Research Screening Committee Meeting
May 25, 2001

This page updated July 12, 2005.

State of California


Research Screening Committee Meeting

University of California, San Diego
Jacob's School of Engineering
Conference Room 7307
9500 Gilman Drive
La Jolla, CA 92093-0411

May 25, 2001



"Effects of Nitrogen Dioxide on Airway Inflammatory Responses in Allergic Asthmatic Subjects," University of California, San Francisco, $380,000
  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.


"Children's Microenvironmental and Personal Pollutant Exposures for SB 25 with NAP Health Status Survey," University of California, Los Angeles, $400,000
  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.


"Assessment of the Ozone and Aerosol Forming Potentials (Reactivities) of Organic Compounds Over the Eastern United States," Georgia Institute of Technology, $15,000
  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.


"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
  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.


"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
  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.


"Adaptation of Biological Fingerprinting Methods to Source Apportionment for Fugitive Dust Monitoring," University of California, Davis, $408,929, Contract No. 97-321
  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.


"Resuspension of Contaminated Soil as a Source of Airborne Lead," University of California, Davis, $99,591, Contract No. 97-325
  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.


"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
  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.


"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
  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.


"Evaluation of Technology to Support a Heavy-Duty Vehicle Inspection and Maintenance Program," West Virginia University, $51,097, Contract No. 98-319
  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.


"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
  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.


"Demonstration of Emissions and an Emissions Control Technology for Small Two-Stroke Utility Engines," University of California, Riverside, $49,994, Contract No. 97-313
  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.


"Refinement of Selected Fuel-Cycle Emissions Analyses," Arthur D. Little, Inc., $124,215,
Contract No. 98-338
  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.


"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
  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.

Research Screening Committee