Asbestos bodies and the diagnosis of asbestosis in chrysotile workers

Our plain-English summary of Asbestos bodies and the diagnosis of asbestosis in chrysotile workers, by J. Holden, A. Churg (Environmental Research, 1986).

The study

• Authors: J. Holden, A. Churg
• Journal: Environmental Research
• Published: 1986;39(1):232-6
• Cited by: 27 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. 001177).

Abstract

It has been suggested that because chrysotile asbestos forms asbestos bodies poorly, use of the traditional histologic requirements (diffuse interstitial fibrosis plus asbestos bodies) for the diagnosis of asbestosis, may lead to an underdiagnosis of this condition in workers exposed only to chrysotile. We examined lungs from 25 chrysotile miners with diffuse interstitial fibrosis. Asbestos bodies were found easily in histologic section using hematoxylin and eosin stains in all cases. Mineralogic analysis of four cases showed that 46 of 72 (64%) bodies isolated and examined contained chrysotile cores, and 21 of 72 (29%) bodies contained cores of the amphiboles tremolite and actinolite. By contrast, tremolite and actinolite constituted the majority of uncoated fibers in these cases. The mean length for bodies formed on chrysotile was 35 micron, and for bodies formed on tremolite or actinolite, 36 micron. We conclude that (1) the usual histologic criteria for the diagnosis of asbestos are applicable to chrysotile-exposed workers; (2) in workers with occupational chrysotile exposure, bodies form readily on this mineral; and (3) asbestos bodies in these lungs reflect the presence of long asbestos fibers.

In plain English

This study examined autopsy lungs from long-term chrysotile miners and millers at Thetford Mines, Quebec. It asked whether asbestosis can be diagnosed in chrysotile-exposed workers using the usual pathology criteria, which are diffuse interstitial fibrosis plus asbestos bodies. Among 93 consecutively autopsied workers, 25 had diffuse interstitial fibrosis. Asbestos bodies were found in all 25 using routine hematoxylin and eosin stained sections. Four cases were analyzed for minerals. In them, 46 of 72 bodies (64%) had chrysotile cores and 21 (29%) had tremolite or actinolite cores. Three were formed on amosite and 2 on mixed fibers. By contrast, tremolite and actinolite made up most of the uncoated fibers in three of the four cases. Mean body length was 35 micrometres for chrysotile cores and 36 micrometres for tremolite or actinolite cores. The authors concluded that the usual criteria apply to chrysotile-exposed workers, that bodies form readily on chrysotile with occupational exposure, and that the bodies reflect long fibers. They noted that bodies might not form after exposure to a very-short-fiber product.

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: Autopsy lung pathology study (case series) with light microscopy and electron microscopic mineral analysis of asbestos bodies and uncoated fibers
• Who was studied: 25 long-term chrysotile miners and millers with diffuse interstitial fibrosis, selected from 93 consecutively autopsied at a hospital in Thetford Mines, Quebec. Four of the 25 were arbitrarily selected for mineral analysis. Dates are not given.
• Exposure: Occupational exposure to chrysotile ore through mining and milling. The ore naturally contains the amphiboles tremolite and actinolite. Some amosite was also found in the lungs, which the authors thought more likely came from occupational amosite exposure in regional factories.
• Main results:
  • Asbestos bodies were found in all 25 cases on routine hematoxylin and eosin stained sections. Iron stains were never required.
  • In the four analyzed cases, 72 bodies and 985 fibers were isolated and identified.
  • Of the 72 bodies, 46 (64%) had chrysotile cores and 21 (29%) had tremolite or actinolite cores.
  • Of the 72 bodies, 2 (3%) had mixed chrysotile and tremolite cores and 3 (4%) were formed on amosite, which is not part of the chrysotile ore.
  • Tremolite and actinolite made up the majority of uncoated fibers in three of the four analyzed cases. In every case, the majority of bodies were formed on chrysotile.
  • Mean body length was 35 plus or minus 18 micrometres for chrysotile bodies and 36 plus or minus 20 micrometres for tremolite and actinolite bodies.
  • Only 1 body was shorter than 10 micrometres; it was formed on chrysotile and was 8 micrometres long. Six of 46 chrysotile bodies and 3 of 21 tremolite or actinolite bodies were longer than 50 micrometres.
  • By light microscopy, bodies formed on chrysotile looked like classic asbestos bodies and could not be told apart from amphibole-containing bodies.
  • In an additional analysis of one chrysotile textile worker's lungs, 9 of 10 isolated bodies were formed on chrysotile.
• The authors' conclusion: The authors concluded that the usual histologic criteria for diagnosing asbestosis apply to chrysotile-exposed workers. In their view, there is in general no justification for assuming that interstitial fibrosis without identifiable bodies is asbestosis. They also concluded that with occupational chrysotile exposure, bodies form readily on chrysotile and may serve as a marker of the number of very long fibers in the lung.
• Limitations the authors state:
  • The authors said bodies might not form in someone exposed to a very-short-fiber product, and that rare cases of 'occult asbestosis' have been reported.
  • The extension of the findings to other types of chrysotile exposure rests on a limited sample: one textile worker.
  • The authors said it is not clear whether the predominance of chrysotile bodies reflects high absolute fiber numbers or preferential coating of chrysotile.
  • The authors framed the diagnostic finding as applying at least to this group of workers.

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Bodies, Chrysotile, Interstitial Fibrosis, Amphibole Group, Tremolite, Actinolite.

Related studies

• Development of asbestos bodies on amosite, chrysotile and crocidolite fibres in guinea-pig lungs — S.K. Botham, P.F. Holt (1971)
• Asbestos bodies or fibers and the diagnosis of asbestosis — M.L. Warnock, G. Wolery (1987)
• Lung asbestos content in chrysotile workers with mesothelioma — A. Churg, B. Wiggs, et al. (1984)
• Fiber size and number in workers exposed to processed chrysotile asbestos, chrysotile miners, and the general population — A. Churg, B. Wiggs (1986)
• Mineral fibres, fibrosis, and asbestos bodies in lung tissue from deceased asbestos cement workers — M. Albin, L. Johansson, et al. (1990)
• Asbestos, asbestosis, and lung cancer: observations in Quebec chrysotile workers — B.W. Case, A. Dufresne (1997)

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