PCDD/F and PCB transfer to milk in goats exposed to a long-term intake of contaminated hay.

The purpose of this study was to determine the feed to milk transfer of 17 PCDD/Fs and 18 PCBs in goats exposed to a 10-week long-term intake of contaminated hay collected in the vicinity of a hazardous municipal waste incinerator. The sum of PCDD/Fs and PCBs WHO-I-TEQ was found to be higher than 3 ng kg(-1) of milk fat after the first experimental week. Carry-over rates (CORs) of PCDD/Fs and PCBs could be established at steady state conditions for each compound studied. For PCDD/Fs, 2,3,7,8-TCDD appeared as the compound having the highest COR (38.8%). Within dioxin-like-PCBs the highest COR were found at a similar level (higher than 80%) for PCBs 105, 118 and 157. Concerning indicator-PCBs, COR ranged from 5% (PCB 101) to more than 40% (PCBs 118, 153 and 180). The intensity of this transfer appeared to be a function of physico-chemical properties (chlorination or logK(ow)) of the molecules and their metabolic behaviour.