The latest chapter in the debate over bisphenol-A, or BPA, is that the chemical does not pose a risk to fetuses when it’s ingested by pregnant women. BPA is used in the linings of food and beverage containers and food safety advocates have long argued that it should be more tightly regulated and that it poses special dangers to fetuses and infants.
But a new government study has produced strong evidence that the chemical is effectively metabolized by the mother and the fetus -- meaning essentially that the body processes the chemical completely, leaving no significant residue behind.
A study released in February also found no significant health effects from BPA. In that study, a toxicologist examined 150 previous studies involving 30,000 people in 19 countries and found the exposure levels generally much too low to have any impact.
The latest study was conducted by a team of researchers from the U.S. Food and Drug Administration and the National Toxicology Program. It first looked at BPA as it was metabolized in pregnant mice and rats.
The researchers found that the mice and rats had no trouble metabolizing the chemical. They then turned to monkeys, who more closely resemble humans and found that they, too, deactivated the BPA effectively, even when it was injected directly into their bloodstream, at much higher concentrations than normal.
When BPA is ingested normally, through the digestive tract, it is reduced to undetectable levels in the fetus, the study found.
How it's processed
The latest study is what is called a pharmocokinetics study, one that traces how a chemical is ingested and processed by the body. Such a study does not determine whether or not a chemical is harmful -- only whether it is retained in the body in significant quantities.
At harmful levels, BPA is thought to be an endocrine disruptor, which mimics the effects of hormones in the body, leading to fears that it could cause developmental and behavioral problems. But there have been 10 pharmocokentics studies in recent years that have found that BPA is effectively deactivated by the body, researchers said.
“The net result is that more than 99% of dietary BPA is detoxified by conversion to BPA-G before it enters the bloodstream for delivery into the tissues where even more metabolism can occur,” said Daniel Doerge, an FDA chemist who was the lead researcher in the latest study. He was quoted by Food Safety News http://www.foodsafetynews.com.
Californians' fears
The latest studies haven't done much to quell the clamor over BPA among activist groups, however. In San Francisco, a senior scientist at the Natural Resources Defense Council, Sarah Janssen, said recently that there's "a ton of new science that has come out that further supports BPA's being a reproductive and developmental toxicant."
Her group group has petitioned California's Environmental Protection Agency to add BPA to the state's annual list of suspect chemicals under the consumer-safety law Proposition 65. That would mean that manufacturers would have to put warning labels on anything containing the chemical. Because California is such a huge market, manufacturers usually affix the warning labels nationwide, leading to lost sales and consumer angst.
Chemical industry representatives sued the state last month, hoping to keep BPA off the toxin list, saying the state had not proven its case.
The latest chapter in the debate over bisphenol-A, or BPA, is that the chemical does not pose a risk to fetuses when it’s ingested by pregnant women....