Carbon Nanotubes May Be as Harmful as Asbestos

Carbon nanotubes, one of the most promising materials for the future of technology, could be as harmful as asbestos if inhaled, claims a new study.

Researchers at the University of Edinburgh (United Kingdom) and other institutions examined the potential for long and short carbon nanotubes, long and short asbestos fibers, and carbon black to cause pathological responses known to be precursors of mesothelioma. The materials were injected into the abdominal cavity of mice--a sensitive predictor of long fiber response in the lung lining. After one week, there was an inflammatory response to long multiwalled carbon nanotubes, which resulted in asbestos-like, length-dependent, pathogenic behavior. This behavior included inflammation and the formation of soft-tissue lesions known as granulomas. The study was published early online on May 20, 2008, in Nature Nanotechnology.

"This study is exactly the kind of strategic, highly focused research needed to ensure the safe and responsible development of nanotechnology,” said co-author Andrew Maynard, Ph.D., chief science advisor to the U.S. federal project on emerging nanotechnologies (Washington, DC., USA). "It looks at a specific nanoscale material expected to have widespread commercial applications and asks specific questions about a specific health hazard. Even though scientists have been raising concerns about the safety of long, thin, carbon nanotubes for over a decade, none of the research needs in the current U.S. federal nanotechnology environment, health and safety risk research strategy address this question.”

"Short or curly carbon nanotubes did not behave like asbestos, and by knowing the possible dangers of long, thin carbon nanotubes, we can work to control them,” said lead author Professor Kenneth Donaldson, B.Sc., Ph.D., D.Sc., of the University of Edinburgh. "It's a good news story, not a bad one. It shows that carbon nanotubes and their products could be made to be safe.”

Carbon nanotubes are atom-thick sheets of graphite formed into cylinders, 10,000 times thinner than a human hair. As light as plastic and stronger that steel, they are being developed for use in new drugs, energy-efficient batteries, and futuristic electronics. While the diameter of a nanotube can vary from a few nanometers up to tens of nanometers, they can be hundreds or even thousands of nanometers long. Carbon 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.


Related Links:
University of Edinburgh
Project on emerging nanotechnologies