Longitudinal changes in lung function among asbestos-exposed workers.
Schwartz-DA; Davis-CS; Merchant-JA; Bunn-WB; Galvin-JR; Fossen-DS; Dayton-CS; Hunninghake-GW
Am J Respir Crit Care Med 1994 Nov; 150(5):1243-1249
The determinants of persistent or accelerated loss of lung function among workers exposed to asbestos (1332214) were examined. The 117 study subjects each had at least 1 year's work in a high exposure setting where there was direct contact with asbestos and a minimum of 20 years between the first exposure and entry into the study. The mean duration of exposure was 32 years and the mean interval from first exposure was 38 years. Baseline studies included an independent assessment of dyspnea, lung volumes, diffusing capacity of carbon-monoxide (DLco), a chest radiograph, a high resolution computed tomography scan (HRCT), and bronchoalveolar lavage (BAL). Observation of subjects averaged 2 years. An average 1.5% decrease in the TLC and a 2.5% decrease in the DLco were reported. There was a persistent decline in lung function during the observation period. About 25% of the subjects had Class-III or worse dyspnea. Lower values for TLC were significantly associated with moderate to severe dyspnea, asbestosis on the chest radiograph, interstitial changes in the HRCT scan, diffuse pleural thickening on the chest radiograph, pleural fibrosis on the HRCT scan, and an increased concentration of macrophages, eosinophils, fibronectin, and albumin in the BAL fluid. Cigarette smoking was not significantly related to TLC during the observation period. Lower values for DLco were significantly associated with moderate to severe dyspnea, cigarette smoking, specific interstitial changes on the HRTC scan, higher concentrations of all cells in the BAL fluid, and an increased concentration of protein in BAL fluid. The authors suggest that consideration be given to using these risk factors in identifying high risk patients who could be approached with innovative disease modifying drug regimens.
NIOSH-Grant; Pulmonary-system-disorders; Pulmonary-function-tests; Asbestos-fibers; Risk-analysis; Epidemiology; Lung-irritants; Cigarette-smoking; Occupational-exposure
Internal Medicine University of Iowa Pulmonary Disease Division Iowa City, IA 52242
Pulmonary System Disorders
American Journal of Respiratory and Critical Care Medicine
University of Iowa, Iowa City, Iowa