silicosis

Silicosis is an occupational lung disease caused by inhaling crystalline silica dust. It leads to lung fibrosis and impaired gas exchange. It most often affects workers in mining, quarrying, sandblasting, stone cutting, and related industries. Silicosis is classified by exposure pattern into chronic (long-term, low-level), accelerated (intermediate exposure), and acute (massive exposure within weeks to months).

Inhaled silica particles are deposited in the airways and alveoli. Alveolar macrophages try to engulf them but are damaged, releasing inflammatory mediators that recruit cells and promote fibrosis. Nodules form, usually in the upper lungs, which may coalesce into progressive massive fibrosis. Silica exposure also increases susceptibility to tuberculosis and other infections.

Symptoms include shortness of breath on exertion, cough, and fatigue, but early disease may be asymptomatic. Chest radiographs show nodular opacities in the upper lungs; CT is more sensitive. Pulmonary function tests frequently show a restrictive pattern with reduced diffusion. Diagnosis relies on exposure history, imaging, and exclusion of other causes, with testing for active tuberculosis as indicated.

There is no cure for silicosis. Prevention focuses on reducing silica exposure through dust controls, ventilation, wet work methods, and personal protective equipment. Regular medical surveillance and vaccination are recommended. Management targets symptoms and complications: supplemental oxygen, pulmonary rehabilitation, bronchodilators, and treatment of tuberculosis or infections. In advanced disease, lung transplantation may be considered.

Prognosis depends on exposure level and progression; acute forms can be rapidly fatal, while chronic silicosis often progresses slowly. It increases the risk of tuberculosis and respiratory failure. Globally, silicosis remains a major occupational health problem in mining, construction, stone processing, and sandblasting, though regulation and protective measures have reduced incidence in many settings.