A study of the causes of progressive airways obstruction in chronic bronchitis.
D000328:Adult; D000368:Aged; D000397:Air Pollution; D001991:Bronchitis / Q000150:complications*; D002908:Chronic Disease; D003371:Cough; D006801:Humans; D008131:London; D008297:Male; D008875:Middle Aged; D009093:Mucus / Q000378:metabolism*; D012140:Respiratory Tract Diseases / Q000209:etiology*; D012907:Smoking; D013147:Spirometry; D013183:Sputum