Elimination of dioxins in milk by dairy cows after the long-term intake of contaminated sugar beet pellets.

Dried feed materials, such as sugar beet pellets, may be a source of high levels of PCDD/Fs. The studies followed up dioxin congener elimination from contaminated milk (5.02 ± 1.39 pg WHO PCDD/F-PCBs-TEQ g-1 fat) up to 338 days after withdrawal of polluted feed ingredient (4.37 ± 0.25 ng PCDD/F/DL-PCBs-TEQ kg-1 feed). The main objectives of the study were to estimate the length of the time needed to achieve an acceptable PCDD/F milk level as set by European Union law, to track the fate of the PCDD/F congeners, and to assess the potential risk for consumers associated with long-term consumption of contaminated milk. After approximately 200 days, the PCDD/F levels reached ML (2.5 pg WHO-TEQ g-1 fat), then decreased to the action level after more than 300 days (1.75 pg WHO-TEQ g-1 fat) for most of cows. The potential risk of PCDD/F/DL-PCBs intake was characterised by comparing the theoretically calculated weekly and monthly intakes with the toxicological reference values (TRVs). The dioxin intake for the average adult and high-milk consumers did not exceed half of any of the TRVs applied (TWI, PTMI). The consumption of milk by children in the amount recommended by nutritionists (500 ml day-1) resulted in an exposure equal to 317% TWI and 275% PTMI.