Characterization of biologically available wood combustion particles in cell culture medium

Combustion of wood produces particulate matter (PM) emissions having the potential to induce respiratory tract diseases in humans. To date, however, few, if any, in vitro submerse exposure adverse effect studies characterized the actual particle characteristics within the culture medium. Indeed, the availability of particles and adsorbed toxic compounds in liquids may depend on particle characteristics, i.e. aggregation, size, composition, type (complex solids, salts, etc.) and thus affect toxicity. Using polystyrene nanoparticles as reference, the particle size distribution and aggregation status of wood furnace PM and quartz particles in standard cell culture medium and water was characterized. Characterization was carried out via scanning electron microscopy (SEM), light microscopy, dynamic light scattering (DLS), and laser diffraction. Moreover, the biological availability of particles and adsorbed polycyclic aromatic hydrocarbons was tested using an Ah-receptor reporter gene assay, which demonstrated that particle characterization and knowledge of toxin bioavailability prior to experimentation is key for understanding potential biological interactions.