During lactation, a woman's body uses this fat to enrich the energy content of breast milk. Any pollutants stored in the fat also pass to the baby with the fat in that milk. Because a woman's cumulative lifetime exposure to estrogen is one of the best established risk factors for breast cancer, there is a growing suspicion that exposure to estrogen mimics may also pose a cancer risk. To date, the jury remains out on the carcinogenic potential of those pollutants. However, there's no doubt that babies are being exposed.
Nursing protects moms from breast cancer.
Titus-Ernstoff, L., et al. Exposure to breast milk in infancy and adult breast cancer risk. Raloff, J. 1996. PCBs' legacy can affect next generation. Breast effects of hormonal pollutants.