silicosis

silicosis (sĭlĭkō`sĭs), occupational disease of the lungs caused by inhalation of free silica (quartz) dust over a prolonged period of time. Free silica is dispersed in the air and inhaled by workers engaged in the mining of lead, hard coal, and gold, in cutting sandstone and granite, in sandblasting, and in the manufacture of silica abrasives. The irritative action of the silica in the lung results in the formation of nodular lesions; these may coalesce and form massive areas of fibrous tissue. In advanced cases patients experience difficult breathing, coughing with sputum, chest pain, and a tendency to develop tuberculosis or repeated attacks of pneumonia. Once fibrosis has developed there is no cure, and treatment is directed at the management of symptoms. Preventive measures adopted in industries where the hazard of silicosis exists have greatly reduced its incidence.

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silicosis

Common pneumoconiosis caused by long-term inhalation of silica mineral dust. Known since the 18th century, it usually occurs after 10–20 years of exposure in jobs such as mining, stonecutting, grinding, or polishing. The smallest particles do the most damage, killing macrophages (see reticuloendothelial system) that engulf them in the pulmonary alveoli. Dead cells accumulate, forming fibrous masses that reduce lung elasticity. Decreased lung volume and poor gas exchange lead to shortness of breath and then to coughing, difficulty in breathing, and weakness. Patients are vulnerable to tuberculosis, emphysema, and pneumonia. In the absence of effective treatment, control of silicosis depends on prevention with face masks, proper ventilation, and X-ray monitoring of workers' lungs.

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silicosis

Pathol a form of pneumoconiosis caused by breathing in tiny particles of silica, quartz, or slate, and characterized by shortness of breath and fibrotic changes in the tissues of the lungs