关键词：大气；空气污染；环境保护
摘 要：Workplace exposure to respirable crystalline silica can cause silicosis, a progressive lung disease marked by scarring and thickening of the lung tissue. Quartz is the most common form of crystalline silica. Crystalline silica is found in several construction materials, such as brick, block, mortar and concrete. Construction tasks that cut, break, grind, abrade, or drill those materials have been associated with overexposure to dust containing respirable crystalline silica. Fiber-cement products can contain as much as 50% crystalline silica, and cutting this material has been shown to cause excessive exposures to respirable crystalline silica. NIOSH scientists are conducting a study to develop engineering control recommendations for respirable crystalline silica from cutting fiber-cement siding. This site visit was part of that study.