As a reported hormone disrupter, Bisphenol-A has been in the news a lot, with some reports on its dangers for humans and some reports on its safety. This has been a hotly contested topic for two reasons. One, the effects in humans are difficult to document because human cannot be used in controlled studies, so that studies are carried out on lab animals. Two, production of BPA is a huge business, with its vested financial interest. BPA is used in epoxy resins (e.g., in linings of food cans) and in polycarbonate plastic bottles and containers (e.g., in baby nursing bottles).
Difficulty in reaching consensus about the safety or danger of BPA is seen in recent reports by two government-convened panels that reached nearly opposite conclusions on the health risks from BPA. Scientists of the National Institute of Environmental Health Sciences (NIEHS) concluded that in rodents, low levels of BPA caused breast cancer, enlarged prostates, reduced sperm counts, and led to early onset of puberty in females, type-2 diabetes. In contrast, scientists for the Center for Evaluation of Risks to Human Reproduction (CERHR) concluded that they have “negligible concern” that prenatal exposure to BPA would cause reproductive tract abnormalities, and they expressed only “minimal concern” that in- utero exposure causes enlarged prostates or accelerates puberty. The National Institute of Health released its report on bisphenol A, and one of the Directors, Dr. John Bucher, stated that “There are a number of remaining uncertainties in the scientific evaluation of BPA….We have concluded that the possibility that BPA may affect human development cannot be dismissed.” British medical researchers said that “Using data representative of the U.S. population, we found higher urinary concentrations of BPA were associated with an increased prevalence of cardiovascular disease, diabetes, and liver-enzyme abnormalities.” A study at Tufts University School of Medicine supports the hypothesis that widespread exposure to bisphenol A during fetal life causes breast cancer in adult women. Government-funded experiments with low doses of BPA on lab animals and tissues found adverse effects in 153 cases and no effect in only 14 cases. When newborn rats are exposed to low doses of BPA, they develop early-stage prostrate cancer as adults.
The latest sign of this controversy centers on a report by an advisory committee of the German Society of Toxicology, which concluded that “the current tolerable daily BPA intake value of 0.05 mg/kg body weight/day (set by the European Food Safety Authority) is adequately justified.” To get the other side of this issue we turn to an April 28, 2011 article in the Daily Report of the California Watch. The writer (Susanne Rust) interviewed Frederick vom Saal, and endocrinologist who specializes in the health effects of BPA. Referring to the German report, vom Saal said “It’s just the same old nonsense…This study was organized and funded by Bayer, the largest maker of BPA in Europe. They are simply protecting their product.” Pete Myers, CEO and chief scientist of Environmental Health Sciences (a nonprofit group) said, “The German report is rife with scientific errors and misrepresentations, and it ignores or dismisses some of the best science available to date on BPA’s effects.”
It seems prudent to use the Precautionary Principle and avoid unnecessary exposure to BPA, especially by pregnant women.