Mesothelioma among car mechanics?

Our plain-English summary of Mesothelioma among car mechanics?, by H.J. Woitowitz, K. Rödelsperger (The Annals of Occupational Hygiene, 1994).

The study

• Authors: H.J. Woitowitz, K. Rödelsperger
• Journal: The Annals of Occupational Hygiene
• Published: 1994;38(4):635-8
• Cited by: 39 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

This paper, read at a 1993 workshop on health risks of chrysotile asbestos, reported the final results on car mechanics from a completed German case-control study of mesothelioma. Of 324 mesothelioma cases, 16 (4.9%) were classified as motor vehicle mechanics. This compared with 16 (5.1%) of 315 hospital controls, who were patients who had undergone lung resection for other reasons (mostly lung cancer), and 12 (6.6%) of 182 population controls. Employment as mechanics began between 1925 and 1972. The median start year was 1949 for cases and hospital controls and 1946 for population controls, and median duration was longer for controls than for cases. Some mechanics in each group reported brake repair work: six or seven cases (the text and table differ), nine hospital controls and three population controls. In all three groups some individuals had substantial asbestos exposure in other jobs, such as power plants or shipbuilding. Four cases had no history of other asbestos exposure, and three of these had done brake repairs. Lung tissue analysis was available for two cases and one hospital control. It found no fibres longer than 5 µm in one case, amphibole fibres in the other case, and numerous long chrysotile fibres in the control. The authors concluded that there was no evidence of an increased mesothelioma risk for car mechanics, even with brake repairs. They added that asbestos exposure in other employment was an important confounder, so a small risk would not be detectable.

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 short report gave the final car-mechanic results from a German case-control study of mesothelioma. It was presented at a 1993 workshop on chrysotile asbestos. Among 324 mesothelioma cases, 16 (4.9%) had worked as motor vehicle mechanics. The comparison groups were 315 hospital controls, of whom 16 (5.1%) were mechanics, and 182 population controls, of whom 12 (6.6%) were mechanics. The hospital controls had mostly had lung surgery for lung cancer. Some mechanics in each group reported brake repair work, and some individuals in all three groups had substantial asbestos exposure in other jobs, such as power plants or shipbuilding. Only four of the mechanic cases had no other asbestos exposure. Lung tissue was analysed for three mechanics. One case had no fibres longer than 5 micrometres, one case had amphibole fibres, and one control had many long chrysotile fibres. The authors concluded there was no evidence that car mechanics had an increased mesothelioma risk, even with brake repair. They added that exposure in other jobs was a confounding factor, so a small risk would not be detectable.

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: Case-control study of mesothelioma; this report gives the final results for motor vehicle mechanics within it (no risk ratios or odds ratios are reported)
• Who was studied: 324 mesothelioma cases, 315 hospital controls (patients who had lung resection for reasons other than mesothelioma, mostly lung cancer) and 182 population controls, in Germany. Mechanics were identified by German Federal Statistical Office occupation code 421. Four of an earlier 14 mechanic cases were dropped because pathologists classified them only as 'possible mesothelioma'.
• Exposure: Work as a motor vehicle mechanic, including brake repair, which began between 1925 and 1972. Asbestos exposure in other jobs (e.g. power plant, ship-building) was also recorded.
• Main results:
  • Motor vehicle mechanics made up 16 of 324 mesothelioma cases (4.9%), 16 of 315 hospital controls (5.1%) and 12 of 182 population controls (6.6%).
  • Some of the 16 mechanic cases had not done typical car repair: one worked with locomotive engines, one with trams, and one only fitted windscreens in automobile production.
  • Median duration of mechanic employment was shorter for cases than for controls. The table gives 4 years (range 1 to 8.4) for cases, 5 years (3 to 43) for hospital controls and 5.5 years (0.6 to 35) for population controls.
  • Some individuals in all three groups had substantial asbestos exposure in other employment. Four of the mechanic cases had no history of asbestos exposure, and three of these four reported brake repairs.
  • Mesothelioma case No. 1 had no fibres longer than 5 micrometres in lung tissue. He had worked 8 years as a car mechanic from 1972, doing brake repairs, with no suggestion of other asbestos exposure.
  • Mesothelioma case No. 2 had amphibole fibres longer than 5 micrometres (282 in the table's units of thousands of fibres per gram dry lung). He had worked as a car mechanic for only 1 year, in 1940, and then as a Luftwaffe pilot, with no known asbestos exposure from other employment.
  • Hospital control No. 3 had numerous long chrysotile fibres (1 630 in the table's units) and no amphibole fibres. He had worked as a car mechanic from 1934 to 1939, and later as a prisoner of war he arc-welded steel structures and installed glass fibre insulation.
• The authors' conclusion: The authors concluded that their results gave no evidence that car mechanics have an increased risk of mesothelioma, even if they do brake repairs. They also doubted that the amphibole and chrysotile fibres found in two patients' lungs were related to their car mechanic work.
• Limitations the authors state:
  • Asbestos exposure in other employment was a confounding factor, so a small mesothelioma risk for car mechanics would not be detectable.
  • Finding no fibres in one case's lung tissue does not exclude the possibility that chrysotile fibres acted on the target cells decades before.
  • Brake service was recorded only where definitely reported; other mechanics may also have done brake work.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Auto mechanics and brake work, Chrysotile, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Chrysotile, Case-Control Study, Lung Cancer, Asbestos Exposure, Amphibole Group.

Related studies

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• Asbestos exposure among transmission mechanics in automotive repair shops — N. Salazar, M.F. Cely-García, et al. (2015)
• Brake mechanics, asbestos, and disease risk — M. Huncharek (1990)
• Asbestos-related diseases in automobile mechanics — J. Ameille, N. Rosenberg, et al. (2012)
• Chrysotile asbestos exposure associated with removal of automobile exhaust systems (ca. 1945-1975) by mechanics: results of a simulation study — D.J. Paustenbach, A.K. Madl, et al. (2006)
• Lung function and exposure to asbestos among vehicle mechanics — M. Dahlqvist, R. Alexandersson, et al. (1992)

Browse more research in The Annals of Occupational Hygiene, or return to medical research.