Planned Air Pollution Research - Full Descriptions
Fiscal Year 1999-2000

This page updated November 3, 2005.

Research Plan

Proposed Projects for Fiscal Year 1999-2000

TITLE: Analysis of Weekend Episodic Activity
PROBLEM: Both the on- and off-road mobile source emission inventory models purport to estimate ozone episodic inventories. However, the activity estimates contained in the models are based on either monthly or yearly averages. It is widely known that ozone episodes occur more often on weekends than during the week, but little is known regarding changes in activity that might contribute to these episodes.
PREVIOUS WORK: Analyses of weekday vs. weekend episodes have been performed by Dr. Winer of UCLA. However, these studies have been limited to meteorological influences and the analysis of ambient monitoring station data.
OBJECTIVE: To conduct a comprehensive study of the activity changes in the mobile source fleet from weekday to weekend, with emphasis on understanding the relationship between activity and air quality.
DESCRIPTION: This study will gather information on the variation in activity occurring in the

on-road  fleet on weekdays and on the weekends such as the number of trips per day, miles per day and speed of each trip. The off-road fleet will also be monitored to determine the influences of increased activity in such areas as lawn and garden and recreational vehicle usage. This information will then be used to modify the on- and off-road models to reflect weekend and seasonal variations in activity.

BENEFITS: The performance of this study will allow emissions modelers to produce ozone episodic inventories that depict activity more realistically. This approach will improve cost effectiveness analyses of ozone abatement strategies and the estimated results from airshed models.
COST: $500,000

TITLE: Analysis of Emissions from Portable Fuel Containers
PROBLEM: Millions of gasoline cans are in use in California, primarily to provide fuel for

small off-road  equipment, such as lawn mowers and chainsaws. Each of these containers is the source of hydrocarbon emissions in the form of both raw fuel from spillage and evaporative breathing losses. In order to properly inventory these emissions, it is important to know the actual number of containers in use, fuel capacity, average fill level, percentage of metal vs. plastic containers, number of times the containers are used to refill equipment, number of times the containers are refilled, storage locations and useful lifespan (frequency of replacement).      

PREVIOUS WORK: Some work has been performed by the U.S. EPA and others in an attempt to characterize the various aspects of evaporative emissions from gasoline cans; however, these analyses were relatively simplistic. Recently, an ambient air respeciation analysis was performed by Dr. Rob Harley. He concluded that a great deal more raw gasoline is found in the ambient air than either the mobile or stationary source inventory can account for.
OBJECTIVE: To improve the overall hydrocarbon emissions inventory, by studying the emissions from gasoline cans.
DESCRIPTION: This study will quantify the number and make-up of the gasoline can fleet (plastic and metal), determine fueling and refueling habits, and assess evaporative emissions through limited testing.
BENEFITS: The performance of this study will lead to a more accurate hydrocarbon emissions inventory.
COST: $100,000

TITLE: A Large Scale Global Positioning System (GPS) Instrumented Vehicle Study for the Collection of Statewide Automobile Activity Data
PROBLEM: The current motor vehicle emission inventory model relies largely on output from travel demand models to provide spatially resolved vehicle activity. However, the motor vehicle activity data inputs to these travel demand models are generally collected using such tools as highway loop counters, written and telephone surveys, and conventional instrumented vehicles. These data collection methods have a number of limitations, including a scarcity of motor vehicle activity data for facility types other than freeways and major arterials and a reliance on participant recall.
PREVIOUS WORK: Although there are several on-going studies using GPS to collect heavy-duty motor vehicle activity in California, only one GPS study is known to have been conducted to collect regional scale automobile activity data. This ARB-sponsored study focused on the analysis of driving patterns, primarily in the Sacramento area. The ARB recently began soliciting proposals to conduct a GPS instrumented automobile activity study in the San Joaquin Valley. However, a statewide survey of automobile activity using GPS has not yet been attempted.
OBJECTIVE: To improve the spatial and temporal resolution of automobile activity data inputs to the mobile source emissions inventory model.
DESCRIPTION: The proposed study will involve developing between 500 to 1000 low cost GPS dataloggers, soliciting the participation of a statistically significant number of drivers in California, and instrumenting their vehicles. Based upon the number of individuals interviewed by the California Department of Transportation (CalTrans) in their most recent statewide travel survey, it is anticipated that approximately 15,000 vehicles will be instrumented for one to two days each and minute-by-minute GPS data collected. Allocating the resulting GPS-derived vehicle locations to grid cells using a Geographic Information System (GIS) will result in a highly resolved spatial distribution of automobile activity and emissions by time of day.
BENEFITS: By improving the spatial and temporal resolution of the mobile source emissions inventory, this study will allow improved population exposure and risk assessment studies in California. In addition, a more accurate mobile source emissions inventory will assist in the formulation of more effective and cost efficient air pollution regulations.
COST: $500,000

TITLE: A Study to Validate Concentrations Estimated from Air Dispersion Modeling for Source-To-Receptor Distances of Less than 100 Meters
PROBLEM: Air dispersion modeling is used to estimate the downwind concentration of a pollutant emitted from a facility. Conventional Gaussian-based air dispersion models are designed to estimate concentrations at source-to-receptor distances from 100 to 1000 meters. Currently, modeling at distances less than 100 meters from the source to the receptor site is based on extrapolation of the Pasquill-Gifford dispersion curves. Human receptors are commonly found within 10 meters of a source. Risk assessment and risk management decisions impacting business costs, business practices, and public relations are routinely based on concentrations estimates modeled at much closer than 100 meters from the source. Over 30,000 small businesses may be affected by modeling using this extrapolation technique. Some examples of small businesses that may be impacted include gasoline stations, dry cleaners and automotive repair facilities that perform brake services. Air dispersion modeling algorithms need to be validated or revised to address near-source concentrations of pollutants to illustrate that the modeling supporting the risk assessment and risk management decisions are reliable.
PREVIOUS WORK: None at the Air Resources Board and none published by the U.S. EPA.
OBJECTIVE: To validate air dispersion modeling at distances less than 100 meters from the source to the receptor site.
DESCRIPTION: The research would involve development of analytical tools to represent air contaminant concentrations less than 100 meters for the source to the receptor. This work may include an air monitoring program and development of new air dispersion modeling algorithms, as well as a literature review to assess the other work in this area. This would also address a component of the Risk Assessment Advisory Committee's recommendations to help improve the characterization of uncertainty in exposure assessment.
BENEFITS: Because current risk assessment practices are based on air dispersion modeling results, it is important that the modeling is reliable. Valid modeling will enable us to better estimate the human health risks associated with exposure to toxic air contaminants. This will be a key component in assessing a facility's potential exposure and risk.
COST: $150,000

TITLE: Maximum Incremental Reactivities for Volatile Organic Compounds Used in Architectural Coatings
PROBLEM: Emissions from architectural coatings contribute a significant portion of the daily volatile organic compound (VOC) emissions in California. Control strategies that encourage the use of less photochemically reactive VOCs may be an economical means to achieve ozone reductions. However, this would require data that quantifies the ozone forming potentials of the most common VOCs used in architectural coatings. The ARB is currently developing an update to the 1989 Suggested Control Measure for Architectural Coatings (SCM) that will be used by local districts to amend their architectural coating rules. Some members of the architectural coatings industry have expressed support for voluntary reactivity-based standards for as an alternative to mass-based standards for complying with district coating rules.
PREVIOUS WORK: Until recently, the only speciation profiles for architectural coatings were those provided in a June 1996 study by Censullo, et al., "Improvement of Speciation Profiles for Architectural and Industrial Maintenance Coating Operations." In the 1998 ARB Architectural Coatings Survey, manufacturers quantified VOCs used in their coatings. ARB has sponsored several recent studies to investigate the reactivities of compounds used in ARB's consumer products regulations, and maximum incremental reactivities (MIR)-based standards have been proposed for aerosol paints. MIRs are also used in the clean fuels / low emission vehicle regulations.
OBJECTIVE: To determine the MIR, and the degree of uncertainty associated with each value, of any compounds identified in the 1998 Architectural Coatings Survey that have not already been studied or for which there is a large degree of uncertainty in the MIR values.
DESCRIPTION: The contractor would utilize the 1998 Architectural Coatings Survey and any other relevant data to identify the most commonly used solvents in architectural coatings that do not already have MIR values. The contractor would then determine the estimated MIR and the degree of uncertainty in each value. The estimates of uncertainty, which quantify the degree of confidence with the predictive modeling data and the chemical mechanism, would be used to develop adjustment factors to modify the estimated MIR value in the regulation.
BENEFITS: The study results will be used to support possible reactivity-based standards in the ARB's SCM and, ultimately, architectural coating rules of the local air districts. Manufacturers would gain compliance flexibility by using solvents with low MIR values and have information about the lowest reactivity solvents to be used when reformulating products.
COST: $200,000

TITLE: Update the Industrial Coatings Emission Inventory
PROBLEM: There have been many changes in the Industrial Coatings category due to improvements in coating technology and rule implementation. This category includes marine, paper, fabric, metal furniture and fixtures, can and coil, metal parts and products, wood furniture, and unspecified industrial coatings. Total emissions from this category represent 8 percent of the stationary source emission inventory. Over 50 percent of the emissions from this category come from the area source inventory, with the remainder in the point source inventory. The South Coast Air Quality Management District has raised the limit in the definition of a point source from two to four tons per day. This will put more facilities into the area source inventory, increasing the uncertainty of the area source emission inventory for this category. As a result, smaller businesses will not be included in the point source inventory. The current emission inventory for the Industrial Coatings Category was last updated in 1982 with emission factor data from a 1976 and 1977 Stationary Source Division (SSD) study.
PREVIOUS WORK: The last study to quantify emissions from this category was performed in a 1976 and 1977 SSD study.
OBJECTIVE: To quantify the activity and emissions from the industrial coatings category. To determine if current coating technology in this category reduces emissions and if there are any projected changes in formulation to further reduce air pollution emissions.
DESCRIPTION: This research will survey the manufacturers of industrial coatings to determine the current activity and emission factors from formulation data to develop an emission inventory. This research study will quantify current technology to reduce air pollution from coatings in this category.
BENEFITS: This research will allow staff to update the State's emission inventory with more accurate data. This updated inventory will assist ARB to develop improved control strategies and help districts meet SIP commitments.
COST: $200,000

TITLE: Update the Thinning and Cleaning Solvents Emission Inventory
PROBLEM: The current emission inventory for the Thinning and Cleaning Solvents Category is based on census data from 1982 updated to 1983. This category includes thinning and cleaning operations from both industrial coatings category and the architectural coating categories. There have been many changes in coating formulations and coating application practices. Therefore, the emissions in the inventory may not represent current practices. In addition, some districts question whether the current emission factors and usage from this category are overestimated. The Stationary Source Division conducted an architectural coating survey in 1998 which does not include surveying thinning and cleaning solvents. The emissions represents 1.5 percent of the stationary source inventory. This study will look at current formulations and current activity for this category. Results will be used to quantify emissions and assess technology designed to reduce air pollution from solvents in this category.     
PREVIOUS WORK: The last study to quantify emissions from this category was performed in 1983.     
OBJECTIVE: To quantify the activity and emissions from this category. To determine if current solvent technology in this category reduces emissions and if there are any projected changes in formulations that may further reduce air pollution emissions.
DESCRIPTION: This research will survey users of coatings to determine their application practices and methods. Emission factors for different coating applications will be established.
BENEFITS: Results will be used to update the State's emission inventory with more accurate data, determine future control strategies, and help districts meet their State Implementation Plan commitments.
COST: $150,000

TITLE: Development of a Test Method to Measure the Emissions from Portable Engines
PROBLEM: Engines registered under the Statewide Portable Equipment Registration Program are required to satisfy specified emission limits and requirements. Current test methods for portable engines are not intended for field use. These methods were intended to determine the compliance of newly manufactured engines with established emission standards. Testing is typically done in a laboratory using a dynamometer to simulate load changes, and only CO, HC and NOx are measured.
PREVIOUS WORK: Historically, stationary source test methods have been used to measure emissions from stationary industrial and portable engines. The stationary source test methods have not been demonstrated to be equivalent to the tests using a dynamometer and it is not practical to take portable engines to a laboratory for testing. The U.S. EPA is developing an
in-the-field testing system for engines subject to federal standards. Because of the potential cost of the system, it may not be cost effective for testing State-registered portable engines.
OBJECTIVE: To develop a test method for portable engines that would be used to verify compliance with specified emission limits and newly manufactured engine standards set by the ARB and the U.S. EPA.
DESCRIPTION: The first step of this project would be a review of existing test methods that apply to portable engines and identify the major issues that need to be considered in developing an in-the-field test method. A proposed procedure would be developed based on the issues initially identified. The final step would entail using the proposed test method on a representative sample of portable engines and providing a final evaluation based upon the results of the tests. A test method would be developed that could: 1) be used in the field, 2) be equivalent to current test methods applicable to newly manufactured portable engines and 3) could be done at a reasonable cost.
BENEFITS: The development of an in-the-field test method for portable engines is important for ensuring compliance with the program's requirements. The reductions achieved by the Program are important for maintaining or achieving compliance with State and federal ambient air quality standards. In addition, as more of these portable engines are tested with the newly developed method, staff will be able to provide accurate estimate of emissions from portable engines for the emissions inventory. The inventory currently has limited information for this category. Finally, with the availability of an in-the-field test method, staff could study the impact of engine deterioration on emissions for engines used in portable applications.
COST: $250,000

TITLE: Analysis of Data Collected During the 1997 Southern California Ozone Study
PROBLEM: A vast amount of air quality, meteorological and emission data were collected during the 1997 Southern California Ozone Study (SCOS97) at a cost of approximately seven million dollars. The staffs of the ARB and local air pollution districts are currently validating the data and will shortly begin photochemical modeling to support the development of attainment plans for ozone air quality standards. However, various additional data analyses are needed in a timely manner to address issues pertinent to ARB programs.
PREVIOUS WORK: Major findings of the 1987 Southern California Air Quality Study include discrepancies between ambient air quality and emission inventory estimates of CO and Reactive Organic Gases, and the need for more information on meteorological and air quality conditions aloft and offshore to improve model performance.
OBJECTIVE: To analyze the data collected during SCOS97.

DESCRIPTION: Various data analyses are needed to address issues critical to ARB programs (e.g., VOC vs. NOx control strategies for 1-hour and 8-hour ozone attainment plans, PM attainment plan, emission inventory improvement). Because needs are urgent, ARB staff will conduct limited analyses in-house. However, additional data analyses that are needed in a timely manner must be contracted out. The specific analyses requested would be designed to complement work by local air quality districts, the U.S. EPA, and other research groups (e.g., PAMS data analysis contracts, Baja California air quality analysis contract). These analyses will:

  • Document the spatial and temporal variations in pollutant concentrations during the summer. How do they compare to more typical (i.e., non-El Nino) summers and what are the implications for the interpretation of modeling results (particularly 8-hour ozone) and data analyses? Compare and contrast with the 1987 Southern California Air Quality Study.

  • Investigate / characterize the three-dimensional processes creating significant ozone concentrations aloft or offshore; quantify the effect of these ozone layers on surface concentrations via fumigation and transport; assess the performance of models in handling these layers and fumigation / transport events.

  • Quality control and then analyze and summarize implications of the specialty data sets collected during SCOS97 (e.g., biogenic hydrocarbons, PAN, halocarbons).

  • Quality control the rawinsonde and radar wind profiler data routinely collected throughout the summer of SCOS97-NARSTO and integrate the meteorological data aloft (rawinsondes, ozonesondes, radar wind profilers, sodars) into one data base.

  • Test the performance of the diagnostic and prognostic meteorological models with full and partial data sets to identify critical areas for future monitoring (e.g., Where is monitoring needed to ensure that model performance is realistic? Is the current meteorological monitoring network sufficient to model any day of interest?).
BENEFITS: These data analyses will help ensure that the ozone attainment plans are technically well-founded and that any future field studies are efficiently designed.
COST: $500,000

TITLE: Adaptation of Air Quality Models to Use More Accurate Treatments of Pollutant Deposition
PROBLEM: Ozone concentrations and air quality simulations are sensitive to the rate of pollutant deposition. Pollutant deposition rates are not well represented in current regulatory air quality models, particularly for deposition of pollutants on native vegetation in California.
PREVIOUS WORK: Interim recommendations from the California Ozone Deposition Experiment, were incorporated into the SARMAP air quality model to improve treatment of ozone deposition, mainly for agricultural areas. The revised model was applied for the 1994 ozone SIP for the San Joaquin Valley. This (and previous work) showed that the air quality simulations for ozone are sensitive to the uncertainty in estimates for deposition rates. Additional analyses over the last five years have provided further recommendations to improve the accuracy of deposition rates. These recommendations are documented in a series of peer-reviewed papers and an ARB report "Estimating Ozone Deposition Rates for Areas of Central California" (Massman, May 1997). This work also provided a new method for accurately mapping vegetation density (i.e., leaf area index [LAI] which is defined as the ratio of one-sided leaf area to ground area) and demonstrated the value of using LAI as an extrapolating variable for pollutant deposition. The new method for generating LAI from satellite observations, by using an inverted radiation model, was shown to provide better agreement with ground observations than previous methods. Fine-scale maps (nominal 1 kilometer resolution) of LAI for all of California will be provided in early 1999 through a cooperative ARB / U.S. Forest Service project. The 1 km maps of LAI will be compared with similar maps made at 30 meters resolution with ground observations. The ground observations will be provided through an existing ARB project for improving characterization of leafy biomass inputs used for modeling of biogenic hydrocarbons emissions.       
OBJECTIVE: To incorporate recommended improvements for treatment of gaseous pollutant deposition into two existing air quality models.
DESCRIPTION: The proposed study would be a model coding effort and subsequent model testing to ensure the coding was correctly implemented. It would incorporate state-of-the-science deposition algorithms into two existing regulatory air quality models. Improvements would include the range of recommended changes (Massman, 1997). These would be implemented as options to the current (modified Weseley) formulation. One of the improvements would be preparing the air quality model to incorporate and use newly available inputs of leaf area index. The code changes and the results of test simulations would be documented. Documentation would include detail suitable for a users' manual and backup appendices.
BENEFITS: Improved accuracy for air quality simulations.
COST: $50,000

TITLE: Dust Mitigation in the Deserts of California
PROBLEM: Blowing dust from disturbed desert lands, and the health risks associated with it, is a major air quality problem for many Californians. Potential methods for reducing the windblown PM need to be identified and evaluated for feasibility and cost effectiveness.
PREVIOUS WORK: Since about 1993, research has been underway to mitigate dust from abandoned and overgrazed farmlands in the western Mojave Desert in the Antelope Valley. The first phase of this research, supported in part by the CARB, was completed in 1996. The objective of this first phase was to revegetate these barren farmlands. Results were mixed. Several published papers and final reports were written.
OBJECTIVE: To develop cost-effective solutions for mitigating windblown dust and PM10 in the California desert, including agricultural acreage, dirt roads, burned lands, and disturbed lands in general.
DESCRIPTION: The research for this second phase is multi-faceted. The San Diego State Soil Restoration and Ecology Group is growing and field testing a variety of native seedlings of shrubs and grasses under a variety of soil, water, and mulch conditions. This year, the Midwest Research Institute portable wind tunnel will be used to evaluate the erosion potential of the test plot land. On four-acre test plots, various types of roughness elements will be tested, including new dust suppressants, wind fences, and furrowing to determine the reduction in PM10 from these various control measures. University of California Riverside Parlier group will study the plant physiology associated with these newly planted seedlings.
BENEFITS: Air quality problems associated with blowing dust in the deserts of California is probably the number one nuisance facing the citizens of these desert communities. While a difficult problem to solve, our technical team believes it is possible to greatly mitigate the blowing dust from disturbed and burned lands in these communities, and thus reduce the associated health risks.
COST: $100,000 (Project duration is four years.)

TITLE: Valuing Health Effects of Particulate and Ozone Pollution
PROBLEM: The primary role of the ARB is to protect public health by reducing air pollutants through regulatory actions. The proposed regulations are generally analyzed in terms of the cost and cost effectiveness. However, some board members have expressed concerns over the lack of information on the impact to health benefits when making regulatory decisions, such as postponing a regulation that reduces ozone emissions. The ARB has not performed any health benefits studies for 12 years. The techniques used in the last study in 1986 are outdated. Although South Coast and San Francisco Bay Area districts have quantified health benefits in recent years, the data used were more than a decade old.
PREVIOUS WORK: Recently, Kaiser Permanente conducted a study investigating how daily changes in ambient air pollution are related to hospitalization for cardiovascular and respiratory problems. The study had accessed extensive air quality data at multiple sites and correlated it with hospital admissions among 1.6 million Kaiser members in the South Coast District. The preliminary results indicate that increases in daily levels of ozone and fine particle pollution are closely correlated with increases in the number of people admitted to hospitals for air pollution-related illness. The study provides a unique opportunity to further collaboratively evaluate the economic impact of particulate and ozone pollution on individuals and families. 
OBJECTIVE: To estimate the total health benefits of avoiding specified particulate and

ozone-related  morbidity, using both the cost of illness and the contingent valuation (CV) methods.     

DESCRIPTION: This study will be an extension of the Kaiser study. The contractor will collect data on direct medical expenditure through the Kaiser Permanente. The contractor will also develop a contingent valuation survey instrument to collect data on direct and indirect costs to the patients with air pollution-related illness, and to measure both the patients' and non-patients' willingness to pay (WTP) to avoid adverse effects of air pollution. The focus will be on capturing costs not reflected in the cost of medical services. These include, but are not limited to the loss of work time, increased costs on care of a sick child or adult, and non-pecuniary losses such as pain, suffering, inconvenience, and other social losses. The results from the two methods will be compared.
BENEFITS: The result of this study will provide more information on the health-related costs of particulate and ozone pollution to residents of the South Coast Air Basin. The study will reduce information bias and improve CV estimates by surveying a group that has an adequate information about air pollution-related illness. The study will extend both empirical and methodological basis for economic benefit valuation of air quality control measures. It will also provide more accurate and up-to-date health benefit estimation and increase the ARB's ability to assess the benefits of reducing particulate and ozone exposure.
COST: $150,000

TITLE: Exposure Effects and Toxicity of Ambient Particulate Matter
PROBLEM: Numerous epidemiological studies have suggested a link between particulate matter (PM) air pollution exposure and a variety of adverse health effects. However, the biological mechanism of how PM air pollution causes these effects is largely unknown. Particulate matter is a complex air pollutant made up of many different kinds and sizes of particles. It is very likely that different particles, acting by a variety of biological mechanisms, cause the various health effects attributed to PM. The most effective way to identify which biologic mechanisms are involved or which kinds or sizes of particles may be more harmful (toxic), is to conduct carefully controlled animal and human exposure toxicology studies.
PREVIOUS WORK: The USEPA recently reviewed its ambient air quality standard for PM and found PM to be harmful; in fact, it has been associated with premature death in humans. The mechanisms of these effects have not been identified. It has been suggested that people with existing cardiovascular disease are the most stronly impacted. Some studies have found that measures of heart function change when ambient PM fluctuates. Others have looked at the effects of PM exposure on the immune system. In the past few years the ARB has sponsored research to quantify the impact of specific components of ambient PM on humans and animals. These studies have identified several new markers of PM action in sensitive animal models. New technologies have also been developed that allow the study of concentrated ambient particles. Research performed with these concentrators has demonstrated that cardiac function in dogs and rodents undergoes measurable change following even brief exposures. This work has been performed in the Eastern United States and in Canada and application of these results to California is difficult because our PM is different from those regions.
OBJECTIVE: To determine the mechanisms by which ambient PM causes adverse health impacts and the role of the various components of California's PM in causing these effects.

DESCRIPTION: This study will:

  • Investigate potential mechanisms and the effects of ambient particle mixtures to identify levels of toxicity and other effects associated with varying PM concentrations (dose response).

  • Extend and apply markers of PM effect identified in ongoing studies to address factors such as variable combinations of components, confounding effects of other criteria pollutants, as well as varying health effects in animals of different health status.     

  • Investigate other potential mechanisms, especially with reference to immune and cardiac system impacts.

Results from these exposure studies would then be used to design experimental exposures performed on both animals and people. This work would be instrumental in identifying mechanisms associated with ambient PM that may more fully explain the health effects seen in epidemiology studies.

BENEFITS: This study would clarify the nature of health impacts of California PM by providing information on the mechanisms of effects, the levels of effect, and how specific components may prove harmful. It would also provide information that may allow the toxicity of California PM to be compared to PM from other parts of the country.
COST: $1,150,000 (Project duration is four years.)

TITLE: Exposure Estimation Enhancement and Validation for Southern California Children
PROBLEM: The Children's Health Study was initiated by the ARB in 1991 to determine whether long-term exposure to Southern California's ambient air pollutants during childhood leads to changes in lung function or adverse health effects, especially chronic respiratory effects, and to quantify the prevalence and severity of the observed effects and levels of exposure to pollutants at which the effects occur. To accurately estimate the exposures of children in Southern California, exposure estimation models are being constructed. These models rely on a combination of outdoor, indoor (at home and in school) and personal air quality data and location-time activity data for the children. There is uncertainty in the validity and accuracy of these models and resulting exposure estimates because inadequate indoor and personal air quality measurements have been made. In addition, evidence is accumulating that ultra fine particles may be a major health concern. No measurements of this particle size fraction are being made; therefore, their effects cannot be assessed.
PREVIOUS WORK: Health and activity assessments for each child have occurred each year. Ambient air monitoring for ozone, oxides of nitrogen, particulate matter (PM10 mass and PM2.5 mass and chemistry), and vapor phase acids has occurred in each of the 12 study communities. Limited indoor / outdoor and personal ozone measurements have also been made. A separate exposure assessment study included indoor and outdoor measurements of PM in a small number of residences. Based on data from these and other indoor air quality studies, preliminary exposure models have been constructed. However, they have not been thoroughly validated. It has not been possible to develop and apply models to estimate several important components because of missing data.
OBJECTIVE: To measure indoor / outdoor and personal exposure of particulate matter (PM2.5 and PM10), oxides of nitrogen and ozone, and to use this data to refine and validate the exposure estimation models developed for the Children's Health Study. To measure ultra fine particles at Southern California ambient monitoring sites.
DESCRIPTION: This study will make indoor and outdoor measurements of O3, PM10, PM2.5 and NOx in participating schools and a subsample of residences. These data will be used to refine and validate the exposure estimation models. Ultra fine particle monitors will be deployed to each of the 12 ambient monitoring sites.
BENEFITS: This project will enhance our ability to quantify the levels of specific pollutant(s) associated with specific health effects.
COST: $100,000 - Extramural Research Funding. Project duration is three years. The total cost of the project is $900,000.

TITLE: Asthma and Community Air Pollution
PROBLEM: The number of asthma cases is increasing in California and around the world. This epidemic disproportionately affects African Americans. In addition to possible socioeconomic reasons, it has also been postulated that blacks may be more immunologically responsive to environmental challenges than other races. Asthma is a disease associated with chronic inflammation and the more immunologically responsive one is, the greater one's risk of a severe reaction to immunologic triggers. Ambient air pollutants can elicit pulmonary immunologic responses, even in non-asthmatics, and they have been associated with increased allergic response to aeroallergens. Evidence suggests that ambient air pollution plays a critical role in the exacerbation of existing cases and may induce asthma in subclinical cases. However, the availability of data to evaluate its impact on the African American population or the general public is limited and few investigators are currently focusing on this issue.
PREVIOUS WORK: African Americans have been part of the study population in a number of investigations addressing risk factors for asthma, including ambient air pollution, in the inner cities. However, no asthma studies have been conducted that evaluate the immunologic and physiologic clinical aspects of the disease among African Americans, Caucasians and Hispanics from a population not burdened by the socioeconomic and health risk factors present in inner-city populations.
OBJECTIVE: To develop a study protocol that will outline procedures for defining the clinical, immunologic, and physiologic responses to ambient air pollutants among an ethnically diverse study population with consideration of other potential risk factors.
DESCRIPTION: This study will identify racially diverse communities in California with high numbers of hospitalizations for asthma and high levels of ambient air pollution. The Office of Statewide Health Planning hospital discharge database will be used to identify and geographically map the asthma-related hospitalizations. This map will be matched with maps of air pollution levels, census track data, and, potentially, traffic patterns / density and land-use maps. The contractor will use the summary of these distributions, along with evaluations based on the biology of asthma, to identify the best candidate study community and develop a study protocol. The protocol will outline procedures for defining the clinical, immunologic, and physiologic responses to ambient air pollutants, and other potential risk factors, and will identify new strategies for clinical and environmental interventions to reduce the occurrence and severity of asthma in the general population. A follow-up study, the specifics of which will be proposed following completion of this project, will evaluate a panel of asthmatics for three years, and will include both health and comprehensive exposure assessments.
BENEFITS: This project will provide the foundation and preliminary data for investigating the physiologic and immunologic effects of air pollution on a free-living panel of asthmatics, with emphasis on the susceptibility of African Americans.
COST: $150,000

Fiscal Year 1999-2000 Research Plan
Short Descriptions of Projects