Levels of polychlorinated biphenyls (PCBs) in fish: the influence on local decision making about fish consumption

In 1989, the level of Aroclor 1254 (a mixture of polychlorinated biphenyls with 42 percent chlorine by weight) in fish collected from a recreational pond in Toledo, Ohio, was reported to be 44.4 milligrams per kilogram (mg/kg), prompting local health officials to declare a "no fishing advisory" for the pond. A second study conducted in 1990 did not identify elevated levels of polychlorinated biphenyls (PCBs) in fish tissue. In other words, the two studies gave conflicting results. The purpose of this study was to determine the level of Aroclor in fish tissues and then evaluate whether consumption of fish from the pond would pose a serious health risk. Fish samples collected on several occasions in 1998 and 1999 were filleted, and tissues were analyzed, as composite or individual samples, with gas chromatography. The levels of Aroclor 1254 ranged from 0.2 mg/kg in white crappies to 1.0 mg/kg in carp. These levels, while far less than the level reported in 1989, nevertheless were greater than 0.05 mg/kg, which is the maximum level established by the Great Lakes Fish Advisory Task Force for "no restriction in fish consumption." Levels of other Aroclor formulations ranged from less than the 0.02 mg/kg (the minimum detectable limit) to 0.1 mg/kg. Given current knowledge about the potential health consequence of exposure to PCBs and the results of this study, the authors have recommended that local health officials develop a new fish consumption guideline for PCBs. Any decisions about maintaining or lifting the restrictions on the pond, however, should be based on additional studies that determine the levels of other chemicals that are present in the pond and deemed hazardous to human health.