Environmental Factor, July 2008, National Institute of Environmental Health Sciences
Draft BPA Report Gets Public Comment and Board Review
By Eddy Ball
Less than two months after the eagerly anticipatedwas made publicly available, the NTP Board of Scientific Counselors (BSC) considered the draft brief as part of its semi-annual public meeting on June 11 - 12 at the Research Triangle Park Radisson Hotel. The draft brief represents NTP's assessment of the risks of BPA exposure for affecting reproduction and development in humans. The draft brief is based on review of an Expert Panel Report issued in August 2007, public comments and new relevant scientific literature.
Chaired by birth defects specialist Gail McCarver, M.D., the meeting gave scientific staff of the NTP Center for the Evaluation of Risks to Human Reproduction (CERHR), who prepared the draft brief, a forum for explaining their conclusions to the BSC. The group also had an opportunity to hear comments on the draft brief from the public as well as receive input from the BSC and several scientists who were designated ad hoc discussants.
The meeting opened with welcome remarks by Acting NIEHS/NTP Director Sam Wilson, M.D., who expressly reinforced "the NTP's position toward full peer review and toward full public input into the peer review process - and at the same time the commitment toward full transparency. Our aim is to sort through the science and come to the best solution possible based on the scientific information."
Wilson's remarks were followed by a review of NTP activities since the BSC's December 2007 meeting, presented by NTP Associate Director John Bucher, Ph.D. CERHR Director Mike Shelby, Ph.D., then explained the process for preparing the draft brief, presented an overview of the draft brief and explained the NTP's rationale for reaching its conclusions.
Shelby emphasized several times in his presentation that CERHR reports are assessments of potential effects on human health and should not be confused with regulatory documents. He also articulated the charge to the BSC to evaluate whether the draft is technically correct, clearly stated and supportive of the conclusions. Shelby was followed by Centers of Disease Control and Prevention (CDC) toxicologist Richard Wang, M.D., who presented the National Health and Nutrition Examination Survey (NHANES)(http://www.cdc.gov/nchs/nhanes.htm) study data that support the exposure of more that 90 percent of the population to BPA.
With a few exceptions, the draft conclusions of the NTP were in general agreement with those of the expert panel. The NTP conclusions reflected a higher level of concern(http://www.niehs.nih.gov/health/topics/agents/sya-bpa/index.cfm) than those expressed by the expert panel for possible effects of BPA on prostate gland, mammary gland and early onset of puberty in exposed fetuses, infants and children. The CERHR staff considered the Expert Panel report and all public comments on the final expert panel report, and reviewed relevant scientific papers that were published subsequent to completion of the expert panel evaluation.
Members of the BSC and ad hoc reviewers engaged in some lively discussion about specific details of the draft brief, but they generally agreed that NTP had done a commendable job of integrating a large amount of sometimes conflicting data into a cohesive draft. The detailed four-hour review was characterized by extensive reference to specific papers on the long list of citations reviewed during preparation of the draft brief. The BSC agreed with most of the conclusions presented in the draft brief, but recommended a lower level of concern for possible effects on the mammary gland and puberty in females. Publication of the final NTP Brief on BPA is expected in late summer of this year.