recommended short-and long-term timing, phasing, and estimated costs of such research. In developing its research recommendations, the committee did not undertake to evaluate the adequacy of the scientific foundation for EPA's 1997 decision to establish new PM standards, recognizing that such a decision must involve policy judgments beyond the realm of science that the committee was neither charged nor constituted to make.
In response to the committee's first report, Congress and EPA made substantial changes in EPA's research program and other technical activities related to particulate matter. Congress quickly gave strong support to the committee's recommendations in EPA's Fiscal Year 1999 appropriations report and provided $47.3 million for EPA's PM research in 1999, an increase of $25.4 million over President Clinton's 1999 budget request. An additional $8.3 million was provided to EPA's research program for related technical work in 1999. The President's request for Fiscal Year 2000 tracks the committee's recommendations closely, designating a total of $51.6 million for PM research and an additional $10.3 million for related technical work. Through in-house studies at EPA laboratories and centers, EPA funding of university-based research centers and investigator-initiated competitive research grants, and enhanced collaboration with other agencies and organizations, the overall research effort on particulate matter has been substantially increased. For example, in terms of overall resources, Congress increased the budget for research on quantitative relationships between outdoor concentrations of particulate matter and actual human exposures (recommended as Research Topic 1 in the committee's 1998 report) from $3.6 million in the President's proposed budget for Fiscal Year 1999 to $8.2 million in the 1999 appropriations, and EPA has proposed $7.9 million for Fiscal Year 2000. The committee also considers it noteworthy that EPA's National Exposure Research Laboratory has increased its in-house activities and scientific expertise in this research area. In the area of research to identify the biologically active constituents and toxicity-determining characteristics of particulate matter that