Deposition and accumulation of airborne organic contaminants in Yosemite National Park, Calfornia

Environmental Toxicology and Chemistry
By: , and 



Deposition and accumulation of airborne organic contaminants in Yosemite National Park were examined by sampling atmospheric deposition, lichen, zooplankton, and lake sediment at different elevations. Passive samplers were deployed in high-elevation lakes to estimate surface-water concentrations. Detected compounds included current-use pesticides chlorpyrifos, dacthal, and endosulfans and legacy compounds chlordane, dichlorodiphenyltrichloroethane-related compounds, dieldrin, hexachlorobenzene, and polychlorinated biphenyls. Concentrations in snow were similar among sites and showed little variation with elevation. Endosulfan concentrations in summer rain appeared to coincide with application rates in the San Joaquin Valley. More than 70% of annual pesticide inputs from atmospheric deposition occurred during the winter, largely because most precipitation falls as snow. Endosulfan and chlordane concentrations in lichen increased with elevation, indicating that mountain cold-trapping might be an important control on accumulation of these compounds. By contrast, chlorpyrifos concentrations were inversely correlated with elevation, indicating that distance from source areas was the dominant control. Sediment concentrations were inversely correlated with elevation, possibly because of the organic carbon content of sediments but also perhaps the greater mobility of organic contaminants at lower elevations. Surface-water concentrations inferred from passive samplers were at sub-parts-per-trillion concentrations, indicating minimal exposure to aquatic organisms from the water column. Concentrations in sediment generally were low, except for dichlorodiphenyldichloroethane in Tenaya Lake, which exceeded sediment guidelines for protection of benthic organisms.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Deposition and accumulation of airborne organic contaminants in Yosemite National Park, Calfornia
Series title Environmental Toxicology and Chemistry
Volume 31
Issue 3
Year Published 2012
Language English
Publisher Wiley
Publisher location Hoboken, New Jersey
Contributing office(s) Colorado Water Science Center, Columbia Environmental Research Center, National Water Quality Laboratory
Description 10 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Environmental Toxicology and Chemistry
First page 524
Last page 533
Time Range Start 2008-01-01
Time Range End 2009-12-31
Country United States
State California
Other Geospatial Yosemite Naitonal Park;Sequoia National Park;Kings Canyon National Park;San Joaquin Valley;Sierra Nevada
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