Scientists Link Widely Used Chemical to Health Problems in Animals

WASHINGTON — A pervasive hormone-mimicking chemical is in the blood of virtually every American at levels that can cause cancer, genital abnormalities, diabetes and behavioral disorders in laboratory animals, a panel of experts said Thursday.

Low doses of BPA during pregnancy can have profound effects on fetal prostate, breast, testicle and mammary glands and brain development in animals, the panel said in a "consensus statement" published online by the Journal of Reproductive Toxicology.

Also, they said, recent experiments indicate that bisphenol A, or BPA, may have previously unrecognized effects on human fetuses that are not apparent until long after exposure has occurred.

"The wide range of adverse effects of low doses of BPA in laboratory animals exposed both during development and adulthood is great cause for concern with regard to potential similar adverse effects in humans," the panel concluded.

Over 6 billion pounds of BPA are used every year. It is in cans containing food and soft drinks and in a wide range of other products, including plastic food containers, shatterproof baby bottles, compact discs, sunglasses and even dental fillings.

Scientists say most people are exposed to BPA after it has migrated from containers into food and drink. However, because it leaches from landfills into water supplies and is found in indoor air, they also can inhale it or soak it up from bathwater.

The panel said studies have shown 95 percent of humans who were sampled had blood concentration levels that were found to be "biologically active" in animal experiments.

A Coca-Cola Co. spokesman acknowledged that BPA is used in its soft drink cans, as well as "thousands of packages worldwide," but said it poses no risk to consumers.

"BPA has been studied extensively and determined to be safe by regulatory authorities worldwide," the company said. "The safety of this ingredient is supported by comprehensive laboratory research, including studies conducted over multiple generations that are specifically designed to detect adverse health effects."

The report released Thursday was signed by scientists from the United States, the United Kingdom, Germany, Israel, Japan and Spain who attended a government-financed conference last year in Chapel Hill, N.C., to review recent BPA research.

The scientists said recent trends in human diseases appear to involve biochemical processes similar to those observed in laboratory animals exposed to low doses of BPA.

"Specific examples include the increase in prostate and breast cancer, uro-genital abnormalities in male babies, a decline in semen quality in men, early onset of puberty in girls, metabolic disorders including insulin-resistant (Type 2) diabetes and obesity and neurobehavioral problems such as Attention Deficit Hyperactivity Disorder," the panel said.

Emory University epidemiologist Michele Marcus, one of the 37 scientists signing the report, said in a telephone interview that additional studies are needed to tease out the effects BPA may be having on humans.

"We know virtually nothing about human health effects of BPA and we know there are a lot of harmful effects in animals," she said.

"We are exposed to BPA pretty continuously. We know that," she said.

Marcus said BPA is one of dozens of estrogen-mimicking substances in the environment, and only epidemiological studies can "disentangle" the results different ones may have.

The study was released a week before a panel of scientific advisers to the National Toxicology Program meets to review a draft statement advising that agency on potential reproductive and developmental hazards of the chemical

The meeting — from which scientists who have studied BPA extensively are excluded — was arranged by a private company the agency had contracted to collect scientific data for that panel's review.

But the agency fired the company after an environmental group revealed that it also had contracts with chemical interests involved in the production and use of BPA.

Dr. Mike Shelby, director of the toxicology program's Center for the Evaluation of Risks to Human Reproduction (CERHR), said the contractor-written report had been "audited" and represented a thorough review of scientific reports on BPA.

He said experts on a particular subject are excluded from toxicology program panels to allow a "more candid" discussion of scientific reports, some of which the experts might have written.

There were no such restrictions on the panel which released Thursday's report, and many of new findings on which it is based were produced by its members.

The American Chemistry Council, a trade group that represents companies that produce and use BPA, said in a written statement that it was "dismayed" at the release of Thursday's report.

"With the scientifically sound CERHR evaluation of bisphenol A so near to completion, we're dismayed to see a competing and far less sound evaluation released and publicized this week, apparently in an attempt to upstage CERHR," said Steven Hentges, a spokesman for the industry group.

"Unlike CERHR, the competing evaluation was conducted in a closed process with no opportunity for public input or participation," he said. "Although conclusions are represented as a scientific consensus, conflicts of interest and the potential for bias are apparent in the list of authors, which includes several with well established positions who have actively advocated against bisphenol A."

University of Missouri at Columbia biologist Frederick vom Saal, who organized the meeting of the group that reported Thursday, noted that his panel's deliberations were financed by the National Institutes of Health and the Environmental Protection Agency.

He said he is convinced BPA poses a serious threat to human health.

"For example, I don't eat or drink anything that comes in a can," he said.