Danger: Lack of Research on Dust, Smoke and Soot

WASHINGTON, DC, March 26, 2004 (ENS) - The U.S. Environmental Protection Agency (EPA) should boost funding for an array of research into the health effects of particulate matter, a federal panel of experts said on Wednesday. The pollutant - linked to respiratory and heart ailments - consists of tiny airborne particles in dust, smoke and soot created by the emissions of cars, trucks, power plants and other sources.

The new report from the National Research Council committee says the government's continued support and enhancement of research into particulate matter would "undoubtedly yield substantial benefits for years to come."

The panel says it is critical that new research commence as the EPA revises standards for particulate matter.

"Much has been learned in the last five years, and the evidence gained is already being used by decisionmakers," said committee chair Jonathan Samet, professor and chair, department of epidemiology, Bloomberg School of Public Health at Johns Hopkins University. "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 last revision of particulate matter standards was finalized in 1997 by the Clinton administration. Those standards took aim at fine particulate matter - particles smaller than 2.5 microns.

New smog rules aim to reduce particulate matter in the air over cities such as Denver, shown here. (Photo courtesy U.S. Environmental Protection Agency)

But EPA estimates that it would cost industry some $30 billion to comply with the standards prompted a legal challenge by groups representing the trucking, automotive and power plant industries.

The Supreme Court upheld the standards in 2001, and the EPA now says its revised standards should be ready within three years.

Environmentalists and public health groups say the standards are still too lax.

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.

Current regulations treat all particulate matter the same - something the panel said needs to change.

New studies 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.

"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," Samet said. "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."

The panel recommends more studies of the effects of chronic exposure on different population groups as well as research to better characterize and track particles from various emissions sources.

Power plants are a key source of particulate matter. (Photo courtesy NASA)

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.

The committee re-emphasized an earlier recommendation to include scientists from many disciplines in the overall research effort.

The report also called on the EPA to research the health effects of multiple air pollutants - the panelists noted that real world exposures involve complex mixtures of hundreds of air contaminants.

The committee praised the EPA's current research agenda for particulate matter - the federal agency has spent some $60 million annually since 1997. The Bush administration says it has requested $64 million for 2005.

Along the lines of the report's recommendations, EPA officials say they are recommitting the agency to a "multi-disciplinary research and monitoring program that achieves a robust understanding of the science of particulate matter."

"Achieving a relatively full understanding of the health effects of particulate matter, as well as the means of controlling it, will be a steep and costly climb, but one in which EPA must and will engage," said Dr. Paul Gilman, EPA Science Advisor. "EPA will adapt its management practices and priorities to achieve a better understanding of the consequences of particulate matter for people and the environment."