Environmental Science & Technology, November 7, 2007
U.S. BASELINE FOR BISPHENOL A
[Rachel's introduction: A federal government survey of more than 2500 U.S. residents shows that nearly everyone in the country carries the industrial chemical bisphenol A (BPA) in their bodies and that children carry the highest burden.]
By Naomi Lubick
A Centers for Disease Control and Prevention (CDC) survey of more than 2500 U.S. residents shows that nearly everyone in the country carries bisphenol A (BPA) in their bodies and that children carry the highest burden.
The chemical, used in plastics and food containers, acts as an endocrine disrupter. It has been shown to lead to obesity, depressed growth rates, and prostate cancer in laboratory animals, according to recent reviews by a National Institute of Environmental Health Sciences (NIEHS) panel.
Led by Antonia Calafat of CDC's National Center for Environmental Health, researchers analyzed samples collected during the National Health and Nutrition Examination Survey (NHANES) of 2003-2004. The team reported online October 24 in Environmental Health Perspectives that concentrations of a BPA metabolite in urine ranged from 0.4 to 149 micrograms per liter (micrograms/L), with an average of 2.6 micrograms/L. The researchers also established that children carry "significantly higher" BPA concentrations than adolescents, who in turn have higher levels than adults.
The new data suggest that people's everyday exposures to BPA are higher than the no-harm level (50 micrograms/L) set by the U.S. EPA, says Frederick vom Saal, a University of Missouri Columbia BPA specialist who served on the NIEHS panel. Animal studies indicate that an exposure dose would be about 10 times the amount found in blood and urine measurements. The observations from NHANES are also "disturbing in that it confirms without a doubt that the youngest are most at risk," he says. Babies probably have the highest BPA levels, but NHANES only includes children 6 years and older.
The release of the CDC's analysis means that the BPA data and accompanying behavioral survey information are available to epidemiologists for the first time, giving them an opportunity to tease apart the effects of lifestyle and BPA exposure.
Copyright 2007 American Chemical Society