Polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethene (DDE) in human milk: effects on growth, morbidity, and duration of lactation.

We followed 858 children from birth to one year of age to determine whether the presence of polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethene (DDE) in breast milk affected their growth or health. Neither chemical showed an adverse effect on weight or frequency of physician visits for various illnesses, although differences were seen between breast-fed and bottle-fed children, with bottle-fed children being heavier and having more frequent gastroenteritis and otitis media. Children of mothers with higher levels of DDE were breast-fed for markedly shorter times, but adjustments for possible confounders and biases did not change the findings. In absence of any apparent effect on the health of the children, we speculate that DDE may be interfering with the mother's ability to lactate, possibly because of its estrogenic properties.