title: Angular and fibrous particles in lung are markers of job categories.
abstract: BACKGROUND
  The lung concentration of angular and fibrous particles has been measured when cases are stratified into their job categories; 21 miners (metallic mines such as gold, zinc and copper), 18 iron foundrymen, 22 non-iron foundrymen, four welders, three sand-blast workers, four construction workers, three technicians and professionals, seven workers in other trades excluding welding. Twelve asbestos miners representing a positive exposure to asbestos and 20 people representing a background population were added to the previous groups.
  
  
  METHODS
  Particles, both angular and fibrous, were extracted from lung parenchyma by a bleach digestion method, mounted on copper microscopic grids by a carbon replica technique and analyzed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). Quartz concentration was also determined by X-ray diffraction (XRD) on a silver membrane filter after the extraction from the lung parenchyma.
  
  
  RESULTS
  (1) The highest concentrations of quartz were found in mines (metallic mines), iron foundrymen and sand-blast workers. Notable amounts quartz were found in welders and professionals. (2) The highest concentrations of short fibres were found in non-iron foundrymen, asbestos miners and construction workers. (3) The highest concentrations of long fibres were found in non-iron foundry men and asbestos miners. (4) The highest concentrations of ferruginous bodies were found in non-iron foundrymen and asbestos miners. (5) The non-iron foundrymen were exposed to ceramic fibres and asbestos fibres.
  
  
  CONCLUSIONS
  The results of the study may not be representative of the broad spectrum of workers in the industrial activities in which they have been involved. However, the detailed composition of the retained particles of our workers is explained both qualitatively and quantitatively by their work histories. Finally, the broad range of particle types identified in the lungs of these workers illustrate the complexity or trying to determine disease origins in these occupational settings.
authors.affiliation: McGill University, Department of Occupational Health, Faculty of Medicine, Montréal, Québec, Canada. cydu@musica.mcgill.ca
authors.forename: A
authors.initials: A
authors.lastname: Dufresne
authors.forename: R
authors.initials: R
authors.lastname: Bégin
authors.forename: C
authors.initials: C
authors.lastname: Dion
authors.forename: J
authors.initials: J
authors.lastname: Jagirdar
authors.forename: W N
authors.initials: WN
authors.lastname: Rom
authors.forename: P
authors.initials: P
authors.lastname: Loosereewanich
authors.forename: D C
authors.initials: DC
authors.lastname: Muir
authors.forename: A C
authors.initials: AC
authors.lastname: Ritchie
authors.forename: G
authors.initials: G
authors.lastname: Perrault
mesh_terms: D001682:Biological Availability; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D008168:Lung / Q000737:chemistry*; D008297:Male; D019216:Metals, Heavy / Q000032:analysis* / Q000378:metabolism; D008906:Mining; D009790:Occupations; D012989:Soil Pollutants / Q000032:analysis*; D014896:Welding
chemical_list: D019216:Metals, Heavy; D012989:Soil Pollutants