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Residues of polychlorinated biphenyls in breast milk of women non-occupationally exposed to PCBs.

Samples of breast milk were collected from 27 women and examined for residues of polychlorinated biphenyls (PCBs) using gas-liquid chromatography. A questionnaire was used to obtain information on environmental factors relevant to the women's exposure to PCBs. The levels of breast milk PCB residues were considered in relation to the women's medical history before and during pregnancy and to the health status of the infants. Despite the fact that the production and use of PCBs were banned in Czechoslovakia in 1982, all breast milk samples tested had detectable levels of PCBs, with the average value of 2,411 ng.g-1 milk fat (i.e., 22.8 ng.g-1 whole milk). In 25% of the women the PCB levels were higher than 2,500 ng.g-1 milk fat, which is considered a limit concentration for PCB in breast milk.