Re: Mesothelioma in railroad machinists

Our plain-English summary of Re: Mesothelioma in railroad machinists, by A. Churg, F. Green (American Journal of Industrial Medicine, 1990).

The study

• Authors: A. Churg, F. Green
• Journal: American Journal of Industrial Medicine
• Published: 1990;17(4):523-30
• Type of article: Comment, Letter
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 000007).

In plain English

This is a letter to the editor, not a full study. The authors responded to Mancuso's 1988 report on mesothelioma among railroad workers described as exposed only to chrysotile. They argued that the report's validity depended on whether exposure was to chrysotile alone, because amosite and crocidolite are generally considered more potent causes of mesothelioma. The authors measured lung asbestos fibers in two long-term railroad workers with pleural mesothelioma. To the authors' knowledge, neither worker had other asbestos exposure. Their exposure periods were 1922-1971 and 1937-1974. In the first worker, the table listed 1,500,000 amosite, 600,000 crocidolite, 2,200,000 chrysotile and 1,800,000 tremolite fibers per gram of dry lung. The general-population 95th percentile for amosite plus crocidolite was 10,000 fibers per gram of dry lung. The authors stated that the amosite plus crocidolite values in both workers were well within the range they had previously found in shipyard workers and insulators with mesothelioma. Noting that limited conclusions can be drawn from two cases, the authors concluded that amphibole was likely present in Mancuso's cohort and probably largely responsible for its mesotheliomas.

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 responding to Mancuso's 1988 report, including a lung-tissue fiber analysis of two cases
• Who was studied: Two long-term railroad workers with pleural mesothelioma; the letter does not say where they worked, or when or where the analysis was done
• Exposure: Railroad work, with exposure periods listed as 1922-1971 (Case 1) and 1937-1974 (Case 2). To the authors' knowledge there was no other asbestos exposure. Lung content of amosite, crocidolite, chrysotile and tremolite was measured.
• Main results:
  • Case 1 (exposure 1922-1971), fibers per gram of dry lung: amosite 1,500,000; crocidolite 600,000; chrysotile 2,200,000; tremolite 1,800,000
  • General population comparison (95th percentile values, from Churg and Wiggs 1986): amosite plus crocidolite 10,000 fibers per gram of dry lung
  • The authors stated that the amosite plus crocidolite values in both railroad workers were well within the range they had previously found in shipyard workers and insulators with mesothelioma
• The authors' conclusion: The authors concluded that amphibole was likely present in the cohort Mancuso studied and probably was largely responsible for the mesotheliomas observed
• Limitations the authors state:
  • Only two cases were analyzed, so the authors said limited conclusions can be drawn

Topics

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

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

Related studies

• Relative risk of mesothelioma among railroad machinists exposed to chrysotile — I. Higgins (1989)
• Relative risk of mesothelioma among railroad machinists exposed to chrysotile — T.F. Mancuso (1988)
• Mesothelioma among machinists in railroad and other industries — T.F. Mancuso (1983)
• Mesotheliomas due to asbestos used in railroads in Italy — C. Maltoni, C. Pinto, et al. (1991)
• Mesotheliomas following exposure to asbestos used in railroads: the Italian cases — C. Maltoni, C. Pinto, et al. (1991)
• A retrospective cohort study of lung cancer and diesel exhaust exposure in railroad workers — E. Garshick, M.B. Schenker, et al. (1988)

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