10/01/2008 - They can look like asbestos and behave like asbestos—so they deserve careful scrutiny as a potential health hazard. The “they” are some forms of carbon nanotubes, which a recent study finds can be as harmful as asbestos if inhaled in sufficient quantities.
Carbon nanotubes have been called a poster child for the nanotechnology revolution. They are sheets of graphite only an atom thick and formed into cylinders that are as light as plastic and stronger than steel. They are used in new drugs, energy-efficient batteries and electronics; nanotube sales are predicted to reach $2 billion annually in four to seven years.
Nanotubes come in many forms, with different shapes, different atomic arrangements and varying amounts and types of added chemicals—all of which affect their properties and might influence their impact on human health and the environment.
In a study published in May in Nature Nanotechnology, researchers used established methods to see if specific types of nanotubes have the potential to cause mesothelioma, an asbestoscaused cancer of the lung lining that can take 30 to 40 years to appear following exposure. Long, thin, multi-walled carbon nanotubes that look like asbestos fibers, the results show, behave like asbestos fibers.
The scientists tested for fiber-like behavior only, and it is possible that carbon nanotubes could damage the lungs in other ways. “More research is still needed if we are to understand how to use these materials as safely as possible,” says Kenneth Donaldson, D.Sc., an expert in particle toxicology at the University of Edinburgh, who led the team.
“This study is exactly the kind of strategic, highly focused research needed to ensure the safe and responsible development of nanotechnology. It looks at a specific nanoscale material expected to have widespread commercial applications and asks specific questions about a specific health hazard,” says Andrew Maynard, Ph.D., a co-author on the paper and the chief science advisor to the Project on Emerging Nanotechnologies, a partnership between the Woodrow Wilson International Center for Scholars and Pew.
“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.”
A PDF of the paper can be found on the journal’s Web site, www.nature.com/nnano. For more on nanotechnology issues, plus the project’s oversight recommendations for the new administration, go to its Web site, www.nanotechproject.org. Also, see “Managing Safely the Gigantic Future of Very Small Things” in the fall 2007 issue of Trust.
Pew is no longer active in this line of work, but for more information, visit the Project on Emerging Nanotechnologies.