EFFECTS OF DIETARY EXPOSURE TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN INADULT FEMALE MINK (MUSTELA-VISON)

Adult female mink were fed diets supplemented with 0, 0.001, 0.01, 0.1 , 1, 10, or 100 ppb 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for up to 125 days. There was a dose-dependent decrease in feed consumption a nd body weights indicative of the ''wasting syndrome'' previously repo rted for mink and other species exposed to chlorinated hydrocarbon com pounds. Mortality reached 12.5, 62.5, and 100% by day 28 in the 1-, 10 -, and 100-ppb groups, respectively, and by day 125, mortality increas ed to 62.5 and 100% in the 1- and 10-ppb groups, respectively. Adrenal gland weights were significantly greater in the three highest dose gr oups compared to the control group. The percentage of band neutrophils was also significantly greater in the TCDD-treated groups compared to the control. LC50 (+/-SE) values for 28 and 125 days of dietary expos ure to TCDD were calculated to be 4.8 +/- 4.99 ppb and 0.85 +/- 0.64 p pb, respectively. Based on feed consumption of control mink, these LC5 0 concentrations approximate 0.264 and 0.047 mu g TCDD/kg body weight/ day for the 28- and 125-day exposure periods, respectively. These resu lts confirm the sensitivity of mink to TCDD.