Smoking and duration of asbestos exposure in the production of functional and roentgenographic abnormalities in shipyard workers.

Functional and roentgenographic abnormalities in 131 asbestos-exposed shipyard workers were assessed in terms of duration of asbestos exposure and smoking history to determine the relative contributions of these factors. Both exposure and smoking contributed to the frequency of abnormalities in FEV1 and FVC. In contrast, airways obstruction (FEV1/FVC less than 70%) was unrelated to exposure but correlated closely with smoking. Abnormalities in DLCO were minimally associated with asbestos exposure, but were strongly related to smoking history, suggesting that diffusion impairment in these workers is more likely to be related to smoking and emphysema than to interstitial disease. Significant roentgenographic pleural abnormalities were associated with both duration of exposure and smoking. Interstitial disease did not correlate with exposure and was only mildly associated with smoking. Smoking contributes to many of the functional and roentgenographic abnormalities in asbestos-exposed workers.