Objective: To observe the longitudinal changes in pulmonary function associated with exposure to asbestos in a group of highly exposed workers.
Methods: Pulmonary diffusing capacity (DLco) and spirometry of 243 Chinese asbestos workers were measured and remeasured after 5 and 10 yr. Their annual changes in relation to cumulative asbestos exposure and asbestosis were determined using multivariate analysis.
Results: The greatest annual decline was observed in DLco, particularly in workers with asbestosis, followed by FVC and FEV(1). A greater decline in DLco accorded with a higher level of cumulative asbestos exposure. A similar trend was also seen in FVC, in which the highest exposure level was associated with 223 ml loss over each 5 yr period or 45 ml/yr.
Conclusions: There were substantial declines in DLco and FVC over time in the asbestos workers, and a dose-response trend between asbestos exposure and accelerating functional loss.