Relation of Particle Size with Toxicity of Calcite Particles

The importance of certain types of nanomaterials and mineral nanoparticles, namely clays and the smallest mineral colloids, has been known for a long time. Mineral nanoparticles also behave differently than larger micro and macroscopic crystals of the same mineral. The variations in chemical properties are most likely due to differences in surface and near surface atomic structure, as well as crystal shape and surface topography as a function of size in this smallest of size regimes. Although most of the nanotoxicological studies were performed using unrealistic exposure conditions. Knowledge about potential human and environmental exposure combined with dose response, toxicity information will be necessary to determine real or perceived risks of nanomaterials following inhalation, oral or dermal routes of exposure. Because the respiratory tract is the major portal of entry for airborne nanoparticles, this exposure route can be used as an example to discuss some key concepts of nanotoxicology, including the significance of dose, dose rate, dose metric and biokinetics