Protection by Iron Against the Toxic Effects of Quartz

Details

• Personal Author:
  Cullen RT ; Donaldson K ; Hagen S ; Vallyathan V
• Description:
  Inhalation of quartz (crystalline silica) can lead to the fibrosing lung disease, silicosis (Morgan and Seaton, 1984). Exposure to quartz alone is rare and most exposures occur through the presence of quartz in other dusts produced by activities such as mining, quarrying and sandblasting. Consequently, silicosis is often combined with mixed dust pneumoconiosis. A number of studies in iron-ore miners (Reichel et al., 1977; Moore et al., 1987) and in animals (Gross et al., 1960) have indicated that iron can protect against the effects of quartz. It is now believed that the characteristics of the surface of quartz particles determine their interaction with biological molecules and hence their toxicity. For example, the surface can generate a range of reactive oxygen species such as hydrogen peroxide (H2O2) and the hydroxyl radical (.OH), agents known to be toxic to cells and tissues (Fantone and Ward, 1984). The production of reactive, oxygen species can be measured using electron spin resonance (ESR) techniques. ; The two main chemical activities of the silica surface are those involving siloxane bridges (Si-O-Si) and silanols (SiOH) (lIer, 1979). Silanol groups can form hydrogen bonds with cell membranes, thought to be the main site of quartz toxicity. These groups can also dissociate at physiological pH giving a net negative charge on the silicate surface which can lead to adsorption, or coordination, of organic and inorganic cations, such as iron and aluminium. This binding of metals has been shown to reduce the toxicity of quartz (Nolan et al., 1981). Paradoxically, the interaction of iron with H2O2 can also produce .OH radicals, extremely potent oxidants, through the Fenton reaction: Fe2t + H202= Fe3 + .OH + OH- The H202 for this reaction can be produced at the quartz surface or be released from macrophages and neutrophils. The objective of our study was to examine whether treating quartz particles with iron, using ferrous or ferric chloride solutions, or mixing quartz with carbonyl iron particles could alter the surface activity of quartz and the toxic and pulmonary inflammatory effects of quartz. [Description provided by NIOSH]
• Subjects:
  Aluminum Compounds Aluminum Silicates Dust Ferrous Compounds Fibrosis Hazardous Substances Lung Lung Diseases Occupational Health Quartz Respiratory System Respiratory Tract Diseases Safety Silicon Dioxide

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• Keywords:
  Aluminum-compounds Cell-damage Cell-function Iron-compounds Lung-disease Lung-disorders Pneumoconiosis Quartz-dust Silica-dusts Silicates Silicosis Surface-properties Toxic-effects

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• ISBN:
  0080427405
• ISSN:
  0003-4878
• Publisher:
  Pergamon
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  420-425
• Volume:
  41
• NIOSHTIC Number:
  nn:20025020
• Citation:
  Ann Occup Hyg, Inhaled Particles VIII 1997 Aug; 41(Suppl 1):420-425
• CAS Registry Number:
  Aluminum (CAS RN 7429-90-5) ; Iron (CAS RN 7439-89-6) ; Quartz (SiO2) (CAS RN 14808-60-7)
• Editor(s):
  Cherry N; Ogden T
• Federal Fiscal Year:
  1997
• Peer Reviewed:
  True
• Source Full Name:
  Annals of Occupational Hygiene, Inhaled Particles VIII
• Supplement:
  1
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:aa440efe591e8cb95e25efff0be822713000ed94be1b59d3aea6db9cbeec459c699cdb110fc05ba37dfe61a70ea1f6cdea02537d98ca0079e29fe6c3c3fe8183
• Download URL:
  https://stacks.cdc.gov/view/cdc/196540/cdc_196540_DS1.pdf
• File Type:
  [PDF - 471.93 KB ]