| Autor: |
Child AW; School of the Environment, Washington State University, P.O. Box 646420, Pullman, WA, 99164, USA. awchild@uidaho.edu.; Chemical and Materials Engineering, University of Idaho, 1031 N Academic Way, Coeur d'Alene, ID, 83814, USA. awchild@uidaho.edu., Moore BC; School of the Environment, Washington State University, P.O. Box 646420, Pullman, WA, 99164, USA., Vervoort JD; School of the Environment, Washington State University, P.O. Box 646420, Pullman, WA, 99164, USA., Beutel MW; School of Engineering, University of California-Merced, 5200 N. Lake Road, Merced, CA, 95343, USA. |
| Abstrakt: |
Heavy metal discharge from mining and smelting operations into aquatic ecosystems can cause long-term biological and ecological impacts. The upper Columbia River is highly contaminated with heavy metal wastes from nearby smelting operations in Trail, British Columbia, Canada, and to a lesser extent, Northport (Le Roi smelter), Washington, USA. Airborne emissions from the Trail operations were historically and are currently transported by prevailing winds down the Columbia River canyon, where particulate metals can be deposited into lakes and watersheds. In lakes, sediment cores contain records of past environmental conditions, providing a timeline of fundamental chemical and biological relationships within aquatic ecosystems, including records of airborne metal depositions. We analyzed trace metal concentrations (Ni, Cd, Zn, As, Cu, Sb, Pb, Hg) and Pb isotope compositions of sediment cores from six remote eastern Washington lakes to assess potential sources of atmospheric heavy metal deposition. Sediment cores displayed evidence to support trace metal loading as a direct consequence of smelting operations in Trail. Smelter contamination was detected 144 km downwind of the Trail Smelter. Cd, Sb, Pb (p < 0.001), and to a lesser extent As and Hg (p < 0.05) concentrations were correlated with Pb isotope compositions, suggesting that the Trail operations were likely the main source for these trace metals. |
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