PCB congener accumulation in biota and sediments involves several processes, including physical factors characterized by octanol-water partition coefficients and water solubility, and chemical factors which are influenced by the degree of chlorination and the substitution pattern of the individual congeners. The present study was conducted to determine if PCB congeners are distributed in a consistent pattern in two lakes known to have received point-source contamination with PCBs, and a control lake with no known point source. Samples of 4 groups of biota, water and sediment indicated that each lake had a unique pattern of congener distribution which was probably related to the source of the contamination. A comparison of total and individual PCB congener concentrations within each study lake showed that no one species consistently contained the highest residues of PCBs. Smallmouth bass had the highest concentration of PCBs in Rice lake while yellow perch was highest in Lakes Clear and Scugog. Sediments contained lower concentrations of PCBs than biota and did not show enrichment of higher chlorinated congeners, despite having high organic carbon content. Within the contaminated lakes, young-of-the-year (YOY) and older yellow perch had the same congener pattern, and there was no significant difference in their PCB concentration. This indicates that equilibrium concentrations of PCBs are established rapidly in the young fish and that all congeners equilibrate at the same rate.

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