One thing I’m very concerned about these days is bisphenol A, or BPA, the chemical that has become famous for turning up uninvited in plastics, tinned food cans, shopping receipts, and—surprise!—us. A whopping 95 percent of Americans have traces of this plastic building block in their bodies, according to the CDC in Atlanta.
BPA mimics the hormone estrogen, binding to its receptors and activating biochemical cascades that impact the brain, bone, liver, and heart as well as cancer risk, fertility, and obesity. Hormones like estrogen aren’t just responsible for reproduction; they are the messengers the body uses to communicate about pretty much everything. And they are incredibly potent, having “evolved to act as powerful amplifiers,” according to a 2005 commentary published in Environmental Health Perspectives.
Low levels of BPA have been shown to increase the risk for infertility, organ and nervous system problems, cancer, and obesity in animals, and a 2008 study published in the Journal of the American Medical Association found that people who have high levels of BPA in their urine are more likely than others to suffer from heart disease and diabetes. (A 2010 study in PLoS One has confirmed the heart disease findings.)
Still, an informational website maintained by the American Chemistry Council, the trade group that represents the plastics industry, maintains that “there is no basis for human health concerns from exposure to BPA.” Dig a little deeper, and I find that most of the industry’s claims about BPA’s safety are spurious. Here are five industry arguments that just don’t stand up to scrutiny—for reasons, I’m sure, they would prefer you didn’t know.
WHAT THEY SAY: “BPA is one of the most extensively tested materials in use today… The weight of scientific evidence clearly supports the safety of BPA and provides strong reassurance that there is no basis for human health concerns from exposure.”
THE TRUTH: It’s true that BPA has been studied quite extensively, although more research is desperately needed. But does the weight of the evidence support the safety of BPA? No way. According to TEDX, the Endocrine Disruption Exchange, a non-profit organization founded by University of Florida Gainesville biologist Theo Colborn, which compiles information about endocrine disruptors like BPA, as of June 2009, 391 studies have assessed the effects of 1 part per million exposures to BPA—a level 50 times lower than the EPA’s recommended safe dose. 82 percent of the studies reported that BPA caused significant biological effects at these tiny doses; only 18 percent found no effect.
WHAT THEY SAY: “The most definitive tests of BPA’s safety at low doses are two large-scale reproductive and developmental toxicity studies using accepted protocols. Both of these studies clearly demonstrated the absence of a low-dose effect of BPA.”
THE TRUTH: Oh yes, those two studies. The same ones that the FDA relied for in its 2008 safety assessment of BPA, in which the agency deemed the chemical safe. Upon being questioned by Congress later that year, the FDA admitted that the two studies were funded by the American Plastics Council, an obvious conflict of interest. (Among other things, one of the studies used a strain of rat that is not sensitive to estrogen disruption.) In addition, the Milwaukee Journal Sentinel uncovered that a medical device manufacturer that considers BPA fears to be exaggerated gave $5 million to Martin Philbert, the chairman of the agency’s BPA safety panel. In 2009, Congress concluded that these findings “raised serious questions about the extent to which FDA relied on the industry for independent scientific advice,” and sent the agency back to the drawing board. Finally, in January of this year, the agency admitted, along with the National Toxicology Program, that it had some concern about the safety of the chemical and its effects on the brain, behavior, and prostate gland of fetuses, infants and children.
WHAT THEY SAY: Findings from human studies “cannot support a conclusion that bisphenol A causes any disease.”
THE TRUTH: This is true, but what’s important to understand is why it is true, and why there aren’t more data. Certainly, if a study finds that people who have more BPA in their bodies are more likely to have heart disease and diabetes, that doesn’t mean that BPA necessarily causes heart disease and diabetes. But when it comes to BPA, it’s practically impossible for scientists to prove causality. Researchers can’t compare the health of people who are exposed to BPA to the health of people who are not, because we’re all exposed. There is no control group, and without a control group, scientists have no means for comparison. (My husband made this point on the radio last week, should you be interested in hearing it.) So yes, the results from human studies aren’t definitive, but that is not evidence that BPA is safe. It’s evidence that the situation has become so dire, we can no longer ascertain what the chemical does to us.
THE TRUTH: First, this ignores the fact that we are exposed to BPA from a range of sources. Water bottles, food storage containers, shopping receipts (which the Environmental Working Group recently showed contain up to 1000 times more BPA than tin cans do)—the list goes on and on. Second, the EPA’s safety assessment was only designed to look at gross changes in development, mortality, body weight, and tumor incidence and were “not designed to detect more subtle developmental effects that impact the health of the individual,” according to a 2009 study published by Tufts University researchers in Endocrine Reviews. In addition, the EPA assessment involved testing only adult animals, so it says nothing about how BPA might affect the offspring of animals treated during pregnancy, an important window of vulnerability. Finally, as explained earlier, hundreds of studies have found evidence that BPA causes problems at doses lower than the EPA’s safe level. And at least 11 studies have even found BPA to cause problems at low doses but not at higher doses, for as yet unknown reasons.
THE TRUTH: If that were true, then Gerber, Nalgene, Eden Organic, and a number of other companies that have voluntarily phased out BPA must have had some serious tricks up their sleeve. This is my biggest problem with the plastics industry: no, we don’t know enough about it to definitively conclude what it does. We can’t prove that it causes this disease or that disease. But does that really matter? The hundreds of studies we do have are highly concerning, and since companies don’t have to use BPA to make their resins and plastics, why don’t we just play it safe and get rid of it for good?
To me, that seems like a no brainer.
The A close look at the plastics industry’s spin on BPA by Body Politic, unless otherwise expressly stated, is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.