US study finds no significant effects related to low dose BPA exposures

Chemical Watch: "In the USA, a study funded by the Environmental Protection Agency (EPA) has concluded that low dose maternal exposure to bisphenol A (BPA) has no significant effects on key developmental end-points of laboratory rats.

The study, conducted by the EPA’s National Health and Environmental Effects Research Laboratory and North Carolina State University, looked for endocrine effects such as changes to sexual behaviour, puberty, fertility and the anatomy of female rats and compared exposures in utero and through lactation of ethinyl estradiol – an oral contraceptive – and BPA."

The researchers noted that many chemicals released into the environment display estrogenic activity including ethinyl estradiol and BPA and that the US National Toxicology Program has rated the potential effects of low doses of BPA on behaviour and the central nervous system as an area of “some concern”. The current study was designed to determine the effects of maternal exposure to relatively low oral doses of the two substances.

For the end points studied, the report recorded no effects related to BPA exposure, while exposure to ethinyl estradiol produced permanent adverse effects. The report notes these conclusions are consistent with other “robust, well designed, properly analyzed multigenerational studies”.

In future studies the researchers plan to assess other endocrine effects, such as impacts on the estrous cycle and ovarian function, and to more thoroughly investigate the substances’ dose response relationship.

The American Chemistry Council commented: "This EPA-funded, well-conducted study is a significant development in better understanding the safety of BPA." The study has been published in Toxicological Sciences.

At the same time, an investigation by Consumer Reports magazine has discovered levels of BPA in a wide range of food cans despite manufacturers claiming their products to be BPA-free. The survey has prompted health campaign group the Breast Cancer Fund to demand regulation of the chemical.

Janet Nudelman, program and policy director at the Breast Cancer Fund said: "The report results are sobering, and confirm what we already know: Americans are exposed to BPA every day through canned foods. A synthetic estrogen linked to breast cancer should not be in our food, period. It’s well past time to ban BPA from food and beverage containers.”