Potency versus importance in fiber pathogenicity

Our plain-English summary of Potency versus importance in fiber pathogenicity, by J.M. Hughes, H. Weill (American Journal of Industrial Medicine, 1994).

The study

• Authors: J.M. Hughes, H. Weill
• Journal: American Journal of Industrial Medicine
• Published: 1994;25(4):609-10
• Type of article: Comment, Letter
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

This letter to the editor responded to a study by Roggli et al. [1993] that analyzed asbestos fiber types in lung tissue from 94 mesothelioma cases. Of 1,512 fibers identified in that study, the most frequent type was amosite, followed by other mineral fibers, tremolite, crocidolite and chrysotile. Crocidolite and chrysotile each made up 3%, or approximately 45 fibers. From this, Roggli et al. concluded that the order of importance of asbestos fiber types for mesothelioma in the U.S. was amosite > tremolite > chrysotile = crocidolite. Hughes and Weill argued that the study blurred the difference between relative potency and relative importance. In a population with much more exposure to amosite than to crocidolite, a fiber could be more important without being more potent. They noted that among U.S. insulators and shipyard workers, crocidolite exposure was rare or nonexistent, while chrysotile and amosite exposure was common. They also stated that the study had no comparison group of people without mesothelioma. Because most people have asbestos fibers in their lungs, much of it chrysotile, noncases might show similar chrysotile levels but lower amosite and crocidolite levels. The authors concluded that without a reference population, no conclusions could be drawn about the relative importance or potency of chrysotile. They stated that the data did not weaken the evidence from human studies that crocidolite and amosite are far more potent than chrysotile in causing mesothelioma.

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 was a letter to the editor, not a new study. In it the authors criticized a 1993 paper by Roggli and colleagues analyzing asbestos fiber types in lung tissue from 94 people with mesothelioma. The letter restated that paper's figures: among 1,512 fibers identified, amosite was most common, and crocidolite and chrysotile each made up 3% (about 45 fibers). Roggli and colleagues had ranked amosite, then tremolite, then chrysotile and crocidolite equally, in importance for mesothelioma in the U.S. The authors argued that this confused a fiber's relative importance with its relative potency. They said amosite's high count may reflect more exposure to amosite, since crocidolite exposure was rare or absent among U.S. insulators and shipyard workers. They said that, without lung tissue from people without mesothelioma for comparison, no conclusion could be drawn about the relative importance or potency of a commonly found fiber such as chrysotile, since most people have asbestos fibers in their lungs, much of it chrysotile. The authors concluded that the data did not weaken human evidence that crocidolite and amosite are far more potent than chrysotile in causing mesothelioma.

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 published study (Roggli et al. 1993); no new data
• Who was studied: No population studied by these authors. The letter discussed the Roggli et al. (1993) analysis of lung tissue from 94 mesothelioma cases.
• Exposure: Asbestos fiber types found in lung tissue in the Roggli et al. study: amosite, other mineral fibers, tremolite, crocidolite and chrysotile
• Main results:
  • As restated from Roggli et al.: of 1,512 fibers identified in the 94 mesothelioma cases, crocidolite and chrysotile each made up 3% (approximately 45 fibers)
  • The authors argued that Roggli et al. blurred the distinction between the relative potency and the relative importance of fiber types in causing mesothelioma
  • The authors argued that amosite being more common than crocidolite in these cases may reflect more exposure to amosite and says nothing about relative potency
  • The authors noted that among U.S. insulators and shipyard workers, crocidolite exposure was rare or nonexistent, while chrysotile and amosite exposure was common
  • The authors noted that most people have asbestos fibers in their lungs, much of it chrysotile
  • The authors argued that, without a reference population of people without mesothelioma, no conclusions could be made about the relative importance or potency of a commonly identified fiber such as chrysotile
• The authors' conclusion: The authors concluded that the Roggli et al. data did not weaken human evidence that crocidolite and amosite are far more potent than chrysotile in causing mesothelioma

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Amosite, Mineral Fiber, Tremolite, Crocidolite, Chrysotile, Insulator.

Related studies

• Fiber potency vs. importance — V.L. Roggli, P.C. Pratt, et al. (1994)
• A comparison of asbestos fiber potency and elongate mineral particle (EMP) potency for mesothelioma in humans — D.H. Garabrant, S.T. Pastula (2018)
• Short-term inhalation and in vitro tests as predictors of fiber pathogenicity — R.T. Cullen, B.G. Miller, et al. (1997)
• Mortality by cause of death and risk behaviors in farmers versus non-farmers: the importance of avoiding the healthy worker effect — G. Zhao, E. Ronda, et al. (2019)
• Empirical model of mesothelioma potency factors for different mineral fibers based on their chemical composition and dimensionality — A. Korchevskiy, J.O. Rasmuson, et al. (2019)
• Initiation-promotion versus complete skin carcinogenesis in mice: importance of dark basal keratinocytes (stem cells) — T.J. Slaga, A.J. Klein-Szanto (1983)

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