Buffering Capacity of Coal and Its Acid-Soluble Fe2+ Content: Possible Role in Coal Workers’ Pneumoconiosis

Details

• Personal Author:
  Chen LC ; Fournier J ; Huang X ; Koenig K
• Description:
  Epidemiological studies have shown that the prevalence of coal workers' pneumoconiosis (CWP) differed remarkably between different coal mine regions despite comparable exposures to respirable dust. In the United States, CWP was found to be most common in Pennsylvania coal miners and least common in miners from Utah. The active component(s) responsible for the regional differences in CWP has not yet been identified. In the present study, we found that coals from Pennsylvania, compared with Utah coals, showed a much lower buffering capacity as determined by the amount of acid consumed in order to reach pH 4.5, which is the pH of the phagolysosomes of macrophages. Moreover, the coals from Pennsylvania released large amounts of Fe2+ in the acidified extract, whereas the coals from Utah released little Fe2+. Using electron spin resonance (ESR), we found that the coals from Pennsylvania, but not from Utah, were effective in oxidizing formate by a radical pathway. Two coals, one from Utah with high buffering capacity and low acid-soluble Fe2+ and the other from Pennsylvania with low buffering capacity and high acid-soluble Fe2+, were then selected for cell treatment. We found that human tracheal epithelial (HTE) cells treated with the coal from Pennsylvania (10 microg/cm2) showed a 36% increase in oxidant formation over the control as detected by dichlorofluorescein assay, whereas the coal from Utah had no effect. An electrophoretic mobility shift assay was used to test the binding affinity of nuclear proteins extracted from the coal-treated HTE cells to an oxidative stress-responsive transcription factor activator protein-1 (AP-1) element. The coal from Pennsylvania with high acid-soluble Fe2+ (1 microg/cm2) activated AP-1 to the same extent as 10 microM H2O2, while the coal from Utah without acid-soluble Fe2+ had no effect. These results support our hypothesis that the prevalence of CWP may be higher in coal workers exposed to coal with high acid-soluble Fe2+ and low buffering capacity than in workers exposed to coal with low acid-soluble Fe2+ and high buffering capacity. [Description provided by NIOSH]
• Subjects:
  Calcium Compounds Coal Coal Mining Dust Environmental Monitoring Epidemiology Lung Lung Diseases Mining Occupational Exposure Occupational Health Respiratory System Respiratory Tract Diseases Safety

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• Keywords:
  Calcium-compounds Coal-dust Coal-miners Coal-mining Coal-workers Coal-workers-pneumoconiosis Dust-exposure Dust-particles Dusts Exposure-assessment Exposure-levels Occupational-exposure Respirable-dust

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• ISSN:
  0893-228X
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  New York ; OSHA Region 2
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  11
• Issue:
  7
• NIOSHTIC Number:
  nn:20030557
• Citation:
  Chem Res Toxicol 1998 Jul; 11(7):722-729
• Contact Point Address:
  Department of Environmental Medicine, New York University Medical Center, 550 First Avenue, New York, New York 10016, USA
• Email:
  xihuang@charlotte.med.nyu.edu
• CAS Registry Number:
  2′,7′-Dichlorofluorescein (CAS RN 76-54-0) ; Calcium oxide (CAS RN 1305-78-8) ; Iron (CAS RN 7439-89-6)
• Federal Fiscal Year:
  1998
• Performing Organization:
  New York University, New York, New York
• Peer Reviewed:
  True
• Start Date:
  19940930
• Source Full Name:
  Chemical Research in Toxicology
• End Date:
  19960929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:33de03edec39dd69a5ab378b474bec488eecc129fdd60b0ae64db6a87b05c70548aeaceca1a0fced1b5252838f80bb0c3e9ac7092abae57094a28eb24cc10304
• Download URL:
  https://stacks.cdc.gov/view/cdc/191120/cdc_191120_DS1.pdf
• File Type:
  [PDF - 149.37 KB ]