Inaccuracies in article on mesothelioma in brake workers

Our plain-English summary of Inaccuracies in article on mesothelioma in brake workers, by P.A. Hessel (International Journal of Occupational and Environmental Health, 2009).

The study

• Author: P.A. Hessel
• Journal: International Journal of Occupational and Environmental Health
• Published: 2009;15(2):232-4; author reply 234-8
• Type of article: Comment, Letter
• Read it: PubMed · Publisher

In plain English

This item is a letter to the editor, not a new study, followed by a reply. The author, a consultant to automotive friction product makers, disputed a 2007 amicus brief article by Welch and 51 co-signers arguing that asbestos brake work can cause mesothelioma, saying it contained inaccuracies. The author wrote that about 18 epidemiologic studies of vehicle mechanics existed and none showed an increased mesothelioma risk. A Spanish study by Agudo et al., the author noted, reported an odds ratio of 0.62 for motor vehicle mechanics (three cases, 14 controls). The author also argued case reports mean little for a common exposure: 13.5% of controls in the Spirtas et al. study had done brake work. In reply, Welch and co-signers wrote that the meta-analysis they meant contained seven case-control studies with fewer than 200 cases or controls recorded as mechanics. They also wrote that exposure misclassification and other occupational asbestos exposures meant these studies could not give useful information on mesothelioma risk among brake installation and repair workers. They concluded they found nothing showing brake asbestos exposure is without risk.

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) disputing a published article, with a reply from that article's authors; no new data were collected
• Who was studied: No people were studied. The letter discusses published epidemiologic studies of vehicle (brake) mechanics. The letter's author disclosed consulting work for automobile and automotive friction product manufacturers.
• Exposure: Asbestos exposure from brake work by vehicle mechanics (asbestos-containing brakes)
• Main results:
  • The author stated that about 18 epidemiologic studies of mesothelioma among vehicle mechanics exist and that none showed an increased risk.
  • The author pointed out that the Agudo et al. study, cited by Welch and co-signers, reported 3 cases and 14 controls who were motor vehicle mechanics, with an odds ratio of 0.62.
  • The author argued that case reports are of limited value for common exposures, noting that in the Spirtas et al. study 13.5% of controls had done brake work.
  • On asbestosis, the author stated that the first chest x-ray study cited had no comparison group. The second did not find more irregular opacities among brake mechanics.
  • The author stated that the industry-funded meta-analysis and expanded analysis were done on the understanding that results would be published whatever they showed.
  • In reply, Welch and co-signers stated that the Goodman meta-analysis included seven case-control studies with fewer than 200 cases or controls whose occupation was specifically recorded as vehicle mechanic or similar.
  • In reply, Welch and co-signers stated that in the Spirtas case-control data re-analyzed by Hessel, 28 cases and 63 controls had done brake work. Of these, only one case and nine controls had no other significant asbestos exposure.
  • In reply, Welch and co-signers stated that exposure misclassification and confounding by asbestos exposure in other occupations mean these case-control studies cannot provide useful information on mesothelioma risk among workers doing brake installation and repair.
  • In reply, Welch and co-signers cited a review by Michaels and Monforton. Of 26 litigation-sponsored papers on automobile mechanics, 18 were by experts mainly associated with defendants and 8 by experts mainly working for plaintiffs.
• The authors' conclusion: The author concluded that the accusations in the Welch article were not supported by a fair presentation of the data. In reply, Welch and co-signers concluded that, because of exposure misclassification and confounding by other occupational asbestos exposure, the case-control studies cannot provide useful information on mesothelioma risk among brake installation and repair workers. They also concluded that nothing in the evidence Hessel cited shows that asbestos exposure from brakes is without risk.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma.

Related studies

• 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)
• The analysis of asbestos count data with "nondetects": the example of asbestos fiber concentrations in the lungs of brake workers — M.M. Finkelstein (2013)
• Estimation of personal exposure to asbestos of brake repair workers — M.F. Cely-García, F.C. Curriero, et al. (2017)
• Asbestos fibre concentrations in the lungs of brake workers: another look — M.M. Finkelstein (2008)
• Mesothelioma in a brake repair worker — A.M. Langer, W.T. McCaughey (1982)
• Asbestos Fiber Concentrations in the Lungs of Brake Repair Workers: An Updated Analysis Using Several Regression Methods to Handle Nondetectable Measurements — Y. Liu, G.M. Marsh, et al. (2018)

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