• Histological Lesions in Mink Jaws are a Highly Sensitive Biomarker of Effect after Exposure to TCDD-like Chemicals: Field and Literature-based Confirmations

      Haynes, James M.; Wellman, Sara Tucker; Beckett, Kerrie J.; Pagano, James J.; Fitzgerald, Scott D.; Bursian, Steven J.; The College at Brockport (2009-07-21)
      The mink (Mustela vison) is one of the most sensitive mammals to 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD)-like chemicals. By literature review we established that a histological lesion of the jaw bone of mink, evidenced by squamous epithelial hyperplasia in the gingival tissue that forms nests or cords that infiltrate the periodontal ligament and alveolar bone causing osteolysis of the mandible and maxilla that could lead to squamous cell carcinoma, is the most sensitive known biomarker of effect following exposure of mink to TCDD-like chemicals. Lesions have been observed when total TCDD toxic equivalents (TEQ: dioxins, furans, co-planar polychlorinated biphenyls or PCBs) in liver exceed 40 ng/kg-ww or when total PCB exceeds 1,698 ng/g-ww. This is the second report of histological evidence of this lesion in wild-caught mink, and it is the first report of the lesion being grossly detectable in naturally exposed mink. Some mink living near the south shore of Lake Ontario (exposed to the lake’s food web) but not inland mink (not exposed to the lake’s food web) accumulate more than 40 ng total TEQ/kg or 2 1,698 ng total PCB/kg in liver. Because of its sensitivity, the jaw lesion biomarker is very useful for assessing the health of wildlife populations exposed to TCDD-like chemicals.
    • Model Estimates Bioaccumulation of Total PCBs, Dioxin-Furan TEQs, and Total Mercury in Mink Liver Based on Concentrations in Lake Ontario Water

      Wellman, Sara Tucker; Haynes, James M.; Pagano, James J.; The College at Brockport (2009-07-23)
      We used stable isotope analysis and a bioaccumulation model to estimate concentrations of total polychlorinated biphenyls (PCB), dioxin-furan toxic equivalents (TEQ), and total mercury (Hg) in mink and to compare predicted ranges with their chemical concentrations in mink liver (PCB, TEQ) and brain (Hg). Actual concentrations were within predicted bounds for total PCB, dioxin-furan TEQ, and Hg except in two cases (lowest PCB and highest Hg) which were very close to predicted bounds. Based on 15N analysis, the trophic level of mink ranged from 3.4 to 3.9. Animals at the upper end of the range were exposed to Lake Ontario water and its food web while those at the lower end were captured at inland locations. Because of the complexity of wetland (an important habitat for mink in this study) food webs with pelagic, littoral, and terrestrial carbon sources and overlapping 13C signatures, whether the origins of mink diets were aquatic or terrestrial could not be determined. We have established a non-destructive biomonitoring tool to reasonably estimate concentrations of total PCB, TEQ and total Hg in mink tissues as concentrations of these chemicals change in their water supply.
    • Total PCBs, Dioxin-Furan TEQs and Total Mercury Concentrations in Mink In and Out of the Rochester Embayment Area of Concern Near and Inland from the Shore of Lake Ontario

      Haynes, James M.; Pagano, James J.; Wellman, Sara Tucker; The College at Brockport (2009-07-29)
      In terms of reproductive and other adverse outcomes after exposure to polychlorinated biphenyls (PCBs), dioxins and furans, the mink (Mustela vison) is one of the most sensitive mammals. Our objective was to determine if there are differences in the concentrations of total mercury (Hg), total PCBs, and dioxin-furan toxic equivalents (TEQs) between mink living in and out of the Rochester Embayment of Lake Ontario (RELO) Area of Concern (AOC) and between mink living near the shore of Lake Ontario and inland. Concentrations of total Hg in brain, total PCB and dioxin-furan TEQ in adipose, and total PCB in liver were significantly higher for mink living near the shore of Lake Ontario than inland. For mink living in and out of the AOC, differences in total PCB and dioxin-furan TEQ in adipose and liver were substantial but not significant. Correlations between concentrations of total Hg, total PCB, and dioxin-furan TEQ in mink were high. Our results suggest that contamination of mink living near the southern shore of Lake Ontario primarily comes from contact with the Lake Ontario food web, not from sources in the RELO AOC.