Prevalence of bronchitis and airway obstruction in American bituminous coal miners.

Abstract

As part of an epidemiologic study, 8,555 bituminous coal miners underwent a limited medical examination consisting of spirometry, a posteroanterior radiograph of the chest, and a respiratory questionnaire. The relationship of bronchitis and airway obstruction to dust exposure and cigarette smoking was determined. The prevalence of bronchitis was significantly higher in smoking miners than in their nonsmoking or exsmoking co-workers. Surface workers had less bronchitis than face workers, reflecting their lower dust exposure. This difference was statistically significant only for nonsmokers and exsmokers. Measurements of the ratio of 1-second forced expiratory volume to forced vital capacity were less than predicted in 37.6 per cent of nonsmokers, 50.5 per cent of exsmokers, and 58.8 per cent of smoking miners. Airway obstruction occurred in surface workers less frequently than in face workers. When the difference between smoking face workers and nonsmoking surface workers was analyzed, the effect of smokin...