Post-1990 temporal trends of PCBs and organochlorine pesticides in the atmosphere and in fish from lakes Erie, Michigan, and Superior.

We have analyzed concentration data sets covering the period 1992-2010 from the Great Lakes Integrated Atmospheric Deposition Network and from the Great Lakes Fish Monitoring and Surveillance Program to determine and compare pollutant time trends in the atmosphere and in fish. The analytes of interest were polychlorinated biphenyls, DDTs, chlordanes, dieldrin, and α- and γ-hexachlorocyclohexane (HCHs), and the sites of interest were Lakes Erie, Michigan, and Superior. Overall, we found no significant differences between the atmospheric and fish temporal trends for any of these compounds in any of the lakes. Polychlorinated biphenyl concentrations are decreasing in both the atmosphere and in the fish with halving times of 14 ± 2 years. The halving times for DDTs, chlordanes, and dieldrin are 8.7 ± 0.4 years for both the atmosphere and the fish. The most rapid temporal trend was observed for α- and γ-HCH concentrations, which are decreasing in both the atmosphere and in fish with halving times of 3.3 ± 0.4 years. The practical implications of these results are discussed.