3. Bio- and ecotoxicology of nanoparticles

3.1 Towards a common frame of reference: the relational object

The relational properties that define nano objects justify both the cognitive interest in them and the risks they raise. The focus on unusual behaviors and surface properties also underpins debates on the toxicology and eco-toxicology of certain nano-objects, notably nanoparticles (a nanoparticle is a small inorganic solid, or the smallest crystal there is; it's an intermediate object between a molecule and a solid). The effect of nanoparticles on human health and the environment depends in particular on their ability to bind selectively to other entities present in their environment. In short, if NSTs are interesting, and if their objects raise very specific toxicological problems, it's because a nano object is defined...