The pulmonary ventilatory function of coal miners in the United Kingdom.

During recent years epidemiologic surveys have played an increasingly important role in the study of chronic respiratory disease. This method has been used not only to identify the factors associated with the development of respiratory disease, but also to assess the effect of such disease upon the health and well-being of the individual subject. Surveys of random samples of the total population in different parts of the United Kingdom have been described by Higgins and associates (1-5). A similar approach was adopted by Olsen and Gilson (6) to compare the prevalence of respiratory disease in the United Kingdom with that on Bornholm, a Danish island. As a result of these and other studies, three main factors have been incriminated in the etiology of chronic bronchitis. First, although not necessarily the most important, is atmospheric pollution, which has been found to be associated with mortality from bronchitis (7-9) and with the admission rate to London hospitals of adults with respiratory disease (10). Fairbairn and Reid (11) found a significant association between bronchitis mortality and morbidity and the incidence of fog. Second, numerous workers in many countries (12-15), have demonstrated that smoking habits and respiratory disease are closely related. Third, the steep gradient in age-standardized mortality from bronchitis in socioeconomic terms is well known (16). Other factors, including respiratory infections in childhood and in later life (17) and climatic conditions (10, 18) may also be involved. The etiology is well reviewed by Higgins (19) and Holland (20). In addition to studies of the general public, investigations carried out in particular industries and occupations have also made a useful contribution to knowledge about the general