Bisphenol A Safety

A STUDY conducted by researchers at the University of Missouri, Columbia, strikes at the heart of a federal panel's conclusions about the health concerns of bisphenol A (BPA)—the high-production-volume chemical used to make polycarbonate plastic (Repro. Tox. DOI:10.1016/j.reprotox.2008.01.001), say experts in the field.

Last August, a panel appointed by the National Toxicology Program's Center for the Evaluation of Risks to Human Reproduction (CERHR) reported that it had "some concern" that prenatal exposure to BPA causes neural and behavioral defects in infants and children, and "minimal" or "no concern" about any other health effects. It reached these conclusions by considering only those studies in which lab animals had been exposed orally to BPA and disregarding all experiments in which the animals had been injected or given the compound subcutaneously.

Biologist Frederick S. vom Saal and colleagues at Missouri disagreed strongly with the CERHR conclusions because fetuses and newborns lack, or express at very low levels, the liver enzyme needed to deactivate BPA, in contrast to adults who metabolize it quickly. This fact, the researchers argue, indicates that exposure by any means will affect fetuses and newborns.

To test this theory, vom Saal separated three-day-old mice into four groups. Two groups were exposed to oral doses of BPA. The other two groups were injected with BPA. Blood measurements of biologically active BPA over the next 24 hours showed that the route of administration made no difference, vom Saal says.

"Vom Saal's study is a very important piece of work," Gail S. Prins, a professor of physiology at the University of Illinois, Chicago, says. It could invalidate the CERHR panel's conclusions, she adds.

"Our research shows that the decision by the CERHR panel is without merit and unsupported by the scientific literature," vom Saal says.