Study of the effect of agglomeration on the respiratory toxicological properties and the toxicokinetics of inhaled nanoparticles of titanium dioxide in rats

Due to the growing use of nanoparticles in industrial processes, the number of workers potentially exposed is increasing while the toxicological properties of these compounds are not fully known. Since these particles can be aerosolised, the major route for occupational exposure is inhalation, and the first organs to be exposed are those from the respiratory system. The studies published so far regarding operations using nanomaterials in powder form indicate that the aerosols to which operators are potentially exposed are, to a very large extent, made of particles in aggregated or agglomerated form. But, since it cannot be excluded that mechanical processes may lead to the generation of an aerosol with a size distribution different from that obtained when handling the original powder, it is interesting to know whether two aerosols having different size distribution but obtained from the same nanopowder sample can have distinct toxicological properties in terms of inflammatory response and pulmonary biopersistence or toxicokinetics.

In order to study the toxicological properties of such aerosols with distinct size distribution, we will develop an experimental system in order to expose laboratory animals to aerosols obtained from manufactured nanoparticles. Prior to animal exposure and toxicological evaluation, a development phase meant to 1) prepare particle samples giving aerosols with a specified particle distribution and 2) set up tools for generating and characterizing aerosols for animal exposure, will be required.

This work will be disseminated through presentations at conferences and at least one publication in a peer-reviewed international scientific journal.