Carbon nanotube dosimetry: from workplace exposure assessment to inhalation toxicology

Details

• Personal Author:
  Antonini JM ; Battelli L ; Bilgesu SA ; Birch, M. Eileen ; Castranova, Vincent ; Chen BT ; Dahm, Matthew M. ; Deddens JA ; Erdely A ; Evans DE ; Fernback, Joseph E. ; Frazer DG ; Hulderman T ; Kashon ML ; Leonard HD ; McKinney W ; Porter DW ; Schubauer-Berigan, Mary K. ; Schwegler-Berry D ; Zeidler-Erdely PC
• Description:
  Background: Dosimetry for toxicology studies involving carbon nanotubes (CNT) is challenging because of a lack of detailed occupational exposure assessments. Therefore, exposure assessment findings, measuring the mass concentration of elemental carbon from personal breathing zone (PBZ) samples, from 8 U.S.-based multi-walled CNT (MWCNT) manufacturers and users were extrapolated to results of an inhalation study in mice. Results: Upon analysis, an inhalable elemental carbon mass concentration arithmetic mean of 10.6 µg/m3 (geometric mean 4.21 µg/m3) was found among workers exposed to MWCNT. The concentration equates to a deposited dose of approximately 4.07 µg/d in a human, equivalent to 2 ng/d in the mouse. For MWCNT inhalation, mice were exposed for 19 d with daily depositions of 1970 ng (equivalent to 1000 d of a human exposure; cumulative 76 yr), 197 ng (100 d; 7.6 yr), and 19.7 ng (10 d; 0.76 yr) and harvested at 0, 3, 28, and 84 d post-exposure to assess pulmonary toxicity. The high dose showed cytotoxicity and inflammation that persisted through 84 d after exposure. The middle dose had no polymorphonuclear cell influx with transient cytotoxicity. The low dose was associated with a low grade inflammatory response measured by changes in mRNA expression. Increased inflammatory proteins were present in the lavage fluid at the high and middle dose through 28 d post-exposure. Pathology, including epithelial hyperplasia and peribronchiolar inflammation, was only noted at the high dose. Conclusion: These findings showed a limited pulmonary inflammatory potential of MWCNT at levels corresponding to the average inhalable elemental carbon concentrations observed in U.S.-based CNT facilities and estimates suggest considerable years of exposure are necessary for significant pathology to occur at that level. [Description provided by NIOSH]
• Subjects:
  Aerosols Animals Environmental Exposure Environmental Monitoring Laboratories Nervous System Occupational Health Radiation Dosimeters Risk Assessment Risk Factors Safety

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• Keywords:
  Analytical-processes Author Keywords: Workplace Exposure Assessment Dosimetry Environmental-exposure Exposure-assessment Exposure-levels Gene Expression Inhalation Exposure Laboratory-animals Molecular-biology Molecular-structure Mouse Model MWCNT Dose Response And Time Dependence Nanotechnology Neurological-reactions Neurological-system Physiological-effects Physiological-function Physiology Protein Risk-analysis Risk-factors Workers

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• ISSN:
  1743-8977
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Ohio ; OSHA Region 3 ; OSHA Region 5 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division ; DSHEFS - Division of Surveillance, Hazard Evaluations, and Field Studies ; DART - Division of Applied Research and Technology
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  53
• Volume:
  10
• NIOSHTIC Number:
  nn:20043362
• Citation:
  Part Fibre Toxicol 2013 Oct; 10:53
• Contact Point Address:
  Aaron Erdely, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, 26505-2888, USA
• Email:
  efi4@cdc.gov
• Federal Fiscal Year:
  2014
• NORA Priority Area:
  Manufacturing ; Public Safety
• Peer Reviewed:
  True
• Source Full Name:
  Particle and Fibre Toxicology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:18ac37f9af420236ab1bb2e60c00f862ee57282428b8b4fad7ab3e768afa926bfaa2b4af1d1dd3bb7f57dcf23c7b34567dabb947f8b3342713530f12f979e30e
• Download URL:
  https://stacks.cdc.gov/view/cdc/195279/cdc_195279_DS1.pdf
• File Type:
  [PDF - 2.59 MB ]