ADDENDUM TO: DIOXIN AND HEAVY-METAL CONTAMINATION OF SHELLFISH AND SEDIMENTS IN ST. LOUIS BAY, MISSISSIPPI AND ADJACENT MARINE WATERS

Abstract Dioxins, furans, and trace metals were evaluated in shellfish and sediments from St. Louis Bay, Mississippi and adjacent waters of Mississippi Sound. Highest concentrations and the most toxic dioxin congener were found in St. Louis Bay sediments in closest proximity to the effluent outfall from the titanium dioxide refinery on the northern shore of the bay. Using conservative assumptions, we estimated the dioxin and furan burden of 17 measured congeners in St. Louis Bay sediments to be between 3.72 and 6.16 kg. Comparison of lipid-adjusted dioxins and furans in oysters (Crassostrea virginica) from this study with those collected from seafood markets and grocery stores in southern Mississippi in 1997 shows dioxin and furan contamination about 1.7 to 8 times higher in the samples from this study, depending on collection location. Oysters from St. Louis Bay and adjacent marine waters may accumulate higher concentrations of dioxins and furans than measured here, at other times during the year, due to...