Surface Properties of Silica in Mixed Dust

Details

• Personal Author:
  Attfield MD ; Brower PS ; Grayson, R. Larry ; Harrison JC ; Keane MJ ; Stephens JW ; Wallace WE
• Description:
  Attempts to distinguish the contribution of quartz to the pathogenic potential of mixed-composition work place dusts are not without ambiguity. While exposure to pure respirable quartz is known to induce pulmonary fibrosis, epidemiological studies of workers exposed to mixed dusts have not always shown a clear role for quartz in disease induction. This anomaly has been extensively detailed in British and European epidemiological studies of coal workers' pneumoconiosis (CWP) and progressive massive fibrosis (PMF). Those studies generally have shown a correlation of disease prevalence with cumulative exposure to total respirable dust and coal rank, but not with the explicit quartz component of the cumulative dust exposure. A general hypothesis to explain the seeming failure of quartz, a strongly pathogenic agent for fibrosis, to contribute to CWP or PMF, especially when the other components of the dust are not so strong in isolation, is that the mass percent silica component of a dust, as conventionally measured, is not necessarily a measure of biologically available of toxic silica surface. Several methods are being used to characterize the degree of availability or purity of the surface of silica particles in mixed-composition dusts. We review here a fraction of the literature of studies of silica exposure and CWP, and of experimental silicosis in lab animals exposed to mixed-composition dusts. One method used to detect surface "occlusion," or sub-micrometer coating, of aluminosilicate clay on respirable-sized silica particle is outlined. Application of the method to a set of Pennsylvania coal mine dusts is reviewed, demonstrating the occurrence of such clay occlusion of silica particles and showing that the fraction of such silica particles can significantly vary between exposure situations. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Aluminum Silicates Coal Coal Mining Dust Environmental Monitoring Fibrosis Irritants Lung Lung Diseases Mining Occupational Health Particulate Matter Quartz Respiratory System Respiratory Tract Diseases Safety Silicon Compounds Silicon Dioxide Surface-Active Agents

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• Keywords:
  Airborne-dusts Airborne-particles Coal-dust Coal-mining Dust-exposure Dust-particles Exposure-assessment Fibrous-dusts Lung-disease Lung-irritants Mining-industry Particulate-dust Pulmonary-system-disorders Quartz-dust Respiratory-irritants Respiratory-system-disorders Silica-dusts Silicates Silicon-compounds Silicosis Surfactants

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• ISBN:
  9780849347092
• Publisher:
  CRC Press
• Document Type:
  Text
• Genre:
  Book
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DRDS - Division of Respiratory Disease Studies
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  107-117
• NIOSHTIC Number:
  nn:20034306
• Citation:
  Silica and silica-induced lung diseases. Castranova V, Vallyathan V, Wallace WE, eds. Boca Raton, FL: CRC Press, 1995 Dec; :107-117
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7)
• Editor(s):
  Castranova V; Vallyathan V; Wallace WE
• Federal Fiscal Year:
  1996
• Peer Reviewed:
  False
• Source Full Name:
  Silica and silica-induced lung diseases
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:552c31a7f3b273a81c56b09694cc8c5d3721c4b5be33c0ff618c451580f917004652ebf371da62225f98ec688e744805116e7e11ff75d65ca9008f388ba1a4eb
• Download URL:
  https://stacks.cdc.gov/view/cdc/189557/cdc_189557_DS1.pdf
• File Type:
  [PDF - 1.63 MB ]