Pleural involvement and functional effect of asbestosis in 380 exposed patients

: A large number of pleural abnormalities was detected by radiological and functional monitoring of 380 persons (mean age: 47 years) working in an asbestos processing factory. There were 127 cases of parietal pleura thickening (after 22 1/2 years' exposure), 11 cases of pleural calcifications (after 26 years' exposure) and 29 cases of obliteration of the costophrenic angle. Fourteen images of pulmonary asbestosis were encountered, 7 of which were associated with pleural effusion; they occurred at a mean age of 50 years, after 22 years' exposure. Pleural lesions had a restrictive influence on respiratory function in 24% of the cases and were sometimes painful. Small airway obstruction was detected by flow-volume loops in 9% non-smokers with pleural thickening, which suggests that intra-radiological lung lesions exist in asbestosis.