FARAI CHIDEYA, host:
I'm Farai Chideya. And this is NEWS & NOTES from NPR News.
It's one of the great consumer products of the last century. Now, some scientists are saying that the miracle known as plastics can emit chemicals that are hazardous to our bodies.
Jane Kay is an environmental reporter for the San Francisco Chronicle. She's been flowing this story and joins me now.
JANE KAY (Environment Writer, "San Francisco Chronicle"): Thanks.
CHIDEYA: So what exactly do we know about the unintended side effects of plastics?
Ms. KAY: Well, most of our evidence comes from laboratories and studies on animals. And researchers are just beginning to find disturbing effects that make them wonder if trace levels could be hurting humans.
CHIDEYA: Give me an example of the animal research first.
Ms. KAY: Well, basically, we're looking at two families of chemicals that are used in plastics. Bisphenol A is an ingredient in something called polycarbonate plastic. And those are the really hard, brittle, rigid baby bottles, sports bottles, water bottles. They're actually - bisphenol A is also used as a lining inside of cans. And it has been found in the animal studies to alter the function of the thyroid gland and the brain and the pancreas and the prostate gland. It's a chemical that mimics estrogen, the hormone. And so of course, you know, that guides how people develop.
The other chemical is - they're called phthalates. And these, of course, are chemicals that we are barely able to pronounce. And they are used as softeners in polyvinyl chloride, PVC. So they're in everything from toys, raincoats, shower curtains. They are pretty much all over the place. And the lapse studies on those are showing, as well, you know, interference with hormonal systems. In this case, disruption of testosterone production, malformation of sex organs in the lab animals, and this is causing worry.
CHIDEYA: Now, when you talk about malformation of sex organs, without being too graphic, tell us what you're talking about and can it happen in humans?
Ms. KAY: Well, now, what they're - in lab studies, they use biomarkers. And they measure how genitals develop - say, in males. And if there is - they can see if it is not a normal development. And there has only been one study on humans to see if there was a similar condition happening.
And a scientist from the University of Rochester went to clinics around the country - in Minnesota, in California - and she - they measured the levels of phthalates in the urine of pregnant mothers. And then, once the babies were born, they measured the genital formation and they found conditions that were similar to what they were seeing in the phthalate - rats in the labs. And this, of course, has caused them concern.
CHIDEYA: So does this affect the ability of these babies, once they grow up, to have kids of their own and to, you know, their reproductive health?
Ms. KAY: Well, what - all they can do, of course - they don't know this, so all they can do is what has happened to the rodents. And with the rodents, they've seen undescended testicles. They've seen smaller penises. And of course, these are just symptoms of other kinds of reproductive problems.
So that's a question they can't answer. There is a great lack of human study for both phthalates and bisphenol A. And of course, the manufacturers of the chemicals question these studies. And they say that they have studies of their own that don't show these kind of changes. And so there's a great controversy going on.
They just say that there's just little or no human evidence to support these claims and they say that U.S. government agencies, you know, haven't removed products that contain these chemicals and they say, you know, nowhere else in the world are you seeing, you know, removal of bisphenol A.
The European Union has banned some forms of phthalates in its child-care products and in its toys. And California, actually, has followed that lead. And there is a bill before Governor Schwarzenegger right now that would ban phthalates in toys and children care products for kids 3 and under that would be - it would be the sale distribution, that kind of thing.
CHIDEYA: So when you talk about a bill like that, you must be talking about, potentially, millions of people whose lives will change in terms of the products that they get.
Ms. KAY: Well, I don't know about that. We were doing a story on that. And we did some research in the European Union. And even the industry there said that, you know, people were still getting a wide array of products that they had been getting before. There are just other ways to make them.
CHIDEYA: Well, Jane, thanks so much.
Ms. KAY: You're welcome.
CHIDEYA: Journalist Jane Kay joined us from the San Francisco Chronicle where she reports on the environment.