The effects of occupation and smoking on respiratory disease mortality

The effects of occupation and smoking on respiratory symptoms and ventilatory lung function were examined in 1957 among random samples of men 25 to 34 and 55 to 64 yr of age from 4 occupational categories (miners, foundry workers, mixed dust and chemical workers, and non-dust-exposed workers) living in an industrial English town. Mortality has been established 20 yr after the initial survey. This report focuses on the effects of smoking, lung function, and respiratory symptoms among the older men. All-cause mortality was very similar in the nondusty, foundry, and mixed dust groups, but slightly lower in the miners and ex-miners. In contrast, smokers had 2 times the death rates of nonsmokers. There was consistency in the smoking effect within each occupational group. Poor lung function and to some extent bronchitic symptoms in 1957 were predictive of mortality by 1977, regardless of smoking habits. However, the effect of symptoms in the absence of concomitant poor lung function, though consistent, was small.