Lung Cancer Risk Associated with Regulated and Unregulated Chrysotile Asbestos Fibers

Details

• Personal Author:
  Dement, John M. ; Hamra GB ; Loomis D ; Richardson DB ; Dement, John M. ; Hamra GB ; Loomis D ; Richardson DB
• Description:
  Background: Regulation of asbestos fibers in the workplace is partly determined by which fibers can be visually counted. However, a majority of fibers are too short and thin to count this way and are, consequently, not subject to regulation. Methods: We estimate lung cancer risk associated with asbestos fibers of varying length and width. We apply an order-constrained prior both to leverage external information from toxicological studies of asbestos health effects. This prior assumes that risk from asbestos fibers increases with increasing length and decreases with increasing width. Results: When we apply a shared mean for the effect of all asbestos fiber exposure groups, the rate ratios for each fiber group per unit exposure appear mostly equal. Rate ratio estimates for fibers of diameter <0.25 microm and length <1.5 and 1.5-5.0 microm are the most precise. When applying an order-constrained prior, we find that estimates of lung cancer rate ratio per unit of exposure to unregulated fibers 20-40 and >40 microm in the thinnest fiber group are similar in magnitude to estimates of risk associated with long fibers in the regulated fraction of airborne asbestos fibers. Rate ratio estimates for longer fibers are larger than those for shorter fibers, but thicker and thinner fibers do not differ as the toxicologically derived prior had expected. Conclusion: Credible intervals for fiber size-specific risk estimates overlap; thus, we cannot conclude that there are substantial differences in effect by fiber size. Nonetheless, our results suggest that some unregulated asbestos fibers may be associated with increased incidence of lung cancer. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Air Pollution Asbestos Carcinogens Environmental Exposure Inorganic Chemicals Lung Lung Diseases Microbiology Mortality Neoplasms Occupational Exposure Occupational Health Respiratory System Respiratory Tract Diseases Risk Assessment Safety Textile Industry

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• Keywords:
  Air Analysis Air Contaminants Air Pollutants Air Quality Monitoring Asbestos Fibers Cancer Rates Electron Microscopy Exposure Assessment Exposure Levels Lung Cancer Microscopic Analysis Mortality Rates Occupational Exposure Occupational Respiratory Disease Quantitative Risk Assessment Textile Workers

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• ISSN:
  1044-3983
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article ; Journal Article
• Place as Subject:
  North Carolina ; OSHA Region 3 ; OSHA Region 4 ; Pennsylvania ; South Carolina
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• Pages in Document:
  275-280
• Volume:
  28
• Issue:
  2
• NIOSHTIC Number:
  nn:20052103
• Citation:
  Epidemiology 2017 Mar; 28(2):275-280
• Contact Point Address:
  Ghassan B. Hamra, Department of Environmental & Occupational Health, Drexel University School of Public Health, 3215 Market St., Philadelphia, PA 19104
• Email:
  ghassan.b.hamra@drexel.edu
• CAS Registry Number:
  Asbestos (CAS RN 1332-21-4) ; Chrysotile (CAS RN 12001-29-5) ; Asbestos (CAS RN 1332-21-4) ; Chrysotile (CAS RN 12001-29-5)
• Federal Fiscal Year:
  2017
• Performing Organization:
  University of North Carolina, Chapel Hill
• Peer Reviewed:
  True
• Start Date:
  20140901
• Source Full Name:
  Epidemiology
• End Date:
  20160831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:670f46fbc24a6b5d3c8b4ba1d4a3a271b0a2c2d4121a09bdad8ff8fe064ecdde0bec6adcda5c782af41a3491297da63eaadf4ff55ebf95353fae968e221601ed
• Download URL:
  https://stacks.cdc.gov/view/cdc/211695/cdc_211695_DS1.pdf
• File Type:
  [PDF - 424.20 KB ]