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Research Plan
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Proposed Projects for Fiscal Year 1999-2000
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| 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 |
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|
| 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 |
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|
| 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 |
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|
| 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 |
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|
| 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 |
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|
| 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 |
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|
| 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 |
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|
| 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 |
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|
| 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 |
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