The story of asbestos in this country ought to serve as a cautionary tale: A seemingly miraculous fiber was widely introduced into common consumer products; only after it was already in millions of homes did the general public realize that it causes a particularly terrible form of cancer. Now, treating victims and cleaning up contaminated communities is costing billions of dollars, and thousands of people endure the toll of a debilitating and deadly disease.
Nanotechnology is another innovation that promises to bring consumer products to a whole new level -- and, once again, it looks like nano products will become widespread and entrenched before we have a complete picture of what the risks are.
Nanotechnology involves extremely small particles measuring 1-100 nanometers (down to 0.00001 times the width of a human hair). This gives the particles more surface area relative to their weight, which can make them more reactive and change their properties in other ways. Such changes can offer new opportunities, but they can also pose dangers. In fact, a pilot study published in the latest issue of Nature Nanotechnology suggests that carbon nanotubes behave like asbestos, causing mesothelioma-like lesions in the body.
Here's the study abstract (references omitted):
Carbon nanotubes have distinctive characteristics, but their needle-like fibre shape has been compared to asbestos, raising concerns that widespread use of carbon nanotubes may lead to mesothelioma, cancer of the lining of the lungs caused by exposure to asbestos. Here we show that exposing the mesothelial lining of the body cavity of mice, as a surrogate for the mesothelial lining of the chest cavity, to long multiwalled carbon nanotubes results in asbestos-like, length-dependent, pathogenic behaviour. This includes inflammation and the formation of lesions known as granulomas. This is of considerable importance, because research and business communities continue to invest heavily in carbon nanotubes for a wide range of products under the assumption that they are no more hazardous than graphite. Our results suggest the need for further research and great caution before introducing such products into the market if long-term harm is to be avoided.
There are the usual caveats about making any sweeping assumptions based on this: It's one short pilot study, the subjects were mice, and the nanotubes were injected directly into the body, which is not how most of us would be exposed to the fibers. It does tell us that we ought to slow down and quit pumping these fibers into workplaces and the marketplace until we know more.
Carbon nanotubes are already used in dozens of products, including electronic components, tennis rackets, and golf clubs, and the Washington Post's Rick Weiss states that they're expected to be a $2 billion industry within the next few years. Kenneth Chang's New York Times article suggests that consumers aren't likely to inhale nanotubes from bicycle frames, but he cites one of the study authors who cautions that workers may be at more of a risk, just as construction workers and mechanics have a higher risk of asbestos exposure.
As Olga Naidenko pointed out last week, though, most nano workplaces don't have the kind of monitoring or controls necessary to protect employees -- and they're not getting information and best-practice guidance from industry or government, which might help them put appropriate programs in place.
Regulating nanotechnology is challenging, because we're not exactly sure how fibers of different sizes will behave. Even in this mouse study, shorter nanotubes didn't cause lesions, while longer ones did.
Plus, when considering the nanotechnology field as a whole, there are several different fibers. In addition to the carbon nanotubes, nano particles of silver are widely used to give products antimicrobial properties. As Carole Bass pointed out in The New Republic earlier this month, spreading nano-silver particles far and wide could have serious consequences for the environment as well as for individuals -- for instance, the bacteria we rely on to clean our water and perform other services might suffer. This means that the FDA and EPA both will need to be involved.
"We've got to have the right research, and really fast," nanotube study author Andrew Maynard of the Project on Emerging Nanotechnologies told the Washington Post. But the question is, will we get the right research and put it to use quickly, or will the companies that make and use nanotubes gum up the process?
Like tobacco companies, the companies that made and used asbestos denied that there were problems with the substance long after they knew about the diseases it caused. (I'll put in a quick plug for David Michaels' Doubt is Their Product; chapter two of the book tells the sordid asbestos story, and we've put related documentary evidence online.) Let's hope that the companies using carbon nanotubes don't stand in the way of regulating a substance that has the potential to cause another asbestos-type public health crisis.
This post was created for The Pump Handle, a public health blog.
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Comments
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Gar Lipow Posted 6:31 am
21 May 2008
One field we are already putting a great deal into is nanotech - and we should. We have every reason to expect this field to produce low cost solar cells, low cost environmentally sound electronics, low cost electrolyzers for hydrogen and possibly low cost fuel cells. However there is one aspect of nanotech we are not putting enough effort into - how dangerous the waste is and what needs to be done about it. The current and near future versions of nanotech, unlike portrayals in some of my favorite science fiction, mainly focuses not on bacteria and virus sized machines, but on how materials act when processed into very tiny fibers, crystals, tubes and other nanostructures. Carbon, silicon, glass and metals (just to name a few examples) behave in very different and often useful ways when formed into such structures, compared to their normal forms.
Now any manufacturing process produces some waste; nanotechnology usually results in scrap nanomaterial. We are talking about scrap carbon, glass, metal or silicon - all pretty harmless sounding stuff. And maybe it is just as harmless as it sounds. But just as common materials behave differently in useful ways, when formed into nanostructures, they may behave differently in harmful ways as well. The point is, we don't know. Nanotech has so much potential; we do not want this infant industry to make the same mistake other high tech industries have, and smugly assume their waste products are harmless or that the problem of waste disposal will be solved without effort on their part. Test your material now; find out how harmless it really is; if it is not harmless find out how to turn into something that is. Apply the old business cliché and be proactive.
Is this a real concern? Well bear in mind we see many harmless materials turn dangerous even at the macro level when formed into ordinary small fibers. Cellulose and glass are among the least toxic non-food substances known. But when turned into cellulose fiber for insulation, and fiberglass for many purposes, you do not want to breathe them. Cellulose and fiberglass insulation are always sealed off from building air when properly installed. Workers who install the stuff wear masks and protect themselves in other ways, or they do if their employer cares about their health, or if they have the leverage to force their employer to care. Note that we have not stopped using either material. As a society we investigated what the dangers are, and know how to take appropriate precautions.
That I'm sure is all we need to do with nanotech - find out what the problems are. In some cases there probably won't be any. In others only simple fixes will be required. Some substances may require elaborate precautions or complex post processing. And isn't it better to know that in time not to kill a lot of people and ruin the reputation of an industry that could save us all? Spend the effort now to find out what problems it might create and how to solve them.
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Liz Borkowski Posted 8:16 am
21 May 2008
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johnbalbus Posted 9:20 am
21 May 2008
I've blogged on the Nature Nanotechnology study and the Takagi et al study that preceded it at http://environmentaldefenseblogs.org/nanotechnology/2008/ ...
for readers who want to learn more.
keep up the good work!
John Balbus, MD, MPH
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rwkenn Posted 7:48 pm
21 May 2008
Two Italian scientists, Antonietta Gatti and Stefano Montanari, have been studying the health effects of nanoparticles since 1999 and the results are, at the least, alarming. In fact Dr. Montanari has been spearheading attempts to inform the public of these effects and has been traveling all over Italy denouncing same. Despite this the political cast in Italy sees incinerators as a solution to the growing problem of refuse (see naples) and are pushing for their construction all over the country, claiming that the energy produced from incinerating trash is a form of renewable energy. The real reason behind this push for more incinerators is high profits and kickbacks.
It would appear to me that the research these scientists have done could also assist in understanding the effects of nanotubes on workers??????
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Biodiversivist Posted 12:12 am
22 May 2008
In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
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chellios Posted 4:39 am
28 May 2008
Today's society wants the next new and exciting product without regard to the consequences or true costs. Manufacturers make a product without regard to the product after it is sold. Life cycle analysis is a joke as it is left up to someone else to take responsibility for the recovery of the scrap and recycling of end of life products. Extended Producer Responsibility is either not mentioned or rephrased as "Life Cycle Analysis". The future is bleak unless nano products are properly researched and regulated!
QUESTIONS: If nano-particles conglomerate with other nano-particles and are not yet 100 nm in size, what are the effects of these new compounds? Will they continue to conglomerate into new reactive particles and what effect will they have on people and the environment?
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