SPECIAL SELECTED TOPICS- RESPIRATORY SYSTEM DISORDERS-SSTRSDO-QAA 014

1. List the main pneumoconioses.

Pneumoconioses are chronic occupational lung diseases caused by inhalation of inorganic mineral dusts. Coal workers' pneumoconiosis results from prolonged inhalation of coal dust. Silicosis is caused by inhalation of crystalline silica particles.

Asbestosis develops following exposure to asbestos fibers. Berylliosis occurs in workers exposed to beryllium dust. Talcosis results from inhalation of talc particles. Siderosis is caused by iron dust exposure, while stannosis results from tin dust inhalation.

Most pneumoconioses produce chronic pulmonary fibrosis after prolonged exposure. Prevention through workplace safety and dust control is the most effective management strategy.

2. Which factors are associated with the development of pneumoconiosis?

The risk of pneumoconiosis depends primarily on the duration and intensity of dust exposure. The concentration of airborne dust significantly influences disease development. Smaller respirable particles penetrate deeply into the alveoli and are more harmful.

The chemical composition and fibrogenic potential of the dust determine its pathogenicity. Silica and asbestos are highly fibrogenic compared with many other dusts. Individual susceptibility and smoking may worsen pulmonary damage.

Impaired clearance by alveolar macrophages increases dust retention. Occupational safety measures and protective respiratory equipment reduce exposure. Early recognition and removal from exposure help prevent disease progression.

3. How is coal workers' pneumoconiosis classified according to lung findings?

Coal workers' pneumoconiosis is classified into simple and complicated forms. Simple coal workers' pneumoconiosis is characterized by multiple small coal macules and nodules scattered throughout the upper lung zones.

These lesions are usually asymptomatic or cause only mild respiratory impairment. Complicated coal workers' pneumoconiosis, also called progressive massive fibrosis, develops when nodules coalesce into large fibrotic masses.

Extensive fibrosis distorts lung architecture and markedly reduces pulmonary function. Pulmonary hypertension and respiratory failure may develop in advanced disease. The risk increases with prolonged coal dust exposure.

Smoking further aggravates respiratory disability. Progressive massive fibrosis is irreversible and associated with poor prognosis.

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DR.C.GANESAN M.D

PROFESSOR OF MEDICINE