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Scientists call BPA exposure 'presumed health hazard' for hyperactivity

Bisphenol-A, widely used in plastics, receipt paper and canned food linings, is a culprit in some children developing hyperactivity, researchers say, even as federal regulators insist on its safety.

A review of more than 30 scientific studies concludes early life exposure to the endocrine disrupting chemical BPA leaves children more susceptible to hyperactivity later in life.


The review, published today in Environment International, suggests environmental chemicals such as BPA may be partly to blame for the recent spike in attention deficit hyperactivity disorder (ADHD) and other behavioral issues in children.

The review "is a compelling piece of evidence," said Heather Patisaul, a researcher and associate professor at North Carolina State University's Department of Biological Science.

"What regulators think is a 'safe' dose for the developing brain may have to be re-evaluated," added Patisaul, who was not involved in the review.

The publication comes two weeks after the U.S. Food and Drug Administration released a statement on preliminary findings from a two-year federal study of the compound, commonly used in can linings, food packaging and receipt paper.

Federal regulators—after looking at effects on thousands of rats dosed with different amounts of BPA—concluded: "BPA is safe for the currently authorized uses in food containers and packaging"—an assertion many scientists specializing in endocrine disruptor research do not support.

BPA—used to make plastic hard and shatterproof and to extend the shelf life of canned food—can leach out of products. Studies routinely show that more than 90 percent of people have traces of the chemical in their body.

BPA is an endocrine disruptor, meaning it messes with the body's hormones, potentially at very low levels. In both animal and human studies the chemical has been linked to multiple health impacts in exposed babies and children—including obesity, asthma, low birth weights and genital defects.

In the review of BPA and hyperactivity, researchers analyzed the results from 29 rodent studies and three human studies previously published.

They used a method developed by the National Institute of Environmental Health Sciences to weigh the merits of each study. This type of review, scientists say, helps accurately determine how dangerous a compound is.

They concluded BPA (bisphenol-A) is a "presumed human health hazard" for developing hyperactivity.

"'Presumed hazard' is just one notch down from "known hazard'," said study lead author, Johanna Rochester, a senior scientist with The Endocrine Disruption Exchange (TEDX), a science-based nonprofit founded by Theo Colborn, a pioneer of endocrine disruption research.

ADHD rates rise

The rate of U.S. children with ADHD has been increasing. About 11 percent of children ages 4 to 17 have been diagnosed, according to the most recent U.S. Centers for Disease Control and Prevention data.

The causes of the disorder remain unknown—some suspected causes include brain injuries, alcohol or tobacco use during pregnancy, and premature or low birth weight babies.

However, scientists have increasingly warned that environmental exposures may be in part behind the rise.

It's not clear how BPA may spur hyperactivity or ADHD; however, animal studies show that BPA alters dopamine—a chemical messenger that helps people think and stay alert and focused. BPA also may interact with thyroid hormones, which are critical for proper brain development

Babies can be exposed before they enter the world as BPA can "pass through the placenta and through breast milk," Rochester said.

Carol Kwiatkowski, the review's senior author and executive director of TEDX, said the federal government doesn't usually base chemical assessments on brain development; rather they usually look at reproductive impacts and cancers.

"But the brain is possibly one of most sensitive organs, from BPA exposure specifically," she said.

Feds push BPA safety

Their review comes on the heels of the FDA statement, which referred to a pre-peer review draft of a two-year rodent study on the health effects of BPA. In many ways the FDA statement was the antithesis of TEDX's review, which is an exhaustive, transparent review of peer-reviewed science. The FDA's statement is based on results that are not yet complete and the findings cited have yet to go through a peer-review process.

Independent scientists were quick to criticize the FDA's statement. "It is premature to draw conclusions based on the release of one component of a two-part report," said researcher and assistant professor of environmental health at the University of Massachusetts Amherst Laura Vandenberg in a statement through the Endocrine Society.

The Endocrine Society pointed out that nearly 100 published studies have linked BPA to health problems.

In a commentary published earlier this week, four academic scientists working with the FDA on analyzing BPA safety said the federal study had uncovered some troubling findings. They echoed Vandenberg, calling the agency's statement "premature."

"From what is already known about BPA, combined with the new data that is emerging, we disagree strongly with the FDA's conclusion," they wrote. "In fact, we believe that the scientific evidence supports reducing exposure to BPA dramatically."

The FDA did not respond to requests for comment on the BPA hyperactivity review.

"Don't be too scared"

Rochester said she was pregnant while conducting this research. Her advice for moms-to-be?

"It's OK—don't be too scared, we're exposed to lots of different things, but if you can avoid touching receipts, canned food, these are really simple things that most people can do."

Kwiatkowski added: "BPA doesn't stay in the body very long, it's metabolized in less than a day, so if you do take measures, it will reduce your body burden. That's a point of good news for people."

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