Peter S Thorne

Manufactured nanomaterials are in more than 1000 consumer products that contain some nanotechnology‐based material on the market today. In the last five years there has been much effort put toward understanding the health effects associated with nanoparticle exposure. Toxicity assessment plays a significant role in this effort since human exposure can occur during production processes, handling, as well as their use and application. Although, though there is a large body of literature on “ultrafine particles” from a pulmonary exposure assessment, one should proceed with caution to expand this information to nanomaterials as we are still just at the beginning stages of their toxicity assessment. In this chapter, we consider the respiratory system as the main route of exposure to nanoparticles and we focus our attention mainly on metal‐based nanomaterials and
in vivo
models used to evaluate them. We also discuss available data for other materials, since similar material properties whether size, shape, or chemical composition could lead to comparable toxicities and this will help in the development of screening strategies for nanomaterials that are very much warranted at this time.