Register Receipts May Be A Source of Bisphenol-A
IRA FLATOW, host:
This is SCIENCE FRIDAY from NPR. I'm Ira Flatow.
Back in 2008, the federal government recommended that parents take steps to minimize the exposure their kids might get to a chemical called Bisphenol A, or BPA. Among the recommendations: Throw out those scratched plastic baby bottles and caps, don't heat plastic in the microwave. I'm sure you've all heard about them by now.
Well, they may want to add another recommendation to that list: Keep kids away from cash register receipts. According to a story in this week's Science News, three new studies show that some type of cash register receipts - you know, the paper that comes out of the cash register - has a significant amount of BPA on them, BPA that can easily get transferred to skin.
Joining me now to talk more about this study is my guest, Janet Raloff senior editor at Science News. You can find her stories on BPA and receipts at sciencenews.org. Welcome back to SCIENCE FRIDAY, Janet.
Ms. JANET RALOFF (Senior Editor, Science News): Hi, Ira.
FLATOW: Give us a little background first. What is Bisphenol A?
Ms. RALOFF: Well, it's the basic building block of polycarbonate plastic. Those are those clear plastic products that you find all over the environment, especially in your kitchen. Every food processor bowl, many of the glasses in the cupboard, lots of spoons and stuff like that, they're made from this plastic. It's very commonly used.
FLATOW: It's the stuff you throw into the microwave.
Ms. RALOFF: It can be, it certainly can be. It's also an ingredient in a resin that's used as a, well, as a dental sealant for kids when they get - trying to seal the teeth from cavities. And it's also that same basic resin is used as a liner in an awful lot of food cans to keep acidic foods from eating away at the metal in those cans.
FLATOW: Let's talk about these cash register receipts. How did anybody think to even look there? What's the story on that?
Ms. RALOFF: Well, it turns out that there is this green chemist in Massachusetts who used to work for Polaroid, and while he was working for them, he'd heard about the formula for making some of these receipt papers, things that were thermal paper so that they would print when they got heated, or pressure-sensitive papers.
And he remembered that they had Bisphenol A in them and sort of, it was a curiosity, nothing more.
And then, all of a sudden, about, you know, five to eight years ago, BPA started getting all over the news, far more than just in the pages of Science News. And he said wow, I wonder if that stuff is still in these receipt papers.
So he at that time was teaching and had some of his chemistry students collect some receipts and start testing them, and every year, they came up with the same, you know, finding, that a large share of the receipts had a large quantity of BPA in them.
FLATOW: And does it get transferred to your fingers when you touch the receipts?
Ms. RALOFF: Well, he didn't look into that. He just started measuring that, and in fact, his first formal publication of those data just came out about a week ago.
But there are some others that started looking in the meantime. One of them was the Environmental Working Group, which is a public interest research group based here in Washington, and also a Swiss group. This was the official Food Control Authority of Zurich. And they both started looking at not only concentrations in cash register receipts but also -and it's not just cash register receipts. This could be your ATM, right.
Ms. RALOFF: But also to see if it rubbed off because in fact, this BPA is in a coating that's placed on top of the paper, and it's sort of loosely there. It was sort of described to me as a little bit like talcum powder. It isn't talcum powder but kind of like that, laced with some of these ingredients that under pressure or temperature, a dye will mix with the BPA, if it's there, and you know, print something on the paper.
So this stuff could actually come off on your fingers, and they measured how much, and in fact it does. A large share of it just does transfer to your fingers, and the Swiss study showed that after a while, some of it's not even, you can't get it off the fingers anymore, which suggests that it started to go into the skin.
If it goes into the skin, how far does it go? Does it go to the bloodstream? Nobody knows. But there are studies planned to look at that.
FLATOW: So we don't know what kind of threat yet this poses for anyone.
Ms. RALOFF: Right. What they do know is that where these receipt papers are using BPA, and they don't all use it, probably about a little less than half do, that the exposures you can get, the amount that goes onto your hands, is probably greater than from any other source in the - you know, for most people, certainly for non-workers.
Now, the question is, if it gets onto your hands, does it go in? If it doesn't get into your body and, you know, get into tissues, then that's not a problem. But the Swiss chemist I was talking to, this Koni Grob, he was mentioning, he said on the worst-case scenario, you've got maybe hand creams or oils to, you know, try and keep your hand comfortable, and that could facilitate the uptake of this into tissue.
And he said the worst-case scenario for him would be a woman that was pregnant and uses hand cream or something, touches receipts all the time, like a cashier. And if this is truly getting in, she could be exposing the fetus, and that's the big risk because the fetus and young children are the populations at highest risk for potential harm from BPA.
FLATOW: And what kind of potential harm are we talking about?
Ms. RALOFF: Well, and it is only potential. They've shown that it definitely can cause some real problems in animals, usually animals exposed to fairly high concentrations of the chemical.
But in a number of studies, they have started finding suggestions that it may be contributing or - in animals, it causes obesity. It can lead to diabetes. It can lead to heart arrhythmias, and they think the same kinds of things could operate in people.
In children that were exposed in the womb to BPA, and they can tell that by looking at concentrations in their moms' urine during pregnancy, those who had the highest exposures, the girls tended to be more aggressive when they become, you know, young children, and the boys became a little more sort of reticent. So there is a question about whether gender-appropriate behavior might be affected.
Those are early studies, but it's got a lot of people worried.
FLATOW: But the government at this point isn't making anyone stop using it, making those paper cash receipts?
Ms. RALOFF: No, it's perfectly legal, and there's been some question about whether there is even any ability to regulate it right now because it's generally considered safe.
So until it gets a different designation based on toxicity studies, and there's a lot of controversy over whether it changes, at what dose it might, you know, pose some kind of risk, no, they can't change anything.
FLATOW: Is there a useful alternative chemical that might be used?
Ms. RALOFF: Well, there is a major receipt-paper manufacturer, Appleton Papers of Appleton, Wisconsin, and they also sort of saw the handwriting on the wall about four years ago and said, you know, this stuff is getting a lot of bad press. We think that this is not what we want to use in our receipt papers, they had been using BPA.
So they switched to an alternative, Bisphenol sulfonate. And it sounds similar, but it doesn't work the same way.
FLATOW: We have a question from - a tweet came in from Pete Myers(ph), who says: Ask Janet about transfer of BPA from receipts to hand to mouth. I mean, if you work at a cash register all day, and you're taking these out all the time, you know, if you put your hand on your tongue to grab it or something, is there a danger here?
Ms. RALOFF: Well, interestingly, both the Environmental Working Group's researchers, who are looking at that for their team, it was at the University of Missouri, Frederick Vom Saal's group, and the Swiss group both looked at what happens if your fingers are wet when you touch this versus when it's dry.
And you get 10 times greater uptake of the Bisphenol A from the paper if your fingers are wet.
Now, also, there's some question, would it be easy to take up in your mouth? And, I mean, in my mind, the biggest concern is if you're worried about children being exposed to the chemical, it gets on Mom's hands. Does it then, when she holds a child's hand, get on the child's hand, and the child puts his hands in the mouth, or does the child play with a receipt and put it in its mouth if it's, you know, a toddler...
FLATOW: And what do the BPA-makers say? How do they respond to this?
Ms. RALOFF: They said that - much ado about nothing at this point, that the risks have not been established, that the federal government has not taken action, and that's true, and that some of the studies suggest that exposures would be well below what should be a tolerable or acceptable dose.
Now, the Swiss group said that's true maybe for a receipt but not if you're handling them all day, necessarily.
The other thing is to show some measure of the interest, the feds are interested. The National Toxicology Program, under the National Institute of Environmental Health Sciences, is looking at the data and considering beginning its own research to look at the uptake of this from paper and how far BPA may get into the body and under what conditions.
In addition, there's another study that's going to be underway at the University of Missouri looking at a similar sort of thing.
But the EPA has also looked at, since it doesn't have the authority right now to restrict use of BPA, it's encouraging companies to do so. And on July 15th, it had a workshop to bring together all kinds of receipt-makers, the people who use receipt paper, environmental groups, other government agencies. And it said what can we do to try and encourage people to use safer alternatives?
And that's, you know, they're brainstorming that right now.
FLATOW: And so no one is saying right now don't touch the papers.
Ms. RALOFF: Well, up until two weeks ago, nobody really thought much about it. It wasn't on anybody's radar screen.
Ms. RALOFF: And in fact, you know, you can't, by looking at the receipt paper, tell which ones have BPA and which ones dont. And I talked to some people at Appleton Paper a while ago, saying, you know, if this is a concern for some people, might you not want to put, you know, something on the paper that says it's BPA-free for those people who are concerned to, you know, alert them, which they might want to touch or not.
And they said, well, you know, nobody's really asked for it. Well, that's changed. In the last three days, they said Janet, we're in the process of working on it right now, that their phone is ringing off the hook from retailers asking how can we get receipt paper that says it's BPA-free.
FLATOW: Yeah, especially if it's being recycled, all that paper, right, going into the recycle stream. It may have the BPA in it.
Ms. RALOFF: Yes, as a matter of fact, apparently almost all recycled paper now has BPA in it as a result of having recycled the thermal paper that had used BPA. And Appleton Paper, which has been trying to avoid BPA, actually stopped using outside-recycled paper just for that reason. It now uses only its own internal thermal paper, which has no BPA, because I think it was finding it was getting traces of BPA from other waste treatment.
FLATOW: All right. We'll keep an eye on it with you, Janet. Thanks for taking time to be with us today.
Ms. RALOFF: My pleasure.
FLATOW: Keep up the good work. Janet Raloff is senior editor at Science News. You can find her stories on BPA and receipts at sciencenews.org.
We're going to take a break, and when we come back, Danica McKellar is here with her new book "Hot X: Algebra Exposed." And she's going to be here to talk about it with us, 1-800-989-8255 if you want to talk about algebra and teenage girls and the best way to get teenage girls interested in mathematics. She's devoted a good part of her life to doing that, and she's here to talk about it some more. So stay with us, 1-800-989-8255. You can tweet us, @scifri, @-S-C-I-F-R-I. We'll be right back.
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FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.