Physicochemical Characterization of Genotoxicity of the Broad Class of Carbon Nanotubes and Nanofibers Used or Produced in U.S. Facilities

Details

• Journal Article:
  Particle and Fibre Toxicology
• Personal Author:
  Fraser, Kelly ; Kodali, Vamsi K. ; Yanamala, Naveena ; Birch, M. Eileen ; Cena, Lorenzo ; Casuccio, Gary ; Bunker, Kristin ; Lersch, Traci L. ; Evans, Douglas E. ; Stefaniak, Aleksandr B. ; Hammer, Mary Ann ; Kashon, Michael L. ; Boots, Theresa E. ; Eye, Tracy ; Hubczak, John ; Friend, Sherri A. ; Dahm, Matthew M. ; Schubauer-Berigan, Mary K. ; Siegrist, Katelyn ; Lowry, David ; Bauer, Alison K. ; Sargent, Linda M. ; Erdely, Aaron
• Description:
  Background: Carbon nanotubes and nanofibers (CNT/F) have known toxicity but simultaneous comparative studies of the broad material class, especially those with a larger diameter, with computational analyses linking toxicity to their fundamental material characteristics was lacking. It was unclear if all CNT/F confer similar toxicity, in particular, genotoxicity. Nine CNT/F (MW #1-7 and CNF #1-2), commonly found in exposure assessment studies of U.S. facilities, were evaluated with reported diameters ranging from 6 to 150 nm. All materials were extensively characterized to include distributions of physical dimensions and prevalence of bundled agglomerates. Human bronchial epithelial cells were exposed to the nine CNT/F (0-24 µg/ml) to determine cell viability, inflammation, cellular oxidative stress, micronuclei formation, and DNA double-strand breakage. Computational modeling was used to understand various permutations of physicochemical characteristics and toxicity outcomes. Results: Analyses of the CNT/F physicochemical characteristics illustrate that using detailed distributions of physical dimensions provided a more consistent grouping of CNT/F compared to using particle dimension means alone. In fact, analysis of binning of nominal tube physical dimensions alone produced a similar grouping as all characterization parameters together. All materials induced epithelial cell toxicity and micronuclei formation within the dose range tested. Cellular oxidative stress, DNA double strand breaks, and micronuclei formation consistently clustered together and with larger physical CNT/F dimensions and agglomerate characteristics but were distinct from inflammatory protein changes. Larger nominal tube diameters, greater lengths, and bundled agglomerate characteristics were associated with greater severity of effect. The portion of tubes with greater nominal length and larger diameters within a sample was not the majority in number, meaning a smaller percentage of tubes with these characteristics was sufficient to increase toxicity. Many of the traditional physicochemical characteristics including surface area, density, impurities, and dustiness did not cluster with the toxicity outcomes. Conclusion: Distributions of physical dimensions provided more consistent grouping of CNT/F with respect to toxicity outcomes compared to means only. All CNT/F induced some level of genotoxicity in human epithelial cells. The severity of toxicity was dependent on the sample containing a proportion of tubes with greater nominal lengths and diameters. [Description provided by NIOSH]
• Subjects:
  Chemistry DNA Damage Nanofibers Nanotubes, Carbon Occupational Health Particulate Matter Research Safety
• Keywords:
  Nanoparticles; Carbon nanotubes; CNT; Carbon nanofibers; CNF; Chemical properties; Physical properties; Genotoxicity; Particle size; Exposure assessment; Oxidative stress; DNA damage
• Source:
  Part Fibre Toxicol 2020 Dec; 17:62
• ISSN:
  1743-8977
• Pubmed ID:
  33287860
• Pubmed Central ID:
  PMC7720492
• Document Type:
  Text
• Funding:
  Project # 939051D/OH/NIOSH CDC HHS/United States
• Genre:
  Journal Article
• Place as Subject:
  Colorado ; Ohio ; OSHA Region 3 ; OSHA Region 5 ; OSHA Region 8 ; Pennsylvania ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division ; RHD - Respiratory Health Division ; DFSE - Division of Field Studies and Engineering
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  26 pdf pages
• Volume:
  17
• Issue:
  62
• NIOSHTIC Number:
  nn:20061632
• Contact Point Address:
  Aaron Erdely, Health Effect Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Rd, MS-2015, Morgantown, WV 26505-2888, USA
• Email:
  efi4@cdc.gov
• CAS Registry Number:
  Carbon nanotubes (CAS RN 308068-56-6)
• Federal Fiscal Year:
  2021
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  True
• Collection(s):
  CDC Public Access National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:805e366351ef863b17c89fb238da14fa3a3363eb5a3bce9dcfd1233e26dc4161628bdb7fca39b0e976363b6c8e07616669d24445ef139c6a577c53c6bd6dfec0
• Download URL:
  https://stacks.cdc.gov/view/cdc/105060/cdc_105060_DS1.pdf
• File Type:
  [PDF - 3.40 MB ]