Silica dust is common in worksites, can scar the lungs and cause cancer. Symptoms sometimes don't appear for 10 years. / / The source of silica dust is the element silicon, which is common in quartz and other rocks. The rocks themselves aren't a danger, but when crunched into dust, scarred lungs and cancer can result from silicosis. / / Workers sandblasting, tunneling, or using concrete or mortar are at risk. / / Silicosis may take up to 10 years to show symptoms of chronic coughing and other breathing issues. There is no cure. / / Protect workers from silica dust with industrial hygiene planning, appropriate PPE, and by using other materials, if available.