End Game on Bisphenol A? Have we reached a tipping point on the science of this ubiquitous chemical?

10/17/2011 03:46 pm ET | Updated Dec 17, 2011
  • Jon Entine Exec Director, Genetic Literacy Project; Senior Fellow, Institute for Food and Agricultural Literacy, University of California-Davis

When the tide begins to turn, it flushes fish into deeper waters and a feeding frenzy begins. It happens in scientific controversies, too, when the consensus changes and the old guard panics. We've seen that scenario play out in the near hysterical Republican denial of climate change. It's now happening in the debate over BPA, but in unexpected ways.

BPA is an additive used in plastic containers and many other products, from CDs to car dashboards to dental sealants and epoxy resins that line cans to protect from bacterial contamination, including botulism.

If you monitor the web, you might think the science is converging on the conclusion that BPA is harmful, when the opposite is the case. Since the signing of a bill earlier this month by California Governor Jerry Brown banning the use of BPA in baby bottles and sippy cups, cyberspace has been flooded with blogs by advocacy groups pushing the tipping point thesis. "California parents are cheering and letting out a sigh of relief with the news," chortled the Environmental Working Group. They are right. The tide is changing. But you need to look behind the headlines to see the direction of the shifting waters.

The California vote is grandstanding. Infant bottle manufacturers have not been using BPA for years. Before Brown signed the ban, the American Chemistry Council had petitioned the Food and Drug Administration to pull its authorization of BPA in infant containers because BPA is no longer used in such products. The FDA promptly indicated it agreed and is expected to institute the change. In other words, as one wag wrote, anti-BPA campaigners just succeeded in banning kryptonite. If they had cared about informing the public rather than trying to score deceptive public relations points at the expense of science, they could have petitioned the FDA long ago, rendering this a non-issue.

This ban is a political vote. It has nothing to do with science or health. It does not mean that BPA has been shown to be harmful. In response to the recent spate of publicity over the meaning of the California vote, the FDA reaffirmed the chemical's safety. "FDA has not changed its position on BPA, which is that standardized toxicity tests support the safety of current low levels of human exposure to BPA," said an agency spokesperson. "FDA would take regulatory action if it thought that the current exposure to BPA through some food container materials was unsafe."

Nor does the ban mean that the proliferation of "BPA free" containers will make our children safer. The USFDA and every major science-based regulatory agency around the world--in Canada, Europe, Australia, New Zealand and Japan among others--has determined that BPA is safe as encountered by infants and adults. Science has reached its consensus, but political bodies, like the California legislature, are capitulating to campaigns and imposing bans. This toxic roulette will result in the substitution of "mystery" chemicals, such as bisphenol AF and bisphenol S, whose primary virtue is that their effects are unknown. The most vulnerable members of society will pay the price for cynical advocacy campaigning.

Sloppy journalism

The feeding frenzy is well underway at advocacy NGOs. One high-profile and quite typical example: Rachel Lincoln Sarnoff, who is head of Healthy Child Healthy World, wrote a recent Huffington Post blog claiming that the BPA story "just gets bigger and bigger," by which she implied that the evidence of its harm is growing. But the facts, including the links in her piece, counter that fearful conclusion.

She began her article by citing a study noting that BPA found on register receipts or money is absorbed through the skin, making it sound alarming. She didn't read the study, didn't understand it or chose to misrepresent it. Authors Chunyang Liao and Kurunthachalam Kannan conclude: "The estimated daily intake of BPA through dermal absorption ... was on the order of a few nanograms per day"--an amount that "appears to be minor." Rather than a cause for alarm, even when the "worst case" exposure is taken into account, BPA exposure from receipts or money is still 140-thousand-fold lower than doses considered safe by worldwide regulatory authorities, such as World Health Organization. Oops, she left that out.

Sarnoff misreported two studies commented upon by Environmental Health News, which is an organization founded to disseminate articles hyping the dangers of BPA and other chemicals while ignoring more robust research that contradicts that thesis. One study showed that gene alterations in newborn male rats affected reproductive hormones when the rodents reached adulthood; the other study found that in pregnant rats exposed to BPA the fetus showed higher levels of BPA than the mother. Sarnoff either didn't read the actual reports or selectively left out data that undermine her strident position.

In both studies rodents were injected with BPA. Adults and children are exposed to microscopic amounts through food, but as studies have consistently shown, almost all the BPA consumed orally is quickly deactivated by the liver and safely excreted. Reviews by the National Toxicology Program, Center for Disease Control and Prevention and by World Health Organization scientists, among many others, show that injecting BPA into animals is a poor proxy for evaluating the chemical's effects in humans because we metabolize BPA and are far less sensitive. In the fetal study abstract touted by Sarnoff, the authors state that rats given BPA by mouth showed no ill effects: "Oral administration of the same dose did not produce measurable levels of aglycone BPA in fetal tissues." Oops, she left that out.

Sarnoff also selectively discusses a recent study that found BPA exposure might cause an increase in milk duct cells in breast tissue in mice, suggesting the finding has dangerously serious implications for women. But the authors state, "We cannot extrapolate from mice to humans." The study is similar to many university "hypothesis" studies on animals that have shown, time and again, not to apply to humans. Should we pursue further research on BPA? Certainly, there are complex concerns to address, including in the area of epigenetics, but you don't recklessly ban products, which would result in the substitution of untested chemicals, based on small-scale mice "association" studies unless more robust studies find direct links.

Shifting tides of evidence

Increasingly, mainstream journalists are waking up to the science. One year ago, each new media release about yet another small-scale injection rat study that showed one effect would have resulted in headlines in major newspapers and magazines. Now they ignore the noise.

Why? Over the past two years, five prominent international regulatory agencies or toxicology organizations--USFDA, European Food Safety Authority, World Health Organization, German Society of Toxicology and Japan's Research Institute of Science for Safety and Sustainability--collectively have reviewed thousands of BPA studies by government, university, and industry, including cases in which animals were exposed to BPA by mouth or injection. They've all found the injection studies unconvincing, concluding that BPA is not harmful as used.

The old saw that the small-scale studies are more reliable because they are "independent" and "university-based" has also fallen by the wayside. U.S. regulators under President Obama have moved aggressively to fund researchers at several government laboratories to address the frequently heard complaint that the more robust studies relied upon by regulators are "tainted" by industry connections. Among their findings on BPA: (1) Efficiently metabolized and rapidly eliminated, making it unlikely to cause health effects (FDA, CDC, Pacific Northwest National Laboratory); (2) No developmental neurobehavioral effects (EPA, FDA); (3) No developmental effects on male reproductive organs (EPA); and (4) Fetus is not significantly exposed to bioactive BPA after oral exposure to mother (National Center for Toxicological Research).

In sum, a string of small-scale studies, widely promoted by advocacy groups, led to a media-driven popular but not a scientific consensus that BPA might be harmful. Now, independent and government scientists carefully examining that thesis are finding it wanting.

The shifting consensus has set off alarm bells among campaigning journalists who put ideology ahead of science. Consider a recent article in Mother Jones by Amy Silverstein attacking the prominent breast cancer research organization Susan G. Komen for the Cure. Reflecting the scientific consensus, the non-profit posts on its website: "there is no evidence to suggest a link between BPA and risk of breast cancer." In what can only be characterized as a direct smear, Silverstein cited "critics"--she names none--claiming that Komen posted that information (which is factual) because it is on the take from "private industries that use those same chemicals." She goes on to write: "It's hard, to ignore mounting scientific evidence that strongly suggests a link."

She must know, or should know, and has a responsibility to tell readers, that no study has shown a direct link between orally ingested BPA and breast cancer. As Forbes columnist and STATS's Editor at Large Trevor Butterworth explains, "The most advanced technologies for finding BPA have found that even in people given a diet high in BPA, it is below the level of detection in their blood. And if it is below the level of detection, how is active BPA supposed to get to the breast cells in similar quantities to the [rodent] experiments, which claimed a link?"

The clamor on marginal websites and by journalists with little grasp of scientific risk brings to mind the Emerald City overseen by a bellowing Wizard of Oz, a powerful disembodied presence. Dorothy's Toto pulls back the green curtain, revealing that the verbally awe-inspiring Wizard--in this metaphor the anti-BPA campaigners--is nothing more than a tiny man furiously spinning dials in a frantic attempt to keep the deception alive. Many politicians have not taken a careful look at the dwindling science backing these campaigns. The scattershot legislative bans that have resulted only underscore the danger of taking regulatory powers out of the hands of scientists and granting them to politicians.

Campaigners are now targeting the removal of BPA from can liners, although there are no effective substitutes that protect the public against spoilage. The Natural Resources Defense Council, dissatisfied with FDA's actions on BPA, has filed a complaint in federal court demanding that the agency take final action on its 2008 "Citizen Petition" and ban its use in all food packaging, including in epoxy linings. The Washington-based advocacy group should be careful what it wishes for. If it should succeed in its procedural move, based on independent state-of-the-art scientific studies, literature reviews and government actions around the world, the answer is almost certain to be "no."

Jon Entine is Senior Fellow at the Center for Health & Risk Communication and STATS at George Mason University.