A major study published in Nature Nanotechnology in May 2008 suggested some forms of carbon nanotubes could be as harmful as asbestos if inhaled in sufficient quantities. ... The study shows there is strong evidence that if carbon nanotubes get into the wrong place, they can cause mesothelioma.

What are the negatives of nanotechnology?

Disadvantages include: Potential dangers to humans and the environment. Loss of manufacturing and agricultural jobs. Economic market crashes related to a potential lower value of oil due to more efficient energy sources and gold or diamonds, materials that can be reproduced with molecular manipulation.

Will nanotechnology have unexpected effects?

Nanotechnology has direct beneficial applications for medicine and the environment, but like all technologies it may have unintended effects that can adversely impact the environment, both within the human body and within the natural ecosystem.