Aug. 8, 2007 — An expert panel today noted no major health risks in theirreview of data on a plastic chemical called bisphenol A.
Bisphenol A, or BPA, is found in polycarbonate plastic, which is used invarious products including food and drink containers, as well as resins thatline metal food cans.
The expert panel was convened by the Center for the Evaluation of Risks toHuman Reproduction (CERHR) of the National Toxicology Program.
The 12-member panel included doctors and researchers from universities, thefederal government, the American Cancer Society, and the drug companies Pfizerand Schering-Plough.
Their task was to review reams of research on bisphenol A’s safety, based onlab tests on animals and studies of human exposure to bisphenol A.
The panel notes “some” concern that exposure to bisphenol A causesneural and behavioral effects in fetuses, infants, and children.
The panel notes “negligible” concerns that fetal exposure tobisphenol A produces birth defects and malformations, and “adversereproductive effects” in adults exposed to bisphenol A. The panel’s reportdoesn’t define “adverse reproductive effects.”
The CERHR will solicit public comments on its report.
Reaction to Panel’s Work
The panel’s conclusions are “very reassuring,” Steven Hentges,PhD, tells WebMD. Hentges is the executive director of thepolycarbonate-bisphenol A global group of the American Chemistry Council, anindustry organization that represents firms including companies that makeplastics.
The nonprofit Environmental Working Group issued a statement criticizing thepanel’s conclusions, claiming that the panel endorsed “an error-riddled,industry-influenced ‘report’ minimizing the risks that BPA poses tohumans.”
The panel’s work comes in the wake of a statement written by 38 scientistswho voice concern about bisphenol A’s safety. That statement appears online inthe journal Reproductive Toxicology.
About Bisphenol A
Data from lab tests and research on animals indicate that bisphenol A”may mimic the natural female sex hormone, estradiol,” according toCERHR background information.
Bisphenol A leaches out of polycarbonate plastics, with more bisphenol Aleaching out of heated plastics, note Ana Soto, MD, and Michele Marcus, PhD,MPH.
Soto is a professor of anatomy and cellular biology at Tufts University nearBoston. Marcus is a professor of epidemiology at Emory University’s RollinsSchool of Public Health in Atlanta.
Soto and Marcus have studied bisphenol A. They’re among the 38 scientistswho note concerns about bisphenol A in a consensus statement publishedReproductive Toxicology.
Concerns About Bisphenol A
“The main concern is that bisphenol A is an estrogen. It mimics theaction of the female hormone estradiol,” Soto tells WebMD.
“My lab and other labs have found that bisphenol A causes diverseeffects, and to me, the most critical ones are those that happen in fetal lifewhere all these organs are being formed,” says Soto.
Marcus agrees, noting that “the developing embryo is generally morevulnerable to the effects of exposures than adults.”
Bisphenol A “has been shown to cause chromosomal abnormalities in miceand to cause early pubertal development in rodents,” says Marcus.
Some research suggests that bisphenol A may have effects that span more thanone generation, according to Soto and Marcus.
“It seems there is mounting evidence that bisphenol A would producetransgenerational effects,” says Soto.
However, there have been “virtually no” studies of bisphenol A’sdirect effects in humans, says Marcus.
Bisphenol A: What to Do?
“What we know is that there a lot of harmful effects in animals and theexposure is ubiquitous. We don’t know whether or not exposure is harmful tohumans,” says Marcus.
“However, if you would like to reduce exposure, there are a few thingsthat you can do,” Marcus notes.
Her suggestions: “You can refrain from heating foods in plasticcontainers and you can refrain from putting plastic containers in thedishwasher. Harsh alkaline detergents do increase the leaching of bisphenol Afrom polycarbonate containers.”
Soto also has some ideas about reducing bisphenol A exposure.
“I think if I had a baby, I would use baby bottles that do not containbisphenol A,” Soto says. “For microwaved food, you can use ceramicdishes,” she adds.
Still, people who take those steps wouldn’t know the extent to which itreduces their overall exposure to bisphenol A, Soto notes.
“This is something that you cannot address only as an individual,”says Soto. “I think that it is up to citizens to demand that the governmentpursues a policy that protects and preserves public health,” she says.
Hentges says the expert panel looked at “a lot” of data on bisphenolA.
“What they found, overall, is that human exposure to bisphenol A isquite low. It’s extremely low, well below levels that could be harmful,”says Hentges.
“Looking at their overall conclusions, they did not find any high-levelhealth concerns,” says Hentges. “The handful of concerns that theyidentified were all flagged as ‘minimal’ or ‘negligible’ with one exception,which was flagged as ‘some’ concern, but that was primarily just an indicationthat they think additional research in that area might be helpful.”
Hentges says that bisphenol A leaching out of polycarbonate food containershas been studied “many, many times.”
“We do know quite well what kind of level could come out of thosecontainers, and that level is extremely low,” he says, adding that studieshave shown no reason to be concerned about bisphenol A levels that would comeout of those containers “under any typical or expected use.”
As for switching to a different type of baby bottle, “the scientificconclusions don’t support the need to use a different product. People havechoices, though,” says Hentges.