WET DEPOSITION OF ORGANOCHLORINE PESTICIDES AND POLYCHLORINATED-BIPHENYLS TO THE GREAT-LAKES

Wet precipitation samples were collected at land-based stations on Lakes Superior Erie, and Ontario for organochlorine pesticides and total PCBs analyses from 1986 to 1991. Wet deposition of lindane, endosulfans, and dieldrin exhibited seasonal maxima in spring and summer. There were visible declines in concentrations of lindane and dieldrin in precipitation over the 6-year period. On a regional scale, fluxes of dieldrin, endosulfans, and DDE were higher in the lower Great Lakes. Total PCBs deposition showed no seasonal variations and were relatively homogeneous within the Great Lakes Basin. Year-to-year variations in wet deposition estimates of organochlorine pesticides and total PCBs were about 45%.