California's legislature is now debating whether to ban a chemical found in plastic consumer products of many types, Bisphenol A, based on the so-called precautionary principle. This principle asserts that if a substance is suspected of being harmful, it must be banned or restricted until it's proven "safe."
But how does anyone go about proving a substance completely safe, and to whose satisfaction must it be proven?
In the case of bisphenol A (BPA), the accuser of record is Assemblywoman Wilma Chan (D-Oakland), who was also instrumental in the attempt to ban certain cosmetics and kids' toys because of a different chemical constituent. The scare campaign is orchestrated by the same PR operation that brought us the scare over Alar on apples in 1989: Fenton communications, which generates alarm to promote its anti-science agenda and win adherents: they will "save" us from every (non-existent) chemical threat.
Almost all of these scares are based on high-dose rat tests. When fed huge doses of various chemicals, rats sometimes develop cancers and other abnormalities, which are then extrapolated to humans and used by activist groups and their public relations machines as a basis for scare campaigns. The only problem: there is no correlation between rodent toxicity tests and human effects (see the American Council on Science and Health book on this topic, America's War on "Carcinogens", at: http://www.acsh.org/publications/pubID.990/pub_detail.asp ).
For example: BPA has long been used to make tough plastic products such as plastic water bottles, food and drink packaging, and toys and baby bottles, in the form of polycarbonate plastics. It is also used to make epoxy resins, which are needed in water pipes, bottle tops, and children's teeth sealants. There is no evidence that it has caused any adverse health effects in humans.
This should come as no surprise. Not only are the rodent tests done on, well, rodents, which have completely different physiologies from humans, but the doses they are given are many thousands (or millions) of times greater than what we humans are exposed to from these products. Scientists can't even predict effects on mice based on experiments done on rats. The connection between rats and humans is even more tenuous.
Ms. Chan said she was "shocked to find out that there were chemicals in toys that babies put in their mouths and in baby bottles. We just shouldn't have these products on the market in California." Perhaps, since she has oversight over children's health, someone should tell Ms. Chan that we are all composed of "chemicals." The food we eat daily is chock full of perfectly natural chemicals which, if the dose is high enough, cause the same effects in rats as the substances she is so anxious to condemn.
ACSH has written a peer-reviewed paper on BPA, which was published in Medscape, a scientific journal, after being subjected to that journal's own independent review process (see "Bisphenol A: A Scientific Evaluation," at: http://www.medscape.com/viewarticle/484739?src=search ).
Our conclusion: people's current exposures to BPA are not a cause for concern, for adults, children, or pregnant women. This conclusion is in agreement with those of the federal Food and Drug Administration and the Centers for Disease Control and Prevention. The only folks who disagree are the activists, Fenton PR, and the republic of California.
If useful and safe consumer products are banned "at the drop of a rat," as Assemblywoman Chan and her supporters propose, what would replace them? We know that the taxpayers of California would bear the cost of new substances being tested and introduced. And what would the adverse effects of these new products be? How much testing would they have to go through before their release into the marketplace? The scaremongers won't be easily satisfied.
Banning BPA will not improve the health of even one of California's children. Listen to scientists, not hypesters. Pay attention to kid's many real problems, not purely hypothetical ones such as BPA.
Gilbert L. Ross, M.D., is Executive and Medical Director of the American Council on Science and Health.
UPDATE: A related debate between Dr. Ross and Brett Levy about the controversial CHEERS study of chemicals' effects on kids can be found at this post on the DadTalk blog.