Inhalation of crystalline silica is classically associated with which disease?

• A. Asbestosis
• B. Silicosis
• C. Berylliosis
• D. Coal Workers' Pneumoconiosis

Answer: (B)

Inhalation of crystalline silica leads to silicosis, a pneumoconiosis characterized by fibrotic nodules, usually in the upper lung zones. The silica particles are taken up by alveolar macrophages, triggering a cascade of inflammation and collagen deposition that forms nodules and can progress to fibrosis. A classic radiographic sign is nodular opacities with eggshell calcifications of the hilar lymph nodes. Silica exposure also impairs macrophage function, increasing susceptibility to tuberculosis. Silicosis can present in acute, accelerated, or chronic forms depending on exposure intensity and duration. By contrast, asbestos exposure causes pleural plaques with lower-lobe fibrosis, beryllium exposure causes noncaseating granulomas, and coal dust causes coal workers’ pneumoconiosis with coal macules and possible progressive massive fibrosis.