Role of nitrosation in the mutagenic activity of coal dust: A postulation for gastric carcinogenesis in coal miners.
Whong-Z; Long-R; Ames-RG; Ong-M
Environ Res 1983 Jan; 32(3):298-304
The mutagenicity of coal dust solvent extracts with and without nitrosation was studied using the Salmonella and microsome assay system. Three strains (TA-1535, TA-98, and TA-100) of Salmonella- typhimurium were used in the study. Seven coal dust samples were extracted with 250 milliliters (ml) of dichloromethane (DCM) for 16 hours at room temperature by vigorous shaking in a rotary shaker. DCM extraction was collected by filtration. Coal dust residue was extracted a second time with 250ml of 1:1 mixture of methanol plus acetone. Before nitrosation, equal amounts of DCM extract from the same coal dust sample were mixed. Solutions were either used immediately for mutagenicity testing or kept at -20 degrees-C until used. With tester TA-98, mutagenic activity was observed for nitrosated extracts from lignite and sub-bituminous and bituminous coal dusts. Of nitrosated extracts, sub-bituminous coal had the greatest mutagenic potency, followed by bituminous coal and lignite. Both nitrosated polar and nonpolar extracts showed similar mutagenic potency. The authors conclude that simultaneous ingestion of coal dust from lung clearance and nitrite from saliva could result in nitrosation and production of mutagenic and carcinogenic materials in the acidic condition of the stomach.
NIOSH-Author; Medical-research; Carcinogenicity; Comparative-toxicology; Cytotoxic-effects; Synergism; Biological-effects; Mutagenicity; Stomach-cancer; Coal-dust
Mixed Exposures; Work Environment and Workforce