Emphysema in smoking and non-smoking coalworkers with pneumoconiosis.

The relationships between coalworkers' pneumoconiosis, cigarette smoking and emphysema in a group of 139 deceased coalminers, 19 of whom were non or ex-smokers of 10 years standing, were studied from available clinical and morphological evidence. There was 95 cases of simple pneumoconoiosis and 44 cases with early (Cat. A) progressive massive fibrosis (PMF). The objects were to compare the amounts and types of emphysema in the smokers and non-smokers and also their ventilatory findings. The emphysema content of all the 139 cases of smokers and non-smokers was measured by a standard method and the amounts compared. In addition, the emphysema content of the 19 non- and ex-smokers plus 32 appropriate control cases drawn from the smoking group were measured afresh by a new method devised by the pathologists for the estimation of the extent and type of both emphysema and coalworkers, pneumoconiosis, from large paper lung sections and histological preparations. Both methods compared well in estimating emphysema content and both indicated that the amounts of emphysema in the smoking and non-smoking groups were similar. These findings still applied when both the life-long non-smokers and the cases with simple pneumoconiosis only were looked at separately. It was found that centrilobular emphysema was much commonest type encountered in both smokers and non-smokers. The non-smokers were less disabled in terms of impairment of FEV1.0 than the smokers, although the difference was not statistically significant. The relationship between the centrilobular emphysema and coalworkers' pneumoconiosis is discussed.