Obfuscation: a reply to Dr. Dunnigan

Our plain-English summary of Obfuscation: a reply to Dr. Dunnigan, by D.E. Lilienfeld (American Journal of Industrial Medicine, 1988).

The study

• Author: D.E. Lilienfeld
• Journal: American Journal of Industrial Medicine
• Published: 1988;14(5):625-8
• Cited by: 1 article, 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. 000245).

In plain English

This article is a commentary, not a research study. The author replied to a 1988 commentary by Dunnigan, which had argued that chrysotile asbestos does not cause mesothelioma and that tremolite contaminating chrysotile is responsible. The author presented no new data. Drawing on other researchers' work on fiber length, thinness and surface area, the author argued that chrysotile may be less potent than crocidolite for mesothelioma but could still cause it. The author also wrote that Canadian chrysotile producers never claimed to have removed tremolite during processing. The author challenged the six studies of nonmining chrysotile-exposed workers that Dunnigan cited. For example, the author argued that the Weiss (1977) study, with about 7,100 person-years of follow-up, was too small to be expected to find even one case. The author added that misclassification of mesothelioma and the disease's latency could explain why that study found none. The author pointed to a 1988 report by Mancuso of 14 mesotheliomas in a cohort of approximately 180 railroad employees described as exposed only to chrysotile. The author concluded that Dunnigan's case was unsupported by epidemiologic, lung burden and toxicological data.

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: Commentary (a reply to another author's commentary); no new data were collected
• Who was studied: No study population; the commentary discusses published studies and reports by others
• Exposure: Chrysotile asbestos, its tremolite contaminants, and comparison with crocidolite, in relation to mesothelioma
• Main results:
  • Based on others' work on fiber dimensions and surface area, the author argued that chrysotile would be less pathogenic for mesothelioma than crocidolite but could still cause the disease
  • The author disputed Dunnigan's assumption that tremolite is removed from chrysotile during processing, stating that Canadian mines and mills never claimed this
  • The author argued that the Weiss (1977) study, with about 7,100 person-years of follow-up, lacked the statistical power to observe even one mesothelioma case; the author also cited misclassification and latency as explanations for its finding of none
  • The author cited a 1988 report by Mancuso of 14 mesotheliomas in a cohort of approximately 180 railroad employees exposed only to chrysotile, stating that amphiboles were not present
  • The author cited a 1952 tabulation by Cartier of lung cancers among 4,000 asbestos workers that included two mesotheliomas, one in an executive whose company handled only chrysotile
  • The author contrasted Dunnigan's view with a 1983 Consumer Product Safety Commission finding that chrysotile has a lower potential for peritoneal mesothelioma than other fiber types, but with less evidence of marked differences for pleural mesothelioma and lung cancer
• The authors' conclusion: The author concluded that Dunnigan's argument was unsupported by epidemiologic data, lung burden studies and toxicological data

Topics

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

Related studies

• Reply to Dr. Dunnigan. Chrysotile as a mesothelial carcinogen in man — A. Churg (1988)
• On Dr. Dunnigan's commentary linking chrysotile asbestos with mesothelioma — M.R. Becklake (1988)
• Response to Dr. Dunnigan's commentary. The role of chrysotile in the pathogenesis of mesothelioma — J.M. Craighead (1988)
• On the statement by Jacques Dunnigan — J.M. Davis (1988)
• In reply: asbestos, carcinogenicity, and public policy — W.J. Nicholson, E.M. Johnson, et al. (1990)
• In Reply to "Malignant Mesothelioma and Its Nonasbestos Causes" — R.L. Attanoos, A. Churg, et al. (2019)

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