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Date: March 24, 2004
Contacts: Bill Kearney, Director of Media Relations
Megan Petty, Media Relations Assistant
Office of News and Public Information
202-334-2138; e-mail <>


Sustained Commitment to Research on Particulate Matter Is Critical for Informing
Long-Term Regulatory, Public Health Decisions

WASHINGTON -- Particulate matter research conducted by the U.S. Environmental Protection Agency and other scientists in recent years has led to a better understanding of the health effects caused by the tiny airborne particles, says a new report from the National Academies' National Research Council. However, the committee that wrote the report said that even as EPA implements strategies to control particulate matter in the near term, it should -- in concert with other agencies -- continue research in order to reduce uncertainties further and inform long-term decisions.

EPA should sponsor research to determine which chemical components and other characteristics of particulate matter are the most hazardous -- especially when mixed with other airborne pollutants -- and which population groups are the most susceptible, the report says. Research is also needed to better characterize and track particles from various emission sources. The government's continued support and enhancement of particulate matter research would "undoubtedly yield substantial benefits for years to come," the report concludes.

"Much has been learned in the last five years, and the evidence gained is already being used by decision-makers," said committee chair Jonathan Samet, professor and chair, department of epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore. "We need to continue to invest in developing an even greater understanding to take full advantage of the work already done, and to complete the foundation of evidence needed to protect public health. The emphasis now should shift from studying whether particulate matter causes adverse health effects to studying the dose at which those effects are likely to occur. We also need to know which aspects of particulate matter are most hazardous, and to learn how people are exposed to hazardous particles and how these particles trigger injury."

Particulate matter consists of diverse substances such as dust, smoke, soot, and other small particles emitted by cars and trucks, forest fires, electric power plants, and other sources. The report calls for a continued systematic approach to studying the large variety of possible relationships between particulate matter and health effects. A better understanding of the size and type of particulate matter being emitted by different sources is also needed, as are improved computer models to link pollution sources with concentrations of airborne particulate matter in specific areas. These improvements could lead to emission control strategies which target the particulate matter that presents the greatest threat to public health.

The report is the fourth and final one in a series requested by Congress to provide independent guidance to EPA's long-term particulate matter research program. Congress appropriated substantial funding for such research after EPA in 1997 tightened its standard for allowable concentrations of particulate matter. Under the Clean Air Act, EPA is required to review the scientific basis for the regulations every five years to determine if revisions are warranted. The agency's research effort has largely followed the first five years of a 13-year research agenda recommended by the committee in its first report.

By 1997, studies were already showing that inhaling particulate matter could exacerbate lung ailments, even causing premature death in some instances. New results confirm that outdoor measures of particulate matter are a good indicator for use in public health studies and that more particulate matter is deposited in the lungs of people with asthma or chronic obstructive pulmonary disease. Other findings show that a number of groups – such as seniors, and people with diabetes or heart disease -- may be particularly susceptible to the particles.

Researchers also should conduct a long-term study of the health effects of chronic exposure to particulate matter, the committee said. It also re-emphasized an earlier recommendation to include scientists from many disciplines in the overall research effort. In addition, the research program should move toward one that addresses multiple air pollutants, because real-world exposures involve complex mixtures of hundreds of air contaminants. EPA should continue to seek independent review of its particulate matter research program.

The study was sponsored by EPA. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides science and technology advice under a congressional charter. A committee roster follows.

Copies of Research Priorities for Airborne Particulate Matter, IV: Continuing Research Progress will be available later this spring from the National Academies Press; tel. 202-334-3313 or 1-800-624-6242 or on the Internet at Reporters may obtain a pre-publication copy from the Office of News and Public Information (contacts listed above).

[ This news release and report are available at ]

Division on Earth and Life Studies
Board on Environmental Studies and Toxicology

Committee on Research Priorities for Airborne Particulate Matter

Jonathan Samet, M.D.1 (chair)
Professor and Chair
Department of Epidemiology
Bloomberg School of Public Health
Johns Hopkins University

Judith C. Chow, Sc.D.
Research Professor
Division of Atmospheric Sciences
Desert Research Institute
University and Community College System of Nevada

Bart E. Croes, M.S.
Chief, Research Division
California Air Resources Board

Robert E. Forster, M.D.2
Isaac Ott Professor Emeritus
Department of Physiology
University of Pennsylvania School of Medicine

Daniel S. Greenbaum, M.C.P.
President and Chief Executive Officer
Health Effects Institute

Philip K. Hopke, Ph.D.
Bayard D. Clarkson Distinguished Professor
Departments of Chemical Engineering and Chemistry
Clarkson University
Potsdam, N.Y.

Petros Koutrakis, Ph.D.
Director, Environmental Chemistry Laboratory, and
Professor of Environmental Sciences
Harvard University

Daniel Krewski, M.Sc., Ph.D.
Professor of Medicine, Epidemiology, and Community Medicine
University of Ottawa; and Adjunct Research Professor of Statistics
Carleton University

Paul James Lioy, Ph.D.
Professor of Environmental and Community Medicine
University of Medicine and Dentistry of New Jersey

Joe L. Mauderly, D.V.M.
Vice President
Lovelace Respiratory Research Institute, and
Lovelace Biomedical and Environmental Research Institute
Albuquerque, N.M.

Roger O. McClellan, D.V.M.1
President Emeritus
Chemical Industry Institute of Toxicology
Albuquerque, N.M.

Günter Oberdörster, D.V.M., Ph.D.
Professor, Department of Environmental Medicine, and
Head of the Division of Respiratory Biology and Toxicology
University of Rochester
Rochester, N.Y.

Rebecca Parkin, M.P.H., Ph.D.
Associate Dean for Research and Public Health Practice, and
Associate Professor and Scientific Director
Center for Risk Science and Public Health
George Washington University School of Public Health and Health Services
Washington, D.C.

Joyce Penner, Ph.D.
Geosciences Advisory Committee
National Science Foundation, and
Professor of Atmospheric, Oceanic, and Space Sciences
University of Michigan
Ann Arbor

Richard Schlesinger, Ph.D.
Professor and Chair
Department of Biological Sciences
Pace University
New York City

Frank Speizer, M.D.1
Professor of Medicine
Harvard Medical School, and
Professor of Environmental Science
Harvard School of Public Health

Mark Utell, M.D.
Professor of Medicine and Environmental Medicine
University of Rochester School of Medicine
Rochester, N.Y.

Ronald H. White, M.S.
Associate Scientist
Department of Epidemiology
Bloomberg School of Public Health
Johns Hopkins University

Warren H. White, Ph.D.
Visiting Professor
Crocker Nuclear Laboratory
University of California

Ronald Wyzga, Sc.D.
Technical Executive
Air Quality, Health, and Risk Area
Electrical Power Research Institute
Palo Alto, Calif.

Terry F. Yosie, Ph.D.
Vice President
Environmental, Health, Safety, and Security Performance
American Chemistry Council
Arlington, Va.


Raymond A. Wassel, M.S.
Project Director

1 Member, Institute of Medicine
2 Member, National Academy of Sciences