Most of the Chemical Is Quickly Eliminated in Urine, Researchers Say
Sept. 28, 2011 -- Most of the bisphenol A (BPA) that adults ingest is quickly eliminated in the urine, new research confirms.
In the government-funded study, BPA was virtually undetectable in the blood of adults, even when levels in urine were high.
The study’s lead researcher says the findings show that the “odds are very small” that BPA poses a significant public health risk. And a food packaging trade group called the research “definitive evidence” that adverse health effects from exposure to the chemical are unlikely.
But a CDC investigator who was among the first to show widespread exposure to BPA from food packaging manufactured with the chemical says the new study was not designed to address the health effects of exposure.
“This study confirms that exposure to BPA is common in the adult population,” research chemist Antonia M. Calafat, PhD, of the CDC’s National Center for Environmental Health, tells WebMD. “The study also shows that BPA appears to be excreted rather quickly and that concentrations in serum are much lower than concentrations in urine.”
BPA Health Concerns
BPA is widely used in the manufacture of clear plastic bottles and other food containers and the epoxy resins used in the lining of many canned foods.
Health concerns about the chemical stem from lab and animal studies suggesting that it is an endocrine disrupter, mimicking the female sex hormone estrogen in the body.
Early last year, the FDA concluded that studies have generally supported the safety of low levels of BPA exposure in adults, but agency officials expressed concerns “about the potential effects on the brain, behavior, and prostate gland in fetuses, infants, and young children.”
These fears resulted from studies in rodents designed to test the subtle effects of exposure to the chemical.
The newly reported study, which was funded by the Environmental Protection Agency, is the first to compare BPA levels in urine with levels of the active form of the chemical in the blood over a 24-hour period.
Lead researcher Justin G. Teeguarden, PhD, of the Pacific Northwest National Laboratory in Richland, Wash., says although it was clear that BPA does enter the body from food sources, little has been known about what happens to the chemical after this.