Response to Kay Teschke. Re: Mesothelioma among Motor Vehicle Mechanics: An Updated Review and Meta-analysis

Our plain-English summary of Response to Kay Teschke. Re: Mesothelioma among Motor Vehicle Mechanics: An Updated Review and Meta-analysis, by D.H. Garabrant, D.D. Alexander, P.E. Miller, et al (The Annals of Occupational Hygiene, 2016).

The study

• Authors: D.H. Garabrant, D.D. Alexander, P.E. Miller, J.P. Fryzek, P. Boffetta, M.J. Teta, P.A. Hessel, V.A. Craven, M.A. Kelsh, M. Goodman
• Journal: The Annals of Occupational Hygiene
• Published: 2016;60(8):1036-7
• Type of article: Letter, Comment
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

In this letter, the authors of a 2016 meta-analysis of mesothelioma among motor vehicle mechanics replied to a letter by Dr Kay Teschke. They stated that Dr Teschke had no criticisms of their paper but had focused on how epidemiological evidence should be interpreted in legal cases, which they considered beyond the scope of their paper. They said their meta-analysis asked whether motor vehicle mechanics and brake repair workers were at increased risk of mesothelioma. It did not ask whether these workers were the right setting in which to study the risks of chrysotile. They listed possible reasons why no increased risk was observed. These included low cumulative chrysotile exposure, absence of commercial amphiboles, low potency of chrysotile, short-fiber chrysotile in friction materials that degrades into shorter fibers and forsterite, binding of fibers in resin, and part-time brake work. They argued that studies classifying workers by occupation remain informative even without full exposure characterization. They noted that sub-analyses by duration of work and by brake work also did not show increased risk. They concluded that the epidemiology does not support a conclusion that motor vehicle mechanics and brake repair workers are at increased risk of mesothelioma. Several authors declared legal testimony or consultancy on behalf of automotive and brake-related companies.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This is a letter to the editor, not a new study. The authors replied to a letter by Kay Teschke about their 2016 review and meta-analysis of mesothelioma among motor vehicle mechanics. It reports no new data. The authors said their meta-analysis asked whether motor vehicle mechanics and brake repair workers were at increased risk of mesothelioma, not whether studies of mechanics are the right setting to examine risk from chrysotile. They listed potential reasons for no observable increased risk. These included low cumulative chrysotile exposure, no commercial amphiboles, and short-fiber chrysotile in friction materials breaking down into shorter fibers and the non-fibrous mineral forsterite. They also noted that many mechanics repair brakes only part-time. The authors argued that studies classifying workers by occupation remain valid. They said sub-analyses by duration of work and by brake work also did not show increased risk. The authors concluded that the epidemiology does not support a conclusion that these workers are at increased risk. Several authors declared legal testimony or consultancy for automotive and brake manufacturers.

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: the authors' reply to another letter about their own published meta-analysis. No new data.
• Who was studied: No study population of its own. The letter discusses the authors' 2016 meta-analysis of studies of motor vehicle mechanics and brake repair workers.
• Exposure: Chrysotile asbestos in brakes and other friction materials, as discussed in the letter.
• Main results:
  • The authors said the question their meta-analysis set out to answer was whether motor vehicle mechanics and brake repair workers were at increased risk of mesothelioma.
  • The authors offered potential reasons why there is no observable increased risk. These were: low cumulative exposures to chrysotile; absence of commercial amphiboles; low potency of chrysotile to cause mesothelioma; use of short-fiber chrysotile in friction materials and its breakdown into shorter fibers and the non-fibrous mineral forsterite; lack of potency of fibers shorter than 10 micrometres; and binding of fibers in a resin matrix.
  • The authors noted, as Teschke had, that many motor vehicle mechanics repair brakes part-time or for a small part of their careers.
  • The authors argued that detailed exposure characterization does not invalidate studies that classify workers by occupation at the group level.
  • The authors said some studies in their meta-analysis included sub-analyses by duration of work and by work with brakes specifically, and that these also did not show increased risk.
  • The letter's declaration states there was no direct financial support for the letter. It also states that several authors have provided legal testimony and/or consultancy on behalf of companies that make automobiles, brakes, clutches and automotive gaskets.
• The authors' conclusion: The authors concluded that the epidemiology does not support a conclusion that motor vehicle mechanics and brake repair workers are at increased risk of mesothelioma.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Meta-Analysis, Chrysotile, Amphibole Group, Forsterite, Epidemiology.

Related studies

• Mesothelioma among Motor Vehicle Mechanics: An Updated Review and Meta-analysis — D.H. Garabrant, D.D. Alexander, et al. (2016)
• Mesothelioma and lung cancer among motor vehicle mechanics: a meta-analysis — M. Goodman, M.J. Teta, et al. (2004)
• Asbestos exposures of mechanics performing clutch service on motor vehicles — H.J. Cohen, D.R. Van Orden (2008)
• Malignant Mesothelioma in a Motor Vehicle Mechanic — C. Meisenkothen (2017)
• Mesothelioma in vehicle mechanics: is the risk different for Australians? — M.A. Kelsh, V.A. Craven, et al. (2007)
• Thinking about Occupation-Response and Exposure-Response Relationships: Vehicle Mechanics, Chrysotile, and Mesothelioma — K. Teschke (2016)

Browse more research in The Annals of Occupational Hygiene, or return to medical research.