| Summary: | The Western Airborne Contaminants Assessment Project (WACAP) is an interagency effort to determine if airborne contaminants such as semi-volatile organic compounds (sacs) and metals (e.g. mercury) are impacting National Parks in the western United States. Remote, high elevation and/or high latitude watersheds were studied in twenty National Parks from the Arctic to central California and East to Colorado and Montana to determine if contaminants are present and how they are distributed in ecosystems. Seven National Parks or Reserves have been studied in Alaska. Early results clearly demonstrate that a broad suite of airborne contaminants, both historic and current-use, are present in all parks and that bioaccumulation within the studied ecosystems is occurring. In Alaska, both current-use and historic sac concentrations in snow and sediments are generally considerably lower than concentrations determined for Parks in other states. Significant sac temporal trends in sediments vary with some chemical groups (i.e. current-use) increasing and others (i.e. historic)decreasing in recent years. WACAP research results indicate that the concentrations of current-use and banned pesticides in snow are highly correlated with regional agricultural intensity. Mercury concentrations in salmonids from Alaskan Parks are generally among the highest values found in all Parks while flux rates of Hg to lake sediments are very low. Results from this six year project that ends in 2007 will assist the National Park Service, the United States Environmental Protection Agency and other agencies and states in evaluating the threat posed by various local, regional and hemispheric sources of airborne contaminants.
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