When Studies Collide

You can read newspapers online, say no for a credit card receipt (online banking), and beer, water, juice etc. taste better out of glass anway.

Please read the latest 50-page report released by the Statistical Assessment Service, a non-partisan, non-profit organization at George Mason University - a very thorough review of all the studies that reaches a very different conclusion. http://stats.org/stories/2009/science_suppressed_BPA_intro_jun12_09.html

The purpose of the FDA is not to ensure that companies and industries, which have predicated their ongoing revenues on the predictable use of methods and materials, continue to exist. The purpose of the FDA is to act as a guardian of the nation's health. That means that when the evidence for or against the use of a chemical or a device is mixed and the results of continuation of usage by citzens is uncertain, there are adequate grounds for suspending that chemical's or device's availability to the public until such time when sound and more conclusive evidence for or against its use can be found.

In the past, it has seemed to most Americans that the FDA has behaved as the lap dog to the American chemical industry, something that is repugnant to those who value reason and responsibility on the part of those whom we pay to protect us from threats to human health. Just as a ban on the keeping of pit bulls in kindergarten classrooms would seem prudent in spite of the fact that not all pit bulls are vicious, so a ban on the use of BPA seems prudent, even if there are some instances where its effects may not be as convincingly dangerous.

When consideration is given to regulatory restriction of a material, it's good to have a correct understanding of the scope of the restriction's effects. BPA has a number of human-contact applications other than polycarbonate baby bottles and epoxy can liners. Polycarboantes are used in a wide range of cost-effective medical devices, including syringes. Epoxies are used in many medical devices, including as the key resin in Xray-transparent patient support tables and associated components, Probably replacements can be found for polycarbonate in medical devices, although performance may decrease or cost may increase. It's not cleat at present, though, what replacement might be able to be developed available for epoxies in medical-imaging composites. Certainly it would be disruptive, and would have broad negative health effects, to entirely ban the use of BPA epoxies for Xray-transparent diagnostic imaging patient support systems. In that instance and perhaps others, it should be adequate to require a BPA-migration-resistant barrier between the epoxy medical device and the patient, such as a polyethylene cover.

Wikipedia has a thorough discussion of BPA: http://en.wikipedia.org/wiki/Bisphenol_A including a long reference list for those interested in reading the studies themselves. The evidence is alarming. In addition to the evidence, it speaks volumes when Sunoco, who makes BPA, refuses to sell it for use in childrens' foood or water containers, and retailers, who profit from sales of products made with BPA, pull it from their shelves. The BPA issue is de ja vu with the tobacco issue of years past - you can only hide the evidence for so long. Bravo to Newsweek for keeping this issue in front of the public.

You have several inaccuracies in the above article. For example, you state "First, research in 2002 used a strain of rat that is extremely insensitive to estrogen; it doesn't even show hormonal effects if it's given 100 times the dose of estrogen in human birth-control pills. Since BPA acts like an estrogen, finding no effect in this insensitive rat is about as illuminating as not finding an effect of rain on a waterproof watch" This is not correct. There are several publications showing that this strain of rat, and other rat strains respond to estrogens at the same dose as used by humans (Delclos et al., 2009; Owens, et al, several papers for example.) Exposure to estrogens during development produces profound changes in the reproductive development. But, BPA does not and the negative studies are not limited to the 2002 study. There are numerous, well done negative studies with rats and mice. Furthermore, the selected literature you refer to showing low dose effects has been routinely found to be inadequate by independent scientific committees and government agencies because of flawed experimental design, statitical analysis and lack of reproducibility.

Some of your statements are inaccurate. The strain of rat used in the negative BPA studies is not 100 times less sensitive to estrogens than humans (Delclos et al, 2009). BPA has been compared to other estrogens besides estradiol in several assays. It is about 10,000 fold weaker in producing estrogenic effects in cells in a test tube and in whole animals. Stop perpetuating EDC Mythology and actually read the entire literature, not just carefully selected papers.