Chemical Exposure May Impair Breast Development, New Studies Show

Chemical exposure in early life may affect mammary gland development and increase the chances of developing breast cancer and lactation problems in later years, scientists conclude in a series of new reports. One study showed that when rodents are exposed in the womb or as newborns to some hormonally active chemicals — including estrogens, phytoestrogens, and bisphenol A, a synthetic chemical found in thousands of everyday plastics — their mammary glands do not grow normally and breast development is affected. Later in life, such exposure may impair breastfeeding and increase the chances of developing breast cancer, the study said. Because mammary glands are sometimes more sensitive to the effects of hormone-disrupting chemicals than other parts of the body, even low levels of exposure can have significant impacts, researchers say. “Few chemicals coming into the marketplace are evaluated for these effects,” according to the report, published in Environmental Health Perspectives. In another study, scientists found that mice exposed to a chemical used to make Teflon experienced delayed breast development and impaired lactation.