What disease results from massive carbon dust exposure in coal miners, leading to diffuse pulmonary fibrosis?

• A. Coal workers' pneumoconiosis
• B. Silicosis
• C. Anthracosis
• D. Asbestosis

Answer: (A)

Coal workers' pneumoconiosis, also known as black lung disease, results from inhalation of coal dust. When miners breathe in large amounts of carbon-laden particles, alveolar macrophages engulf the dust and release fibrogenic mediators. This drives a fibrotic response in the lung interstitium, starting with small, scattered fibrotic nodules and often progressing to large, confluent fibrotic masses—progressive massive fibrosis. The carbon pigment deposition by itself (anthracosis) can occur without significant fibrosis, so not all carbon deposition leads to diffuse scarring. Other pneumoconioses have different causative dusts and patterns: silica exposure tends to produce nodular fibrosis with a stronger inflammatory reaction and sometimes calcifications, while asbestos exposure causes interstitial fibrosis commonly in the lower lobes with pleural changes and carries a higher risk of mesothelioma. The description of diffuse fibrosis from massive coal dust exposure best fits coal workers' pneumoconiosis.