Nanotechnologies - neurotoxic effects of nanomaterials
There are certain concerns regarding the safety for the environment and human health from the use of engineered nanoparticles (ENPs), which leads to unintended exposures, in contrast to the use of ENPs for medical purposes. Animal experiments have shown that investigated ENPs (metallic nanoparticles, quantum dots, carbon nanotubes) can translocate to the brain from different entry points (skin, blood, respiratory pathways).
Source: http://osha.europa.eu/en/news/nanotechnologies-neurotoxic-effects-of-nanomaterials