title: Fiber contamination of vermiculites: a potential occupational and environmental health hazard.
abstract: Vermiculite ores from Montana, Virginia, and South Africa have been analyzed for the presence of amphibole contamination. Fibrous actinolite was found in unexpanded Montana vermiculite ore at a maximum concentration of 2.0%. The fibers persisted in the expanded ore at a maximum concentration of 0.6%. Actinolite was also found in the Virginia vermiculite ore but at a lower concentration and mostly as cleavage fragments with low length-to-width ratios. South African ore contained rare anthophyllite fibers also with low length-to-width ratios. Vermiculite ores have the potential for amphibole contamination and can represent potential health hazards without proper occupational and environmental control measures.
mesh_terms: D000538:Aluminum Silicates / Q000009:adverse effects / Q000032:analysis*; D017636:Asbestos, Amphibole; D004782:Environmental Health; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009787:Occupational Medicine; D012822:Silicon Dioxide / Q000032:analysis*; D014961:X-Ray Diffraction
chemical_list: D000538:Aluminum Silicates; D017636:Asbestos, Amphibole; C003760:vermiculite; D012822:Silicon Dioxide