PCB exposure in utero and via breast milk. A review

A review of the literature was conducted to investigate the importance to offspring of in utero and breast milk polychlorinated biphenyl (PCB) exposure. All reports that we could identify (n=25) were included, representing 16 study populations. Tissue-specific PCB concentrations in human placenta, breast milk, maternal blood and cord blood were compared to determine accumulation ratios between tissue compartments. On a lipid basis, the highest concentration of PCB in placenta (5027 ng/g fat) was 2.8 times higher than the highest concentration of PCB in breast milk (1770 ng/g fat). While there are limitations with regard to quantitation methods and statistical methods utilized by the reviewed studies, our results suggest that PCBs may be capable of crossing the placenta to a greater extent than previously believed. Future studies of PCB body burden in the perinatal period should include placenta, breast milk, maternal and cord blood specimens. In order to compare PCB concentrations in various tissues and with other studies, concentrations should be determined on a lipid basis.