Plastics component linked to breast cancer
Fetal exposure to bisphenol A, which leaches from baby bottles and microwave-safe containers, has been connected to breast cancer in rats.
Bisphenol A (BPA), a building block of polycarbonate plastics used in products such as baby bottles, hikers’ water bottles, and microwave-safe containers, has been identified by a growing body of research as a mimic of the hormone estrogen that has significant effects at low doses. Now, researchers at Tufts University have discovered an association between BPA and breast cancer in rats exposed to the compound in their mothers’ wombs.
The study, published in Reproductive Toxicology (2006, DOI: 10.1016/j.reprotox.2006.10.002), treated mother rats with doses of BPA ranging from 2.5 to 1000 micrograms per kilogram of body weight per day (Μg/kg/day), similar to levels measured in the U.S. population. About one-third of their female offspring exposed to 250 Μg/kg/day in the womb developed cancerous lesions in their mammary glands when they reached adulthood.
The researchers did not expose the rats to additional tumor-promoting agents. Although the mechanism behind tumor formation remains largely unknown, the study hints that BPA alters the development of fetal breast tissue in a way that promotes formation of cancer later in life. The study also supports the theory that fetal exposure to estrogen mimics is behind the rise in breast cancer rates over the past 50 years, the authors say. Environmental groups and some scientists have called for the removal of BPA from plastic products.
