Nanoparticles

Additional factors, however, such as species differences, particle aggregation/disaggregation potential, and surface coatings may be important variables in influencing toxicity.Some of these issues are raised in this article and some of our preliminary pulmonary bioassay findings with nanoquartz and nanoscale titanium dioxide dots and rods challenge the currently held conventional wisdom.Indeed, it seems likely that, as the results of newly-generated nanoparticulate toxicity studies are reported in the scientific literature, we will find the issue of nanoparticle toxicity is more complicated than previously thought.Few data exist regarding the health and environmental effects of engineered nanoparticles, yet some organizations are calling for bans or moratoriums on the research, development, and sales of these systems.So, why the intense focus now on this issue? The rat modelThe current interest may relate, in part, to the fact that, in the few pulmonary toxicology studies conducted thus far, ultrafine or nanoparticles (defined as <100 nm, see also Table 1) are reported to produce enhanced levels of lung inflammation, fibrosis, and tumor responses when compared with fine-sized particles (size range >100 nm to 3 µm) of similar or identical composition [1][2][3][4] .It is important to note that the total lung toxicity database for comparing the effects of ultrafine or nanoparticles versus fine-sized particles consists primarily of studies on three particle-types: titanium dioxide (TiO 2 ), carbon by