REPRODUCTIVE EFFECTS IN MINK (MUSTELA-VISON) EXPOSED TO THE PESTICIDES LINDANE, CARBOFURAN AND PENTACHLOROPHENOL IN A MULTIGENERATION STUDY

The mammalian reproductive system is sensitive to exposure to endocrin e disrupting chemicals, particularly during sexual maturation. The pur pose of this study was to examine reproductive function in second and third generation male and female mink exposed to pesticides from conce ption to maturity. The mink were fed untreated feed or feed treated wi th Lindane (1 mg kg(-1) day(-1)), Carbofuran (0.05 mg kg(-1) day(-1)) or Pentachlorophenol (I mg kg(-1) day(-1)) from the time they were wea ned. The second generation mink had also been exposed to the pesticide s in utero and from their mother's milk as their mothers were similarl y fed pesticides, from 3 weeks before breeding. The third generation m ink were the offspring of mink (second generation females) who had the mselves undergone long-term exposure to pesticides from conception onw ards. Blood samples and endocrine tissues were obtained at necropsy fr om both generations of mink. No overt signs of toxicity were seen. The pesticides did not affect the percentage of mink mated. Lindane treat ment reduced the proportion of mated mink that subsequently whelped (P < 0.1) and the litter size of mink that whelped (P < 0.05). Testis si ze was reduced in the Lindane-treated, third generation males (P < 0.0 5). Serum concentrations of cortisol, testosterone and oestradiol were not affected by any pesticide treatment; however, thyroxine concentra tion was reduced by Pentachlorophenol (P < 0.05). In conclusion, expos ure of mink to Lindane from conception resulted in a decrease in repro ductive efficiency when they were subsequently mated, leading to a 60% reduction in the number of kits born.