ANGULAR AND FIBROUS PARTICLES IN LUNG ARE MARKERS OF JOB CATEGORIES

Introduction: 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 fou ndrymen, 22 non-iron foundrymen, four welders, three sand-blast worker s, four construction workers, three technicians and professionals, sev en workers in other trades excluding welding. Twelve asbestos miners r epresenting a positive exposure to asbestos and 20 people representing a background population were added to the previous groups. Material a nd methods: Particles, both angular and fibrous, were extracted from l ung parenchyma by a bleach digestion method, mounted on copper microsc opic grids by a carbon replica technique and analyzed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). Qu artz 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 amo unts quartz were found in welders and professionals. (2) The highest c oncentrations of short fibres were found in non-iron foundrymen, asbes tos 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. Conclusion: The results of the study may not be representative of the broad spectrum of worke rs in the industrial activities in which they have been involved. Howe ver, the detailed composition of the retained particles of our workers is explained both qualitatively and quantitatively by their work hist ories. Finally, the broad range of particle types identified in the lu ngs of these workers illustrate the complexity or trying to determine disease origins in these occupational settings. (C) 1997 Elsevier Scie nce B.V.