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The scientific consensus, however, has been moving away from the idea that BPA is completely safe. When researchers began raising alarms about BPA in the late 1990s, they were in the minority. Under the Bush Administration, the FDA reviewed the chemical and ruled it safe. But that report was criticized by the agency's own science-review board for relying almost exclusively on industry-funded studies. In 2008 Canada deemed infant exposure to BPA potentially unsafe and banned the sale of baby bottles that use the chemical a step later taken by a number of American states and major retailers, including Walmart. Though European regulators declared BPA safe in a 2008 assessment, last month Denmark enacted a ban on BPA in baby bottles.
In 2009 the International Endocrine Society released a statement declaring that endocrine disrupters were a significant concern for public health and called for regulation to reduce human exposure. And even the FDA has changed its tune somewhat: in January the agency expressed "some concern" over BPA as the Obama Administration launched a $30 million study of the chemical. "Especially given that children in the early stages of development are exposed to BPA, the data and the research deserve a closer look," Dr. Josh Sharfstein, the FDA's principal deputy commissioner, told reporters at the time.
The woman in charge of that closer look is Linda Birnbaum, head of the National Institute of Environmental Health Sciences (NIEHS) and the National Toxicology Program. A scientist who has spent decades in government service, Birnbaum isn't quite ready to give up on Paracelsus' axiom, but she knows that toxicology has to catch up with the real world. Scientists must realize that the body doesn't encounter a single chemical in isolation though that's how tests are done but a number of chemicals in combination, which might interact in unpredictable ways. The dose may still make the poison, but we'll never know unless we test the chemical soup we actually experience in the world unless, that is, we find the environmentally relevant dose. "There's been a tendency to ask the old questions in the old way," says Birnbaum. "But if it's dark and you only look for your keys under the lamppost and they're not right there, you'll never find them."
Good science means widening that search, asking not only which chemicals may play a role in illnesses essentially, where else the keys might be but also how those chemicals do their damage. Certain substances including BPA and some phthalates seem to be able to switch in vitro cells from becoming connective tissue to becoming fat cells, and a 2009 study from Belgium found that children exposed to higher levels of toxic chemicals like polychlorinated biphenyls (PCBs) before birth were fatter than those who had lower exposure. Even autism, which remains a mystery, may have environmental triggers. (Vaccines have been repeatedly exonerated in autism debates, a conclusion that's accepted even by scientists who see the possibility of other environmental risk factors in the condition.) And a recent study by Swan found that women who had higher levels of phthalate exposure during pregnancy were more likely to have children with behavioral problems. None of this is proof, but all of it is worrisome. "We need to know where these chemicals are and what they're doing to us," says New York Representative Louise Slaughter, author of legislation that would establish a new research program focused on endocrine disrupters. "We shouldn't be in the dark."
Failure to Protect
If you want to market a new drug, you need to convince the FDA in multiple tests, over the course of years that it won't cause serious harm. If you want to sell a new pesticide, you need to prove the same thing. The burden of proof is on manufacturers to make the grade, and government regulators are the final judge.
But if you want to market a new chemical for use in a product even one that will come into contact with children or pregnant women it's up to the EPA to prove that it's unsafe, using whatever data are provided by the chemical company, with little power to ask for more. And if it's one of the 62,000 chemicals that were already in use when the TSCA went into effect in 1976 a category that includes BPA chances are it was never really tested by the government at all. "Chemicals are deemed safe until the EPA can prove that they are dangerous," says Richard Wiles, executive director of the nonprofit Environmental Working Group. "It's completely backward."