In order to analyse their risk potential, long and short nanotubes, long and short asbestos fibres as well as carbon black were injected into the abdominal cavity of mice. 'The results were clear,' says Professor Kenneth Donaldson, who is a co-author of the study and led the research at the University of Edinburgh, UK. 'Long, thin carbon nanotubes showed the same effects as long, thin asbestos fibers,' the effect being that they have the potential to cause mesothelioma.
Mesothelioma is a cancer of the lung lining that can take 30 to 40 years to appear after a person has been exposed to a harmful substance. In the 1940s, asbestos was revealed to cause mesothelioma, and even now, after its usage has been drastically reduced, asbestos-related cancers are likely to continue for several more decades.
Now, this study has raised the same concerns about MWCNTs. However, some questions have not been answered yet, Professor Donaldson says: "We still don't know whether carbon nanotubes will become airborne and be inhaled, or whether, if they do reach the lungs, they can work their way into the sensitive outer lining. But if they do get there in sufficient quantity, there is a chance that some people will develop cancer - perhaps decades after breathing the stuff."
Dr Andrew Maynard, another co-author of the paper and chief scientific advisor to the Project on Emerging Nanotechnologies, believes that the industry as well as policy-makers will have to react quickly to the threat. Workplaces and products need to be made safe, while from a policy perspective "we've got to make sure that everything is in place to enable us to really take advantage of what is quite an incredible technology as safely as possible," Dr Maynard states.
"We need policies that ensure the right research is done, so that we understand not only what makes some nanotubes harmful, but also how to make them safely. And one of the things that recent research does show is that it is possible to make nanotubes safe, certainly with regard to causing mesothelioma."
"This is a wakeup call for nanotechnology in general and carbon nanotubes in particular," Dr Maynard adds. "As a society, we cannot afford not to exploit this incredible material, but neither can we afford to get it wrong - as we did with asbestos."
MWCNTs are made up of multiple concentric layers of graphite or a single layer of graphite rolled around itself multiple times. They produce extremely light, though strong composite materials and are currently used by the automotive industry, in silicon chip manufacturing, electronics and in sporting goods.
Future fields of application are extensive and include catalysts, solar cells, batteries, fuel cells and sensors as well as innovative medical surfaces and new drugs. According to the Project on Emerging Nanotechnologies, the total global market value of carbon nanotubes is expected to exceed USD 1.9 billion (€1.2 billion) by the year 2010.
Copyright ©European Communities, 2008
Neither the Office for Official Publications of the European Communities, nor any person acting on its behalf, is responsible for the use, which might be made of the attached information. The attached information is drawn from the Community R&D Information Service (CORDIS). The CORDIS services are carried on the CORDIS Host in Luxembourg - http://cordis.europa.eu. Access to CORDIS is currently available free-of-charge.