Scientists Survey Pollutants In Our National Parks' Most Remote Sites
By David Lawrence
For the last four years, researchers on the search for toxic contaminants have trekked to remote locations in national parks ranging from Sequoia in California to Denali in Alaska. They access these sites using any means possible–with mule trains, on skis, with float planes–carrying with them 2,000 pounds of scientific sampling gear. The pollutants they are looking for reach these isolated areas by hitching a ride in the atmosphere.
The National Park Service (NPS) first became interested in the issue of airborne transport of contaminants when they learned that compounds such as DDT and PCBs moved to the Arctic from industrial and agricultural areas.
Areas of high elevation or latitude, including land the agency is charged with protecting, are at risk for concentrating these contaminants. "We were concerned that park service land might serve as a sink for some of these toxic compounds,” says Tamara Blett, an ecologist at the NPS and the project's manager.
The Western Airborne Contaminant Assessment Project (WACAP) began in 2002 and is the first to look for contaminants within eight national parks, sampling sites 1,400 to 10,000 ft in elevation.
Researchers from Oregon State University, University of Washington, U.S. Environmental Protection Agency, U.S. Geological Survey, and the USDA Forest Service have combined their expertise to complete the six-year project, primarily funded by the NPS.
Results from WACAP will shed light on which pollutants can be found in these areas, where they came from, and how they impact the plants and animals that live there.
The primary contaminants of concern are semi-volatile organic compounds (SOCs). These chemicals are light enough to move as vapors in air masses, but under certain conditions, they fall back to land in rain or snow, or attached to dry particles.
Once deposited, the compounds remain land-bound for a time, but if temperatures warm up enough they can return to vapor, rise, and move into the atmosphere again. "As they warm and cool they hop-scotch their way to higher elevation,” says Staci Simonich, a professor at Oregon State University and the project's lead on SOCs. They remain in areas of high elevation or latitude because temperatures do not warm up enough to move them again.
Samples from Sequoia, Rocky Mountain, Olympic, Mount Rainier, Glacier, Denali, Noatak, and Gates of the Arctic national parks are being tested for the presence of contaminants. The sites were chosen to capture a range of latitudes and elevations to provide information on which areas are affected by local and regional pollutant sources, and which are impacted by trans-Pacific contaminants.
In September 2007, the scientific team will submit a report to the NPS describing the findings. The results will provide important baseline data on contaminant concentrations across a wide range of sites and environmental conditions, says Dixon Landers, the project's scientific manager and a senior research scientist at the Corvallis EPA office.
David Lawrence is a research scientist at the University of Washington.
Images
Top: WACAP researchers measure pollutant concentrations in samples collected from snow (upper left), fish (upper right), lake sediment (lower left), and lake water (lower right). In the process, they hope to understand the distribution of these contaminants in the food web and the rate at which they are entering the environment. Photo: National Park Service
Middle: Researchers ski to Camp Muir in Mount Rainier National Park to sample snow. Photo: Don Campbell, USGS
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