Opinion: BPA's Risks Are Vastly Exaggerated

(May 19) -- If you found out that you were exposed to a chemical in food packaging that was linked to a host of health problems including obesity, breast and prostate cancer, diabetes, heart disease, brain disorders and erectile dysfunction, you'd want to have it banned. Even if the risk wasn't that great or the science fully proven, precaution would seem to be the most sensible course of action given those charges.

This would seem to be the case with bisphenol A (BPA), a chemical used to coat the linings of cans and in the manufacture of various plastics.

And Sen. Dianne Feinstein, D-Calif., thinks so. She has proposed an amendment to the current food safety bill to ban the chemical. And to buttress her case, a coalition of activist groups released a "study" Tuesday claiming that "meals involving one or more cans of food can cause a pregnant woman to ingest levels of BPA that have been shown to cause health effects in developing fetuses in laboratory animal studies."

But while public concern about BPA has steadily increased, the science behind the alleged health risk has so far failed to justify any such ban. In fact, banning BPA could do more harm than good.

Here's the background.

Early research did raise concerns about BPA. But those studies involved only a very small number of rodents that were directly injected with the chemical. This, according to Richard Sharpe, one of the world's leading endocrinologists, is the "incorrect" way to assess whether BPA poses a risk to humans.

He points out in the journal Toxicological Sciences that when you use the "correct" route of exposure -- oral, through food and drink -- it turns are that "even at levels of exposure 4,000-fold higher than the maximum exposure of humans in the general population there are no discernible adverse effects."

As Wolfgang Dekant, professor of toxicology at the University of Wurzburg, explains, when you consume food or liquids that have traces of BPA, the chemical is deactivated in the gut and the liver and is quickly excreted. This happens in pregnant women -- and even in fetuses exposed to tiny amounts in the mother's blood. But it doesn't happen if you inject the chemical.

That is why he, and the 20 other scientists who conducted the European Union's risk assessment of BPA, rejected the studies cited by Feinstein and the activist groups backing her. Moreover, no regulatory agency has been able to replicate these early findings through bigger (i.e., more statistically powerful) and better designed studies.

This is why the Food and Drug Administration, the Environmental Protection Agency, the U.S. National Toxicology Program, and other similar regulatory bodies in Australia, Britain, France, Germany, Korea and Japan, all have taken basically the same position on BPA. The FDA, for example, has said that "studies employing standardized toxicity tests have thus far supported the safety of current low levels of human exposure."

As Sharpe, who is chairman of Britain's expert panel on endocrine disruption, explained in a British newspaper: "For reasons that have nothing to do with scientific facts, a small minority of (mainly U.S.) scientists have continued to shout about the dangers of bisphenol A by stating that the larger repeat studies are wrong and their initial studies using the incorrect route of exposure, i.e. injection, are right. This is wrong and not the way science works. Just apply common sense -- if several huge studies using the human-relevant route of exposure show no effect but a small preliminary study does show effects, which would you believe?"

There is a price for failing to pay attention to what scientists as opposed to activists see as common sense. As Sharpe notes, tens if not hundreds of millions of dollars are being wasted on doing pointless research on BPA when the answers we need are already in: It's not a problem. There are, however, lots of other chemicals in the environment that need to be urgently studied to see whether they pose health risks.

The second problem is that banning BPA would actually put the public at greater risk from far more deadly toxins.

BPA is in cans so that food can be heat sterilized, which protects it against possible contamination from pathogens such as botulism. Right now, there is no effective substitute for BPA.

The terribly irony of Sen. Feinstein's attempt to ban BPA is that it would expose the public to a real risk at the expense of being protected from an imaginary one.

Does that seem like common sense to you?

Trevor Butterworth is editor of STATS.org, a research project affiliated with George Mason University that examines the use of science and statistics in the media and public policy.


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