I’ve posted previously about the potential biological hazards of nanotechnology and how little is understood about the possible dangers that could result from indiscriminate use of this technology.
Now there is evidence that long, straight nanowires can cause mesothelioma exactly in the same way that asbestos fibers do. Nanotubes in other form factors do not seem to pose the same threat, so clearly there is something about the physical properties of the nanowires and not some underlying molecular-level chemical reaction, but this should put the brakes on a lot of R&D work trying to commercialize nanotube-based innovations while studies are done to determine what sort of exposure risk there really is. In the case of asbestos, natural degradation of asbestos-containing materials over time caused the release of fibers, and the widespread use of asbestos in insulating and fire-proofing materials made the risk of exposure very high. It may be possible that the ways in which long, straight nanotubes could be applied could be restricted to uses which reduced the likelihood of exposure. With asbestos, even a single inhaled fiber is sufficient to cause mesothelioma, so total prevention is impossible. I presume much the same will be true of nanotubes.
