title: The single breath nitrogen test in rural and urban smokers and non-smokers.
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D003011:Closing Volume; D005260:Female; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D009584:Nitrogen; D012424:Rural Population; D012737:Sex Factors; D012907:Smoking / Q000503:physiopathology*; D014505:Urban Population
chemical_list: D009584:Nitrogen