Submitted to: Journal of Environmental Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/1998
Publication Date: N/A
Citation: Interpretive Summary: Polychlorinated biphenyls are industrial fluids used for many years in the US and other industrialized countries. These compounds are extremely persistent in the environment and have been shown to accumulate in wildlife such as fish and birds. This project provides evidence to suggest that polychlorinated biphenyl are entering the Lake Tahoe basin through atmospheric processes. Concentrations of PCBs were measured in the water and fish of Lake Tahoe and Marlette Lake, a small lake in the Lake Tahoe basin. Concentrations in both lakes were similar suggesting that there are no major local sources to Lake Tahoe. Since the only source of water to Lake Marlette is from rain and snow, it is likely that the atmosphere is the only major source to this area
Technical Abstract: Polychlorinated biphenyl (PCB) congener concentrations in air, water, fish and snow were determined in the Lake Tahoe basin and in the water and fish of an adjacent but more remote rural comparison lake, Marlette Lake, to examine whether atmospheric transport and deposition is a primary source of contamination to this alpine region of the Sierra Nevada mountains. Profiles of 92 congeners analyzed by capillary GC-ECD from surface waters of Lake Tahoe and Marlette Lake were closely matched with total dissolved PCB concentrations of 0.37 ng/L in Lake Tahoe and 0.67 ng/L in Marlette Lake. Gas phase PCB concentration measured in air samples from the Tahoe basin averaged 72 ng/m3, and PCB concentrations in snow were 4.8 to 5.1 ng/L. Rainbow trout from Marlette Lake and lake trout from Lake Tahoe had a similar distribution of congeners with PCB tissue levels varying from 3 to 14 ng/g wet weight. The finding of PCBs in all sampled compartments, particularly snow and air, indicates an atmospheric source of contamination. Supporting evidence is the similar pattern of congners in surface waters and fish from Marlette Lake.