Assessing health risks of inhaled nanomaterials: development of pulmonary bioassay hazard studies

This brief discussion provides an overview of current concepts and perceptions regarding the pulmonary toxicity of ultrafine or nanoparticles. These aspects include, but are not limited to comparisons of fine particle vs. ultrafine particle effects and the unique response of pulmonary effects in rats vs. other rodent species, particularly at particle overload concentrations. In the final section, two studies are described which demonstrate that particle size is not the most significant particulate factor in producing exposure-related pulmonary effects.