title: Abundance of siderophages in sputum: indicator of an adverse lung reaction to air pollution.
abstract: OBJECTIVE
  To investigate the lung response to traffic-related air pollution by enumerating hemosiderin-laden alveolar macrophages (AM) in sputum.
  
  
  METHODS
  Sputum samples were collected from 103 urban adult males from Calcutta chronically exposed to automobile exhaust. Forty-nine rural individuals served as controls. AM were identified by nonspecific esterase staining. Perl's Prussian blue technique was employed for the detection of hemosiderin-laden AM (siderophages).
  
  
  RESULTS
  The urban group, consisting of 31 traffic officers, 25 automobile service station workers and 47 street hawkers, had seven times more AM in their sputum than did the matched controls. Besides, a remarkable rise (27-fold) in the number of siderophages in sputum was observed in urban individuals. Smoking further elevated the AM count and number of siderophages.
  
  
  CONCLUSIONS
  Abundant siderophages in the urban group may indicate the toxic effect of airborne pollutants on the lung, leading to phagocytosis of destroyed cells, including erythrocytes, and accumulation of iron in AM. Enumeration of siderophages in sputum appears to be a simple, noninvasive, inexpensive cytochemical technique well suited to preliminary assessment of the adverse effects of air pollution on the lungs in large, population-based studies, especially in developing countries.
authors.affiliation: Chittaranjan National Cancer Institute and Environmental Biology Laboratory, Department of Zoology, University of Calcutta, India.
authors.forename: S
authors.initials: S
authors.lastname: Roy
authors.forename: M R
authors.initials: MR
authors.lastname: Ray
authors.forename: C
authors.initials: C
authors.lastname: Basu
authors.forename: P
authors.initials: P
authors.lastname: Lahiri
authors.forename: T
authors.initials: T
authors.lastname: Lahiri
mesh_terms: D000328:Adult; D002452:Cell Count; D006485:Hemosiderin / Q000032:analysis; D006801:Humans; D008168:Lung / Q000187:drug effects / Q000473:pathology*; D016676:Macrophages, Alveolar / Q000737:chemistry / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D012423:Rural Health; D013183:Sputum / Q000737:chemistry / Q000166:cytology*; D014504:Urban Health; D001335:Vehicle Emissions / Q000009:adverse effects*
chemical_list: D001335:Vehicle Emissions; D006485:Hemosiderin