Environmental and occupational health hazards associated with the presence of asbestos in brake linings and pads (1900 to present): A "state-of-the-art" review

Our plain-English summary of Environmental and occupational health hazards associated with the presence of asbestos in brake linings and pads (1900 to present): A "state-of-the-art" review, by S.S. Paskal (Journal of Toxicology and Environmental Health. Part B, Critical Reviews, 2004).

The study

• Author: S.S. Paskal
• Journal: Journal of Toxicology and Environmental Health. Part B, Critical Reviews
• Published: 2004;7(6):481-2; author reply 482-3
• Type of article: Comment, Letter
• Read it: PubMed · Publisher

In plain English

This letter to the editor and reply reported no new research data. Steven S. Paskal criticized a 2004 review on asbestos in brake linings and pads by Paustenbach and colleagues, noting it was sponsored by defendants in asbestos litigation. The letter argued that the review gave only OSHA's limits of 0.1 fibers per cubic centimeter (f/cc) as an 8-hour average and 1 f/cc over 30 minutes, omitting required work practices. Citing OSHA's risk assessment for a 45-year working lifetime, the letter put the one-in-a-thousand cancer risk level at 0.03 f/cc. OSHA's brake and clutch work practices, the letter said, were meant to cut exposures below 0.05 f/cc. The reply stated that OSHA's permissible exposure limit was 0.1 f/cc and 0.05 f/cc was not an implied limit. It stated that, across data from before and after newer cleaning methods, brake mechanics' average 8-hour time-weighted exposure was 0.04 to 0.05 f/cc. It called OSHA's risk curve outdated because fiber type (chrysotile versus amphiboles) and size affect potency. It also noted Paskal had testified for plaintiffs in a brake asbestos case.

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 criticizing a published review, with the review authors' reply; not an original study
• Exposure: Asbestos in automotive brake linings and pads; how the 2004 review described OSHA exposure limits (8-hour average limit of 0.1 fibers per cubic centimeter, 30-minute excursion limit of 1)
• Main results:
  • The letter writer stated that the review was open about its bias toward its sponsors, who were defendants in asbestos litigation
  • The letter writer argued that the review left out most of the OSHA standard and misled readers into believing that the exposure limits matched risks OSHA considered acceptable
  • The letter presented a figure, taken from OSHA's risk assessment, of excess cancer deaths from asbestos exposure over a 45-year working lifetime
  • According to the letter writer, the exposure level in that figure corresponding to a one-in-a-thousand cancer risk was 0.03 fibers per cubic centimeter
  • The letter writer stated that automotive friction material repairs made up about 93% of asbestos work in the United States at the time of OSHA's latest revision
  • The letter writer stated that OSHA said its brake and clutch work practices would reduce exposures to below 0.05 fibers per cubic centimeter
  • The review authors replied that the OSHA permissible exposure limit is 0.1 fibers per cubic centimeter and that 0.05 fibers per cubic centimeter is not an implied regulatory limit
  • The review authors stated, citing earlier sources and considering data from before and after newer cleaning methods, that the average 8-hour time-weighted average concentration for brake mechanics was 0.04 to 0.05 fibers per cubic centimeter
  • The review authors called the OSHA dose-response curve outdated and said that fiber type (chrysotile versus amphiboles) and fiber size (short versus long) affect the cancer-causing potency of asbestos fibers
  • The review authors noted that the letter writer had given testimony for plaintiffs in a brake asbestos case in which one of them was to testify for the defense
• The authors' conclusion: The letter writer concluded that it was hard to believe the review's omissions about the OSHA standard were accidental. The review authors maintained that the OSHA limit is 0.1 fibers per cubic centimeter, as they had reported.

Topics

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

Medical terms in this study, explained in our Lexicon: Brake Lining.

Related studies

• Environmental and occupational health hazards associated with the presence of asbestos in brake linings and pads (1900 to present): a "state-of-the-art" review — D.J. Paustenbach, B.L. Finley, et al. (2004)
• Asbestos exposure during brake lining maintenance and repair — A.N. Rohl, A.M. Langer, et al. (1976)
• Exposure to chrysotile asbestos associated with unpacking and repacking boxes of automobile brake pads and shoes — A.K. Madl, L.L. Scott, et al. (2008)
• Reduction of the biological potential of chrysotile asbestos arising from conditions of service on brake pads — A.M. Langer (2003)
• Asbestos exposure during routine brake lining manufacture — H. Kakooei, M. Sameti, et al. (2007)
• Asbestos fibres in the lungs of an American mechanic who drilled, riveted, and ground brake linings: a case report and discussion — M.M. Finkelstein (2015)

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