services to buy are based on which items give the most satisfaction, or utility, relative to prices and income. Market prices are therefore accepted as r easonable measures of the value of those items that can be purchased. However, there is no market in which cleaner air (like many other environmental goods) can be bought. Consequently, values for such goods cannot be directly observed from prices. Econ omists have developed alternatives to market prices to measure the value of environmental improvements, including health benefits resulting from cleaner air.

Two generally accepted measures of the value of changes in well

- being due to reducing

the adverse health effects of air pollution are the cost of illness (COI) measure and the willingness to pay (WTP) or willingness to accept (WTA) measures. All three measures have limitations but, when taken together, they yield a generally accepted range of values f or the health benefits of improvements in air quality. In this study, we use the most appropriate available value for each health endpoint.

V. 2.1 Cost of Illness

The COI method was the first to be developed and described in the health and safety

literat ure as a basis to value reductions in risk. It requires calculating the actual direct expenditures on medical costs, plus indirect costs (lost wages), incurred due to illness. This method is still the primary measure used to value the benefit of avoiding hospital admissions and other medical treatments. The COI method has the advantage of being based on real dollars spent to treat specific health effects and the actual market value of work time. Since it includes only monetary losses, however, and does not include losses associated with the value of leisure time, of school or unpaid work time, or of general misery, it does not capture all of the benefits of better health. The method is therefore generally viewed as limited and representing a lower

bound on value. The basic limitation is that it is a measure of the financial impact of illness, not

the change in well being due to illness, since financial loss is only part of the value forfeited by illness and discomfort. Other factors, most notably pain, inconvenience and anxiety, associated with illness can result in a significant disparity between COI estimates and WTP (or WTA) estimates. As discussed below, the COI approach has been shown to produce a lower

- bound value estimate. Overall, COI measures are used when more complete measures are unavailable for a specific effect. While they generally represent a lower bound of value, using them allows the valuation of some adverse effects, such as emergency room visits, which might otherwise not be quantif ied.

V. 2.2 Market Based Values

Because we know that COI measures undervalue adverse health effects, many studies have been conducted to determine more complete values. For improvements in health, we use WTP measures, which are both more complete than CO I and consistent with accepted economic concepts about markets and individual economic choices. Market choices that reduce risks to health or life indirectly indicate the WTP for lower risks, or the WTA for higher risks. Values

derived from this method a re based on relating differences in wages or consumer costs to differing degrees of risk. Those differences indicate the demand for and the WTP for lower risk, or the WTA for greater risk. Because air quality is not a market commodity and has no

observab le market price, many of the values used in benefit assessments for environmental improvements depend on studies of market

- determined wage differentials and consumer66 expenditures in relation to lower risk of harm from other causes. These differentials and expenditures are then surrogates for the market price for reduced risk of harm from air pollution.

There is an extensive economics literature assessing the value of reduced workplace risk of death. It is, however, important to control for factors other th an risk that can influence wage differentials, such as unpleasant working conditions. Studies conducted in the past 20 years do control carefully for job attributes that are not related to differences in risk. (Viscusi 199 2, 1993, 2004; Viscusi and Aldy 2 003) There is a smaller literature that investigates differences in consumer expenditures relative to risk of injury or death associated with product use. The results for the most carefully conducted work, which controls for product characteristics other than relative risk, are generally consistent with the wage

- risk studies (Atkinson and H alvorsen 1990;

Viscusi 1992).

V. 2.3 Contingent Valuation

When values inferred from markets are not available, another means to estimate value

involves the use of surv eys. This method is referred to as contingent valuation (CV) because people are asked to determine what something would be worth as if they were able to purchase

or sell it. CV has become a significant source of values over the past two decades, as the

m ethodology has matured and become more accepted, and as policy

- makers (and the courts) have become more interested in the application of economic values to decision

- making. CV

based values, as with wage

- risk based WTA values, are conceptually better than COI because they are more inclusive. Respondents can value loss of enjoyment and discomfort, as well as the direct costs of an adverse health effect. The survey approach is, however, expensive to administer and the validity of values derived from this me thod depends on careful design and application of the survey instrument. Nonetheless, CV measures are in many cases well

supported and add useful information to ben efits assessment (Carson et al. 2001).

V. 2.4 Strengths and Limitations of Methods

The mo st appropriate basis for valuing reductions in adverse health effects is presently WTP values based on CV studies and WTA based on wage

- risk studies (Viscusi 1993). Cost of illness measures are used when preferred measures are unavailable because a lower bound value is preferable to zero value, which is implied when an effect is not included in the benefits assessment. We use four criteria to choose specific values from the literature.

1. The value used should be appropriate for the type of risk. For exampl e, involuntary risk might carry a higher value than voluntary risk. The degree of risk (1 in 10,000 or 1 in 1,000,000) is a factor, as is whether the risk of harm in increasing or decreasing. Whether harm is prospective or has already occurred is also a factor. 8

2. A measure should be as complete as possible. That is, it should represent gains or losses

in well

- being as fully as possible.

8 The human capital method used in damage a ward legal cases is not used here, for example, because harm has already occurred. In assessing the benefits of environmental improvements we are considering the avoidance of harm, not compensation for harm.67 3. If similar values are derived from studies using different methods, for example from

market

- based studies and CV studies , those values are given a greater weight on the premise that convergence implies a closer representation of true value.

4. If more than one valid study produces values that are similar for comparable adverse affects, those values are given greater weight.

Gi ven these criteria, CV results for WTP are most highly ranked for appropriateness and validity, followed by WTA from wage

- risk studies (supported by WTP from a valid consumer behavior study) and then COI measures.

V. 3 Specific Values for Premature Deat h

Premature mortality is the most significant effect of exposure to unhealthful levels of air pollution that can presently be quantified. Consequently, determining a socially appropriate value to attach to reducing the risk of premature mortality is a cru cial part of any benefit assessment. It is very important to keep in mind that we are not valuing the life of any identifiable individual, but rather the value of reducing a very small risk over a large population enough so that some people would live lon ger than would otherwise have been the case.

V.3 .1 The Concept of the Value of a Statistical Life

Wage

- risk studies tell us how much more compensation workers must be paid to accept jobs with very slightly elevated risks of job

- related death. Consider t his example:

There are 10,000 workers and the annual risk of job

- related death is 1/10,000 greater than in a lower wage job. This means that we would expect one job

- related death in this group annually (10,000 x 1/10,000). Let’s say that each worker is p aid $700 a year more as a result of this risk, and workers not facing this risk are paid $700 a year less than those at risk. The implied value of reducing risk just enough to prevent one death is $700 x 10,000 = $7,000,000.

This is what economists call the value of a statistical life (VSL). Studies of consumer choices and product risk are based on the same approach

– the small difference that each consumer pays to reduce a slight risk aggregated to the level of reducing risk enough to prevent a single de ath.

V. 3.2 The Range of Values

There is a very wide range across all studies that assess VSL. However, this range can be narrowed significantly by considering characteristics of the population in each study relative to the population with which we are co ncerned (the San Joaquin Valley), and by reviewing the methods used in each study. In a recent meta

- analysis of VSL from US wage

- risk studies (Viscusi and Aldy 2003), most estimates fell into the range of $3.8

- $9.0 million (in 2000 dollars)

with a median for “prime

- aged workers” of $7 million. This range is also consistent with the most robust consumer choice study (Atkinson and Halvorsen 1990), which found a VSL of $5.1 in 2000 dollars. Contingent valuation studies produce values at or above the upper e nd of the Viscusi and Aldy meta

- analysis (Viscusi 1993; Jones

- Lee 1976).68 V. 3.3 Issues in Selecting Specific Values

To assess the value to society of reducing the risk of premature death associated with elevated levels of air pollution, we want a value th at is based on risk of a similar scale (in this case a very small annual risk) and is based on the preferences of people similar to the population at risk from pollution exposure. The need to match the degree of risk and population

characteristics as clos ely as possible raises several issues, largely relating to factors such as age

and income.

V.3.3.1 Groups Most at Risk

For mortality, we have evidence for the very young

– newborns

– and those aged 30 and over associating elevated pollution with prematu re death. We also know that the very young, those whose health is already compromised, and those aged 65 and older are at greater risk than the general population.

V.3.3.2 Age and the Value of Life

Because wage

- risk studies are based largely on blue col lar workers, they reflect the preferences of younger workers, and not those outside the workforce who are very young or older, but who are likely at greater risk of early death related to air pollution. Since younger people have longer life expectancies, using a VSL based on their preferences might overstate the appropriate VSL for the older. Similarly, it is likely to understate society’s value for young children, as several studies indicate that parents and society more broadly place greater value on

pr eventing harm to children than to adults. Further, to the extent that blue collar workers have incomes below the average, their job choices might reflect a lower VSL than would be the case for white collar workers. Complicating this further, older adults are more likely to experience impaired health and could therefore have a lower VSL than is the case for a healthy younger or

middle

- aged adult or a child, although evidence suggests that this effect, if any, is small (Alberini et al. 2004). In determining which VSL to use to value air quality improvements, these factors

are all considered.

The most recent research regarding health status and older age (Alberini et al, 2004) finds no strong evidence that VSL declines significantly with age, and then only a t age 70 and above. Further, those with underlying health conditions report little difference in VSL than those who are healthier. At the other end of life, there is evidence (Dickie and Messman 2004; EPA 2003a and the references therein) that families and society place a higher value on children’s well

being, but there is no well established basis to adjust adult values to account for this. Although these are some studies that assess how much more we are willing to pay for children’s health,

there has b een little work regarding how we value their lives.

Consistent with these findings and the recommendations of peer

- review advisory groups, benefit assessments carried out for proposed federal and state rules and programs (EPA 2003 b

, 2004, 2005; ARB 2005) d o not make any adjustment for age or health status.69 V.3.4 The Value of a Statistical Life Used in this Study

As noted above, the convergence of values from US

- based wage

- risk studies is $3.8 to $9.0 million in 2000 dollars. Converting this to 2005 dol lars (using the US all

- item CPI) produces a range of $4.3 to $10.2 million. The value from a consumer choice study is $5.8

million in 2005 dollars.

The most recent final EPA regulatory analysis (EPA 2005) used $5.5 million in 1999 dollars. Converting thi s to 2005 dollars gives us $6.5 million. We further adjust this for the increase in per capita income in California from 1999 to 2004 9 , and assume an income elasticity

of 0.5 10

V. 4 Specific Values for Health Endpoints (Viscusi and Aldy 2003). This leads to a VSL of $6.7 million, which is the valu e used in this study.

Generally accepted values for many endpoints have been developed over the past decade and are widely used in benefit assessments and regulatory analyses by USEPA and the states.

These value s have been peer

- reviewed by advisory bodies, including committees of EPA’s Scientific Advisory Board, and many have also been published in the peer reviewed literature. We generally follow this established protocol, adjusting specific values for inflatio n and

California

- specific incomes. Where California

- specific COI data are available, as for hospitalizations, we use those values.

Onset of Chronic Bronchitis

Apart from premature death, the onset of chronic bronchitis is one of the most serious

adverse e ffects that is associated with PM exposure and is quantifiable. The value of avoiding this effect has been estimated in two CV studies (Krupnick and Cropper 1989; Viscusi et al. 1991) and is $374,000 in current dollars, beginning with the value used by EP A (2003b; 2004; 2005) to account for the severity of the disease relative to the underlying studies.

Hospitalizations

Respiratory

- related hospitalizations are costly both in terms of treatment and loss of work, household and leisure time. We use a Califor nia

- based value derived from Chestnut et al. (2006), of $32,000 per admission. While Chestnut et al. assessed the COI and WTP for adults, we apply this value to the entire population because when children are hospitalized, one or more adults faces the opp ortunity cost of time diverted from work, caring for other children and other

normal activities.

Minor Restricted Activity Days

Willingness to pay to avoid a day when normal activities are limited by a combination of pollution

- related symptoms derives from Tolley et al.’s 1986 study, reported by EPA (2005) as

9 The most recent final data available.

10 As in comes rise, consumers place greater value on many goods. The degree to which this value rises with income and leads to more consumption of a good is called income elasticity. While EPA most recently used 0.4 as the adjustment for this effect, Viscusi and Aldy found that the appropriate value for the income elasticity of VSL is 0.5

- 0.6.70 $51 in 1999 dollars and 1990 income. ARB (2005) converted this to current dollars and adjusted for income, yielding a value of $61 per MRAD.

Work Loss Days

Apart from MRADs, when productivity might be lower, some work days are lost outright

as a result of PM 2.5 exposure. These days are valued at the daily wage rate for each county, ranging from $123 in Merced to $141 in Kern and San Joaquin (EDD 2003).

School Absence Days

To value days of school abse nce, Smith et al. (1997) estimated lost productivity to the

adult care

- giver, under the assumption that one adult stayed home to take care of the sick child. In situations where two caregivers were involved, the lower income was used to estimate lost prod uctivity. In cases where only one adult had an income (about 39 percent of the cohort studied), an imputed value for household work was used.

Using this methodology, Smith et al. estimated the total indirect cost of 3.6 million school loss days to be $1 94.5 million (in 1994 dollars) This translates into a per

- day value of $54.03 (again, in 1994 dollars).

To apply these national figures to our analysis, two adjustments were then made. First, the value was updated to 2005 dollars. Second, it was modified to reflect wage levels in the SJV. This is the approach adopted by EPA (2005) and used by Hall et al. (2003). This method produces a range of values from $65 in Tulare County to $79 in San Joaquin County.

Upper and Lower Respiratory Symptom Days

For t hese effects we adjusted the value that EPA (2005) has adopted, again adjusting for income and inflation to 2005 values. A lower respiratory symptom day is valued at $20 and an upper respiratory day at $32.

Acute Bronchitis

Bronchitis typically involve s multiple symptoms and each occurrence has a duration of about six days (EPA 2005). To construct a value for this effect, we combine Loehman et al.’s (1979) values for chest discomfort and cough and update this number to 2005 dollars, producing

a value f or one day of $18.30. Over a six day period, this reaches a total of $110.

Asthma Attack

This effect is valued based on a 1986 CV study conducted in Los Angeles (Rowe and Chestnut) that estimated WTP to avoid a “bad asthma day.” Adjusting EPA’s most recent peer

reviewed figure to current dollars and adjusting for income, this value is $50 per event.71 Emergency Room Visits

Emergency room visits are valued at $335 in 2005 dollars based on two combined COI studies (EPA 2005). This dollar measure do es not include time lost at work or school, or the value of avoiding the pain and anxiety caused by the underlying condition and ER visit.

V. 5 Estimated Economic Value from Reduced Adverse Health Effects with Attainment of the NAAQS for Ozone and PM 2.5

Unsurprisingly, given the great value that individuals and society more broadly place on life, the overall benefits of attaining the NAAQS are dominated by premature mortality. Across the Valley 460 people are estimated to avoid premature death each year , accounting only for the

effect of PM 2.5 and only for the population age 30 and older. With a value for each life of $6.7 million, this effect alone offers a benefit of attainment of more than $3 billion each year. While this consequence of elevated f ine particle levels is by far the most striking, other effects are also important.

For example, an additional 325 new cases of chronic bronchitis annually could be

avoided with attainment of the PM 2.5 NAAQS. At a value of $374,000 each

– reflecting the

s ignificant costs of treatment and loss of enjoyment and activity

– avoiding this effect would generate benefits of over $120 million annually. Ozone attainment offers thousands fewer school absence days, conservatively valued at nearly $13 million a year. It should be noted that this only reflects the value of time lost to an adult caregiver and not any medical costs or loss of educational opportunity. Minor restricted activity days (MRADs) would cost adults over 190,000 days a year when their daily rout ine is limited to some degree by exposure to elevated

ozone or PM 2.5 . Avoiding this offers an economic benefit over $10 million annually.

Tables V

- 1 and V

- 2 show the overall benefits, both in numbers of effects and in dollars

for ozone and for PM 2.5 , res pectively. Looking at the overall benefits, residents of the San Joaquin Valley could expect annual benefits of $3.2 billion if both the ozone and PM 2.5 NAAQS

were attained.

It is also worth considering the per capita benefits, to provide a sense of pers pective. On a Valley

- wide average, annual benefits are nearly $1,000 per person. This varies across counties with the levels of pollution and the size of the more vulnerable populations, and very slightly with income (which determines or influences the val ue of some effects). The county

- level average benefits per resident range from nearly $650 in Merced County to over $1,200 in Kern County. 11

11 Fresno $1,124; Kern $1,209; Kings $785; Madera $679; Merced $645; San Joaquin $789; Stanislaus $973; Tulare $1,020; all counties $970.72 Table V

- 1 Ozone

- Related Effects and Economic Value

Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare Total

Respiratory Hospital

Admissions Ages 0

- 64 55 45 10 10 10 15 20 30 195

Respiratory Hospital

Admissions Ages 65+ 25 15 0 5 5 0 5 10 65

Respiratory Hospital

Admissions All ages 80 60 10 15 15 15 25 40 260

Value(milli ons) $2.56 $1.92 $0.32 $0.48 $0.48 $0.48 $0.8 $1.28 $8.32

Asthma Attacks Asthmatic population all ages 5,900 4,700 900 1,100 1,300 1,500 1,900 3,000 23,300

Value(thousands) $295 $235 $45 $55 $65 $75 $95 $150 $1,015

Emerge ncy Room

Visits All ages 20 15 5 5 5 5 5 10 70

Value (thousands) $6.70 $4.31 $1.68 $1.68 $1.68 $1.68 $1.68 $3.35 $23.45

School Absences Ages 5

- 17 34,000 28,700 4,900 6,000 8,000 8,200 9,300 18,400 117,500

Days of School

Absences Ages 5

- 17 54,500 45,900 7,800 9,600 12,800 13,100 14,900 29,400 188,000

Value(millions) $3.60 $3.12 $0.53 $0.66 $0.87 $1.03 $1.13 $1.91 $12.85

Minor Restricted Activity Days Ages 18

- 64 49,900 38,200 9,000 9,200 10,800 13,200 16,200 24,600 171,100

Value(millions) $3.04 $2.33 $0.55 $0.56 $0.66 $0.80 $0.99 $1.5 $10.43

Total Value in

Millions $9.5 $7.61 $1.45 $1.76 $2.08 $2.39 $3.02 $4.84 $32.6473 Table V

- 2 PM 2.5 - Related Effects an d Economic Value

Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare All

Counties

Minor Restricted Activity Days Ages 18

- 64 4,610 3,800 870 880 1,050 2,070 2,160 1,840 17,280

Val ue(thousands) $281.2 $231.8 $53.1 $53.7 $64.1 $126.3 $131.8 $112.2 $1,054.2

Premature Mortality Ages 30 and older 130 100 15 15 20 65 65 50 460

Value(millions) $871.0 $670.0 $100.5 $100.5 $134.0 $435.5 $435.5 $335.0 $3,082. 0

Work Loss Days Ages 18

- 64 800 660 150 150 180 360 380 320 3,000

Value(thousands) $106.0 $93.1 $21.0 $19.8 $22.0 $50.8 $52.0 $39.7 $403.8

Lower Respiratory Symptoms Ages 5

- 17 240 195 35 40 60 100 105 100 875

Value(thousands) $4.8 $3.9 $0.7 $0.8 $1.2 $2.0 $2.1 $2.0 $17.5

Upper Respiratory Symptoms

Asthmatic Children 4,440 3,670 660 760 1,100 1,860 1,940 1,880 16,310

Value(thousands) $142.1 $117.4 $21.1 $24.3 $35.2 $59.5 $62.1 $60.2 $521.9

Acute Bronchitis Ages 5

- 17 860 750 130 140 210 390 360 390 3,230

Value(thousands) $94.6 $82.5 $14.3 $15.4 $23.1 $42.9 $39.6 $42.9 $355.3

Chronic Bronchitis Ages 27 and older 85 75 15 15 20 4 0 40 35 325

Value (millions) $31.8 $28.1 $5.6 $5.6 $7.5 $15.0 $15.0 $13.1 $121.6

Total Value in

Millions $903.4 $698.6 $106.2 $106.2 $141.6 $450.8 $450.8 $348.4 $3,20674 VI. C ONCLUSIONS AND IMPLICATIONS

Conc lusions

Almost every resident of the San Joaquin Valley regularly experiences air pollution levels known to harm health and to increase the risk of early death. For example, from 2002 through 2004 each person was on average exposed to unhealthful levels of ozone on 70 days a year. Even in the county with the lowest exposure (San Joaquin County ) residents we re exposed to
levels over the California 8

- hour standard on ten days each year. In Kern County, this rises to over 100 days each year. This is unsu rprising, given how frequently and pervasively the health

based air quality standards are violated. These exposures translate directly into poorer health and an elevated risk of premature death. Further, some groups are more at risk than the average,

wi th Hispanics experiencing six more days of ozone exposure above the California air quality standard than the average resident.

Some other noteworthy results of the analysis include:

**•** Valley

- wide, the economic benefits of meeting the federal PM 2.5 and o zone standards average nearly $1,000 per person per year , or a total of more than $3 billion.

This dollar value represents the following:

**•** 460 fewer premature deaths among those age 30 and older

**•** 325 fewer new cases of chronic bronchitis

**•** 188,400 fewer d ays of reduced activity in adults

**•** 260 fewer hospital admissions

**•** 23,300 fewer asthma attacks

**•** 188,000 fewer days of school absence

**•** 3,230 fewer cases of acute bronchitis in children

**•** 3,000 fewer work loss days

**•** More than 17,000 fewer days of respiratory sympto ms in children

To place the reduction in premature deaths in perspective, attaining the federal PM 2.5 standard would be the equivalent of reducing motor vehicle deaths by over 60% Valley

- wide, and by more than 70% in Fresno and Kern Counties.

Implication s

Residents of the San Joaquin Valley face significant public health risks from the present unhealthful levels of ozone and fine particles. This is in addition to other health challenges, including a high rate of poverty, which exceeds 30% in Fresno Cou nty, compared to a statewide rate below 20%. The region overall would experience substantial economic and health gains from effective policies to reduce pollution levels. For the more populous and more polluted areas in Kern and Fresno Counties, this is even more pronounced. Attaining the California air quality standards, which are more protective of health, would double the health benefits listed

above.75 The adverse impacts of air pollution are not distributed equally. Both Hispanics and non

Hispanic blacks are exposed to more days when the health

- based standards are violated. Residents of Fresno and Kern Counties experience many more days when the PM 2.5 standards are violated than the Valley

- wide average. Tulare County joins Fresno and Kern in be ing well above average for the number of days of exposure above the ozone standards. Children under age 5 are exposed to ozone concentrations above 70 ppb on more days than older adults.

Because ozone is elevated during the summer months, and the PM 2.5 24

- hour standard is typically violated more frequently in the winter months, there is no “clean” season in this region.

As the population continues to increase, with associated increases in vehicle traffic and economic activity, the gains from attainin g the health

- based air quality standards will grow, but also become more difficult to achieve. Identifying and acting on opportunities now would produce substantial gains to the people of the Valley

.76 VII. REFERENCES

Abbey D.E., F. Petersen, P.K. Mil ls and W.L. Beeson. (1993) Long

- term ambient concentrations of total suspended particulates, ozone and sulfur dioxide and respiratory symptoms in a nonsmoking population, Archives of Environmental Health 48 (10), 33

- 46.

Abbey D.E., B.E. Ostro, F. Petersen a nd R.J. Burchette

. ( 1995 ) Chronic respiratory symptoms associated with estimated long

- term ambient concentrations of fine particulates less than 2.5 microns in aerodynamic diameter (PM2.5) and other air pollutants, Journal of Exposure Analysis and Environm ental Epidemiology 5 (2), 137

- 159.

Adams P.F., G.E. Hendershot and M.A. Marano. (1999) Current Estimates from the National Health Interview Survey, 1996, Vital Health Statistics 10 (100), 1

- 212.

Alberini A., M. Cropper, A. Krupnick, and N. Simon. (2004) Does the value of a statistical life vary with age and health status? Evidence from the US and Canada, Journal of Environmental Economics and Management 48 (1), 769

- 792.

American Lung Association. (2002) Trends in Morbidity and Mortality: Pneumonia, Influenza, and Acute Respiratory Conditions . American L u ng Association, Best Practices and Program Services, Epidemiology and Statistics Unit.

Atkinson S.E. and R. Halvorsen. (1990) The valuation of risks to life: evidence from the market for automobiles, Review of Economics and Statistics 72 (1), 133

- 136.

Bell M.L., F. Dominici and J.M. Samet. (2005) A meta

- analysis of time

- series studies of ozone and mortality with comparison to the national morbidity, mortality, and air pollution study, Epidemiology 16 (4), 436

- 445.

Bell M.L., R.D. Peng and F. Dominici. (2006) The exposure

- response curve for ozone and risk of mortality and the adequacy of current ozone regulations, Environmental Health Perspectives On

- line (available at http://dx.doi.org/).

Burnett R.T., J.R. Brook, W.T. Yung, R.E. Dales and D. Krewski. (1997) Association between ozone and hospitalization for respiratory disease in 16 Canadian cities, Environmental

Research 72 (1), 24

- 31.

Burnett R.T., R.E. Dales, M.E. Raizenne, D. Krewski, P.W. Summers, G.R. Roberts, M Raadyoung, T. Dann and J. Brook. (1994) Effects of low ambient levels of ozone and sulfates on the frequency of respiratory admissions to Ontario hospitals, Environmental

Research 65 (2), 172

- 194.

California Air Resources Board (ARB). (2005) Emission Red uction Plan for Ports and International Goods Movement in California , California Environmental Protection Agency, Sacramento, CA.

Carson R.T., N.E. Flores and N.F. Meade. (2001) Contingent valuation: controversies and evidence, Environmental and Resource E conomics 19 (2), 173

- 210.77 Chay K.Y. and M. Greenstone. (2003) The impact of air pollution on infant mortality: evidence from geographic variation in pollution shocks induced by a recession, Quarterly Journal of Economics 118 (3), 1121

- 1167.

Chen L., B.L. Jen nison, W. Yang and S.T. Omaye. (2000 ) Elementary school absenteeism and air pollution, Inhalation Toxicology 12 , 997

- 1016.

Chestnut L.G., M.A. Thayer, J.K. Lozo and S.K. Van Den Eeden. (2006) The economic value of preventing respiratory and cardiovascular hospitalizations, Contemporary Economic Policy 24 (1), 127

- 143.

Cody, R.P., C.P. Weisel, G. Birnbaum and P.J. Lioy. (1992) The effect of ozone associated with summertime photochemical smog on the frequency of asthma visits to hospital emergency departments, Environmental Research 58 (2), 184

- 194.

DHS. (2005) County Health Status Profiles 2005 , Sacramento, CA. http://www.dhs.ca.gov/hisp/chs/OHIR/reports/healthstatusprofiles/ 2005/

Dickie, M. and V.L. Messman. (2004) Parental altruism and the value of avoiding acute illness: are kids worth more than their parents? Journal of Environmental Economics and Management 48 (3), 1146

- 1174.

Dockery D.W., J. Cunningham, A.I. Damokosh, L .M. Neas, J.D. Spengler, P. Koutrakis, J.H. Ware, M. Raizenne and F.E. Speizer. (1996) Health effects of acid aerosols on North American children: respiratory symptoms, Environmental Health Perspectives 104 (5),

500

- 505.

Ebelt S.T., M. Brauer and W.E. Wilso n. (2003) A comparison of health effects from exposure to

ambient and non

- ambient particles. Poster P02

- 08 presented at the 2003 AAAR PM Meeting, Particulate Matter: Atmospheric Sciences, Exposure and the Fourth Colloquium on PM and Human Health , Pittsburg h, PA, March 31

– April 4.

Employment Development Department. (2003) Occupational Employment Statistics Survey

, Sacramento, CA.

EPA. (1999) The Benefits and Costs of the Clean Air Act, 1990

- 2010 . Prepared for U.S. Congress by U.S. EPA, Office of Air and Ra diation/Office of Policy Analysis and Review, Washington, DC. November; EPA report no. EPA

- 410

- R

- 99

- 001.

EPA. (2003a) Children’s Health Valuation Handbook , Washington D.C.

EPA. (2003b) Benefits and Costs of the Clean Air Act 1990

- 2020: Revised Analytical P lan for EPA’s Second Prospective Analysis , May, Washington D.C.

EPA. (2004) Final Regulatory Analysis: Control of Emissions from Nonroad Diesel Engines

, May, Washington D.C.

EPA. (2005) Clean Air Interstate Rule: Regulatory Impact Analysis , March, Washingt on D.C.78 EPA (SAB

- HEES). (2004) Advisory on Plans for Health Effects Analysis in the Analytical Plan for EPA’s Second Prospective Analysis

– Benefits and Costs of the Clean Air Act 1990

- 2020 , EPA

- SAB

- Council

- ADV

- 04

- 002, Washington, D.C.

Fruin S.A., M.J. St . Denis, A.M. Winer, S.D. Colome and F.W. Lurmann. (2001) Reductions in human benzene exposure in the California South Coast Air Basin. Atmospheric

Environment 35 (6), 1069

- 1077.

Gilliland F.D., K. Berhane, E.B. Rappaport, D.C. Thomas, E. Avol, W.J. Gauder man, S.J. London, H.G. Margolis, R. McConnell, K.T. Islam and J.M. Peters. (2001) The effects of ambient air pollution on school absenteeism due to respiratory illnesses, Epidemiology

12 (1), 1

- 11.

Hall J.V., A.M. Winer, M.T. Kleinman, F.W. Lurmann, V. Braj er and S.D. Colome. (1992) Valuing the health benefits of clean air, Science 255 (5046): 812

- 817.

Hall J.V., V. Brajer and F. W. Lurmann. (2003) Economic valuation of ozone

- related school

absences in the South Coast air basin of California. Contemporary Eco nomic Policy

21 (4), 407

- 417.

Ito K. (2003) Associations of particulate matter components with daily mortality and morbidity in Detroit, Michigan, in: Revised Analyses of Time

- Series Studies of Air Pollution and

Health , Special Report, Health Effects Instit ute, Boston, MA.

Jerrett M., R.T. Burnett, R. Ma, C.A. Pope, D. Krewski, K.B. Newbold, G. Thurston, Y. Shi, N. Finkelstein, E.E. Calle and M.J. Thun. (2005) Spatial analysis of air pollution and mortality in Los Angeles. Epidemiology 16 (6), 727

- 736.

Jones

- Lee M.W. (1976) The Value of Life: an Economic Analysis , University of Chicago Press, Chicago.

Jones

- Lee M.W. (1992) Paternalistic altruism and the value of statistical life , The Economic

Journal 102 (410), 80

- 90.

Krewski D., R. Burnett, M. Goldberg, K. H oover, J. Siemiatycki, M. Jerrett, M. Abrahamowicz and M. White. (2000) Reanalysis of the Harvard Six Cities Study and the American Cancer Society Study of Particulate Air Pollution and Mortality , Health Effects Institute, Cambridge, MA.

Krupnick A.J. and M.L. Cropper. (1989) Valuing Chronic Morbidity Damages: Medical Costs, Labor Market Effects, and Individual Valuation , Final Report to U.S. EPA, Office of Policy Analysis, Washington D.C.

Liu J.T., J.K. Hammitt, J.

- D. Wang and J.

- L. Liu. (2000) Mother’s wi llingness to pay for her own and her child’s health: a contingent valuation study in Taiwan, Health Economics

9 (4) , 319

- 326.79 Loehman E., S. V. Berg, A. A. Arroyo, R. A. Hedinger, J. M. Schwartz, M. E. Shaw, R. W. Fahien, V. H. De, R. P. Fishe, D. E. Rio, W . F. Rossley and A. E. S. Green. (1979) Distributional analysis of regional benefits and cost of air quality control, Journal of Environmental Economics and Management 6 (3), 222

- 243.

Loomis D., M. Castillejos, D.R. Gold, W. McDonnel, V.H. Borja

- Arbuto. (1 999) Air pollution and infant mortality in Mexico City, Epidemiology 10 (2), 118

- 123.

Lurmann F.W. and N. Kumar. (1996) Symptom

- valuation model SYMVAL Version 1.1: User’s

Guide , South Coast Air Quality Management District, Diamond Bar, CA, September.

Lurman n F.W., J.V. Hall, M. Kleinman, L.R. Chinkin, V. Brajer, D. Meacher, F. Mummery, R.L. Arndt, T.L. Haste

- Funk, S.B. Hurwitt and N. Kumar. (1999) Assessment of the Health Benefits of Improving Air Quality in Houston, Texas , City of Houston Office of the May or, November.

Lurmann F.W., A.M. Winer and S.D. Colome. (1989) Development and application of a new regional human exposure (REHEX) model. In Proceedings from the U.S. Environmental Protection Agency and Air & Waste Management Association Conference on Tot al Exposure Assessment Methodology: New Horizons, Las Vegas, NV, November 27

- 30 , Air & Waste Management Association, Pittsburgh, PA.

Lurmann F.W. and M.E. Korc. (1994) User’s guide to the regional human exposure (REHEX) model. Draft report prepared for Bay Area Air Quality Management District, San Francisco, CA, by Sonoma Technology, Inc., Santa Rosa, CA, STI

- 93150

- 1414

- DR, April.

Moolgavkar S.H. ( 2000 ) Air pollution and hospital admissions for diseases of the circulatory system in three U.S. metropolitan a reas, Journal of the Air and Waste Management

Association 50 , 1199

- 1206.

Moolgavkar S.H., E.G. Luebeck and E.L. Anderson. (1997) Air pollution and hospital admissions for respiratory causes in Minneapolis St. Paul and Birmingham, Epidemiology

8 (4), 364

- 370

.

Office of Statewide Health Planning and Development (OSHPD). (2003) Inpatient Hospital Discharge Frequencies for California , California Health and Human Services Agency, Sacramento, CA.

Ostro B.D. (1987) Air pollution and morbidity revisited: a specific ation test, Journal of Environmental Economics and Management 14 (11), 87

- 98.

Ostro B.D. and S. Rothschild. (1989) Air pollution and acute respiratory morbidity: an observational study of multiple pollutants, Environmental Research 50 (2), 238

- 247.

Pereira L .A.A., D. Loomis, G.M.S. Conceicao, A.L.F. Braga, R.M. Arcas, H.S. Kishi, R.M. Singer, G.M. Bohm and P.H.N. Saldiva. (1998) Association between air pollution and intrauterine mortality in Sao Paulo, Brazil, Environmental Health Perspectives 106 (6),

325

- 329

.80 Pope C.A., D.W. Dockery, J.D. Spengler and M.E. Raizenne

. ( 1991 ) Respiratory health and PM10 pollution

— a daily time series analysis, American Review of Respiratory Disease

144 (3), 668

- 674.

Pope C.A., M.J. Thun, M.M. Namboodiri, D.W. Dockery, J.S. Evans, F.E. Speizer and C.W. Heath. (1995) Particulate air pollution as a predictor of mortality in a prospective study of U.S. adults, American Journal of Respiratory Critical Care Medicine 151 (3), 669

- 674.

Pope C.A., R.T. Burnett, M.J. Thun, E.E. Calle, D. Krew ski, K. Ito and G.D. Thurston. (2002) Lung cancer, cardiopulmonary mortality, and long

- term exposure to fine particulate air pollution, Journal of the American Medical Association 287 (9), 1132

- 1141.

Rowe R.D. and L.G. Chestnut. (1986) Oxidants and Asthmati cs in Los Angeles: A Benefits

Assessment

, Report to the U.S. EPA, Office of Policy Analysis, E PA

- 230

- 09

- 86

- 018, Washington, D.C.

San Joaquin Valley Air Pollution Control District. (2005) State implementation plans for federal

8

- hour ozone and PM 2.5 standar ds for the San Joaquin Valley, Public meeting presentation, San Joaquin Valley Unified Air Pollution Control District, Fresno, CA, January 4.

Schwartz J. and L.M. Neas ( 2000 ) Fine particles are more strongly associated than coarse particles with acute resp iratory health effects in schoolchildren, Epidemiology 11 (1), 6

- 10.

Schwartz J. (1994a) Air pollution and hospital admissions for the elderly in Detroit, Michigan, American Journal of Respiratory and Critical Care M edicine 150 (3), 648

- 655.

Schwartz J. (199 4b) PM(10), ozone and hospital admissions for the elderly in Minneapolis St. Paul, Minnesota, Archives of Environmental Health 49 (5), 366

- 374.

Schwartz J. (1995) Short term fluctuations in air pollution and hospital admissions of the elderly for respirator y disease, Thorax 50 (5), 531

- 538.

Schwartz J., D.W. Dockery, L.M. Neas, D. Wypij, J.H. Ware, J.D. Spengler, P. Koutrakis, F.E. Speizer and B.G. Ferris, Jr. (1994) Acute effects of summer air pollution on respiratory symptom reporting in children, American Journal of Respiratory Critical Care Medicine

150 (5), 1234

- 1242.

Smith, D.H., D.C. Malone, K.A. Lawson, L.J. Okamoto, C. Battista and W.B. Saunders. (1997). A national estimate of the economic costs of asthma, American Journal of Respiratory

and Critical C are Medicine 156 (3), 787

- 793.

Thurston G.D. and K. Ito. ( 1999 ) Epidemiological studies of ozone exposure effects, in: Air

Pollution and Health , edited by Holgate S.T., J.M. Samet, H.S. Koren and R.L. Maynard, Academic Press, San Diego, CA.

Thurston G.D., K . Ito, C.G. Hayes, D.V. Bates and M. Lippmann. (1994) Respiratory hospital admissions and summertime haze air pollution in Toronto, Ontario: consideration of the role of acid aerosols, Environmental Research 65 (2), 271

- 290.81 Tolley G.S. and L. Babcock, et a l. (1986) Valuation of Reductions in Human Health Symptoms

and Risks

, Final Report to USEPA, Office of Policy Analysis, Washington, D.C.

USBLS http://www.economagic.com/em

- cgi/data .exe/blscu/CUUR0400SA0

U.S. Department of Health and Human Services. (2005) National Hospital Discharge Survey

, National Center for Health Statistics, Hyattsville, MD.

Viscusi W.K. (1992) Fatal Tradeoffs: Public and Private Responsibilities for Risk , O xford University Press, New York.

Viscusi W.K. (1993) The value of risks to life and health, J ournal of Economic Literature 31 (4),

1912

- 1946.

Viscusi W.K. (2004) The value of life: estimates with risks by occupation and industry, Economic Inquiry 42 (1)

, 29

- 48.

Viscusi W.K.

, W.A. Magat and J. Huber (1991) Pricing environmental health risks: survey

assessments of risk

- risk and risk

- dollar trade

- offs for chronic bronchitis J ournal of Environmental Economics and Management 21 (1)

, 32

- 51.

Viscusi W.K. and J

. Ald y. (2003) The value of statistical life: a critical review of market estimates throughout the world, J ournal of Risk and Uncertainty 27 (1)

, 5

- 76.

Wang X., H. Ding, L. Ryan and X. Xu. (1997) Association between air pollution and low birth weight: a communi ty

- based study, Environmental Health Perspectives 105 (5), 514

- 520.

Weisel C.P., R.P. Cody and P.J. Lioy. (1995). Relationship between summertime ambient ozone levels and emergency department visits for asthma in central New Jersey, Environmental

Health Per spectives 103 Suppl(2)

, 97

- 102.

Whittemore A.S. and E.L. Korn. (1980). Asthma and air pollution in the Los Angeles area, American Journal of Public Health 70 (7)

, 687

- 696.

Wilson W.E., D.T. Mage and L.D. Grant. (2000) Estimating separately personal exposur e to ambient and nonambient particulate matter for epidemiology and risk assessment: why

and how

, Journal of the Air & Waste Management Association 50 (7), 1167

- 1183.

Woodruff T.J., J. Grillo and K.C. Schoendorf

. (1997) The relationship between selected cau ses of postneonatal infant mortality and particulate air pollution in the United States, Environmental Health Perspectives 105 (6), 608

- 612.82 APPENDIX

A.1 The Benefits of Attaining the California A mbient Air Q uality S tandards

T he state health

- based standards for ozone and PM 2.5 provide a greater degree of protection than do the federal standards. Consequently, the benefits of attaining the California Ambient Air Quality Standards ( CAAQS ) are significantly larger. While the pr esent focus is on attainment of the NAAQS, there is clear evidence that health will continue to be impaired until the CAAQS are also atta ined. The health

- related benefits of attaining the ozone CAAQS are

shown in Table A

- 1. PM 2.5

– related benefits are sh own in Table A

- 2. It should be noted that there is no separate state 24

- hour standard for PM 2.5 , so only effects associated with longer term (annual average) exposure are included here. Generally, attaining the California standards would approximately do uble the gains that will result from meeting the NAAQS.83 Table A

- 1 Reductions in Ozone

- Related Health Effects Resulting from CAAQS Attainment

Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare Total

Respiratory Hospital

Admissions Ages 0

- 6 4 120 85 15 20 20 35 40 60 395

Respiratory Hospital

Admissions Ages 65+ 55 35 5 10 10 0 10 25 150

Respiratory Hospital

Admissions All ages 175 120 20 30 30 35 50 85 545

Value(millions) $5.60 $3.84 $0.64 $0.96 $0.96 $1.12 $1.60 $2.72 $17.44

Asthma Attacks Asthmatic population all ages 12,600 9,300 1,900 2,300 2,800 3,500 4,200 6,100 42,700

Value(thousands) $630 $465 $95 $115 $140 $175 $210 $305 $2,135

Emergency Room

Visits All ages 30 20 5 5 5 10 10 15 100

Value (thousands) $8.61 $5.74 $1.44 $1.44 $1.44 $2.87 $2.87 $4.31 $28.72

School Absences Ages 5

- 17 78,200 59,900 11,000 13,800 18,900 19,800 22,200 38,800 262,600

Days of School

Absences Ages 5

- 17 125 ,100 95,800 17,600 22,100 30,200 31,700 35,500 62,100 420,100

Value(millions) $8.26 $6.51 $1.20 $1.52 $2.05 $2.50 $2.70 $4.04 $28.80

Minor Restricted Activity Days Ages 18

- 64 96,800 69,400 16,100 18,100 21,000 27,400 31,7 00 43,900 322,400

Value(millions) $5.90 $4.23 $0.98 $1.10 $1.28 $1.67 $1.93 $2.68 $19.80

Total Value in

Millions $20.40 $15.06 $2.92 $3.71 $4.44 $5.47 $6.44 $9.74 $68.1884 Table A

- 2 Reductions in PM 2.5 - Related Health E ffects Resulting from CAAQS Attainment

Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare Total

Premature Mortality Ages 30 and older 240 180 30 30 40 120 130 110 880

Value(millions) $1,608.0 $1,206.0 $201.0 $201.0 $268.0 $804.0 $871.0 $737.0 $5,896.0

Acute Bronchitis Ages 5

- 17 1,540 1,290 240 250 380 740 700 780 5,920

Value(thousands) $169.4 $141.9 $26.4 $27.5 $41.8 $81.4 $77.0 $85.8 $651.2

Chronic Bronchitis Ages 27 and old er 155 130 30 30 35 80 75 75 610

Value (millions) $58.0 $48.6 $11.2 $11.2 $13.1 $29.9 $28.0 $28.0 $228.1

Total Value in

Millions $1,666.2 $1,254.7 $212.2 $212.2 $281.1 $834.0 $899.1 $765.1 $6,124.7

A.2 Sensitivity Ana lysis by Endpoint

The results presented in S ections IV and V above report a mid

- value for each effect, based on a professional consensus regarding the concentration

- response relationships that “best” represent the association between exposure and result ing adverse health effects. It is generally accepted, however, that the real association lies with in a range. Here we present the results of sensitivity tests that estimate benefits based on such a range, generally based on 95% confidence

intervals. Uns urprisingly, this analysis produces a wide range in the res ults, and the results are

shown in Tables A

- 3 and A

- 4.

There is one noteworthy result, which is the high estimate for premature mortality, indicating over 1,200 deaths a year associated with vi olations of the NAAQS for PM 2.5 , in

contrast to 460 estimated with the mid

- range concentration

- response function. The difference results entirely from the use of Pope et al.’s (2002) central value for the “base” case and Jerrett et al.’s (2005) result fo r the high case. As noted in section IV, Jerrett et al. is likely a better representation of risk for the SJV population than is the Pope et al. result, a conclusion reached by several peer reviewers who addressed this question recently for ARB (CARB 2005 ).85 Table A

- 3 Ozone

- Related Effects Low and High Case Ranges

Adverse Effect All Counties

– Range of Effects All Counties

– Range of Value Respiratory Hospital Admissions All ages 150

- 360 $4,800,000

– 11,520,000

Asthma Attacks Asthmatic population al l ages 4,670

- 35,690 $233,500

– 1,785,000

Emergency Room Visits All ages 40

- 80 $11,480

– 22,960

Days of School Absences Ages 5

- 17 88,560

- 282,300 $3,786,000

– 12,070,000

Minor Restricted Activity Days Ages 18

- 64 69,500

- 270,400 $4,240,000

– 16,490,000

Ta ble A

- 4 PM 2.5 - Related Effects Low and High Case Ranges

Adverse Effect All Counties

– Range of Effects All Counties

– Range of Value Minor Restricted Activity Days Ages 18

- 64 14,070

- 20,460 $858,270

- $1,248,060

Premature Mortality Ages 30 and older 160

- 1,220 $1,072,000,000

- $8,174,000,000

Work Loss Days Ages 18

- 64 2,540

- 3,470 $342,800

– 466,400

Lower Respiratory Symptoms Ages 5

- 17 195

- 1510 $3,900

- 30,000

Upper Respiratory Symptoms

Asthmatic Children 2,770

- 29,370 $88,640

– 939,800

Acut e Bronchitis Ages 5

- 17 1,240

- 5,070 $136,400

– 557,700

Chronic Bronchitis Ages 27 and older 165

- 480 $61,710,000

- $179,500,000