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Western Parks Polluted by Airborne Contaminants

by aseligmann — last modified Jul 18, 2010 12:00 AM

Pristine parks in America's western states have become polluted by airborne contaminants from agriculture, industry, and urbanization.

Pristine parks in America's western states have become polluted by airborne contaminants from agriculture, industry, and urbanization.

A study of 20 national parks from Alaska to California found that remote ecosystems are contaminated by numerous pollutants. The study looked at eight "core" parks for detailed information on water, snow, plants, lake sediment and fish. Scientists tested environmental samples for residues of more than 100 contaminants. Seventy contaminants were detected. These pollutants originated in local, regional and sometimes distant areas.

"We're looking at some of the most pristine areas left in North America that are under the protection of the national parks, and we're finding some alarming results," said Dixon Landers, the Environmental Protection Agency scientist who headed the study.

Parks located closest to agricultural areas had the highest levels of both long-banned and currently used pesticides. Industrial contaminants such as PAHs and mercury were sometimes linked to local or regional sources; however, mercury found in Alaskan parks most likely came from other parts of the globe.

Three historically used pesticides — DDT, dieldrin and chlordane — were among the six contaminants identified as being of greatest concern in the core parks. The other three contaminants of special concern were mercury (released by burning coal or hazardous waste), PAHs (combustion products) and PCBs (banned industrial chemicals). All six contaminants have toxic effects, can bioaccumulate and are persistent in the environment. In fact, DDT dieldrin and chlordane were banned 20 to 30 years ago in the U.S.

Chemicals identified as "potential concerns" included the herbicide dacthal, several insecticides, such as endosulfans, lindane and chlorpyrifos, and flame retardants (PBDEs). Researchers were worried about these chemicals because they are currently used, they were detected in plants or fish at relatively high levels, and/or the levels found in lake sediment increased over time.


Bioaccumulation of contaminants in fish not only affects their health but also the health of species that eat them - both human and wildlife.

Abnormalities in male fish found in Glacier and Rocky Mountain National Parks included high levels of female-specific proteins and the "intersex" characteristic of having both eggs and sperm. These conditions could be related to dieldrin and DDT, which can disrupt the hormone system by mimicking estrogen.

Levels of mercury contamination in fish routinely exceeded thresholds set to protect fish-eating birds and mammals. DDT-contaminated fish in two parks exceeded risk levels for kingfishers (birds).

In some parks, concentrations of mercury, dieldrin or DDT found in some fish exceeded human health thresholds set by the EPA.

Tests of lake sediments show that some currently used pesticides as well as the flame retardant PBDES are increasing over time in some areas. The effects of these "emerging contaminants" are not known, but fish in Mount Rainier National Park contained the highest amounts of flame retardants that likely came from Seattle and other urban areas.


Researchers looked for pollutants in lichen and conifer tree needles. Two current pesticides, endosulfans and dacthal, were the dominant contaminants of lichen and conifer needles. Other current use pesticides detected in various parks included the herbicides trifluralin and triallate and the insecticide chlorpyrifos. Researchers found a strong correlation between plant contamination and regional agriculture.


The Western Airborne Contaminants Assessment Project was a five year study involving the collaboration of several federal agencies and state universities. The primary national parks or preserves studied were: Denali (AK), Gates of the Arctic (AK), Glacier (MT), Mount Rainier (WA), Noatak National Preserve (AK), Olympic (WA), Rocky Mountain (CO), and Sequoia and Kings Canyon (CA).

"The results are a reminder," said Sean Smith, Northwest regional director of the nonprofit National Parks Conservation Association, that "the choices we make today can have long-lasting consequences."



Quotes in the above article came from this news source:
Trout bearing chemicals are even in our national parks.
Lisa Stiffler, Seattle Post-Intelligencer. Last updated February 26, 2008.

Western Airborne Contaminants Assessment Project - Results [4 page fact sheet]
US Dept. of Interior. National Park Service. Air Resources Division. January 2008


Landers, DH et al. 2008. The fate, transport, and ecological impacts of airborne contaminants in Western national parks (USA) [Western airborne contaminants assessment project final report: Vol. 1] EPA/600/R-07/138. US Environmental Protection Agency, Office of Research and Development, NHEERL, Western Ecology Division. Corvallis, Oregon.
Chapter 4 Contaminant distribution (88 pages)
Chapter 6: Recommendations and conclusions (10 pages)