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Executive Summary
Pages 1-20

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From page 1...
... following directions from Congress in EPA's fiscal year 1998 appropriations report. The congressional request for this study arose from the uncertainties in the scientific evidence used by EPA in reaching the July 1997 decision to establish new National Ambient Air Quality Standards (NAAQS)
From page 2...
... In addition, the research recommendations from the committee's first report were updated, and two of the recommended research topics were substantially revised. THE PARTICULATE-MA1lER RESEARCH PROGRAM Congress and EPA have given strong support to the recommendations presented in the committee's first two reports, as indicated in Table ES-1, which shows funding levels budgeted during fiscal years 1998-2001 for EPA's PM research and related technical work.
From page 3...
... Because this period represents the initial stage of the PM research program, the committee's assessment necessarily focused more on current and planned research projects than on published results. Therefore, the committee's evaluation shouIc!
From page 4...
... The current studies are expected to expand greatly the database on personal exposures and the influencing factors, such as indoor PM concentrations, human activities, and characteristics ofthe places where people spend time (microenvironments)
From page 5...
... that after obtaining and interpreting results of studies from research topic i, studies be conducteci to examine human exposures to specific chemical constituents of PM considered relevant to health effects. The recommenciation included exposures to both the general population anti potentially susceptible subpopulations.
From page 6...
... To be used with confidence, the results from receptor models and source models should be cross-compared and also validated against observations from intensive fieldmeasurement campaigns. Current studies are expected to make substantial contributions to our understanding of chemical and physical processes that determine the size distribution and chemical composition of ambient particles.
From page 7...
... Research Topic 5. Assessment of Hazardous Particulate-Matter Components The committee's previous reports outlined an agenda to improve understanding of the role that specific PM characteristics (such as particle-size distribution, shape, and chemical constituents)
From page 8...
... In epidemiological investigations, because insufficient monitoring data for specific particle characteristics have been available, opportunities for testing hypotheses related to the characteristics have also been somewhat insufficient, and few studies have incorporated substantial monitoring of both particle concentration and other specific characteristics of particles. Epidemiological studies need to include sufficient exposure assessment to provide findings to guide toxicological studies of PM characteristics.
From page 9...
... Research Topic 7. Combined Effects of Particulate Matter and Gaseous Pollutants Because ambient PM is part of a pollutant mixture also containing gases, any biological effects attributed to PM in an observational study might also reflect contributions of gaseous pollutants.
From page 10...
... Furthermore, there appears to be insufficient toxicological research effort on the role of gases in influencing particle toxicity in comparison to the effort directed at studies of specific components of PM, absent gaseous copollutants. However, the epidemiological research portfolio for this topic is relatively strong; most epidemiological studies of PM include data on gaseous copollutants.
From page 11...
... Mechanisms of Injury The major potential biological responses which have been suggested as underlying the reported human health effects from ambient PM exposures include oxidative stress, pulmonary inflammation, airway hyperreactivity, and alterations in the cardiovascular system, such as changes in blood viscosity, heart rate and pattern of beating, and heart rate variability. The issue of mechanistic plausibility has been addressed with a number of approaches: animal models, in vitro systems, and clinical models.
From page 12...
... Studies are under way in potentially susceptible populations and are planned in other subgroups with pre-existing diseases. Despite the small number of facilities available for carrying out human exposures, the array of studies under way should provide valuable information on PM toxicity.
From page 13...
... Disincentives and Incentives for Multidisciplinary Interaction Among Particulate-Matter Researchers Institutional and cultural obstacles often discourage attempts to perform research across disciplines, agencies, and institutions (including public, private, and nongovernmental orzanizationsi. Such obsta ~ - - , 2Harvesting issues are concerned with questions of whether deaths occurring in response to air pollution are those of people who are highly susceptible and near death or the air pollution advances the deaths of people who are not otherwise near death.
From page 14...
... . The committee is aware that the Air Quality Research Subcommittee ofthe interagency Committee on Environment and Natural Resources (CENR)
From page 15...
... In addition, the assistant administrator for ORD had tasked its Board of Scientific Counselors to review the management of the program in detail and provide specific recommendations on how to improve it. Across the federal government, the charter of the Air Quality Research Subcommittee ofthe CENR has been expanded, and efforts are under way, as a critical first step in creating an integrated federal strategy, to create a complete federal inventory of PM research and to make it available through the Particulate Matter Research Activities web site (www.pmra.org)
From page 16...
... An enhanced management structure for the PM technical program within OAR is needed to ensure full coordination with ORD, to catalyze active involvement of the state air agencies in cleveloping and managing the speciation network (a key source of future data to support health research) , and to develop fully the source-emission inventories needed for accurate source apportionment.
From page 17...
... Therefore, the committee recommends that EPA develop a research-management strategy to address key uncertainties concerning implementation of air-quality standards for PM. Accessibility of Information The committee has found the ongoing research-projects inventory initiated by the EPA and Health Effects Institute (HEN)
From page 18...
... Overall Evaluation of Particulate-Matter Research Progress Although the initial phases of the nation's PM research program have shown promise, and a substantial number of peer-reviewed publications are forthcoming, there is as yet insufficient evidence for the committee to predict the program's ultimate effectiveness. In general, the PM research program, following on the committee's priorities, is appropriately addressing many ofthe key uncertainties.
From page 19...
... , concentration of the indicator in air, time over which measurements are made or averaged, statistical form of the standard used to determine the allowable number of exceedences, and the effective and efficient implementation of emission-control programs to achieve the NAAQS. In the future, it will also be important to ask whether the PM research and this committee's role offer a mode} for conducting major research initiatives on other key areas, such as endocrine-disruption effects of chemicals and potential health impacts of genetically engineered organisms.
From page 20...
... In fiscal year 1997, EPA's enacted budget for PM research and related technical work was about $21 million. However, for fiscal years 1998-2001, that amount was increased substantially by Congress: $50.2 million, $55.7 million, $62.4 million, and $65.3 million, respectively.


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