Transfer of Polychlorinated Biphenyls to Infants from their Mothers

Abstract

Transfer of polychlorinated biphenyls (PCBs) which are environmental pollutants, to infants from their mothers was investigated from 1974 to 1977. The following samples were collected and analyzed for PCBs using a gas chromatographic determination: (a) maternal blood at 8 and 4 months prepartum, delivery, and 1, 3, 5, and 7 months postpartum; (b) cord blood at delivery; (c) human milk at 1, 3, 5, and 7 months postpartum; and (d) newborn infant blood at 3 months, 1, 2, and 3 yr after birth. The PCB levels in maternal blood gradually elevated with the progress of gestation and then decreased, reaching a general population level at 5 months postpartum. The PCB level in maternal blood at delivery was significantly higher than that in the cord blood. The mean values of PCB levels in human milk at 3 months postpartum-both the whole and fat basis-showed some differences in each sampling time period, however, those values were generally obtained within the normal range of ordinary Japanese lactating women. When the cord blood at delivery was considered as newborn infant blood at birth, the PCB levels in the blood of breast-fed infants rose markedly with ingestion of human milk, exceeding the level in themore » blood of their mothers at 3 months postpartum, and tended to increase until 1 yr of age, and then gradually decreased at 2 and 3 yr of age. However, the PCB levels in the blood of bottle-fed infants remained at a low concentration level during the same period. In this survey, the concentration of PCBs in the blood of two newborn infants who received their mothers' milk for a longer period of time than the other infants, continued to increase exponentially, finally reaching about a four-fold value of their mothers. These results suggest that the quantity of PCBs transferred to infants from their mothers via lactation was much greater than that transferred placentally.« less