Carbon Nanotubes May Cause Same Diseases as Asbestos Does
The nanotechnology industry creates extremely small particles of different substances, such as carbon, for various uses. These particles are called nanoparticles when they are less than 100 nanometers in size. For comparison, a human hair is about 100,000 nanometers in diameter, so it would take 1000 nanoparticles to equal the thickness of one hair.
Research indicates that some nanoparticles may pose an environmental or health risk, depending on composition, size, shape, and use. The extent of this risk is not yet known, nor have scientists yet been able to clarify exactly which nanoparticles pose significant concern. However, carbon nanotubes (a type of fullerene) are of particular interest because they are similar in size and shape to asbestos fibers.
Carbon nanotubes are a type of fullerene created in tube-like shapes. They have high aspect ratios and are only nanometers in diameter but sometimes microns (one millionth of a meter) long. Usually carbon nanotubes are affixed to a substrate; however, future applications may include use nanotubes in unbound applications. Scientists recently developed the ability to spin carbon nanotubes into a thread-like substance.
A study by the University of Edinburgh found carbon nanotubes may cause mesothelioma-like cancers. According to the University’s Kenneth Donaldson, “Long, thin carbon nanotubes showed the same effects as long, thin asbestos fibers." In the research protocol, both carbon nanotubes and asbestos fibers were injected into the abdominal cavity of mice, a technique that is accepted in medical circles as a predictor of how pathogens affect lung tissue. The results showed that like asbestos, long nanotube fibers were thin enough to penetrate deep into lungs, but their length prevented the lungs' built-in mechanisms from removing the particles. Donaldson also said, "If nanotubes get into the lungs in sufficient quantity, there is a chance that some people will develop cancer—perhaps decades after breathing it."
Millions of dollars has been spent by the National Science Foundation's (NSF) National Nanotechnology Initiative for development of nanotechnology. Only a small percentage has thus far been spent on safety issues. Health experts are calling for more spending on the safety issues involved with these and other new materials.
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