Pulmonary function loss associated with recent and past coal mine dust exposure.
Am J Epidemiol 1997 Jun; 145(11)(Suppl):S62
The purpose of this study was to determine if work with lower intensity dust exposure helped to slow the loss of lung function among experienced coal miners. Each of the 1829 white male subjects had participated in the National Study of Coal Workers' Pneumoconiosis and completed spirometry at two surveys an average of 15.1 years apart. They were experienced miners who came to their first survey with an average of 10.8 years mining and a mean cumulative coal mine dust exposure of 38.0 milligrams (mg)-year/cubic meter (m3). Least squares linear regression was used to model change in forced expiratory volume in one second (FEV I) from the first to the last survey. There was a statistically significant decline in FEV I associated with coal mine dust exposure accumulated by the first survey (-0.9 m1 per mg-yr/m3, 95% CI -1.7, -0.2). Estimated dust concentrations during the inter-survey period were < / = 1.0 mg/m3 (mean=0.7 mg/m3) for 945 subjects and >1.0 mg/m3 (mean=1.5 mg/m3) for 884 subjects. A more gradual decline in FEV 1 was not associated with lower intensity dust exposure during follow-up except for subjects whose FEV I values at baseline were already considerably reduced. These findings suggest limits to the usefulness of secondary prevention based on transfer to lower exposure jobs among miners who have had substantial dust exposure in the past.
Coal-workers-pneumoconiosis; Coal-mining; Lung-disease; Lung-function; Lung-irritants; Pulmonary-system-disorders; Respiratory-system-disorders; Pneumoconiosis; Miners; Mining-industry; Dust-exposure; Dust-inhalation; Airborne-particles; Particulate-dust
American Journal of Epidemiology