SS4.06 Speciation, Bioavailability, and Impacts of Atmospheric Trace Metals in Aquatic Systems
Date: Wednesday, June 12, 2002
Time: 4:15:00 PM
Location: Esquimalt
ManthorneDJ, INSTAAR, Boulder, CO, USA,
Williams, M, W, INSTAAR, Boulder, CO, USA,  Mark.Williams@Colorado.EDU
Taylor, H, E, USGS/WRD, Boulder, CO., USA,
Atmospheric deposition of mercury is a potential environmental hazard in mountainous environments and their drainages in the Rocky Mountains. One reason for concern is the potential impairment of resources in National Parks and Class 1 wilderness areas that may be at risk of increased atmospheric mercury deposition from proposed construction of new power plants. Due to the lack of wet deposition monitoring sites in the western United States, it is necessary to use lake sediment profiles to evaluate relative rates of atmospheric deposition. We sampled five alpine lakes, because the cold condensation hypothesis suggests that there may be greater levels of atmospheric deposition with increased elevation. A mass flux sediment enrichment factor (SEF) of 2.5 was found at Navajo Lake in southeast Colorado. SEF's near the Denver metropolitan area, including Rocky Mountain National Park, where lakes had a wide range of Mass Flux SEF's from 2.3-5.0, suggest an urban mercury source. These results suggest that mercury contamination requires further research to better evaluate the extent of mercury deposition in the Rocky Mountains.