Epidemiological studies on chronic bronchitis. Results depend on the methods.
D000328:Adult; D000367:Age Factors; D001991:Bronchitis / Q000175:diagnosis / Q000453:epidemiology*; D002908:Chronic Disease; D003032:Coal Mining; D004391:Dust; D004812:Epidemiologic Methods; D006801:Humans; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D014692:Ventilation-Perfusion Ratio; D014797:Vital Capacity
D004391:Dust; D010100:Oxygen