title: A survey of emphysema in coal-workers and the general population.
mesh_terms: D000367:Age Factors; D003032:Coal Mining; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology; D008297:Male; D011656:Pulmonary Emphysema / Q000453:epidemiology* / Q000473:pathology; D012737:Sex Factors; D012907:Smoking