In vitro determinants of particulate toxicity: the dose metric for poorly soluble dusts.

Rats exposed to high airborne mass concentrations of low toxicity poorly soluble particles (LTPSP) have developed lung disease such as fibrosis and lung cancer. These particles are regulated on a mass basis in occupational settings. However, animal studies have shown ultrafine particles producing stronger inflammatory effect than fine particles per unit mass. This study investigates whether the surface area of an LTPSP is a better dose metric than mass (or volume) for describing the particles’ ability to induce pro-inflammatory effects in vitro. Additionally it was hoped that the developed in vitro approach would become a reliable means of screening the toxicity of particles with the advantages of being less expensive and more ethical than animal testing.