Chiral signatures as a tool for source apportionment of PCBs in the Hudson River Estuary

ENVR 15

Brian J. Asher, basher@ualberta.ca1, Charles S. Wong, charles.wong@ualberta.ca1, and Lisa A. Totten, totten@envsci.rutgers.edu2. (1) Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, (2) Department of Environmental Sciences, Rutgers University, 14 College Farm Rd., New Brunswick, NJ 08901
The Hudson River Estuary is subject to significant contamination of polychlorinated biphenyls (PCBs) from numerous sources including the Upper Hudson River, sewer overflows and atmospheric deposition from urban-originating PCBs. However, the relative importance of these sources to the estuary's food web is not fully understood. Sources of PCBs to the estuary were apportioned using chiral signatures of PCBs in air, water, total suspended matter, phytoplankton and sediment. PCBs 91, 95, 136 and 149 were racemic in the atmospheric samples, while the other phases contained nonracemic PCB 95 and, to a lesser extent, PCB 149. Thus, the predominant atmospheric source of these congeners is likely unweathered local pollution and not volatilization from the estuary. Chiral signatures in the dissolved phase and total suspended matter were correlated with Upper Hudson discharge, suggesting that the delivery of nonracemic contaminated sediment from the Upper Hudson, not the atmosphere, controls phytoplankton uptake of some PCBs.