Influence of Exposure Concentration or Dose on the Distribution of Particulate Material in Rat and Human Lungs

Details

• Personal Author:
  Green FHY ; Hahn FF ; Nikula KJ ; Vallyathan V
• Description:
  Differences among species in the anatomic sites of particle retention could influence responses to inhaled particles. In this study, we used morphometric techniques to examine the influence of exposure concentration on particle retention in histologic sections from rats and humans. The rats had been exposed for 24 months to diesel exhaust at 0.35, 3.5, or 7.0 mg soot/m(3). The human subjects were nonsmokers who did not work as miners, nonsmoking coal miners who worked under the current standard of 2 mg dust/m(3) for 10-20 years (mean = 14 years), and nonsmoking coal miners who worked under the former standard of < 10 mg dust/m(3) for 33-50 years (mean = 40 years). The distribution of retained particles within the lung compartments was markedly different between species. In all three groups of rats, 82-85% of the retained particulate material was located in the alveolar and alveolar duct lumens, primarily in macrophages. In humans, 57, 68, and 91% of the retained particulate material was located in the interstitium of the lung in the non-miners, coal miners under the current standard, and coal miners under the former standard, respectively. These results show that chronically inhaled diesel soot is retained predominantly in the airspaces of rats over a wide range of exposures, whereas in humans, chronically inhaled particulate material is retained primarily in the interstitium. In humans, the percentage of particles in the interstitium is increased with increased dose (exposure concentration, years of exposure, and/or lung burden). This difference in distribution may bring different lung cells into contact with the retained particles or particle-containing macrophages in rats and humans and may account for differences in species response to inhaled particles. [Description provided by NIOSH]
• Subjects:
  Animals Coal Coal Mining Dust Environmental Monitoring Inhalation Exposure Laboratories Lung Mining Occupational Health Particulate Matter Respiratory System Safety Vehicle Emissions

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• Keywords:
  Animal-studies Author Keywords: Coal Dust Coal-dust Coal-miners Coal-mining Diesel-exhausts Diesel Soot Dust-particles Dusts Exposure-assessment Exposure-levels Humans Inhalants Inhalation-studies Laboratory-animals Lung-cells Particles Particulates

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• ISSN:
  0091-6765
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  New Mexico ; OSHA Region 3 ; OSHA Region 6 ; 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:
  311-318
• Volume:
  109
• Issue:
  4
• NIOSHTIC Number:
  nn:20021821
• Citation:
  Environ Health Perspect 2001 Apr; 109(4):311-118
• Contact Point Address:
  Lovelace Respiratory Research Institute, PO Box 5890, Albuquerque, NM 87185
• Email:
  fhahn@lrri.org
• Federal Fiscal Year:
  2001
• Peer Reviewed:
  True
• Source Full Name:
  Environmental Health Perspectives
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c617d167cb3257098649f7b68b88171b62ea690ece3ef3f0a7de712e58ac8f4db76bf2320a11a99571a8a2561fb17c20116c952009ece00238ebf14ad4639f2e
• Download URL:
  https://stacks.cdc.gov/view/cdc/198923/cdc_198923_DS1.pdf
• File Type:
  [PDF - 113.45 KB ]