The Plastics Revolution

(By Julia Ewan -- The Washington Post)   |   Buy Photo

And consumers? They've been left to sort out the mess on their own.

Food-Warming Worries

First, a look at BPA.

It's in CDs, dinnerware and sports safety equipment; incubators, heart-lung machines and IV bags; bottle tops, packaging, dental sealants and Nalgene bottles.

It is also in our bodies. A Centers for Disease Control and Prevention analysis detected BPA in urine samples of nearly 93 percent of 2,517 people who took part in a national health survey from 2003 through 2004.

According to the CDC, women had higher average levels (2.9 micrograms per liter) than men (2.6); children age 6 to 11 had higher levels (4.5) than adults over 20 (2.5). These numbers are not in dispute.

Virtually everything else is, starting with what BPA's presence in urine might mean. It could be evidence that the chemicals reside in our body tissue or bloodstream; it could also suggest that our bodies know how to expel them.

Then there's the question of how these chemicals might have gotten there. "What's hard to do is connect the dots," Goldman says, "between finding it in people's urine and which uses are causing the chemicals to be in their urine -- to understand what the pathways of exposure are."

Also unclear is whether having BPAs in our bodies is dangerous.

"It is very difficult to show that exposures lead or have led to adverse health effects in humans," says Shelby, director of the National Toxicology Program's Center for the Evaluation of Risks to Human Reproduction. (The toxicology program is part of the National Institutes of Health.)

Nonetheless, in a report this winter titled "Toxic Baby Bottle," a group of U.S. and Canadian environmental and public health groups reviewed studies showing BPA's tendency to leach out of plastic (and into foods and liquids) when heated. The group called on government agencies in both countries to impose "an immediate moratorium on the use of bisphenol A in baby bottles and other food and beverage containers."

The American Chemistry Council, representing many companies in the plastics industry, protested that the study subjected bottles to higher temperatures than are commonly used and for longer times. "Polycarbonate baby bottles have a 50-year safety track record," reads a statement from the council, which said the report provided no new relevant information on BPA safety.

But the people behind the baby-bottle report argue that exposure -- in and of itself -- is evidence of harm. "There is growing scientific evidence that shows that BPA is harmful even at extremely low levels of exposure," Schade says.