Studies of chronic respiratory disease that have been carried out in mining communities in England, Wales, and the state of West Virginia, in the United States, are reviewed. In each community, miners and exminers have been compared with nonminers, using standardized methods. The influence of pneumoconiosis and dust exposure on respiratory symptoms and lung function has been assessed. A higher prevalence of symptoms and a lower average forced expiratory volume has consistently been found in miners compared with nonminers. Miners with simple pneumoconiosis have not, however, been found to differ consistently either in symptom prevalence or in lung function from miners without pneumoconiosis. An increasing prevalence of symptoms and decreasing lung function with increasing duration of work either underground or at the coal face has been found in some surveys but not in others. These findings suggest that long term dust exposure cannot explain all the excess of chronic nonspecific respiratory disease found in miners.