Toxic effects of nanoparticles and nanomaterials: Implications for public health, risk assessment and the public perception of nanotechnology

Nanomaterials are now being manufactured and used in many products. However, our knowledge of the human health effects and environmental concentrations of engineered nanomaterials or nanoparticles is incomplete. This article gives a toxicologists perspective, outlining possible routes of uptake by humans, environmental concentrations, known or suspected toxic effects, and the practical implication for human health risk assessments and public perception. Humans are already exposed to a range of natural and man-made nanoparticles in the air, and exposure via the food chain, water supply, and medical applications is likely. Toxicology studies on animals, and cells in vitro, raise the possibility of adverse effects on the immune system, oxidative stress related disorders, lung disease and inflammation. However, the doses needed to produce these effects are generally high and it remains to be seen if such exposure is possible via the environment or the work place. Data on exposure is also needed for risk calculations. Current legislation does not specifically address nanoparticles or nanomaterials, and there are concerns about nomenclature, defining nanomaterials as new substance under chemicals regulations such as REACH, and the appropriateness of current test methods.