Environ. Sci. Technol. 1996, 30, 283-291
Dietary Exposure of Mink to Carp from Saginaw Bay. 3. Characterization of Dietary Exposure to Planar Halogenated Hydrocarbons, Dioxin Equivalents, and Biomagnification D O N A L D E . T I L L I T T , * ,† ROBERT W. GALE,† JOHN C. MEADOWS,† JAMES L. ZAJICEK,† PAUL H. PETERMAN,† SILVIA N. HEATON,‡ PAUL D. JONES,§ STEVEN J. BURSIAN,‡ TIMOTHY J. KUBIAK,| JOHN P. GIESY,⊥ AND RICHARD J. AULERICH‡ National Biological Service, Midwest Science Center, 4200 New Haven Road, Columbia, Missouri 65201, Department of Animal Science, Michigan State University, East Lansing, Michigan 48824, Wellington Science Center, ESR Environmental, Gracefield, P.O. Box 30547, Lower Hutt, New Zealand, U.S. Fish and Wildlife Service, Division of Environmental Contaminants, 4401 North Fairfax Drive, No. 330, Arlington, Virginia 22203, and Department of Fisheries and Wildlife, Pesticide Research Center, Institute for Environmental Toxicology, Michigan State University, East Lansing, Michigan 48824
Mink are known to be very sensitive to the toxic effects of planar polychlorinated biphenyls (pPCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs), collectively known as planar halogenated hydrocarbons (PHHs). Previously, we reported the reproductive effects in mink fed a diet containing 10, 20, or 40% fish taken from Saginaw Bay, Lake Huron. The present study reports the chemical characterization of the diets and the adult mink livers, along with a comparison of an additive model of toxicity with the results of the H4IIE bioassay on these samples. The assessment of dietary or tissue-based exposure of the mink to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds revealed that TCDD equivalents of the PHH mixtures largely followed an additive model of toxicity as compared with the H4IIE bioassay. Consistent dietary and liver tissue-based threshold concentrations for reproductive toxicity in mink were determined regardless of whether PHHs were quantified as TEQs (additive toxicity) or TCDD-EQs (H4IIE bioassay). Significant reproductive effects were observed in the
0013-936X/96/0930-0283$12.00/0
1995 American Chemical Society
lowest treatment group (10% fish or 19.4 pg of H4IIE bioassay-derived TCDD-EQs/g). Consumptionnormalized mink liver biomagnification factors (BMFs) were 6.4-74.2 for PCDDs,
