Battlefield relics dug up: Big collection of German helmets
Hello, Sign in. Account & Lists Sign in Account & Lists Returns & Orders. Try Prime Cart Cart Oct 18, 2011· During construction soil, granite, and concrete will be dug, drilled crushed, impacted, abraded. Soil, granite, and concrete contain crystalline silica (sand). Occupational exposure to silica produces silicosis, a chronic, disabling lung disease characterized by nodules of scar tissue in the lungs.