Organochlorine compounds (including polychlorinated biphenyls (PCB) ) and carry-over mechanisms
Heeschen, W.; Bluthgen, A.
Deutsche Tierärztliche Wochenschrift 92(6): 221-228
1985
ISSN/ISBN: 0341-6593 PMID: 2411493 Document Number: 266628
Residues of many chlorinated insecticides in milk in the German Federal Republic have decreased since 1975, but problems remain with alpha - and beta -HCH, (mainly from imported feeds), and with polychlorinated biphenyls (PCB). In 1984, 20% of compound feeds for dairy cows contained more than the legal max. for alpha - + beta -HCH of 0.01 mg/kg DM and 10% contained beta -HCH at >0.005 mg/kg DM. Lindane, alpha -HCH and beta -HCH given orally had biological half lives in milk of about 1, 2-3 and 3-5 wk resp., with carryover rates of 3, 9 and 30%. Carryover into milk fat of pregnant cows given HCH during wk 1-7 of lactation averaged 0.7, 4.7 and 17-34% for lindane, alpha -HCH and beta -HCH resp. Concn. of PCB (as Clophen 60) averaged 0.02 mg/kg in feed and 0.1-0.2 mg/kg in milk fat. PCBs containing 6 or more Cl atoms/molecule tended to be bio-magnified via the food chain while the opposite was true for PCBs with fewer Cl atoms. Particularly high concn. of HCH and PCB have been demonstrated in human milk.