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| INTERAGENCY PROPOSALS |
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1.
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"Effects of Nitrogen Dioxide on Airway Inflammatory Responses in
Allergic Asthmatic Subjects," University of California, San Francisco, $380,000 |
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The Board has asked for a review of the California ambient air quality standard
for nitrogen dioxide (NO2)
by the end of 2004 in response to the requirements of the Children's Environmental Health Protection
Act (Senate Bill 25, Escutia, 1999). Epidemiological evidence, including new data from the Southern California
Children's Health Study, suggests that exposure to high ambient levels of NO2 is associated with worsening of asthma and may be associated with other
adverse health effects. These effects appear to occur at levels significantly below both Federal and State
air quality standards. As a result, some sensitive members of the general population may not be adequately
protected. Data from several controlled human exposure studies indicate that allergic asthmatic subjects exposed
to short-term, relatively high levels of NO2 can lead to enhanced bronchoconstrictor responses to subsequent allergen
exposures. The mechanisms involved have not been identified. The objective of this study is to determine
whether exposure to ambient levels of NO2 increases the inflammatory response to inhaled allergen in asthmatics. Allergic
asthmatics will be exposed to filtered air or to NO2 for two hours on separate days. Following each exposure, the subjects will inhale
allergens, and undergo studies assessing cellular and biochemical markers of airway inflammation that might
be associated with NO2
exposure. The study will increase our understanding of potential mechanisms by which NO2 may cause or worsen asthma. It will
also help assess if the current California ambient air quality standard for NO2 is adequately protecting the general population and its more sensitive members. |
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2.
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"Children's Microenvironmental and Personal Pollutant Exposures
for SB 25 with NAP Health Status Survey," University of California, Los Angeles, $400,000 |
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The objective of this project is to conduct indoor and personal monitoring
in selected schools in three of the communities scheduled for ambient monitoring under the Children's Environmental
Health Protection Act (Senate Bill 25, Escutia, 1999). SB 25 requires the ARB to conduct enhanced neighborhood
monitoring in several communities in California in order to determine if the current statewide monitoring
network collects data adequate for determining exposures of infants and children to air pollutants. ARB
staff will conduct the outdoor sampling in the communities. The required indoor and personal monitoring
data will be obtained through this project. A variety of pollutants will be measured at several
indoor locations at each school studied, and limitedpersonal monitoring will be conducted. In addition,
the health status (i.e., asthmatic / non-asthmatic, allergic / non-allergic, etc.) of a sample
of children attending the schools will be assessed by analyzing data collected from a questionnaire as part of
the ARB's Neighborhood Assessment Program. Information will be provided to the children and their families regarding
ways they can reduce their exposures to indoor and outdoor air contaminants. |
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3.
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"Assessment of the Ozone and Aerosol Forming Potentials (Reactivities)
of Organic Compounds Over the Eastern United States," Georgia Institute of Technology, $15,000 |
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Hydrocarbon reactivity is the phrase used to refer to the fact that different
hydrocarbons react to form different amounts of ozone. In June 2000, the Board approved a regulation for aerosol
coatings based on hydrocarbon reactivity. At the present time, the U.S. EPA has not agreed to allow State
Implementation Plan credit for this regulation due to their concerns regarding the validity of the maximum incremental
reactivity (MIR) scale used by the ARB. To help develop reactivity research priorities, the U.S. EPA
initiated the Reactivity Research Working Group (RRWG), a group with participants from the regulatory, academic,
and industrial communities. The goal of the RRWG is to identify and sponsor research that would address
the technical issues that are relevant to the formulation of a hydrocarbon reactivity policy. To help
address the U.S. EPA's concerns about the applicability of reactivity on a national scale, the RRWG is funding
three modeling studies that will examine reactivity in other areas of the U.S. besides California. This proposal
will provide a quarter of the funding for one of the projects, with the rest of the funding provided
by the U.S. EPA. This project will employ an air quality model, with the same chemical mechanism used in developing
the MIR scale for the ARB's reactivity regulations, to quantify hydrocarbon reactivity for two multi-day ozone
episodes in the Eastern U.S. The findings will be compared with similar work currently underway in the San
Joaquin Valley and the South Coast Air Basin. This will help answer the U.S. EPA's expressed concerns
about the geographic variability in reactivity. |
| SOLE SOURCE PROPOSAL |
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4.
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"Deployment and Operation of Scanning Mobility Particle Sizers (SMPS)
and Low Temperature Tapered Element Oscillating Microbalance (TEOM) in the Children Health Study Communities",
University of Southern California, $74,679 |
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Results from the Southern California Children's Health Study (CHS) suggest
that exposure to increased particle levels leads to retarded lung function growth and other adverse health
consequences in children. The CHS has just deployed the first network of ultrafine particles counters in the
world. Because of their high numbers (up to 100,000 or more per cubic centimeter) and large surface areas,
these particles can be especially harmful to human health. However, the particle counters employed in the
CHS do not provide information on the size of the particles. In addition, the standard PM10 measurement devices
used by the CHS (i.e., TEOMs) are known
to under-report particle mass under many ambient conditions due to losses of volatile compounds. The objectives
of this project are to measure ultrafine particle size distributions and more accurate PM10 concentrations
in the twelve CHS communities. The researchers will deploy two scanning mobility particle sizers (SMPS) on
a rotating basis throughout the CHS communities to measure the size distribution of ultrafine particles. Two
low-temperature, Nafionâ drier-equipped TEOMs will also be deployed. The standard TEOMs operate at 50 degrees
Centigrade to minimize contributions of water vapor to particle mass measurments. The low-temperature TEOMs use
a Nafionâ drier to remove water vapor and operate at near ambient temperatures, minimizing volatilization.
This plan will serve the needs of the CHS to better understand the nature of the particulate matter to which
school-age children are exposed. It will also produce a data set that many health researchers and atmospheric scientist
may find useful in the future. The project is a cooperative effort between the CHS and the Los Angeles
PM Supersite, and funding will be leveraged by $120,000 from the U.S. EPA. |
| FINAL REPORTS |
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5.
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"The Health Impact of Nitric Oxide: Effects on Lung Function and
Cellular and Biochemical Processes in Healthy Humans," University of California, San Francisco, $32,880,
Contract No. 97-329 |
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Nitric oxide (NO) is produced during combustion and is commonly found in
urban atmospheres, as well as indoor environments, throughout California. Although it normally converts to nitrogen
dioxide (NO2)
quite readily in the presence of ozone, high levels of NO are found immediately downwind of combustion sources,
especially near heavy traffic, and during stagnant, wintertime conditions. Recent epidemiological studies
suggest a link between NO2 exposure
and childhood respiratory infection, lung cell damage, asthma, bronchitis, croup, and adverse changes in immune
system functions. But NO2,
under controlled exposure conditions, has not been shown to be harmful. This raises the question as to whether
the observed epidemiological effects may in fact be due to the precursor, NO. Recent research has also indicated
that NO is produced within the body by a variety of cell types. Research has also shown that NO can regulate many
cell functions. The project is a literature review that covers basic scientific, clinical, and epidemiological
literature relating to NO; assesses the effects of ambient levels of NO on humans; and evaluates the
potential for ambient NO to cause or worsen human disease. The results of the literature review suggest that
ambient levels of NO may, in some cases, be sufficient to induce health effects, especially in asthmatics and people
with platelet dysfunction. It may also alter the body's response to infection. The report makes recommendations
for experimental research projects to address remaining questions. |
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6.
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"Adaptation of Biological Fingerprinting Methods to Source Apportionment
for Fugitive Dust Monitoring," University of California, Davis, $408,929, Contract No. 97-321 |
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Fugitive dust from unpaved roads, construction sites, agriculture, and other
sources are a significant component of PM10 in both urban and rural areas in California. The relative
contributions of dust sources are needed to develop the State Implementation Plan for areas that
violate the ambient air quality standard for PM10. Conventional chemical analysis cannot distinguish most dust
sources from one another. Microbial communities within soil contain biochemical material that can be analyzed
as a means of differentiating soils and identifying fugitive dust sources. The objectives of this research
were to continue the development of biological tools to refine the ability to link fugitive dusts to
their source soils. This report covers work with fingerprinting methods based on two classes of biochemicals,
fatty acids and nucleic acids (i.e., DNA and RNA). Results of both methods are closely correlated with
respect to soil relationships. Nucleic acid profiles correlate with crop type and / or geographical
location. DNA fingerprints also contain distinguishing features specific to each sample. Mathematical techniques
for the classification of soils were tested and showed much promise for the classification of samples
from known sites and identification of sources for profiles of unknown origin. |
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7.
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"Resuspension of Contaminated Soil as a Source of Airborne Lead,"
University of California, Davis, $99,591, Contract No. 97-325 |
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Lead is both a criteria pollutant and a toxic air contaminant with no safe
level. The elimination of lead from gasoline and the control of point sources of lead have lowered ambient
lead concentrations by more than 90 percent over the last two decades, eliminating violations of the
ambient air quality standard (1500 ng/m3 for a 30-day average) for acute health effects. Concern persists, however, for chronic
toxic effects of lead at localized "hot spots." A few monitoring sites continue to show occasional
high lead concentrations (above 65 ng/m3 - about four standard deviations higher than the statewide average). These scattered and
infrequent events suggest that there are local fugitive lead emissions that may need to be controlled. This
report details a study of lead in soil and its potential to be entrained in windblown dust. The researchers
collected soil samples at various industrial facilities and along roadsides, and determined their lead content
both in bulk and in resuspended PM10. The report found lead pollution in soils to be highly localized, with
consistently high values only in proximity to lead smelters. The project also detected elevated lead in soil
close to waste piles of soil contaminated with pre-1990 leaded gasoline. The report recommends soil surface stabilization
as a control measure. Temporary stabilization would be accomplished by watering or treating the soil; long term
stabilization would be accomplished by planting or paving. |
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8.
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"Improvement and Evaluation of the Mesoscale Meteorological Model
MM5 for Air-Quality Applications in Southern California and the San Joaquin Valley," San Jose State University,
$300,000, Contract No. 97-310 |
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Air quality models used to formulate the State Implementation Plan require
accurate meteorological information, especially for areas where mountain-valley and land-sea interfaces strongly
influence wind flow patterns. The objective of this study was to improve the accuracy of the meteorological
model widely known as MM5, and extend its capabilities. MM5 both simulates the physical processes
based on theory and assimilates observations provided by meteorological measurements. MM5 has been demonstrated
to reproduce the significant flow features in areas of complex terrain with finer detail than would be
expected from the spacing of the available observations, which is a significant advantage. In this project,
MM5 was modified and tested for simulation of very light winds and formation and dissipation of winter
fog in the San Joaquin Valley (SJV), conditions that lead to high fine particle concentrations. The accuracy
of MM5 was also tested and improved for simulation of the meteorology of two summer-time episodes of
high ozone levels in the South Coast Air Basin (SoCAB), including one with coastal stratus and fog. Simulation
of summer coastal fog is important because it influences the ambient temperatures and available ultraviolet radiation,
both of which, in turn, affect the formation of ozone. The researchers investigated and improved the numerical
and physical processes in the model that affect the quality of meteorological simulations. This work demonstrated
the applicability of MM5 for supplying the necessary meteorological inputs for modeling the formation of ozone
and PM under these specific conditions. This capability is needed for predicting the changes in air quality
that will arise from changes in precursor emissions. |
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9.
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"The Formation of Gaseous Nitrous Acid (HONO): A Key Determinant
of Tropospheric Ozone and Fine Particles," University of California, Irvine, $298,271, Contract No. 97-311 |
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Nitrogen oxides (NOx) react in the atmosphere to form ozone, particles,
and other pollutants. While the chemistry of these compounds in the atmosphere is well understood, their
reactions on surfaces (i.e., particles, buildings) have not been studied to the same extent. This project
investigated some of the reactions of various NOx compounds on surfaces. One of the key goals was to elucidate
the formation of nitrous acid (HONO) - a key ingredient in the formation of ozone - on wetted surfaces. This
project confirmed that NO2
reacts with water on surfaces to form HONO and nitric acid. Further studies found that the nitric acid on
the surface reacts with nitric oxide (NO) to regenerate nitrogen dioxide (NO2). This is a very important discovery because, until this work, the formation
of nitric acid was believed to remove reactive nitrogen from the atmosphere. However, this project found that
nitric acid on a surface can be transformed into NO2 that can then form ozone and particulate nitrate. Preliminary air quality modeling
conducted as part of this project suggests that this reaction may increase the formation of particulate nitrate
and that existing models underestimate the benefits of NOx emission controls in reducing ozone and PM levels. This
finding, if confirmed, would further justify the need to control NOx emissions from diesel engines and other
sources. |
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10.
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"Evaluation of Technology to Support a Heavy-Duty Vehicle Inspection
and Maintenance Program," West Virginia University, $51,097, Contract No. 98-319 |
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Heavy-duty diesel trucks are substantial and growing contributors to the
motor vehicle emissions inventory for nitrogen oxides (NOx) and particulate matter (PM) emissions. The 1994
State Implementation Plan for ozone attainment included an in-use compliance measure (M-17) for heavy-duty vehicles
(HDVs) aimed at reducing NOx emissions. The objective of this project was to evaluate HDV chassis dynamometers
and pollutant measurement instruments as candidate systems for use in a HDV inspection and maintenance (I/M) program.
The researchers evaluated and reported on a variety of dynamometer and instrumentation systems. They presented
recommendations for a lower cost, qualitative system for detecting high NOx emitters, and a higher cost system
that could also quantify gaseous and PM emissions. This report will add to our knowledge regarding HDV chassis
dynamometer systems, and it will be used in the ARB's evaluation of I/M systems. |
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11.
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"Heavy Duty Fleet Characterization for Reduction of NOx and Particulate
Matter Emissions in the South Coast Air Basin," Jack Faucett Associates, Inc., $199,889, Contract
No. 96-317 |
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Heavy-duty vehicles (HDVs), especially diesel-powered trucks, are significant
contributors to the nitrogen oxides (NOx) and particulate matter (PM) emissions inventories in California
and the South Coast Air Basin (SoCAB). The ARB's State Implementation Plan for ozone specifies measures to
reduce NOx emissions from HDVs. The objective of this project was to characterize the HDV fleet in the SoCAB and
to develop incentive concepts to accelerate the introduction of low-emitting heavy-duty engines in the SoCAB.
The fleet characterization was accomplished by conducting telephone surveys of HDV fleet operators, and by equipping
a small number of HDVs with on-board dataloggers equipped with Global Positioning Systems (GPS) receivers.
There are about 302,000 heavy-duty trucks in the SoCAB and about 780,000 statewide. According to the telephone
survey, over 90 percent of the HDV registered in the SoCAB operate in the Basin. Information on fuel
type, age, usage, mileage, and maintenance were also collected. Due to problems with the GPS dataloggers,
only 31 vehicles were instrumented, but even these few provide a rich database. Simple statistics were calculated
regarding numbers of starts, trips, and vehicle miles traveled. Incentives, such as subsidies for lower-emitting
engines or infrastructure improvements such as electrified truck stops to reduce idling emissions, can help accelerate
the introduction of
low-emitting engines in the SoCAB, but additional work is needed to quantify the emissions benefits. |
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12.
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"Demonstration of Emissions and an Emissions Control Technology
for Small Two-Stroke Utility Engines," University of California, Riverside, $49,994, Contract No. 97-313 |
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Leafblowers, string trimmers, and other handheld devices use two-stroke
engines with high levels of pollutant emissions. Due to the wide variety of potential applications, only the engine
is required to be certified for emissions performance. Hence, it is problematic to obtain in-use emissions data
from this category of emissions sources. This project obtained emissions data for two handheld utility
engines. The two standard technology engines, one powering a leaf blower (an Echo), and the second powering a string
trimmer (a Stihl), were tested new and after 100 hours of use. Emissions of carbon monoxide (CO), hydrocarbons,
nitrogen oxides (NOx), and PM10 were measured. The emissions results from the Echo leaf blower were somewhat counter-intuitive;
CO, hydrocarbon, and NOX emissions were lower after 100 hours of operation than before. The emissions results
for the Stihl string trimmer were more in line with expectations, with emissions increasing after 100 hours
usage for all pollutants. |
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13.
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"Refinement of Selected Fuel-Cycle Emissions Analyses," Arthur
D. Little, Inc., $124,215,
Contract No. 98-338 |
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The ARB's Low-Emission Vehicle and Clean Fuels regulations give auto manufacturers
the option of using clean alternative fuels to meet increasingly stringent emission standards, with less need
for control hardware than conventionally fueled vehicles. In an earlier study, Acurex (subsequently ARCADIS
Geraghty & Miller, and now Arthur D. Little, Inc.) evaluated the fuel-cycle emissions of nine
vehicle fuels, calculating emissions from four categories of the fuel-cycle process: extraction, production,
marketing, and distribution. These are upstream emissions separate from the emissions due to vehicle operation.
Nonmethane organic gases (NMOG), nitrogen oxides (NOX) methane, carbon monoxide, and carbon dioxide emissions
were quantified for each vehicle fuel. For NMOG, three fuels were estimated to have fuel-cycle emissions
close to electric vehicles (EVs): diesel fuel and liquefied petroleum gas for internal-combustion vehicles,
and methanol. In this study, the contractor refined the analysis for these three fuels
and reassessed the emissions associated with EVs, taking into consideration the new deregulated
environment. In addition, it considered toxic emissions and the use of methanol in fuel-cell-powered
vehicles. The study focused on the South Coast Air Basin; the South Coast Air Quality Management District
co-funded this study. In general, NMOG emissions were greatest for LPG use, followed by methanol, diesel,
and electric. Carbon dioxide emissions from EVs would be 50 to 75 percent of those from a comparable
gasoline vehicle. The NMOG emissions data will be used to determine appropriate levels of partial zero
emission vehicle credits for vehicles using LPG, methanol, and diesel fuel. |
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14.
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"Investigation of Technologies to Reduce Emissions of Methylene
Chloride from Furniture Stripping Operations," Institute for Research and Technical Assistance, $99,741, Contract
No. 98-334 |
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Methylene chloride is the primary ingredient of the furniture stripping
formulation typically used for removing paint and other coatings from furniture and similar wood items. Methylene
chloride is a possible carcinogen, and is listed as a Hazardous Air Pollutant by the U.S. EPA, and as
a Toxic Air Contaminant by the State of California. This study investigated methods that have the potential
to reduce the risk that furniture stripping facilities pose to surrounding communities. It also examined how effective
these methods are in reducing furniture stripping facility worker exposure to methylene chloride. The study
evaluated the efficacy, cost, and risk reduction that could be achieved by new low- and zero-methylene chloride
content stripping formulations, and by higher airflow ventilation systems in furniture stripping facilities. The
best combination of a low-methylene chloride formulation and improved ventilation tested could reduce risk to the
community by approximately 40 percent. The annual cost of these combined improvements is estimated at six
to nine percent of a facility's profits. This work should prove useful to the South Coast Air Quality Management
District for its regulatory development for this industry in 2002. |
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