Chrysotile asbestos and mesothelioma

Our plain-English summary of Chrysotile asbestos and mesothelioma, by H.J. Woitowitz, K. Rödelsperger (American Journal of Industrial Medicine, 1991).

The study

• Authors: H.J. Woitowitz, K. Rödelsperger
• Journal: American Journal of Industrial Medicine
• Published: 1991;19(4):551-3
• Type of article: Comment, Letter
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

In this letter, the authors responded to published discussion, begun by Dunnigan's 1988 proposal, of whether chrysotile asbestos has only a very limited potential to cause mesothelioma. They drew on their own work in Giessen, Federal Republic of Germany: workplace asbestos measurements, analysis of lung fiber burden, and clinical study of occupational cancer. They reported a marked disparity between extensive workplace chrysotile exposure and the lack of increased chrysotile fibers in patients' lung dust. They did not exclude a long-term cancer effect, possibly a "hit-and-run" phenomenon. They argued that experience from mining and milling could not be transferred to other workplaces, citing German car mechanics. In their clinic and in the files of Professor Otto, they found 10 brake mechanics who developed mesothelioma between 1980 and 1985. Their earlier studies, with 90 measurements in 76 garages and 210 mechanics, showed low exposure that was exclusively chrysotile. Other German data found chrysotile in 611 of 615 respirable dust samples in the friction lining industry, and only chrysotile in 338 garage measurements. In a multicenter case-control study begun in 1988, 14 of 175 mesothelioma patients in Hamburg and Munich hospitals were car mechanics. In at least three of them, car mechanic work was the only known asbestos exposure. The authors concluded that mesothelioma incidence was increased among car mechanics exposed only to chrysotile, with a mean dose below 1 fiber/ml × years.

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. The authors responded to a published debate over whether chrysotile asbestos causes mesothelioma. They reported 10 mechanics who serviced motor-vehicle brakes and developed mesothelioma between 1980 and 1985. These cases were found in the authors' outpatient clinic and in the files of another physician. Citing their earlier measurements in 76 garages, analyzed for 210 car mechanics, they described brake-work exposure as low and exclusively chrysotile, with a mean of 0.54 fiber/ml × years. Among 174 mesothelioma patients at their clinic, the number of car mechanics rose from six to 12 during the period. In a new case-control study, 14 of 175 mesothelioma patients in Hamburg and Munich hospitals were car mechanics. For at least three of them, car mechanic work was the only known asbestos exposure. The other 11 later worked in other trades with potential asbestos exposure. The authors concluded they had found an increased incidence of mesothelioma among car mechanics exposed only to chrysotile, at a mean dose below 1 fiber/ml × years. They said lung-fiber analyses and more case-control data were still expected.

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 reporting case observations, exposure measurements (largely from the authors' earlier work) and early data from an ongoing multicenter case-control study
• Who was studied: 10 brake-servicing motor-vehicle mechanics in the Federal Republic of Germany who developed mesothelioma between 1980 and 1985. They were identified in the authors' outpatient clinic (IPAS) and the files of Professor Dr. Otto. The letter also reports 174 mesothelioma patients at the authors' clinic and 175 mesothelioma patients in Hamburg and Munich hospitals since 1988.
• Exposure: Asbestos exposure from brake repair work by car mechanics, described as low and exclusively chrysotile. Measured from 90 measurements of fibers longer than 5 micrometers in 76 garages.
• Main results:
  • 10 mechanics who serviced brakes on motor vehicles developed mesothelioma between 1980 and 1985.
  • Among 210 car mechanics, mean cumulative exposure was 0.54 fiber/ml × years. This comes from the authors' earlier study; the spread figure is garbled in the scan.
  • Only chrysotile was found in garages (338 measurements).
  • In the friction lining industry, the German Institute of Occupational Safety found chrysotile in 611 of 615 respirable dust samples. Crocidolite was found only four times, in a single plant, between 1981 and 1982.
  • Among a total of 174 mesothelioma patients at the authors' clinic, the number of car mechanics increased from six to 12 during the period.
  • In the multicenter case-control study begun in 1988, 14 of 175 mesothelioma patients in Hamburg and Munich hospitals were car mechanics.
  • Of these 14, at least three had car mechanic work as their only known occupational asbestos exposure.
  • The other 11 started as car mechanics but later worked in trades with potential asbestos exposure, such as turbine fitter, shipbuilding mechanic, rigger or welder.
• The authors' conclusion: The authors concluded that they had found an increased incidence of mesothelioma among car mechanics exposed only to chrysotile, with a mean dose of less than 1 fiber/ml × years. They also stated that they do not exclude a long-term cancer effect of chrysotile despite low chrysotile levels in lung dust at autopsy.
• Limitations the authors state:
  • Lung tissue fiber analysis of these patients had not yet been done; the authors expected it to provide further data.
  • Further data from the multicenter case-control study were still to come.
  • For one mechanic (born 1939), only the duration of exposure could be determined, not the year exposure began.

Topics

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

Medical terms in this study, explained in our Lexicon: Chrysotile, Mesothelioma, Fiber Burden, Case-Control Study, Asbestos Exposure.

Related studies

• The risk of mesothelioma from exposure to chrysotile asbestos — C.M. Yarborough (2007)
• Mortality and mesothelioma incidence among chrysotile asbestos miners in Balangero, Italy: A cohort study — D. Ferrante, D. Mirabelli, et al. (2020)
• Cause-specific mortality in relation to chrysotile-asbestos exposure in a Chinese cohort — S. Lin, X. Wang, et al. (2012)
• Exposure-response estimate for lung cancer and asbestosis in a predominantly chrysotile-exposed Chinese factory cohort — M.N. Courtice, X. Wang, et al. (2016)
• Analysis of mortality in chrysotile asbestos miners in China — L. Du, X. Wang, et al. (2012)
• Re Ferrante et al (2020). Mortality and mesothelioma incidence among chrysotile asbestos miners in Balangero, Italy: A cohort study — J. Schüz, H. Kromhout (2020)

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