Changes in pulmonary function in household contacts of asbestos workers

The relationship of environmental asbestos exposure to mesothelioma and radiologic abnormalities has been documented. Diminution of pulmonary function (particularly vital capacity) is characteristic of asbestosis. To determine the effects of household exposure on pulmonary function, household contacts of workers formerly employed in an asbestos factory have been studied. Using an automated spirometer, 204 household contacts have been investigated. 81 (39.7%) had functional impairment. There were 20 (9.8%) with restriction alone (FVC ≤ 79% of predicted of Morris et al.), 22 (10.7%) with obstruction (FEV₁/FVC ≤ 0.74) and 8 (3.9%) with combined impairment. In all, 28 (13.2%) subjects had reduced VC. There were 31 additional subjects who showed obstructive changes, using the criteria of a reduced FEF(25-75) (≤ 67% predicted) and/or FEF₇₅/FVC ≤ 0.29. Current and ex smokers (133 of 204 or 65.2%) had an increased prevalence of abnormal pulmonary function. 71 of 204 (or 34.3%) had abnormal chest X rays. Neither smoking nor any pulmonary function abnormality by itself correlated with X ray changes. However, smokers with abnormal pulmonary function were more likely to have abnormal X ray findings. The mean VC of those showing a reduction was 2.56 liters (71.7% of predicted) compared to 4.06 liters in the obstructive group and 3.92 liters in the normals.