Carbon nanotube health hazard

Experts are warning of potential health dangers to workers handling carbon nanotubes used in everyday objects from tennis racquets to paint.

Research led by the University of Edinburgh focused on carbon nanotubes - cylindrical molecules that are 1/50,000th as wide as a human hair - which are a key product of nanotechnology industries.

The researchers found that when the carbon nanotube fibres were short they appeared harmless. However, the body’s scavenger cells were unable to deal with the longer fibres, which provoked inflammation and disease in sensitive tissue surrounding organs in the body including the lungs.

The reaction is similar to asbestos, where longer fibres are also more harmful and can cause mesothelioma - a cancer in the tissue that lines the lung.

While there would seem to be little risk to consumers using products containing nanotubes, toxicologists are concerned that there might be a health risk to workers involved in the manufacture of carbon nanotubes and to those who make products containing them.

The study, published in the journal Nature Nanotechnology, follows concerns that carbon nanotubes could pose a health threat due to their similarity in shape to asbestos.

Led by the University of Edinburgh, the research was carried out in collaboration with the Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars in Washington, the Institute of Occupational Medicine, Napier University and the University of Manchester.

The authors urge more research to investigate the potential risks during the manufacture of carbon nanotubes. These would include looking at how long the fibres are, how much is in the air, the likelihood of them being breathed in and the determination of safe exposure levels.

While we have identified a potential hazard, more research is needed to show what, if any, the health risk is. There should be minimal risk in handling items made of carbon nanotubes because the fibres are so embedded. We are more concerned that there may be higher exposure of the workers involved in production of items containing nanotubes. With the global market for carbon nanotubes predicted to exceed £1 billion by 2010 more research is needed.