Relative risk of mesothelioma among railroad machinists exposed to chrysotile

Our plain-English summary of Relative risk of mesothelioma among railroad machinists exposed to chrysotile, by I. Higgins (American Journal of Industrial Medicine, 1989).

The study

• Author: I. Higgins
• Journal: American Journal of Industrial Medicine
• Published: 1989;15(4):483-6
• Type of article: Comment, Letter
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 000092).

In plain English

This item is a letter to the editor, not a research study; it reported no new data. The author commented on a 1988 paper by Thomas F. Mancuso, which, as the letter recounts, found 14 cases of mesothelioma among 181 railroad machinists described as exposed to chrysotile, with mesothelioma making up 34% of all cancer deaths. The author wrote that, if correct, this would cast doubt on the view that mesothelioma usually follows amphibole exposure and only rarely pure chrysotile exposure, but raised three questions. First, the paper did not give enough information to judge whether the 14 diagnoses were valid, and the author asked for the evidence behind each. Second, the cohort was defined from a 1945 seniority list but follow-up covered men hired from 1920 through 1929, so men who left before 1945 were not included. The author argued this made the risk impossible to estimate. Third, the author wrote that it was impossible to be sure the men were not also exposed to some amphibole.

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 another author's study (Mancuso 1988); no original data
• Who was studied: No population was studied in this letter. It discusses Mancuso's cohort of 181 railroad machinists, among whom Mancuso reported 14 mesothelioma cases
• Exposure: Chrysotile asbestos, which Mancuso said was the machinists' only asbestos exposure. The letter's author questioned this.
• Main results:
  • The letter's author argued that Mancuso's paper did not give readers enough information to judge whether the mesothelioma diagnoses were valid. The paper did not say how many of the 14 rested on death certificates and how many on other criteria.
  • The letter's author pointed out that men hired in the 1920s who left the company before 1945 would not be included in Mancuso's follow-up.
  • Because of likely bias in identifying those who died, the letter's author argued that the risk of mesothelioma in this cohort could not be estimated. The author asked for company turnover rates for 1920 to 1945.
  • The letter's author wrote that it could not be ruled out that the machinists were also exposed to some amphibole asbestos.
• The authors' conclusion: The author did not reject Mancuso's observation outright. The author wrote that it would cast doubt on the amphibole view if correct, and that several questions needed to be answered first.

Topics

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

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

Related studies

• Relative risk of mesothelioma among railroad machinists exposed to chrysotile — T.F. Mancuso (1988)
• Re: Mesothelioma in railroad machinists — A. Churg, F. Green (1990)
• Mesothelioma among machinists in railroad and other industries — T.F. Mancuso (1983)
• Asbestos-related mesothelioma risk among railroad workers — M. Huncharek (1987)
• Is chrysotile a significant risk factor for mesothelioma? — C.G. Ohlson (1989)
• Mesotheliomas among railroad workers in the United States — T.F. Mancuso (1991)

Browse more research in American Journal of Industrial Medicine, or return to medical research.