title: Differential elemental distribution of retained particles along the respiratory tract.
abstract: BACKGROUND
  Prolonged exposure to ambient particles is associated with premature mortality due to cardio-respiratory diseases and lung cancer. The size and composition of these particles determine their toxicity, which is aggravated by their long-term retention in the lungs.
  
  
  OBJECTIVE
  To compare the elemental profile of particles retained along the bronchial tree and lymph nodes by combining laser capture microdissection (LCM) and elemental composition analysis through energy dispersive x-ray (EDX) and scanning electron microscopy (SEM).
  
  
  METHODS
  Twenty-four right lung middle lobes from autopsied cases were obtained from two cities with different pollution backgrounds. Lung samples were collected from three distinct sites within the lung at the time of autopsy: peribronchial tissue, peripheral parenchyma and hilar lymph nodes. Areas of potentially increased particle deposition were microdissected using LCM and analyzed for elemental composition through EDX "allied" with SEM.
  
  
  RESULTS
  Elemental analyses of the particles retained along the bronchial tree showed two groups of distribution: peribronchiolar or lymph node deposition. The elemental profile of peribronchial areas were significantly different between the two cities and were better discriminators of past air pollution exposure.
  
  
  CONCLUSIONS
  Our data suggest that particle uptake varies along the bronchial tree and human lung tissue retains particles indicative of regional air pollution background.
authors.affiliation: Department of Pathology, University of São Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Mauro A
authors.initials: MA
authors.lastname: Saieg
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Cury
authors.forename: John J
authors.initials: JJ
authors.lastname: Godleski
authors.forename: Rebecca
authors.initials: R
authors.lastname: Stearns
authors.forename: Luis G P
authors.initials: LG
authors.lastname: Duarte
authors.forename: Liz
authors.initials: L
authors.lastname: D'Agostino
authors.forename: Henrique
authors.initials: H
authors.lastname: Kahn
authors.forename: Emilia M
authors.initials: EM
authors.lastname: Pinto
authors.forename: Thais
authors.initials: T
authors.lastname: Mauad
authors.forename: Paulo H N
authors.initials: PH
authors.lastname: Saldiva
authors.forename: Fabiola D C
authors.initials: FD
authors.lastname: Bernardi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D001938:Brazil; D001980:Bronchi / Q000737:chemistry / Q000187:drug effects* / Q000648:ultrastructure; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects*; D007834:Lasers; D008198:Lymph Nodes / Q000737:chemistry / Q000187:drug effects* / Q000648:ultrastructure; D008297:Male; D008670:Metals / Q000032:analysis*; D042282:Microdissection; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity*; D013052:Spectrometry, X-Ray Emission; D014504:Urban Health
chemical_list: D000393:Air Pollutants; D008670:Metals; D052638:Particulate Matter