A SIZE-BASED PROBABILISTIC ASSESSMENT OF PCB EXPOSURE FROM LAKE MICHIGAN FISH CONSUMPTION

The state of Wisconsin has recently issued a fish consumption advisory that includes suggested consumption rates for Lake Michigan fish, bas ed on fish size and PCB concentration. To evaluate the size-based expo sure risk from Lake Michigan fish consumption, we estimated PCB exposu re probabilities for five Lake Michigan fish species using two Bayesia n models. The models confirm that very few individuals of any of the f ive species are likely to have PCB concentrations low enough to fall i nto the category in which consumption is unrestricted. Among smaller f ish (<50 cm), brown trout have the highest PCB levels, while lake trou t are the most contaminated among larger fish (> 60 cm). Eating meals from multiple individuals of some species results in a high probabilit y that at least one of the meals will exceed 1.9 mg/kg, the upper PCB concentration recommended for consumption in the advisory.