Do Silicon-Oxygen Radicals Play a Role in the Quartz-Induced Hemolysis and Fibrogenicity?
Dalal-NS; Shi-X; Vallyathan-V
NIOSH 1990 Nov:1424-1428
An investigation was conducted to determine whether silicon oxygen radicals have a part in quartz (14808607) induced hemolysis and fibrogenicity. Crystalline quartz particles with a size range of 0.2 to 2.5 millimeters were crushed in air to obtain quartz dust samples with particle sizes smaller than 20 microns. Hemolytic activity of silica was measured as the amount of hemoglobin released from a 2% suspension of sheep erythrocytes after incubation with 10 milligrams of silica (7631869) dust for one hour at 37 degrees-C. Peroxidation of the polyunsaturated lipid linoleic-acid by freshly ground or aged silica was monitored using a fluorescence method. This investigation demonstrated that fracture induced silicon oxygen radicals are not directly involved in the mechanism of the erythrocyte hemolysis by quartz. The authors suggest however that these radicals may be directly or indirectly involved in an oxidative type chain reaction leading to macrophage membrane perturbation through lipid peroxidation and eventual fibrosis.
Airborne-particles; In-vitro-study; Fibrogenesis; Dust-exposure; Mineral-dusts; Lung-irritants; Quartz-dust;
DHHS (NIOSH) Publication No. 90-108
Proceedings of the VIIth International Pneumoconioses Conference