Asbestos, above, has been linked to diseases, including a type of cancer called mesothelioma. New research suggests that one type of carbon nanotube could be similarly dangerous to health.
Tiny tubes made of carbon atoms have been the poster child for nanotechnology, promising to revolutionize all kinds of industries. But a new study in mice suggests that at least one kind of carbon nanotube could potentially be as harmful as asbestos.
"This study clearly shows that there is a possibility of danger here," says Andrew Maynard, who works on the Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars in Washington, D.C.
Maynard says that while carbon nanotubes can look like a "light, fluffy black powder" to the naked eye, under a powerful microscope they are revealed to be "anything from what looks like a very open spider's web to a tangled ball of wool to very, very long, straight, thin fibers."
Some scientists have wondered if long, thin nanotubes could act like fibers of asbestos, the mineral that used to be found in everything from car brakes to insulation until it was linked to diseases, including a type of cancer called mesothelioma.
So in this new study, scientists injected different kinds of carbon nanotubes into the bellies of mice, to see if the fibers would create biological changes that could lead to mesothelioma.
They found that long, thin, multiwalled carbon nanotubes that looked like asbestos fibers would produce changes similar to those created by asbestos. But short or curly nanotubes did not.
Preparing in Advance
Maynard and his colleagues published the finding this week in the journal Nature Nanotechnology, and it has been getting some attention.
Vicki Colvin, a chemist at Rice University in Houston who works on nanomaterials, was a bit concerned when she first heard about the study. "It made me pensive because of the potential cause for alarm that people could have, seeing asbestos connected in some way to a nanomaterial," she says.
Colvin says it's important to remember that this is just one preliminary study showing that one particular nanomaterial had this effect. Since the experiment was on mice, it's also unclear what it will mean for people.
Unlike with asbestos, research into nanotechnology's potential health impacts is coming long before the materials are in widespread use. So scientists can test theories to help them predict which properties of nanomaterials could pose dangers.
While all that testing is going on, nanotube manufacturers can take steps to protect workers who might come into contact with the stuff. Currently, exposure is mostly limited to people involved in making and testing nanomaterials in corporate or academic labs.
"Workers are essentially the first people in society to be exposed to new technologies, and nanotechnology is no exception," says Paul Schulte, who works on nanotechnology with the National Institute for Occupational Safety and Health.
The institute has already made some recommendations about safety equipment and best handling practices for industry.
Many Questions Remain
Still, Schulte says, there's a long list of open questions about nanomaterials: How can they enter the body? Once they're inside, where do they go and what do they do? How can scientists measure people's exposure?
He says his agency is currently able to spend only a few million dollars a year trying to answer those questions. "That money is just a drop in the bucket to address all that," he says.
And that money is just a small fraction of the billions of dollars that the federal government has invested in developing nanotechnology over the past few years. But Congress may soon be making some changes. It's considering legislation that would require the government to make health and safety research more of a priority.