Understanding risk assessment of nanotechnology

Article commissioned by the National Nanotechnology Coordination Office giving a background for understanding the risk assessment of nanotechnology. The article sketches the essential basics of physics and biology of nanomaterials and explains the possible implications these unique properties may have for toxicology and the risk of human exposure. Finally the author suggests some questions and things to consider when reading reports of the toxicology of nanotechnology, such as looking for other possible reason for toxicity, refraining from generalizing results from one study to another, and looking for qualifiers such as "preliminary" and "this particular material."