Chicago Tribune 09-17-2008 (BPA)
BPA SAFETY
A Chemical Risk You Can’t Avoid
New study links common product to diabetes and heart disease
By Deborah L. Shelton
Tribune Reporter
Industry representatives and health advocates gave federal officials vastly different assessments Tuesday of the effects of exposure to a chemical so prevalent that it can be found in the system of almost every American.
Bisphenol A, commonly known as BPA, is used extensively in the linings of food and drink containers, plus countless consumer products, including baby bottles and sippy cups. The chemical also has been found in drinking water, dental sealants and even household dust.
Adding to a growing sense of unease about the chemical’s potential effects was a study released before federal hearings Tuesday that linked exposure to bisphenol A with cardiovascular disease, type 2 diabetes and liver-enzyme abnormalities in adults.
Researchers said the study, in Wednesday’s Journal of the American Medical Association, offered the first scientific evidence that adults with higher levels of BPA in their bodies were more likely to develop such diseases. This month the federal National Toxicology Program reported the chemical may affect the development of the brains and prostate glands of fetuses and young children.
Pressure has been growing for more government and corporate action on BPA, in part because the chemical is so common that it is difficult for consumers to avoid it.
Some state and federal lawmakers have sought to ban BPA in children’s products, and some companies have decided no to produce or sell BPA products. Wal-Mart is phasing out sales of baby bottles containing BPA from its U.S. stores next year, and Nalgene is removing BPA from its popular water bottles.
On Capitol Hill, Sen. Charles Grassley (R-Iowa) cited the study as he opened an investigation of the way the U.S. Food and Drug Administration has regulated the chemical.
At Tuesday’s hearing, the FDA defended a draft assessment it issued last month declaring that FDA-regulated products on the market that contain BPA are safe.
“Right now, our tentative conclusion is that it’s safe, so we’re not recommending any change in habits,” said Laura Tarantino, head of the FDA’s office of food additive safety. The agency said more research was needed.
For the study released Tuesday, Dr. David Melzer and colleagues from the Peninsula Medical School in Exeter, England, divided a representative sample of 1,455 U.S. residents ages 18 to 74 into quartiles based on BBPA concentrations in their urine. The BPA data came from a 2003-04 survey conducted by the Centers for Disease Control and Prevention.
The researches found that people in the group with the highest concentration of BPA had almost three times the odds of cardiovascular disease as did those in the lowest quartile, even when factors such as race, income and education levels were accounted for. That group had a 2.4 times higher risk of diabetes.
Higher BPA levels also were associated with clinically abnormal concentrations of three liver enzymes. Researchers did not find a link to any other health problems.
Although previous research in animals had linked BPA to diabetes and liver damage, Melzer said the new finding on human heart disease was unexpected. Steven G. Hentges, executive director of the Polycarbonate/BPA Global Group of the American Chemistry Council, an industry trade group, noted several limitations of the research.
“Urinary concentrations tell you the exposure over the last 24 hours, but heart disease and diabetes to no occur overnight,” he said. “Bisphenol A would have to be measured over the time period when heart disease or diabetes is actually occurring, so that’s a major limitation of the study.”
Hentges also said the study showed that people were being exposed to very low levels of the chemical, “levels that are far below scientific-based safety standards established by government agencies.”
Small amounts of BPA can leach into the contents of food or drinks from some types of plastic containers and the linings of cans. The chemical is excreted in urine, making urinary tests the best available measure of recent exposure, the researchers said.
The authors cautioned that further research is needed to confirm their findings.
“From this one study we can say that the effects of BPA in humans need to be examined more closely,” said Melzer, a professor of epidemiology and public health. “Until we are able to repeat these results and clarify that the effects are definitely due to BPA itself, we cannot say for certain that BPA causes disease in humans.”
Frederick vom Saal, a professor of biology at University of Missouri at Columbia, said the findings were “absolutely no surprise” to scientists who have studied the chemical, which he described as “one of the largest food contact items in existence.” He served on a scientific consensus panel of 38 experts that recently reviewed 700 studies of BPA and concluded that it had a high probability of causing harm.
“If a study comes out of nowhere on a subject that has never been studied, you might say, ‘How in God’s name can bisphenol A possibly be related to diabetes?’ ” said vom Sall. “But we have a large literature of animal studies that explains the molecular details.”
Dr. Anila Jacob, senior scientist for the Environmental Working Group, a Washington-based research and public health watchdog organization, said the study suggested BPA might play a more significant part in chronic diseases than had been thought.
“We don’t know causality [in this study], but associations are important in public health,” Jacob said. “These types of large epidemiologic studies are important in pointing us in the right direction.”
Some scientists are urging the FDA to declare the chemical toxic and ban it from products that com into contact with food and drinks.
“We have always been concerned about infants and children because we know they have higher exposures compared to adults and we also know they are more vulnerable because their brains are developing and their organ systems are maturing,” Jacob said. “But we believe there is reason for concern for everyone.”
Tribune wire services contributed to this report.
Note: Attorney Thomas A. Zimmerman, Jr. filed a class action lawsuit on behalf of purchasers of baby bottles and sippy cups containing BPA.
