Studies on the cytotoxicity of ceramic respirable dusts using in vitro and in vivo test systems

The effect of a number of ceramic raw materials and airborne samples in workplaces has been investigated in vitro [erythrocyte haemolysis, macrophage TTC (2,3,5-triphenyl-tetrazolium chloride) reduction and LDH (lactate dehydrogenase) activity] and in vivo (protein, LDH and phospholipid in cell-free bronchopulmonary lavage). In the in vitro experiments described we were able to distinguish between the dusts causing different types of reaction in the lung. Dusts classified as 'quartz type' in vitro were also cytotoxic in vivo. Dusts have also been divided into three groups according to their degree of hazardous nature, taking into consideration the time before an inflammatory reaction is detected and the degree of inflammatory response as characterized by biochemical parameters. One feature of the test systems which is of practical significance is that in vitro experiments require only 15 mg of dust, and in vivo experiments only 100 mg.