Respiratory disease in Utah coal miners.

Two hundred forty-two Utah underground coal miners volunteered to participate in a respiratory disease study. They were an older group (mean, 56 years of age) and had spent a mean of 29 years in the coal-mining industry. The prevalence of chronic bronchitis was 57%, and that of coal worker's pneumoconiosis, 25%; only one worker had progressive massive fibrosis. Significant impairment of pulmonary function was found among those with a history of cigarette smoking. Chronic bronchitis or coal worker's penumoconiosis among nonsmokers did not impair pulmonary function. There was a significant association among the nonsmokers between increasing exposure to coal dust and coal worker's pneumoconiosis, but not for changes in pulmonary function. Coal mine dust had a significant influence in causing the symptom complex of chronic cough and sputum production, and coal worker's pneumoconiosis.