Canada, chrysotile and cancer: Health Canada's Asbestos International Expert Panel report

Our plain-English summary of Canada, chrysotile and cancer: Health Canada's Asbestos International Expert Panel report, by L.T. Stayner (Journal of Occupational and Environmental Medicine, 2008).

The study

• Author: L.T. Stayner
• Journal: Journal of Occupational and Environmental Medicine
• Published: 2008;50(12):1327-8
• Type of article: Editorial
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This article was an editorial, not a research study. The author had served on an expert panel convened by Health Canada that met in Montreal in November 2007 to consider the dose-response and toxicity of commercial chrysotile fibers. The author reported that the panel's report and members' comments, completed in March 2008, had not been published, and that a contract prevented panel members from releasing its contents. The author wrote that the report does not say chrysotile exposure is safe, noting that numerous scientific organizations recognize chrysotile as a cause of lung cancer, mesothelioma and asbestosis. Describing other studies, the author reported a general consensus that chrysotile is less potent than amphiboles for mesothelioma, by a highly uncertain amount. The author called the evidence of a difference for lung cancer "weak at best", citing a South Carolina textile study whose lung cancer slope was about 100 times that of a Quebec study. The author argued that lower potency does not make chrysotile safe, and urged Canada to support listing chrysotile under the Rotterdam Convention and to ban the export and use of asbestos.

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: Editorial (opinion piece) by a member of Health Canada's Asbestos International Expert Panel; not an original study
• Who was studied: No study population. The editorial concerns a 2-day meeting of an International Expert Panel convened by Health Canada's Safe Environments Program in Montreal, Canada, in November 2007
• Exposure: Commercial chrysotile asbestos fibers, which Canada produces and exports
• Main results:
  • The author reported that the panel's report and the members' individual comments, completed in March 2008, had not been published at the time of writing
  • The author stated that panel members had signed a contract preventing them from releasing the report's contents, but that the report does not say chrysotile exposure is safe
  • The author noted that chrysotile, like other forms of asbestos, has been recognized by numerous scientific organizations as a cause of lung cancer, mesothelioma and asbestosis, and wrote that no new information in the panel report would alter this conclusion
  • Describing other research, including a meta-analysis by Berman and Crump, the author reported a general consensus that chrysotile is less potent than amphibole asbestos for mesothelioma, but wrote that the size of this difference is highly uncertain
  • In the author's view, the evidence that asbestos fiber types differ in potency for lung cancer is weak
  • The author reported that the lung cancer slope from a study of South Carolina textile workers, who were mainly exposed to Quebec chrysotile, was about 100 times greater than the slope from a study of Quebec chrysotile miners and millers. These are results of other studies, not of this article
  • The author reported that in the Berman and Crump meta-analysis, leaving out the Quebec study halved the chrysotile lung cancer slope, and leaving out the South Carolina study doubled it. This is a result of another study, not of this article
• The authors' conclusion: The author argued that even if chrysotile is less potent than other forms of asbestos, this does not mean chrysotile exposure is safe. The author urged Canada to support listing chrysotile under the Rotterdam Convention and to ban the export and use of asbestos.

Topics

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

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

Related studies

• Asbestos panel chair mystified by secrecy surrounding report — R. Collier (2009)
• How Canada Changed from Exporting Asbestos to Banning Asbestos: The Challenges That Had to Be Overcome — K. Ruff (2017)
• Health advocates assail Canada's asbestos stance — R. Collier (2008)
• Canada, chrysotile, and the search for truth — T. Ogden (2008)
• Towards health-based nano reference values (HNRVs) for occupational exposure: Recommendations from an expert panel — M. Visser, I. Gosens, et al. (2022)
• A Quantitative Retrospective Exposure Assessment for Former Chrysotile Asbestos Miners and Millers from Baie Verte, NL, Canada — T. Giles Murphy, S. Bornstein, et al. (2021)

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