Nanobots are decades away and may stay that way, but nanotubes are mass-produced and pollution is a problem. The thin fiber is like asbestos except more volatil

Nanobots are decades away and may stay that way, but nanotubes are mass-produced and pollution is a problem. The thin fiber is like asbestos except more volatile, and it can cause cancer. http://www.particleandfibretoxicology.com/content/11/1/59 http://www.particleandfibretoxicology.com/content/11/1/59