EPA considers new call for toxicity testing of BPA

The Environmental Protection Agency solicited public comment, July 26, about whether to require new toxicity testing and environmental sampling of bisphenol A, an ingredient in many plastics and food-contact resins.

“A number of concerns have been raised about the potential human health and environmental effects of BPA,” said Steve Owens, assistant administrator for EPA’s Office of Chemical Safety and Pollution Prevention. Data from the proposed new tests, he said, “would help EPA better understand and address the potential environmental impacts of BPA.”

Moreover, the agency observes on its BPA Action Plan website, because this high-volume commercial chemical “is a reproductive, developmental, and systemic toxicant in animal studies and is weakly estrogenic, there are questions about its potential impact, particularly on children’s health and the environment.”

Past standardized toxicity tests used for regulatory decision-making had indicated that levels of BPA in people and the environment fall below levels of potential concern, EPA notes. “However,” it also observes, “results of some recent studies using novel low-dose approaches and examining different endpoints describe subtle effects in laboratory animals at very low concentrations.” Indeed, EPA acknowledges, some low-dose findings “are potentially of concern.”

Although EPA doesn’t mention which studies’ findings it’s referring to, several recent papers have pointed to impacts in animals (or people) that raise concerns about exposures during development.

 — For instance, studies in the past few months using two different species of mice showed that early exposures — in the womb and up through a period equivalent to puberty — could perturb normal gender-linked behaviors in adults: Males became subtly feminized, and in one instance females appeared somewhat masculinized.

— One human study linked relatively higher BPA exposures in the womb to subtly altered gender-specific behavior in toddlers: Girls became somewhat more aggressive than normal; boys more anxious and withdrawn.

— Low-dose exposures in one study, where mice had been exposed to BPA during fetal development, resulted in later prediabetes when the rodents reached early middle age.

— A 2009 study in mice showed that the uterus of female mice exposed in the womb to BPA became supersensitized to the effects of estrogen in adulthood, a change that the authors said might jeopardize reproduction. (A test-tube study reported by others at the same time — at the Endocrine Society meeting — showed BPA altered the contractile rate of heart-muscle cells, especially in the presence of estrogen).

— And genetic studies that used roundworms as a model critter impaired the genes responsible for successful reproduction; affected genes proved unlikely to self-repair, as would otherwise be expected. The bottom line: Sterility.

For people who want to play it cautious, exposures can be hard to avoid. Recent studies have shown cash-register receipts are often made from BPA-coated paper. A recent FDA study found plenty of foods tainted with the chemical. Some water bottles — even those ostensibly made from metal — may leach substantial amounts of BPA into beverages.

And most recently, BPA has turned up on money.

Chemists with the New York State Department of Health in Albany found the pollutant on currencies from around the world — or at least the 21 shown above. The scientists punched holes in the bills and tested them. Brazil’s reals had the most; dongs from Vietnam hosted some of the highest and lowest levels. Greenbacks fell in about the middle of the pack.

Sandwiching a bill in a wallet for 24 hours between BPA-laced store receipts transferred considerable amounts of the chemical to the bills, possible explaining its source, Chunyang Liao and Kurunthachalam Kannan reported early online July 11 in Environmental Science & Technology.