They have been hailed as one of the greatest inventions of the late 20th century but like a previous miracle substance, asbestos, carbon nanotubes may turn out to be incredibly deadly when inhaled.
A recent study at the University of Edinburgh showed that the long, ultra-thin fibers created through nanotechnology could cause the same health problems as asbestos, and for similar reasons. Professor Kenneth Donaldson of the University of Edinburgh said that long, thin carbon nanotubes showed the same effects as long, thin asbestos fibersand, when injected into mice, caused the same immune system response that is known to be a precursor to cancer and mesothelioma. Short nanotubes (much like short asbestos fibers) did not cause the effect, as the human (and mouse) body is capable of flushing them out.
Long, thin fibers have the ability to penetrate deeply into the tissues surrounding the lungs, and are too long and tough for the bodys immune response to destroy. The persistent attempt by the immune system to destroy the fiber is thought to be a direct cause of scarring in the tissues surrounding the fiber, which eventually leads to cancer such as mesothelioma. Like asbestos fibers, carbon nanotubes are generally much longer than they are wide, with aspect ratios (the ratio of the tubes length to its diameter) of more than 1000 to 1, or even one million to one. When used in electronic devices, nanotubes are generally safely attached to the circuitry, but if they are used in other industries it could lead to devastating health consequences if the long, tough tubes enter the water or air and are breathed in.
Carbon nanotubes were first created in the 1950s by Soviet researchers, but the exorbitant cost and difficulty of their manufacture meant they were purely a scientific curiosity. Even as late as 2000, it cost more than $2000 for a single gram of nanotubes. However, that cost has spiraled downwards and in late 2007 a gram of simple nanotubes could be purchased for as little as $50. As costs continue to drop and the potential uses of nanotubes become more widespread, it is likely that health consequences from nanotubes exposure could become severe. Fortunately, unlike the case of asbestos, modern workers with nanotubes will have access to significantly more information about the potential health risks, and regulatory agencies are already in place to ensure the health of workers dealing with these amazing but potentially deadly objects.