Coal dust is the causative agent. Long term exposure to coal dust causes scarring of the lung tissue. This condition is also called black lung.
Inhalation of the coal dust causes irritation of the lung tissue. Dust particles less than 5 microns usually reach the lung tissue. This initiates an inflammatory process in the lung tissue which progresses to scarring and fibrosis. Prolonged exposure leads to heavy scarring of the lung and makes breathing and air exchange difficult.
Beginning stages are asymptomatic but as the disease progresses, patients may experience cough, with black sputum, difficulty in breathing, and recurrent bronchial and pulmonary infection. Chest tightness may also be seen.
Examination of the chest wall may show barrel chest. Decreased breath sounds will be heard in affected areas, as well as wheezes. Chest x-ray may show nodules 1-5cm, or cavities, irregular opacities, interstitial densities and honey combing. Pulmonary function tests may show decreased vital capacity, decreased total lung capacity, decreased FEV1, and decreased carbon monoxide diffusion. Arterial blood gases may show increased carbon dioxide.
Avoid re-exposure, which will stop progression of disease. Bronchodilators and oxygen therapy may help symptoms. Chest physiotherapy may help clear secretions.
Face mask should be used to prevent dust inhalation. Yearly chest x-ray of workers may help early detection.
Fibrosis, respiratory failure and right heart failure.