Carbon nanotubes and pleural damage: perspectives of nanosafety in the light of asbestos experience

Our plain-English summary of Carbon nanotubes and pleural damage: perspectives of nanosafety in the light of asbestos experience, by G.M. Stella (Biointerphases, 2011).

The study

• Author: G.M. Stella
• Journal: Biointerphases
• Published: 2011;6(2):P1-17
• Type of article: Review
• Cited by: 26 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Carbon nanotubes are molecular-scale one-dimensional manufactured materials which display several potential applications in engineering and materials science. Burgeoning evidence demonstrates that carbon nanotubes and asbestos share comparable physical properties. Therefore carbon nanotubes might display toxic effects and the extent of the toxicity is more specifically directed to lung and pleura. These effects are related to properties of carbon nanotubes, such as their structure, length, aspects ratio, surface area, degree of aggregation, extent of oxidation, bound functional group, method of manufacturing, concentration and dose. At the present there is no global agreement about the risk of carbon nanotubes on human health and in particular on their transformation capacity. Safety concerns regarding carbon nanotubes can be ameliorated. In this context, it is important to put the known hazards of carbon nanotubes into perspective. Here is presented an overview about toxicity issues in the application of carbon nanotubes to biological systems, taking into consideration the already known asbestos-induced mechanisms of biological damages.

In plain English

This article was a narrative review by a single author, not a new study. It summarized published work on the toxicity of single-walled and multiwalled carbon nanotubes and compared it with known mechanisms of asbestos damage to the pleura. It covered how workers might be exposed and how nanotubes behave in the body, drawing on other researchers' air measurements and on animal and cell experiments. Two 13-week animal inhalation studies in the review reported lung inflammation and granulomas, and both reported no toxicity outside the lungs on tissue examination. A mouse study it described found that multiwalled nanotubes reached the tissue under the pleura after one high-concentration inhalation. The review stated that the ability of nanotubes to damage DNA was not clearly determined. The author noted that definitive conclusions about long nanotubes were not yet possible, that short-term studies might not reveal cancer potential, and that animal results cannot simply be applied to humans. The author concluded that, in light of the asbestos experience, the possible toxic and tumor-causing potential of nanotubes should be considered in industrial and research settings.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Narrative review by a single author; no new data were collected
• Who was studied: No study population of its own. The review covered published studies on carbon nanotube exposure and toxicity (workplace air measurements, animal experiments mainly in mice and rats, and cell experiments) and published work on how asbestos damages the pleura
• Exposure: Carbon nanotubes, both single-walled (SWCNTs) and multiwalled (MWCNTs), compared with asbestos fibers (crocidolite, amosite and chrysotile are named)
• Main results:
  • The review described a 13-week aerosol (inhalation) study of multiwalled nanotubes in animals that reported heavier lungs with granulomatous inflammation, with effects related to concentration
  • The same 13-week study, as described in the review, reported no pathological response in other major organs such as the liver, kidney and heart, based on tissue examination
  • A second 90-day (13-week) inhalation study, as described in the review, reported granulomatous changes in the lungs and detected no systemic toxicity at any concentration tested
  • A mouse study cited in the review (Ryman-Rasmussen et al.) showed that multiwalled nanotubes migrated to the subpleura after a single inhalation exposure at a high concentration (30 mg/m3)
  • The review reported that in a cited mouse study the lesions caused by multiwalled nanotubes differed from those caused by asbestos: they were focal and regional fibrosis under the pleura, not the pleural plaques typical of asbestos
  • The review stated that the ability of carbon nanotubes to damage DNA (genotoxic potential) had not been clearly determined
• The authors' conclusion: The author concluded that carbon nanotubes could have a toxic and tumor-causing potential and that, in light of the asbestos experience, this should be considered in industrial and research settings
• Limitations the authors state:
  • The author stated that definitive conclusions about the potential risks of long carbon nanotubes could not yet be drawn
  • The risk data come mainly from subacute and subchronic studies. Because mesothelioma develops long after asbestos exposure, the author stated that these studies may not settle whether nanotubes can cause cancer
  • The author stated that results from rodent models cannot simply be translated to humans
  • The author stated that measurements of human exposure to nanotubes needed improvement

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pleura, Damages.

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• A single intratracheal instillation of single-walled carbon nanotubes induced early lung fibrosis and subchronic tissue damage in mice — E.J. Park, J. Roh, et al. (2011)
• Asbestos, carbon nanotubes and the pleural mesothelium: a review of the hypothesis regarding the role of long fibre retention in the parietal pleura, inflammation and mesothelioma — K. Donaldson, F.A. Murphy, et al. (2010)
• Length-dependent retention of carbon nanotubes in the pleural space of mice initiates sustained inflammation and progressive fibrosis on the parietal pleura — F.A. Murphy, C.A. Poland, et al. (2011)
• Length-dependent pleural inflammation and parietal pleural responses after deposition of carbon nanotubes in the pulmonary airspaces of mice — F.A. Murphy, C.A. Poland, et al. (2013)
• Threshold Rigidity Values for the Asbestos-like Pathogenicity of High-Aspect-Ratio Carbon Nanotubes in a Mouse Pleural Inflammation Model — D.K. Lee, S. Jeon, et al. (2018)

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