title: Respiratory changes due to long-term exposure to urban levels of air pollution: a histopathologic study in humans.
abstract: OBJECTIVE
  To evaluate the potential associations between long-term exposure to air pollution and histopathologic evidence of damage to the lungs in humans.
  
  
  METHODS
  Lung tissue samples were collected during necropsies of individuals who died due to violent causes, selected on the basis of their exposure background.
  
  
  METHODS
  The exposed group was composed of individuals who lived in Guarulhos, an area with high mean levels of inhalable particles. The control group was composed of individuals who lived in two cities with economies based on agricultural activities: Ribeirão Preto and Ourinhos.
  
  
  METHODS
  Information about cigarette smoking and occupational exposure was obtained from family members.
  
  
  RESULTS
  Morphometric evaluation of the main bronchus was conducted to determine the volume ratio of submucosal glands. Histopathologic alterations of the bronchioli were evaluated by scoring the presence of inflammatory reaction, wall thickening, and secretory hyperplasia. The number of spots of carbon deposition was counted along the regions of lymphatic drainage (visceral pleura and axial connective tissue around bronchi and blood vessels). Statistical analysis was done by means of regression models controlled for age, smoking, and occupational exposure. Lungs collected from the high pollution area presented evidence of more histopathologic damage in comparison to those from the clean environments. These effects were observed even after controlling for individual differences in age, sex, and cigarette smoking levels.
  
  
  CONCLUSIONS
  These results suggest that long-term exposure to air pollution may contribute to the pathogenesis of airway disease, and that urban levels of air pollution have adverse effects on the respiratory tract.
authors.affiliation: Laboratory of Experimental Air Pollution, Faculty of Medicine, University of São Paulo, Brazil.
authors.forename: M B
authors.initials: MB
authors.lastname: Souza
authors.forename: P H
authors.initials: PH
authors.lastname: Saldiva
authors.forename: C A
authors.initials: CA
authors.lastname: Pope
authors.forename: V L
authors.initials: VL
authors.lastname: Capelozzi
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects*; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology*; D008297:Male; D012044:Regression Analysis; D012140:Respiratory Tract Diseases / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D013997:Time Factors; D014504:Urban Health
chemical_list: D000393:Air Pollutants