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Your Environment. Your Health.

NTP Speaks about BPA

John Bucher and Michael Shelby
John Bucher, Ph.D., and Michael Shelby, Ph.D., discuss the 2008 NTP report findings.

In September 2008, the National Toxicology Program (NTP) completed a review of available research on the chemical bisphenol A (BPA) and concluded that there was “some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures.”

Shelby describes how BPA gets into the body.

Bisphenol A is a chemical that's used to produce polycarbonate plastics and epoxy resins. Polycarbonate plastic is used to make water bottles as well as baby bottles; and epoxy resin is used to line metal food cans. After producing this polycarbonate plastic and the epoxy resin there's some residual bisphenol A remaining in the product. And this bisphenol A, the individual molecules, can leach out of the plastic or the epoxy resin into food or drink that is contained within these bottles or cans. In addition, we believe that as the plastic or epoxy resin decomposes, that additional bisphenol A becomes available to leach out into food and drink.

How BPA Enters the Body

Shelby describes challenges in evaluating BPA.

Our evaluation of bisphenol A is the most difficult and challenging evaluation that we have ever conducted. There is a vast amount of literature that we took under consideration. The expert panel report cited over 500 references. But I think the main problem that we encountered, the problem that kept repeating itself, was having a body of information, of literature on a specific topic, that was in disagreement, that reported conflicting results, that conducted experiments using protocols that prevented us from making valid comparisons of results from one experiment to another.Ultimately it was a few areas where there was some consistency among the effects reported and the exposure levels at which those effects were observed. We felt that the literature available to us justified the conclusions that we reached; and the reasons for that are spelled out in the brief on bisphenol A.

Challenges in Evaluating BPA

Terms of Use

These audio clips and the three images on this webpage are in the public domain and copyright free. Anyone is freely able to use these files. These materials were created by the Office of Communications and Public Liaison of the National Institute of Environmental Health Sciences. As a courtesy, it is requested that an appropriate acknowledgement be given: "Courtesy: National Institute of Environmental Health Sciences."

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