[26 years of research in pneumoconiosis in the field of British coal mines. Contribution of that research to the epidemiology of pulmonary disorders in miners]

Abstract

Events leading to the start of the Pneumoconiosis Field Research in 1953 are reviewed. Research methods are outlined, progress is described, and the main results are summarised. Three medical surveys were conducted at approximately five-year intervals in 24 coal mines. A further two quinquennial surveys took place at 10 of them, thus completing 20 years' observations. Individual miners' exposures to dust have been measured throughout the periods of study and earlier exposures have been estimated. The dust exposure have been expressed as cumulative timeweighted mass concentrations of dust in the respirable range. Correlations have been demonstrated between this index of exposure and (a) risks of developing various degrees of simple pneumoconiosis, (b) the occurrence of chronic bronchitis symptoms, (c) level of breathing capacity, and (d) among miners with no pneumoconiosis, mortality attributed to respiratory diseases generally, chronic bronchitis and emphysema in particular, and to cancers of the digestive organs. Exposures to quartz amounting to less than about 10 per cent of mixed coal mine dust do not generally affect the probability of developing simple pneumoconiosis. But there is evidence that some miners may show unusual radiological changes over ten years when exposed to dust with a relatively high quartz content. Current work includes continuation of mortality studies and follow-up surveys of miners no longer working at the research collieries. The inter-disciplinary nature of the research team is emphasized and there are suggestions for further work on unresolved problems.