Bisphenol a (BPA): Emerging concerns about a supposedly safe chemical.

ABSTRACT

Bisphenol A (BPA) is a monomer used to manufacture polycarbonate plastics, the resin of cans and other products with global capacity in excess of 6.4 billion pounds per year. Because ester bonds in these BPA based polymers are subjected to hydrolysis, leaching of BPA can lead to widespread human exposure. A recent report prepared by Harvard Center for Risk and funded by the American Plastic Council concluded that evidence for low dose effect of BPA is weak on the basis of a review of only 19 studies; the report was issued after a delay of 2.5 years. A current comprehensive literature review reveals that the opposite is true. As of December 2004, there were 115 published in vivo studies of low dose effect of BPA, and 94 of these report significant effects. In 31 publications of vertebrate and invertebrate animals, significant effect occurred below the predicted “safe” or Reference 50 microgram/kg/day BPA. An oestrogenic mode of action of BPA is confirmed by an in vitro study which describes disruption of cell function at .23ppt. Nonetheless, chemical manufacturers continue to discount these published findings, because no industryfunded reports have reported significant effects of low doses of BPA, although more than 90% of Governmentfunded reports have noted significant effects.