The safety of emerging inorganic and carbon nanomaterials

Persistent inorganic and carbon nanoparticles are increasingly being engineered for practical application but can be hazardous to humans. A relatively great deal is known about the human health hazards of inhaled nanoparticles, which may give rise to respiratory disease and to negative effects in other organs, including the cardiovascular system. Determinants of inhaled nanoparticle risk and/or hazard are size, surface characteristics, shape, rigidity, structure, and the formation of assemblages. A major molecular mechanism underlying the inhalation hazard of nanoparticles is the generation of reactive oxygen species, but other mechanisms such as the release of toxic substances and interactions with proteins and DNA may also contribute. Human health hazards might be linked to the ingestion of persistent inorganic and carbon nanoparticles after their clearance from the lungs. Hazards and risks to ecosystems are highly uncertain. Options for reducing the human hazard linked to the inhalation of engineered nanomaterials include the elimination and substitution of hazardous nanoparticles and the use of engineering controls.