Bisphenol-A: Out of the bottle

A lot of news has been coming out lately about bisphenol-A.

The compound, also called BPA, is in many plastics, including baby bottles, and the linings of cans used as food containers. While the plastics industry says the chemical is safe, researchers have been concerned about possible neural and behavioral effects in fetuses, infants and young children exposed to the chemical at current levels.

Yesterday, Canada's Globe and Mail newspaper reported that tests by Health Canada scientists showed levels of BPA in energy drinks and, to a lesser extent, in soft drinks. Health Canada and the industry said the levels were well below regulatory limits, but Frederick vom Saal, a biologist at the University of Missouri and an authority on BPA, told the Globe and Mail, "We are constantly getting exposed to this chemical. People drink a lot of soda and this needs to be looked at as one of a very large number of sources of exposure to this chemical."

Read the story here.

Meanwhile, the six largest manufacturers of baby bottles have announced that they will stop selling bottles in the United States that contain BPA.

Meanwhile, the six largest manufacturers of baby bottles have announced that they will stop selling bottles in the United States that contain BPA. This was in response to a request by Connecticut Attorney General Richard Blumenthal, joined by the attorney general of New Jersey.

"The evidence seems too clear and emphatic and unequivocal to say we should simply permit this stuff to go into children on a massive scale," said Blumenthal, as quoted in this morning's Washington Post. "And there's no reason for it, because there are substitutes available."

Read the Post's story here.

For background, here's a story I wrote last year about bisphenol-A that has since expired from our website:

PLASTIC PERIL?
An Ursinus College researcher is convinced that a compound in products
from baby bottles to helmets is a hazard to health. And others agree.

Inside her Ursinus College lab, biology professor Rebecca Roberts dons rubber gloves and watches as her students inject spleen samples from mice with a reactive substance.

It's part of Roberts' eight years of work on bisphenol A, an ingredient in plastics ranging from reusable food containers to eyeglass lenses to CDs.

It's also part of her life as a mom: Many baby bottles contain BPA.

"I wholeheartedly believe there are serious concerns with this compound," she says, thoughtfully fingering a test tube partly filled with the white, powdery substance.

Others agree. Two weeks ago, a draft report by a program of the National Institutes of Health concurred with the earlier evaluation of an independent scientific panel, concluding there was "some concern" about possible neural and behavioral effects in fetuses, infants and young children exposed to the chemical at current levels.

The plastics industry says products containing BPA are safe.

Nevertheless, some stores quickly began pulling baby bottles with BPA from their shelves. Manufacturers are working to eliminate the substance. Legislators have proposed bans.

Roberts, in addition to her research, cowrote an essay - "Babies, Bottles and Bisphenol A: The story of a Scientist-Mother" - that PLoS Biology, a journal of the Public Library of Science, published last summer.

A five-minute walk across campus leads to Roberts' backyard, where Siena Johnson, 2 1/2, puts down her plastic sippy cup and leaps up from a plastic picnic table, exclaiming happily, "My mommy's here! "

One-year-old Bristow Johnson is fretful, so in the kitchen, where plastic cups and lids form a colorful pile in the dish drain, Roberts fixes a plastic bottle of formula.

In the living room, Siena drops to the floor to play with her plastic dolls.

"That's one of the problems," says Roberts. "As a mother, you'd go insane if you tried to take away every single plastic thing from your child. That's all there is. "

For that matter, she doesn't want to take away all plastics. They're washable and bleachable, have no splinters, and the embedded colorant won't chip off.

So she prioritizes, focusing on clear, hard plastics (more likely to contain BPA) that will probably end up in her children's mouths.

Bristow's bottles are made by Medela, one of the BPA-free brands that have proliferated in just the short time since Siena was an infant.

Siena's heart was set on a Dora the Explorer sippy cup. Roberts was relieved to discover it, too, was BPA-free.

Bisphenol A is a chemical building block that makes polycarbonate plastic tough, lightweight, shatter-resistant and clear.

It's in helmets, goggles and dental sealants. It's also used in medical devices such as dialyzers and incubators - like the one that Bristow, born prematurely, stayed in for his first 69 days.

And BPA is in the epoxy linings for virtually all canned goods, protecting the food from a metal that might corrode or affect flavor.

But BPA can migrate from these substances to humans - mostly through food or drink. It has been found in human blood, urine and breast milk.

A 2003-04 study by the U.S. Centers for Discase Control and Prevention found detectable levels of BPA in 93 percent of 2,517 urine samples from people aged 6 or older.

Concern arose after reproductive and developmental effects were reported in laboratory animals. BPA is considered to be "weakly" estrogenic, so researchers are investigating its effect on infant development and hormone-related diseases like breast and prostate cancer.

Within days of the NIH's recent National Toxicology Program report, the Canadian government, based on its own risk assessment, began moving toward a ban of baby bottles with BPA.

Wal-Mart, among other stores, has begun pulling baby bottles with BPA from the shelves; a spokesman said the company expects all of its baby bottles to be BPA-free early next year.

Playtex Infant Care is distributing one million free no-BPA "Playtex Drop-Ins Original Nurser Systems" bottle liners. "While U.S. and worldwide regulatory bodies continue to deem the ingredient safe," the company says, "we are listening to consumer concerns. "

Following California, New Jersey legislators have introduced bills banning BPA in toys and child-care products.

The chemical industry has cricticized many of these moves.

"Although I'm sure their intention is to do things that are good for their customers, they're not going to improve health or safety of their customers by taking these products off the shelves," says Steven Hentges, executive director of the American Chemistry Council's Polycarbonate/BPA Global Group.

"We believe BPA is safe for use, based on many scientific reviews," says Hentges, who was authorized to speak for manufacturers of BPA.

There's also the matter of replacing it. "If we want to not use BPA, we will not have polycarbonate plastics. That becomes a real big challenge," he says. "You will find no alternatives that have been tested so well as bisphenol A."

Meanwhile, the research continues.

The National Institute of Environmental Health Sciences, one of the major funders of BPA studies, has given Roberts a three-year, $150,000 grant to study its effect in a new area, the immune system.

"So from that standpoint, it's a unique grant that's very valuable," says Jerrold Heindel, an institute program official. "Her results will be important to help us determine if there should be concerns. "

In her Collegeville lab, Roberts and her research students are looking at cathepsins - enzymes that act like small scissors, cutting to pieces whatever is brought into a body's infection-fighting white blood cell. Some pieces return to the cell surface and become potential flags for the immune system.

Basically, if the cathepsins do their job differently than they are supposed to, the immune response may be faulty.

So Roberts and her students have been injecting Cheerios-shaped cereal with BPA and feeding it to mice. Later, they collect and analyze the mice's white blood cells.

While results are preliminary, she believes she's seeing problems.

Roberts is applying for more grants to continue her enzyme work. She also hopes to start an outreach program in the area, educating mothers about BPA and how to avoid it.

"Do I think more science needs to be done? Always," the biologist says.

Adds Roberts the mother: "I have two little kids at home. I want to make sure they're healthy and growing up the best they can. "