We don’t know the impacts that BPA might have on human beings — especially developing fetuses and young children — and we don’t know whether worrying test results in animal subjects would translate to people. We don’t know if BPA should be banned from baby bottles, as it has been in Canada and the European Union, or whether such fears are overblown. As it has with many potential toxins, our ability to detect chemicals is running ahead of our ability to understand what they may be doing to us.
What we do know for sure is that BPA is all around us — and inside us. An estimated 93% of Americans have detectable levels of BPA in their bodies, based on Centers for Disease Control and Prevention numbers. But here’s the good news: once we stop being exposed to the chemical, BPA levels can drop dramatically. Unlike persistent, long-lasting toxins like mercury, we can rid ourselves of BPA fairly quickly — provided we know how to do it.
That’s the conclusion of a new study published in the journal Environmental Health Perspectives. A team of researchers from the Silent Spring Institute, an environmental health nonprofit, the Breast Cancer Fund and Vassar College took five families from the San Francisco Bay area and had them stop using canned foods and plastic food packaging for several days. The scientists found that BPA levels among the family members dropped by an average of over 60% — but once they went back to their normal diet, the BPA levels went back up as well. That’s pretty strong evidence that restricting use of certain plastics and packaging — or banning BPA — can significantly reduce exposure to the chemical, and whatever harm BPA might carry.
Here’s how the study worked: the five families (each of which had two parents and two young children) provided urine samples for two days while they ate their normal diets. That gave researchers a background level for BPA and some phthalates — plasticizing chemicals that have also been tagged as endocrine disrupters. Next, the researchers gave each family three days’ worth of freshly prepared organic meals and snacks, stored in glass and stainless steel containers. (One popular source of BPA is in the liner inside canned food.) The families gave urine samples on the second and third days of the intervention, and those samples were tested for BPA and phthalates. Lastly, the families returned to their normal diets for three days, and were tested twice again.
In addition to BPA, the researchers also tested for the phthalate DEHP — which is also found in food packaging — as well as DEP and several other chemicals that are not used often in packaging. That mix of chemicals was chosen to give the research team a better idea of the role that plastics and packaging might play in exposure to BPA. The fact that BPA levels among the families dropped when their diet changed — but levels of DEP, which is used in fragrances, didn’t — underscores the importance of food packaging in exposing people to BPA.
What does it all mean? Bear in mind that although this research was peer-reviewed, it was a small study and one that was carried out by groups that have raised concerns about BPA and other potentially toxic chemicals in the past. But if you are worried enough about BPA and phthalates to want to cut down your exposure, avoiding canned foods and using glass rather than plastic containers is a good start.
That won’t be sufficient, though. BPA is also used on thermal paper register receipts and shatterproof plastic items, among other sources. BPA and phthalates are so ubiquitous in the consumer environment that only regulation — including bans on items likely to come into contact with pregnant women and young children — will keep us truly BPA-free.
Update [2:58 PM]: Industry has registered its skepticism of the study as well. From the American Chemistry Council:
This study simply confirms these reassuring points: that consumers have minute exposures to BPA and DEHP from food sources, and that the substances do not stay in the body, but are quickly eliminated through natural means. Additionally, data from U.S. Centers for Disease Control and Prevention and Health Canada have shown that typical consumer exposure to BPA and DEHP, from all sources, is up to 1,000 times lower than government-established safe exposure levels. “Consumers should feel confident that they can continue to eat healthy canned or packaged foods because materials intended for use in food contact are approved by the U.S. Food and Drug Administration