Egilman's assessment regarding exposures of auto mechanics to amphiboles is not accurate

Our plain-English summary of Egilman's assessment regarding exposures of auto mechanics to amphiboles is not accurate, by D.J. Paustenbach, K.R. White (Inhalation Toxicology, 2012).

The study

• Authors: D.J. Paustenbach, K.R. White
• Journal: Inhalation Toxicology
• Published: 2012;24(9):609-13; author reply 614-8
• Type of article: Letter, Comment
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This was a letter to the editor, not a research study, and it reported no new data. The authors answered, point by point, a letter by David Egilman about a 2011 paper by Marsh and colleagues on fiber levels in the lungs of brake repair workers. Citing other studies and legal documents, the authors argued that US automotive brakes contained chrysotile, not commercial amphiboles. They said that tremolite in Canadian chrysotile was present only in trace amounts, and that airborne amphibole fibers had not been measured during brake work. They wrote that they had found no information showing crocidolite in automotive gaskets. They agreed that Borg Warner used crocidolite in some automatic transmission friction plates for a limited period, but argued that mechanics' exposure from these was very low. They said a Ford mention of amosite in brake linings was dropped from the published version of that paper. The authors wrote that it would be reasonable for scientists to conclude that amphiboles in mechanics' lungs came from a job other than car or truck repair. They concluded that Egilman's statements about the implausibility of the Marsh paper's conclusions were unfounded.

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: letter to the editor (commentary responding to another letter); no original data
• Who was studied: No study population. The letter concerns automobile mechanics and responds to Egilman's 2012 letter about the Marsh et al. 2011 paper on lung fiber levels in brake repair workers.
• Exposure: Chrysotile in automotive brakes and clutches; trace tremolite in Canadian chrysotile; crocidolite in gaskets and in Borg Warner automatic transmission friction plates; amosite mentioned in a Ford document
• Main results:
  • Citing Finley et al. (2011), the authors stated that samples from Canadian chrysotile deposits used to make brakes contained asbestiform tremolite at less than 1%.
  • Citing Madl et al. (2008), the authors stated that TEM analysis found no measurable airborne amphibole fibers in air samples, down to 0.001 f/cc.
  • The authors stated that in their review of gasket catalogs and literature they had found no information that crocidolite was used in automotive gaskets.
  • The authors agreed that Borg Warner used crocidolite in some transmission friction plates for a limited period. They argued that mechanics' exposure from automatic transmission plates was very low.
  • Citing a simulation study by Cohen and Van Orden (2008), the authors reported airborne chrysotile during manual clutch work of 0.0016 fibers/cc on an 8-hour time-weighted average basis.
  • The authors stated that a 1968 Ford document by Hickish mentioned brake linings occasionally containing amosite, but the published 1970 version did not mention amosite.
  • On Maremont's use of crocidolite supplied by Ural Asbestos, the authors cited a study of Ural, Russia, quarries (Kashansky et al., 2001) that identified no amphibole fibers.
  • The authors wrote that it would be reasonable for scientists to conclude that amphiboles found in the lungs of mechanics came from an occupation other than repairing cars or trucks.
• The authors' conclusion: The authors concluded that Egilman's statements about the implausibility of the conclusions of Marsh and Roggli were unfounded.

Topics

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

Medical terms in this study, explained in our Lexicon: Amphibole Group.

Related studies

• Comparative long-term toxicity of Libby amphibole and amosite asbestos in rats after single or multiple intratracheal exposures — J.M. Cyphert, D.J. Carlin, et al. (2015)
• Sumas Mountain chrysotile induces greater lung fibrosis in Fischer344 rats than Libby amphibole, El Dorado tremolite, and Ontario ferroactinolite — J.M. Cyphert, A. Nyska, et al. (2012)
• Asbestos fiber concentrations in the lungs of brake repair workers: commercial amphiboles levels are predictive of chrysotile levels — G.M. Marsh, A.O. Youk, et al. (2011)
• Cumulative Retrospective Exposure Assessment (REA) as a predictor of amphibole asbestos lung burden: validation procedures and results for industrial hygiene and pathology estimates — J.O. Rasmuson, V.L. Roggli, et al. (2014)
• Re: Comments on Egilman's response to Hessel regarding the health hazards of brake dust and his reflections on corporate behavior — D. Paustenbach (2019)
• Thinking about Occupation-Response and Exposure-Response Relationships: Vehicle Mechanics, Chrysotile, and Mesothelioma — K. Teschke (2016)

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