Letter to the Editor re Bernstein et al: Health risk of chrysotile revisited. Crit Rev Toxicol, 2013; 43(2): 154-183

Our plain-English summary of Letter to the Editor re Bernstein et al: Health risk of chrysotile revisited. Crit Rev Toxicol, 2013; 43(2): 154-183, by M.M. Finkelstein (Critical Reviews in Toxicology, 2013).

The study

• Author: M.M. Finkelstein
• Journal: Critical Reviews in Toxicology
• Published: 2013;43(8):707-8
• Type of article: Letter, Comment
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This is a letter to the editor, not a new study. The author responded to a 2013 review by Bernstein and colleagues concluding that chrysotile asbestos has relatively short biopersistence. The author argued that the review left out human lung-tissue studies contradicting this, and described five published papers. Churg and colleagues (1984) reported more chrysotile and tremolite-group fibers in five chrysotile miners and millers with pleural mesothelioma than in miners without asbestos-related disease. Churg and Wiggs (1986) found long chrysotile fibers in the lungs of many exposed workers but few general-population controls. Rogers and colleagues (1991), in Australia, reported a mesothelioma odds ratio of 15.7 (95% CI 6.1 to 40) per 10-fold increase in lung concentration of chrysotile fibers under 10 micrometres. Dufresne and colleagues (1996) studied Quebec miners and millers; the author's 1999 reanalysis of that material estimated chrysotile clearance half-times of 3.8 to 8 years, depending on fiber length. The author concluded that chrysotile stays in the lung for decades and that the review was not objective. The author disclosed having been an expert witness in chrysotile litigation.

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 commenting on a published review (Bernstein et al., 2013); it reports no new data and discusses five earlier published lung fiber burden papers
• Who was studied: No study population of its own. The letter discusses earlier studies of chrysotile miners and millers, workers exposed to processed chrysotile ore, general-population controls, Australian mesothelioma cases and controls, and Quebec asbestos miners and millers
• Exposure: Chrysotile asbestos and the amphiboles found with it in chrysotile ore (tremolite, actinolite, anthophyllite); the cited studies also measured amosite and crocidolite
• Main results:
  • The letter reports that Churg et al. (1984) found mean fibers per gram of dry lung of 64 million chrysotile and 540 million tremolite-group fibers in five chrysotile miners and millers with mesothelioma, compared with 23 million and 58 million in chrysotile miner controls without asbestos-related disease
  • The letter reports that Churg and Wiggs (1986) found chrysotile fibers longer than 10 micrometres in 5% of general-population controls, compared with 40% of processed-ore workers and 80% of miners
  • The letter reports that Rogers et al. (1991), comparing 221 mesothelioma cases with 359 postmortem controls in Australia, found an odds ratio for mesothelioma of 15.7 (95% CI 6.1 to 40) for a 10-fold increase in the lung concentration (fibers per microgram) of chrysotile fibers shorter than 10 micrometres
  • The letter reports that Dufresne et al. (1996), studying Quebec asbestos miners and millers, found higher geometric mean concentrations of chrysotile fibres 5 to 10 micrometres long in patients with asbestosis, with or without lung cancer, than in controls
  • The letter reports that in the author's 1999 reanalysis with Dufresne of the 1996 material, chrysotile lung burden of all fiber lengths remained greater than in controls even 15 years after leaving exposure
  • The letter reports clearance half-times calculated in that 1999 reanalysis of 3.8 years for the shortest chrysotile fibers, 5.7 years for fibers 5 to 10 micrometres long, and 8 years for the longest fibers
• The authors' conclusion: The author concluded that chrysotile fibers are retained in the lung for decades, that the human data are inconsistent with the review's claim of short biopersistence, and that by omitting these data the review was not an objective analysis. The author also stated that the review was funded by the International Chrysotile Association in cooperation with The Canadian Chrysotile Association
• Limitations the authors state:
  • The author noted that finding fewer long fibers than short fibers in the lung could reflect the breakup of longer fibers, but could also reflect a higher concentration of shorter fibers in workplace air

Topics

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

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

Related studies

• Response to Murray M. Finkelstein, letter to the editor re Bernstein et al: Health risk of chrysotile revisited. Crit Rev Toxicol, 2013; 43(2): 154-183 — D. Bernstein, J. Dunnigan, et al. (2013)
• Health risk of chrysotile revisited — D. Bernstein, J. Dunnigan, et al. (2013)
• Editor's preface to the report of the workshop on health risks associated with chrysotile asbestos — J.M. Ellison (1994)
• Letter to the Editor on "Chrysotile and rock wool fibers induce chromosome aberrations and DNA damage in V79 lung fibroblast cells" — J.G. Hadley, A.E. Crane (2019)
• Letter concerning: Occupational exposures to cosmetic talc and risk of mesothelioma: an updated pooled cohort and statistical power analysis with consideration of latency period by Gary M. Marsh et al. (Inhal Toxicol. 2019 Aug 5:1-11. doi:10.1080/08958378.2019.1645768) — M.M. Finkelstein (2019)
• Re: Paradis G. Ban all production and export of chrysotile asbestos [Editor's Page]. Can J Public Health 2010;101(5):352 — M. Greenberg (2011)

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