Abstract
The results are presented from an investigation into the mortality of miners and ex-miners employed by the National Coal Board, from a comprehensive survey of respiratory disease in a Welsh mining community, and from a study of the comparative mortality from lung cancer in Welsh mining and non-mining towns. These results, together with previously published data which have been reviewed, show that in Great Britain the death rate of coal-miners from cancer of the lung is appreciably lower than the national rate for men of comparable age. This occupational trend is not explicable by any of the factors which are known to influence the prevalence of the disease in the general population. In particular there is much evidence that the cigarette consumption of miners at least equals that of men in other occupations. The exclusion of this and other recognized aetiological factors suggests that the reduced mortality of miners from this disease is a specific effect of their occupation. This effect might be a consequence of the inhalation of coal-dust, for there is some evidence that the incidence of death from lung cancer is lowest among miners whose exposure to coal-dust has been greatest.