Study Waves Cautionary Flag About Nanotubes Tiny tubes made of carbon atoms have been among the main ingredients of the nanotech revolution. But researchers have found that when injected into mice, nanotubes could behave in a way similar to the way asbestos fibers behave, forming lesions that lead to cancer.
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Study Waves Cautionary Flag About Nanotubes

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Study Waves Cautionary Flag About Nanotubes

Study Waves Cautionary Flag About Nanotubes

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For the rest of the hour, something very small and perhaps maybe very deadly. Carbon nanotubes are very small structures. They're tiny tubes that are actually rolled up sheets of carbon. But they have very unusual properties and so inventors and scientists around the world are working on ways to incorporate the nanotubes into new products. Some are already out there in the market like bicycles and tennis rackets. And you can buy carbon nanotubes by the kilogram on the Internet. But writing this week in the journal, Nature Nanotechnology, scientists are turning on the warning light saying that under the right conditions, some forms of these carbon tubes, these longer carbon nanotubes might be able to cause the same effects in the lungs that long asbestos fiber do, maybe even lead to lung cancer, mesothelioma.

Joining me now to talk about it and the possibility for this causing mesothelioma is Andrew Maynard, Chief Science Adviser to the Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars in Washington. He joins us from our NPR studios there. Welcome back to the program Dr. Maynard.

Dr. ANDREW MAYNARD (Chief Science Adviser, Project on Emerging Nanotechnologies, Woodrow Wilson International Center for Scholars): Hi. Good to be here.

FLATOW: Welcome. Vicki Colvin, she's Executive Director of ICON, the International Council on Nanotechnology. That's a consortium of academic, industrial, government and NGO looking at nanotechnology policy and safety. She's also professor of chemistry, professor of chemical engineering at Rice University in Houston. She joins us from the Baker Institute of Houston. Welcome to the program Dr. Colvin.

Dr. VICKI COLVIN (Executive Director, International Council on Nanotechnology and Professor, Rice University): Thank you.

FLATOW: Andrew, let's talk about the nanotubes themselves. How are they similar to asbestos fibers?

Dr. MAYNARD: Well, first of all, let me just clarify it - only some nanotubes that are similar. And what we're interested in here is things that physically look like asbestos fibers. We know one of the things that make asbestos fibers particularly harmful is when they're very thin, when they're very long or when they're very straight. So, many years ago now people started to ask whether this new - this wonderful new material carbon nanotubes, whether it could produce similar looking fibers. So, this is what we were particularly interested in. Could carbon nanotubes that happen to be very long, very thin, very straight cause the same health effects as these long, thin, straight asbestos fibers.

FLATOW: Mm hmm. And you found?

Dr. MAYNARD: And we found in this particular instance, yes they did. We were looking at one particular disease, mesothelioma which is a cancer of the outside of the lungs, usually associated with exposure to asbestos fibers. And in this particular study which really just showed whether something has got the potential to cause this disease, we found that long thin carbon nanotubes behave the same as long thin asbestos fibers. But short or curly nanotubes didn't show any obvious harmful effect.

FLATOW: Do we know why this happens?

Dr. MAYNARD: We think it's because these long fibers are behaving in the same way as the asbestos fibers. And what happens here is the body just cannot physically deal with them. The way that the body gets rid of material that shouldn't be there especially in the lungs is to send out these scavenger cells, microphages, to route themselves round the material and take it down to the body. But if you got a really long fiber, the microphage cannot physically wrap itself around that fiber and it ends up dying in the process. And so, especially if you got a fiber there which doesn't dissolve, it lasts a long time, you end up causing damage in the body over a long period of time and in some cases that can lead to cancer.

FLATOW: This is Talk of the Nation: Science Friday from NPR News. Talking about the long-tube nanofibers and possibly of being linked to cancer. Vicki Colvin, what is - is this cause for alarm?

Dr. COLVIN: Well, you know, I don't think immediately it's a cause for alarm. It's - the paper's given me a lot to think about in terms of where these materials might be used, right, I think that comes to everybody's mind when you hear about this. So, the first question is, my guess is that they are not widely used but that's a guess and we can talk about that. And then I think the second thing is that we're just now seeing the earliest reports of these kinds of findings in rodents, for example, in the study and then some genetically-engineered mouse and another. And so, in those cases, you know, the data is just beginning to come out and I think the definite causal link in humans and real world exposure conditions is something we'll develop over the next five to 10 years.

FLATOW: Mm hmm. Andrew, you've been thinking about this for a while. You even have a blog about nanotubes and health and safety.

Dr. MAYNARD: That's right.

FLATOW: Why - what first triggered you to start thinking about this?

Dr. MAYNARD: Well, it actually goes back a long, long way when I did some of my first research. I'm a physicist by training and I got interested in how we can use really sophisticated techniques, electro microscopes, to analyze very small particles years and years back. And so that was my first love, if you like, within science. But now, over the last five-10 years, as people began engineering nanoscale materials and nanoparticles, I've been able to apply that interest actually looking at these new materials and asking the question how can we work out what might make them harmful because they're very unusual materials in many cases. But more importantly, how we can engineer them to be safe?

FLATOW: Now, nanofibers are relatively new. The nanotubes are new. We've - but we've had the nanoparticles around the bucky balls, things like that for quite awhile. This is quite something different is it not, Vicki?

Dr. COLVIN: Well, you know, the multi-wire carbon nanotubes are part of a family, you know, nanomaterials which are kind of the backbone of all nanotechnology are an incredibly diverse zoo of different types of, you know materials formulated in different ways. It's a fun place to play. And the particular type they studied in this paper actually is - I would not call it a new material. You know, C60's discovery that big - dates back to the 1980s and carbon fibers and carbon nanotubes were discovered as an entity in the 1990s. So, actually in the history of nano, they are actually pretty old as these things go. So, they are, you know, part of the whole, you know, big gigantic collection and materials in their particular type and they happen to be long and thin with dimensions similar to asbestos. So, the paper kind of explored a pretty interesting avenue.

FLATOW: OK. We're going to have to take a break and we'll come back and take perhaps more time to talk about this and take your calls. Our number, 1-800-989-8255. Talking about this carbon nanotubes and the research published this week that talks about the long ones being similar to asbestos fibers. So, stay with us. We'll be right back after this short break. I'm Ira Flatow. This is Talk of the Nation: Science Friday from NPR News.

(Soundbite of music)

FLATOW: You're listening to Talk of the Nation: Science Friday. I'm Ira Flatow. We're talking this hour about nanotechnology in a recent paper published about carbon nanotubes, the longer ones being very similar to the shape of fibers from asbestos and possibly in laboratory experiments showing that they might actually cause cancer like asbestos fibers do. With one of the paper's author, Andrew Maynard and also with Vicki Colvin, executive director of the International Council on Nanotechnology. Andrew, I imagine this has caused a lot of - you've gotten a lot of reaction to this paper.

Dr. MAYNARD: Yeah. I think that's fair to say. It's been an eye-opener for a lot of people I think. But then again for some people, it's something that was expected and for many people out there that's thoughts, OK, something looks like asbestos, not surprising that it behaves like asbestos.

FLATOW: Hmm. I want to get, I want to just make the point that I was talking with Vicki Colvin about - before the break and that this is not a condemnation of all nanotechnology, is it?

Dr. MAYNARD: I - in fact, I don't think it's a condemnation of any sort of nanotechnology. To start with, this is just one small fraction of one particular type of nanomaterial, carbon nanotubes. But then, although the research indicates that there could be harm here, it also gives us a road map towards developing safe forms of this particular material. So, it's certainly not condemning everything, anything. It's actually opening the route towards developing it responsibly and safely.

FLATOW: Mm hmm. Because we have nanoparticles around us everywhere. We have them in our face creams and sun creams and all. We rub them into our skins but they're not made of carbon nanotubes, are they?

Dr. MAYNARD: Many of them aren't. You can make nanometer-sized particles out of many, many different types of materials. So, for instance, you can buy sunscreen with titanium dioxide or zinc oxide particles in it. You can buy cosmetics with little sort of soft nanoparticles of various molecules in them. So, yeah, there are multiple different types of nanoparticles that we're going to come across.

FLATOW: Mm hmm. You - on your blog you talk about a study done in Great Britain which had basically foreseen this problem or calls for more research into the health effects, of possible health effects.

Dr. MAYNARD: Very much, yes. And I mentioned that a number of people haven't been too surprised by this. Over probably the last 10-15 years, a number of people have flagged up this similarity between some asbestos - oh, between asbestos and some nanotubes. But the important study was one that was carried out in 2004 by the British Royal Society where they looked at this emerging field of nanotechnology. And one of their main conclusions was that this new material carbon nanotubes was so like asbestos that it was a top priority to try and understand whether it actually led to asbestos-like diseases.

FLATOW: Mm hmm. Vicki Colvin, do you think now more money should be going in to researching the health effects, potential health effects of...

Dr. COLVIN: Well, that's kind of a - it's a biased question for me. But, yes, I think that it's - and it should go into there but not just because, you know, we want to make sure, you know, what's going to happen if a particular material ends up in your body. But also to help us, as Andrew said, make all of this technology safe. You know, we can't afford not to do nanotechnology. We have so many big problems that are facing our world that we're going to need every last innovation that this field brings us. And one of those big innovations is actually the innovation of doing it safely the first time around. And that's what the research is there is that we're not taking questions about implications and putting them into one box and then trying to develop the technology in another.

Rather, we can really do it together. And so, predictive models, you know, being able to develop ways before you've even made a nanoparticle to say exactly how it's going to influence the environment or person or actually something we can really imagine doing in the next decade. And that's the kind of, that's the kind of outcome that we can expect if we do research in this area correctly and with a right amount of support.

FLATOW: Mm hmm. Andrew, we can buy these carbon nanotubes by the bottle over the Internet, can we?

Dr. MAYNARD: You can and there are number of companies making them. But there's one company in particular, Cheap Tubes Incorporated, that you can log on and you can buy anything from a gram to 10 kilograms of this stuff.

FLATOW: And that would be pretty dangerous if you inhale it - if I understand you correctly.

Dr. MAYNARD: Well, if you did things with it that you probably shouldn't do with it such as opening it in an unconfined area and snorting it. Yes, it could be harmful I suspect.

FLATOW: And - kids with science fair projects and whatnot, would they not be in danger?

Dr. MAYNARD: Well, that is actually a serious issue and I think this is where people needs to be very careful, not only the manufacturers but people putting out guidelines because it is possible for anybody to buy this material and do something potentially dangerous with it. And at the moment, there are really very few guidelines about how to use it safely.

FLATOW: And where would you hope those guidelines come from and what kind of research - now, you are a researcher and I've seen this, where would you hope that this focuses on?

Dr. MAYNARD: I would hope very much that, first of all, from the government we have a very strategically-targeted research program that looks at the outstanding questions that need to be answered and works out how to address those. So, for instance, we know from the study that we got the potential to cause a very harmful disease there. What we don't know is whether you can actually get these long thin fibers airborne in sufficient quantities to cause disease, whether they could be breathed in and even if they are breathed in, whether they move to the very sensitive outer layer of the lungs.

FLATOW: Mm hmm.

Dr. MAYNARD: These are all very, very clear research questions that we've got to have a strategic research program to address. And I would say first and foremost that's going to come from the government, but industry have got a very clear role there to play as well.

FLATOW: Vicki Colvin, is there a way to make these nanotubes less harmful?

Dr. COLVIN: Yeah, there definitely is. I mean, I think one of the things the study, you know, gave me a lot to think about was actually the fact that we don't know where the materials are. So, I just want to underscore that if you look at asbestos as we draw more on that analogy, you know, the people - you know, it's a disease that doesn't show up for 20 to 30 years after exposure. So, it's not something you can really mess around with. And if you do get diagnosed with mesothelioma, it's pretty much a death sentence. So, you know, we have to take very seriously where the materials are currently being used, and I think that the fact that it's not the producers who know what thin, multi-walled carbon nanotubes are and how to handle them.

It's the fact that, you know, what about the guy who gets the broken tennis racket and decides to, you know, get out his sander and shave down the handle to re-wrap it, well, he might get exposed. So, I think it's incredibly important that people who are profiting right now from the sale of these materials take very good steps to, you know, label, provide information, to everybody who might kind of come in contact about what the materials are even at this early stage.

FLATOW: Right. So, that would be a good first step is to label everything they made out of nanotubes that you can buy in the store.

Dr. COLVIN: Yeah, and absolutely because I think once you begin to get - you know, the information that there is an issue and especially with this particular health effect which takes so long to develop, you know, you can't really wait around until the science is done. You want to have the answers more quickly, but in the meantime, you know finding ways to get product information out there that really works is going to be very important, and certainly of course, you can make everything safe for something that we've looked at as how to do that specifically with carbon nanotubes.

FLATOW: Andrew, you agree, to get labeling going?

Dr. MAYNARD: Yeah, with labeling, it depends what sort of labeling you're talking about, whether you're talking about putting a big yellow sticker around something saying, beware, carbon nanotubes inside or whether you're talking about, putting something a bit more sophisticated on the ingredients label. But whichever way you look at it, people need to know what's in these products so they can make informed decisions.

FLATOW: 1-800-989-8255 is our number on Talk of the Nation Science Friday. Let's go to Gary in San Antonio. Hi, Gary.

GARY (Caller): Hi. My father actually worked to manufacture carbon nanotubes for about a year. I wonder if there is any way to test to see, you know, if he has already inhaled some of these or if he has some of these in his system.

Dr. MAYNARD: You know, I don't think there is an easy test at the moment. We're still just learning how to track these things down or understanding how they might lead to health effects. If he was only working with them for a year, and it was a reasonably clean environment, there's unlikely to be any significant problem there, but obviously, it's worthwhile keeping a check on this potential illness, especially as it has to do with the lungs.

FLATOW: Thanks for calling.

GARY: Thank you.

FLATOW: 1-800-989-8255. Let's go to Will in Flagstaff. Hi, Will.

WILL (Caller): Hello. Thank you, too. I love your show, man.

FLATOW: Thank you.

WILL: I wanted to know, this isn't going to hamper the research on, like, the space elevator because they're trying to make long nanotubes for rope, right?

Dr. COLVIN: Yeah, this is - that's a great question because I think that in the nanotechnology community, one of the - we'll call it one of their fears is, you know, there's so much to do and so much cool stuff, so many hard problems we can solve, what's going to happen to the research, and I think that actually, this kind of data coming out early, well, it's a little bit of a - you know, let's hope people don't ever react. On the other hand, really makes it much easier to do the research because when people do ask you, yeah, what about the effects, you actually have something to say. So, I think that the two go hand in hand. Plus, the fact that you can make a space elevator and you'll know how to coat it, so that if the fibers did come out of it, they would be benign.

FLATOW: All right. Thanks for calling.

WILL: Thank you.

FLATOW: What makes a carbon nanotube so terrific that everybody wants to make something out of them, Vicki?

Dr. COLVIN: Well, I think that the real reason is that they're just an amazing kind of tube. You know, a lot of the things that we have out there that are fibers are solid, right? They don't - they have something in their middle. Are these things really are like straws? And the stuff they're made out of, graphite, has some pretty spectacular properties so that, you know, electrons don't just sort of hack atom to atom, they move ballistically down one of these things. Because of the nature of that, of how the carbons are hooked together, you just - the strength is absolutely extraordinary. And it's all lightweight because it's carbon, you know.

It's not steel, it's not the things that we're more familiar with as structural material. So, it's - this amazing confluence of having carbon at the center of the material in a graphite-type form, which is by the way nothing more than what's in a lot of our pencil lead and this amazing tubular structure. So, it's - they're very, very special materials and really to some extent, the greatest hopes of nanotechnology had been pinned on them.

FLATOW: Daniel in Minneapolis. Hi. Welcome to Science Friday.

DANIEL (Caller): Hi there.

FLATOW: Hi there.

DANIEL: I have a question about carbon bikes.

FLATOW: Go ahead.

DANIEL: Bicycles are now made of carbon. I'm assuming that that would employ nanotechnology and a lot of times you have to kind of cut down, say, your seat tube. Curious if that's a health issue?

Dr. MAYNARD: Interesting you should bring that up. Yeah, and if you look at some of the high-end bike frames out there at the moment, they do use carbon nanotubes. And the argument is usually made that once the nanotubes are in something like a bike frame, they're never going to come out. But, you're right. As you say, if you're really into this area, you are going to customize those frames, those tubes. You are going to cut them at some point. And one of the unknowns here is whether that process actually leads to the release of these fine carbon nanotubes. The chances are, it probably doesn't, but somebody's got to measure that.

Dr. COLVIN: Yeah, and you probably don't want to tale a risk, so you should wear a mask and do your very best to limit exposure. The other good news about the composites too is that because this stuff is so strong, one of the reasons people use it is they don't have to use as much. So, compared to a conventional carbon fiber composite, you'll have a lot less material potentially that comes out. But, my advice is still if you know it's there, take every precaution, and the (unintelligible) website and a few others have some suggestions for what to do.

FLATOW: Talking about the carbon nanotubes this hour, Talk of the Nation Science Friday from NPR News. Will a mask stop a nanoparticle? I mean, I wouldn't think so.

Dr. MAYNARD: Well, you know, it's surprising, but it probably will. If you look at how much their masks work. The particles that are most likely to get through runs about 300 to 500 nanometers wide large. The smaller particles are actually collected more easily, simply because the dynamics of what's happening there. So, the chances are, if you've got a really fine nanofiber, it would get caught by that mask. But again, you know, I don't think we need to be complacent here. I would love to see the research proving that.

FLATOW: Will these stay in the environment forever? I mean, do they biodegrade or do they just hang around?

Dr. COLVIN: Well, yeah, that's a really fascinating scientific question because, you know, there's, for example, organisms that eat wood and are very good at breaking down lots of complex carbons. And a lot of people are studying the biotransformation and biodegradation, you know. Can you get, you know will slime mold even as a nanotube is a great question actually. But, you know, the problem is that it's the shape so a lot of the naturally occurring carbons that are like similar to this one are kind of plainer. And so, what that means is that they - enzymes that do the degradation don't fit the tubes. So, people are looking hard for what those degradation mechanisms might be but some of the obvious pathways haven't proven yet to be effective. So, they may be biopersistent.

Now, if you modify them just so slightly with some chemical help, you can really quickly create systems that biodegrade so it may be that, you know, before you put them in the environment, you treat them with something a little bit stronger than bleach to get that process going so that then nature can finish its job.

FLATOW: But this will have to be guidelines that everyone follows then? That no one, you know, that there aren't - that don't exist now for them.

Dr. MAYNARD: Yeah. Very much so. And at the moment, it's almost like driving blind into the carbon nanotube future. We've really got to understand how to work sensibly, wisely with this material before it appears into many places.

FLATOW: Mm hmm. Do you know if we have - have you heard any reactions from political people, Congress people, you know, committees that say, hey, we better start doing hearings on regulations for these things?

Dr. MAYNARD: Well, I - not directly in response to this, but if you look at what's happening up on hill at the moment especially with the science committee, they are looking at how you develop nanotechnology safely. There was actually a bill going through the motions at the moment that looks at increasing the emphasis on understanding how to use engineered nanomaterials safely. So, this is something that's suddenly very high up on agenda as far as Congress goes. It's a little bit hard to see where it is in terms of the federal agencies at the moment.

FLATOW: Quickly, Caroline at Roseburg, Oregon. Hi, welcome to Science Friday.

CAROLINE (Caller): Hello. I'm slightly horrified by your discussion of labeling the ingredients of - or having some signal on the outside because if somebody is sanding a tennis racket they bought at a garage sale or from a thrift store 10 years from the point of origin or 20, you know, you're going to open Pandora's box to a bunch of unsuspecting people.

Dr. MAYNARD: You mean, in - if that label is there or if that label has come off in the process?

CAROLINE: It's come off in the process and even people who buy used goods often are not - they don't have the instructions or the label or anything.

Dr. MAYNARD: That's actually a very interesting question and it, I think it just demonstrates that if we developed this technology and similar technologies. We've actually got to think through issues like that if we're going to work at how to develop it wisely.

FLATOW: Thank you Caroline.

Ms. CAROLINE: You're welcome.

FLATOW: This obviously bothers you, does it not? Well, she's gone. I guess a lot of people are very concerned about this now and probably rightfully so I would imagine.

Dr. MAYNARD: Well, you know, I think it's right to be concerned, but I think we can't afford to lose sight of what we could actually achieve here. We're really at the very beginning of the curve when it comes to developing this technology, and we actually have a wonderful opportunity of getting it right and not making mistakes that we've made in the past.

FLATOW: Mm hmm. And I guess one of the techno messages is that - and I've said it before and I'll try to say it as we wind up here is that carbon nanotubes are not the same as all the other nanoparticles.

Dr. MAYNARD: Very much so and that is just so important to realize that all these different types of nanoparticles are very, very different with their own risks and in many cases they're likely to be very safe.

FLATOW: All right. Vicki, any final word?

Dr. COLVIN: Well, I mean, I think reacting to the prior caller, I mean, you always have to look at what the benefits of the technology are providing you and, you know, if it were me, I wouldn't - even though, you know, I might like to ride a bike, I wouldn't ride a bike with - that contains asbestos just because it was a little bit lighter. So, maybe in that case, you don't derive enough benefit to really justify what this very uncertain risk. But there are other risks, for example, you know, what if we research this stuff and we made airplanes a lot, lot lighter. Well, they would use less fuel and that would be a really, really huge issue.


Dr. COLVIN: So, I think there are places that makes sense.

FLATOW: All right. Let me thank both of you. Andrew Maynard, Chief Science Adviser for the - to the Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars in Washington. Vicki Colvin, Executive Director of the International Council on Nanotechnology. Thank you both for taking time to be with us today.

Dr. MAYNARD: Thank you.

Dr. COLVIN: Thank you.

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