Air concentrations of organochlorine insecticides and polychlorinated biphenyls over Green Bay, WI, and the four lower Great Lakes

Organochlorine pesticides and polychlorinated biphenyls were determined in high volume air samples collected in Green Bay from the University of Wisconsin (1989), and from shipboard over the four lower Great Lakes (1990). Average concentrations of Σchlordane, DDT, DDE, toxaphene and ΣPCBs in Green Bay were 35, 8.7, 15, 59 and 330 pg m−3, respectively. Air concentrations of the pesticides were positively correlated to each other (R2=0.896–0.997), and analysis of back trajectory data from Green Bay showed that higher atmospheric concentrations of organochlorine insecticides were associated with air masses originating in southern USA. Average concentrations from the Great Lakes were: Σchlordane, 187 pg m−3; DDT, 38 pg m−3; pg m−3; DDE, 59 pg m−3; toxaphene, 33 pg m−3; and ΣPCBs, 385 pg m−3. Higher air concentrations of PCBs were found in areas of industrial and urban development. There was no strong positive correlation of concentration values between any pesticides, with the exception of the chlordane isomers, or between any pesticide and ΣPCB from the Great Lakes cruise. Results from 5-day air mass back trajectory data suggest that, at the time of the cruise, atmospheric sources of organochlorines were not long-range transport from southern USA, but local or regional volatilization