EPA Should Redirect Some Research On Toxic Airborne Particles, Report Says

"Recent studies have consistently shown that airborne particles are somehowassociated with adverse health effects, especially for people with heart andlung ailments," said committee chair Jonathan Samet, professor and chair,department of epidemiology, Johns Hopkins University School of Hygiene andPublic Health, Baltimore. "But as the new standards begin to take effect,further research must be done to determine precisely which particles pose thegreatest health risks, and how. Gathering this information should be of thehighest priority. The results will greatly increase the likelihood that moneyspent on regulating and controlling particulates will fully protect publichealth."

EPA recently set stricter standards for particulate matter -- a broad class ofmaterials that originate from industrial manufacturing processes, forest fires,automobile exhaust, fossil fuel combustion, wind erosion, and a variety of othersources. The standards were changed after several epidemiological studies foundassociations between exposure to the particles and serious health consequences,including the exacerbation of asthma and other respiratory tract diseases --which in some cases were leading to premature deaths. The new standards, setlast July, for the first time target particulates smaller than 2.5 microns indiameter. When inhaled, these tiny particles are more likely than larger onesto reach deeply into the lungs. EPA must review the standards and thescientific data on which they are based every five years to determine whetherrevisions are warranted. In the meantime, the agency is beginning a nationaloutdoor air monitoring program to determine which geographic areas are not in compliance. States with areas not meeting thestandards will have to develop plans to control particulates.

EPA estimates that compliance could prevent 15,000 premature deaths each year. However, because of scientific uncertainties surrounding the standards, andlimited data on the health risks from exposure, Congress directed EPA to conducta major research program to improve understanding of these risks. In addition,Congress asked the Research Council to provide independent guidance to EPA onthe program. The committee's report, Research Priorities for AirborneParticulate Matter, examines EPA's plans for research and identifies the10 most critical needs for strengthening the scientific data. The report, thefirst of four, lays out a comprehensive 13-year national program for the study of particulate matter, with emphasis on critical information neededbefore the next scheduled review of the standards in 2002.

EPA is directing nearly one-third of its particulate matter research budgettoward developing improved monitoring techniques and characterizing the sourcesof emissions and their movement through the atmosphere. While some fundingshould continue to be devoted to these efforts, the agency could defer much ofthis work for three or four years until researchers develop a betterunderstanding of how particulates affect health, the committee said. Moreover,the agency should re-evaluate its plans for developing a national monitoringnetwork. If these efforts are planned and implemented without some of the keydata and guidance from the scientific community, then monitoring might notmeasure the most hazardous air particles or the most serious exposures.

Setting Priorities

The committee's 13-year proposed research program would cost about $440 millionand extend through the year 2010. To carry out the research, funding wouldneed to remain roughly consistent with current levels for several more years. The plan incorporates 10 areas of research that should be the highest priority,based on the scientific value of the information that would result, how usefulthe data would be in decision-making, and schedule considerations. Some of thepriorities are:

• identifying the most harmful particulates, assessing personal exposurelevels, and examining biological mechanisms through which the particles act;

• assessing exposure levels for people who are thought to be most vulnerable,such as children, the elderly, and those with chronic heart or lung ailments;

• studying how particulates might combine with other pollutants to causeshort- and long-term health problems; and

• developing modeling tools to link the sources of particulate matter withpeople who have been exposed.

The study was funded by the Environmental Protection Agency. The NationalResearch Council is the principal operating arm of the National Academy ofSciences and the National Academy of Engineering. It is a private, non-profitinstitution that provides independent advice on science and technology issuesunder a congressional charter.

Copies of Research Priorities for Airborne Particulate Matter: 1.Immediate Priorities and a Long-Range Research Portfolio will beavailable in May from the National AcademyPress; tel. (202) 334-3313 or 1-800-624-6242. The cost of the report is$35.00 (estimated) plus shipping charges of $4.00 for the first copy and $.50for each additional co