[header] How to reduce silica exposure [title] Consider silica substitutes. [step] Most harmful exposure to inhaled silica comes from chipping, grinding, cutting, cleaning, or otherwise disrupting materials like concrete or glass that contain silica. Abrasive blasting (" sandblasting ") to remove paint, rust, etc. 
Is perhaps the most likely source, as the blasting material itself is often primarily silica. [substeps] When possible, consider using materials that don't contain silica for industrial applications.