NHEERL MS-97-019 PARTICULATE MATTER RESEARCH PROGRAM STRATEGY External Review Draft OFFICE OF RESEARCH AND DEVELOPMENT U.S. ENVIRONMENTAL PROTECTION AGENCY RESEARCH TRIANGLE PARK, NC 27711 DISCLAIMER This document is an external draft for review purposes only and does not constitute U.S. Environmental Protection Agency policy. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. LIST OF TABLES Number 1 Summary of Reported Health Effects Associated with Particulate Matter Exposures 2 Integrated Aerosol Samplers and Continuous Particle Monitors 3 Particulate Matter Research Strategy Summary LIST OF FIGURES Page 6 10 31 Number 1 Sampling fractions related to a typical ambient particulate mass distribution 2 Major constituents of particles measured at sites in the western United States 3 Major constituents of particles measured at sites in the eastern United States Page 8 . 12 13 National Ambient Air Quality Standards (NAAQS) are established by the U.S. Environmental Protection Agency (EPA) to protect public health and welfare, based on scientific criteria. Currently, NAAQS exist for ozone, lead, carbon monoxide, nitrogen exides, sulfur dioxide, and particulate matter (PM). Periodic reviews of the standards are required by law to ensure their adequacy. Recent studies of several metropolitan areas in the United States and elsewhere report excess mortality and morbidity in urban populations associated with airborne PM concentrations below the current PM NAAQS. These studies suggest PM exposures may shorten the human life span of susceptible subpopulations (e.g., the elderly) and cause increased morbidity in these and other susceptible groups such as children. There are, however, several aspects of these epidemiologic observations that require further consideration; in particular, a clear biologic explanation for a cause-and-effect relationship has not yet emerged, and the nature of the concentration-response relationship across a wide range of concentrations and conditions is uncertain. These provocative epidemiologic findings underscore EPA's statutory mandate to review and potentially revise the NAAQS for PM. It is imperative to reduce key uncertainties to provide for the most effective and efficient health protection through the NAAQS. The latest available scientific information on PM is evaluated in an ambient air quality criteria document (AQCD) (U.S. Environmental Protection Agency, 1996a) prepared by EPA's Office of Research and Development (ORD) and peer reviewed by the Clean Air Scientific Advisory Committee (CASAC) of EPA's Science Advisory Board (Wolff, 1996a). Key scientific findings from the AQCD have been drawn on and summarized in a Staff Paper for PM prepared by EPA's Office of Air Quality Planning and Standards (U.S. Environmental Protection Agency, 1996b), which also was peer reviewed by CASAC (Wolff, 1996b). The Staff Paper makes recommendations that will form the basis for upcoming EPA decisions regarding proposed actions on the PM NAAQS. In the course of assessing the latest scientific information on PM, various data gaps and uncertainties have been identified, which, if addressed by research, could lead to improvements in the databases later available to support NAAQS review. To this end, EPA has developed a document entitled Particulate Matter Research Needs for Human Health Risk Assessment (U.S. Environmental Protection Agency, 1996c). The PM research needs document is designed |