Roentgenographic evidence of coal workers' pneumoconiosis in three geographic areas in the United States.
D000328:Adult; D000368:Aged; D003032:Coal Mining; D006801:Humans; D008297:Male; D008875:Middle Aged; D011009:Pneumoconiosis / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D013902:Radiography, Thoracic; D014481:United States