Freshly fractured silica exerts greater toxicity to lung macrophages than aged dust: organosilane (prosil 28) coating markedly reduces dust toxicity to cells.
Vallyathan-V; Kang-JH; Dyke-K; Dalal-NS; Castranova-V
Respirable dust in the mineral industries, proceedings of the 3rd symposium on respirable dust in the mineral industries, October 17-19, 1990, Pittsburgh, Pennsylvania. Frantz RL, Ramani RV, eds. Littleton, CO: Society for Mining, Metallurgy, and Exploration, Inc., 1991 Jan; :117-119
Based on the finding that freshly ground silica (14808607)is more cytotoxic to and a more potent activator of alveolar macrophages than aged silica, additional work was done to examine the protective effect of Prosil-28 (81138650) on silica toxicity. The cytotoxic effects were determined by monitoring the silica induced decline in membrane integrity of alveolar macrophages. Both freshly ground and aged ground silica caused dose dependent membrane damage over the 2 week study. Viability after treatment with the fresh silica was 41%+/-9% of control levels compared to 83%+/-1% of control levels following treatment with aged silica. Both silica samples caused significant activation of hydrogen-peroxide secretion, but the fresh was 50% more potent in this regard. The ability of ground silica to induce chemiluminescence generation from alveolar macrophages quickly declined with storage. Silica stored for 1 or 2 days was only 39% or 18%, respectively, as great at stimulating alveolar macrophages than was the fresh silica. Coating freshly ground silica with Prosil-28 effectively prevented the cytotoxicity of the dust. Coating caused a 75% decline in the ability of silica to lyse red blood cells, causes protection of viable alveolar macrophages assayed by propidium fluorescence, and decreased the degree of silica induced chemiluminescence.
Mining-industry; Dust-exposure; Dust-inhalation; Respiratory-system-disorders; Silica-dusts; Coal-dust; Airborne-dusts; Coatings
V. Vallyathan, Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, WV 26505
Respirable dust in the mineral industries, proceedings of the 3rd symposium on respirable dust in the mineral industries, October 17-19, 1990, Pittsburgh, Pennsylvania
West Virginia University