Bisphenol A Saga Continues

Today the Washington Post, Los Angeles Times, and other news sources report that the National Toxicology Program has issued a draft brief stating concerns about the effects of low levels of bispehnol A on fetusus and children. Exposure to bisphenol A can interfere with the development of children's brains and reproductive organs, including alterations to breast and prostate tissues that can incrase the risk of developing cancer later in life. Bisphenol A is used in many plastics and in the liners of some food and beverage containers, and most of us have measurable concentrations of it our bodies.

While the NTP doesn't have any power to regulate BPA, its findings will influence EPA and FDA regulation and state laws. To truly appreciate the importance of this NTP brief, it helps to know how the research on this chemical has emerged, and how federal agencies have dealt with science, conflicts of interest, and industry bias. At DefendingScience.org, we've just posted a bisphenol A case study by Sarah Vogel, a PhD Candidate at Columbia University in the Department of Sociomedical Sciencesâ Center for the History and Ethics of Public Health and Medicine. It's a comprehensive look at what's happened with bisphenol A and what needs to happen to protect public health.  Here's her summary of where things stand:

Political pressure to re-evaluate bisphenol A safety is mounting in response to dozens of studies demonstrating adverse effects from low dose exposure to bisphenol A.  A number of states, including California, Maryland, Minnesota and Michigan, are considering bills to ban or severely restrict bisphenol A in childrenâs products.  In early 2008, federal lawmakers finally began to respond to rising concerns about bisphenol A safety.  Congressmen John Dingell (D-MI) and Bart Stupak (D-MI) initiated an investigation into the presence of bisphenol A in infant formula and sent letters to the FDA noting that the agency's position on bisphenol A's safety appears to be entirely dependent on two studies funded by the American Plastics Council and requesting details about the FDA's determination of the chemical's safety.  These actions of the state, however, are painfully slow when compared with consumer responses to the emerging scientific consensus on bisphenol A risks.  All across the U.S. and Canada, parents are throwing out polycarbonate baby bottles and Nalgene sports bottles, effectively making their own personal decisions about the potential risks of bisphenol A exposure.
 
While consumer demands and choices send an important message to manufacturers and lawmakers, with over 6 billion pounds produced per year, bisphenol A is critically important to the production of plastics used in hundreds if not thousands of productsânot just baby bottles.  It is, therefore, critically important that lawmakers take a strong stand in protecting the publicâs health.  This means stepping beyond the political debate over scientific uncertainty stirred by those with the greatest economic stakesâthe chemical industryâto consider what is known about this chemical.
 
Bisphenol A binds to estrogen receptors (alpha and beta nuclear receptors and plasma-membrane bound receptors). Exposure to very low doses early in development alters the breast and prostate tissues in ways that increase the risk of developing cancer later in life, and disrupts brain development and behavior.  Low dose exposure may also increase the risk of developing insulin resistant diabetes and obesity, and disrupt chromosomal alignment, resulting in one of the most common causes of miscarriage in humans. Its estrogenicity, once considered weak, is now known to be much more potent. Most importantly, these effects are being reported at levels found in the human body.

Click through to read all of "Battles Over Bisphenol A."