In the University of Michigan-led study, published July 22, 2010, in the Journal of Reproductive Toxicology, researchers recruited 190 men through a fertility clinic, with testing of urine samples revealing that 89 percent of men had some level of Bisphenol A, or BPA, present. Men with the highest levels of BPA had sperm concentrations on average 23 percent lower than men with minimal levels of BPA. Results also suggested a 10 percent increase in sperm damage along with high BPA levels.
Thought you only had to worry about BPA when picking out baby bottles? While "much of the focus for BPA is on the exposures in utero or in early life, which is of course extremely important, this suggests exposure may also be a concern for adults," says John Meeker, assistant professor of Environmental Health Sciences at the University of Michigan School of Public Health. "Research should focus on impacts of exposure throughout multiple life stages," he adds.
Meeker also stresses that further study is necessary due to the study's relatively small sample size and design.
Health safety advocates say that BPA mimics the body's own hormones when absorbed in large enough qualities over time and can potentially lead to negative health effects, including cancer. BPA is most commonly used to make plastics and epoxy resins used in food and beverage cans, and people are exposed primarily through diet, although other routes are possible.
More than 6 billion pounds of BPA are produced annually. Canada and many US companies (including most baby product manufacturers) have already banned use of the substance.