People might be exposed to the commonly used chemical bisphenol A (BPA) at levels much higher than the recommended safe daily dose, according to an animal study.
BPA is found in polycarbonate plastic food and beverage containers, such as water and infant bottles, as well as in the epoxy resin lining of cans and other sources.
"BPA is now known to be a potent estrogen," said Frederick vom Saal, PhD, a co-author of the new study and a professor of biological sciences at the University of Missouri-Columbia.
"Human and animal studies indicate it could be related to diabetes, heart disease, liver abnormalities, miscarriage and other reproductive abnormalities, as well as prostate and breast cancer," he added.
During the study, the researchers fed five female adult monkeys an oral dose of BPA (400 micrograms per kilogram of body weight).
Vom Saal says that this amount is more than 400 times higher than the amount that the U.S. Food and Drug Administration (FDA) estimates that human adults are exposed to and 8 times higher than the estimated safe daily amount to consume.
Yet the blood levels of biologically active BPA over the next 24 hours were lower in the monkeys than the average levels found in people in the United States and other developed countries.
Vom Saal said that for levels to be higher in people when measured, their exposure dose must be greater than that given to the monkeys.
"These results suggest that the average person is likely exposed to a daily dose of BPA that far exceeds the current estimated safe daily intake dose," vom Saal said.
The results were presented at The Endocrine Society's 91st Annual Meeting in Washington, D.C.