Scientific researchers have demonstrated that some carbon nanotubes have the potential to be as dangerous as asbestos: They are similar in shape to asbestos fibers and can cause the same type of damage to the lining of the lung cavity, possibly resulting in future lung disease and cancer. But what exactly are carbon nanotubes, and how far-reaching are the implications of this research?
Carbon nanotubes are tiny structures, formed into cylinders, and generally made from sheets of graphite that are about the same thickness as an atom. These structures are so small, they measure roughly one billionth of a meter (one nanometer) in width. But despite their small size, they are also incredibly strong, and carbon nanotubes are seen as a material with huge potential in the future of technology. Today, they are generally used to reinforce plastics, and are found in tennis rackets, bicycle frames and airplanes. Predicted uses in the future range from use in electronics (they act as both conductors and semi-conductors) to the delivery of drugs.
However, since 2003 scientists have been warning about the potential dangers of carbon nanotubes: The microscopic structures bear a close resemblance to asbestos fibers, which, when inhaled, cause lung disease and a cancer known as mesothelioma. The serious health consequences of occupational exposure to asbestos fibers were only discovered decades after the fact, and researchers are keen to ensure that the same negative consequences are not a risk to those working with carbon nanotubes today.
To investigate the potential harm from carbon nanotubes, researchers examined the impact of carbon nanotubes on mice. In this study, the lining of the body cavity of mice was used as a proxy for that of the chest cavity. Results of experiments showed that exposure to carbon nanotubes caused inflammation of the lining and led to the formation of lesions. These were early warning signs that carbon nanotubes could indeed be as dangerous as asbestos fibers if they were inhaled into the lungs. Subsequent results from inhalation studies indicate that carbon nanotube inhalation can result in inflammation and in growth of fibres, although the full extent of danger is not yet clear. Because the full implications of much of this research have not been established, researchers have urged that a cautious approach be taken when dealing with these materials.
The implications of this research are far-reaching, since businesses and research centers have invested heavily in carbon nanotube technology under the assumption that the materials are no more harmful than graphite. However, the results of the medical research were not intended to halt the development of new products and technologies based on carbon nanotubes, but instead to highlight the potential dangers for people working in their development, and to ensure that safeguards are implemented to mitigate against potential health risks in the future. The risks of working with carbon nanotubes, as identified to date, are seen as manageable: Technology companies continue to invest in research, and in production of goods that contain carbon nanotubes, but are now doing so in the knowledge that precautions to protect both workers and consumers need to be taken in order to continue their technological developments.