the dust which is stirred and beaten up by digging penetrates into the windpipe and lungs and produces difficulty in breathing. (Agricola, 1556)
Crystalline silica (silicon dioxide) has long been recognized as an occupational hazard. The Occupational Safety and Health Administration (OSHA) estimated in 2003 that over 2 million workers were potentially exposed to crystalline silica dust in general industry, construction and maritime industries. Based on OSHA compliance inspection data, Yassin et al estimated that about 119,000 of such workers were exposed. Inhalation of crystalline silica can cause silicosis, a preventable but incurable type of lung fibrosis. At current U.S. levels of exposure, chronic inhalation generally takes a decade or longer to cause disease. However, high levels of exposure can cause disease more quickly. Severe cases can be disabling or even fatal. Breathing silica dust is also associated with tuberculosis, lung cancer, and chronic obstructive pulmonary disease (COPD). Exposure to silica dust may also cause various autoimmune diseases and chronic renal (kidney) disease.
