Abstract

The impairment of lung function associated with different types of asbestos related disease was examined in 1298 men. The 310 men with circumscribed pleural lesions (plaques) or diffuse pleural thickening without asbestosis were compared with 596 men with asbestosis only and with 322 men with pleural abnormalities and asbestosis, as classified from chest radiographs by ILO pneumoconiosis criteria. Spirometric indices and total lung capacity (TLC; determined by planimetry) were measured and expressed as percentages of predicted values. Non-smoking men with pleural disease only had reduced values of mid and terminal expiratory flows (80.6 and 69.9% predicted) and a reduced FEV1 (89% predicted) with a forced vital capacity (FVC) of 94% predicted. TLC was 104% predicted. Thus they had airways obstruction with-out restriction. Non-smoking men with pulmonary asbestosis (ILO profusion of opacities mostly 1/0 and 1/1) had pulmonary function similar to that of men with pleural disease. FEV1 and FVC and flow rates at other lung volumes were lower in smokers with asbestosis (after adjustment for duration of smoking) than in the non-smokers with asbestosis. Airflow limitation was worse in the men with both pleural abnormalities and pulmonary asbestosis with lower values for mid expiratory flow, FEV1 and FVC (but not TLC) than those with either abnormality alone, in both non-smokers and current smokers. Men with diffuse pleural thickening that included the costophrenic angles had more airways obstruction and air trapping and lower FVC values than those with circumscribed pleural disease.