[Health risks of engineered nanomaterials and nanotechnologies].

Manufactured nanomaterials enable the promotion of nanotechnologies, i.e. the use of matter at nanoscale, and several revolutionary industrial and consumer applications. Nanomaterials have at least one dimension between 1 and 100 nm. Some of them may induce toxic effects in humans, even though most of the particles are most likely harmless, but the identification of harmful materials is challenging. The number of workers exposed to nanomaterials is reaching millions, and those of consumers hundreds of millions. Toxic effects of some of these materials include pulmonary inflammation, cardiovascular and cerebral toxicity as well as genotoxicity and cancer. Limited knowledge, and associated remarkable uncertainty, on the toxicity of, and exposure to nanomaterials renders their reliable risk assessment problematic. A major challenge today is to assure safe use of these nanomaterials.