Published on 05/01/03

Scientist studies effects of forest-fire smoke

By Brad Haire
University of Georgia

All across the United States, prescribed fires are set to promote forests' health. But nobody can say how the air pollution from them affects the people in homes downwind from them and the firefighters who set and control the fires. A University of Georgia expert is finding out.

A prescribed fire is any fire intentionally set to meet land-management objectives, such as reducing fuels on the forest floor or helping restore ecosystem health.

Each year about 80,000 firefighters with the U.S. Forest Service do about 70,000 prescribed burns on about 2 million acres, said Luke Naeher, an environmental health scientist with the UGA College of Agricultural and Environmental Sciences. He wants to know the health risks of these fires.

Health risks

"There are several pieces to our study," he said. "But what we want to determine are the short- and long-term health risks associated with exposure to the smoke of these fires ... if the health-related problems are reversible."

Naeher focuses on particulate matter, or the dust and unburned organic matter in the air during a fire. It's well established, he said, that particulate matter can cause severe and chronic health problems in humans' respiratory systems.

"We're most concerned with fine (particles), the size of human hair or smaller," he said. "They penetrate the deepest into the lungs and are believed to have the most impact on health."

In this year's prescribed-fire season, January through April, Naeher and his team monitored the respiratory systems of firefighters doing prescribed burns at the Savannah River Site in South Carolina. (The SRS was built in the 1950s to produce materials for nuclear weapons. It became a national environmental research park in 1972.)

Smoke's effects

Naeher checked the fighters before and after their fire shifts. He wanted to know how the smoke affected their respiratory functions, including their lung capacity and how quickly they could empty their lungs, he said.

Data from the study will help fire-crew chiefs come up with better ways to protect firefighters. In the coming years, Naeher hopes to develop and use less intrusive monitoring equipment and techniques. Biomarkers could be used to test urine and blood for exposure levels.

Fire managers must coordinate carefully with the state and federal agencies that monitor smoke and air pollution in an area for prescribed burns. But smoke management isn't an exact science. A slight shift in the wind could cause major problems for communities downwind.

Effects downwind

Naeher is also monitoring carbon monoxide and particulate levels downwind from the burns. He wants to better understand how forest-fire smoke affects people a half-mile and six miles away.

This will help fire managers plan safer fires. It will shed light, too, on the health risk of wildfires, like the ones that often hit the western United States in summer.

"We're studying the issues related to forest fires and related worker and community smoke exposure through a number of studies," Naeher said. "All of (them) are aimed at filling existing data gaps."

The U.S. Forest Service funds this study. Both the firefighter and the community parts of it will continue for several more years.

(Brad Haire is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)

Brad Haire is the former news editor with the University of Georgia College of Agricultural and Environmental Sciences.