Role of asbestos and other fibres in the development of diffuse malignant mesothelioma

Our plain-English summary of Role of asbestos and other fibres in the development of diffuse malignant mesothelioma, by A.R. Gibbs (Thorax, 1990).

The study

• Author: A.R. Gibbs
• Journal: Thorax
• Published: 1990;45(9):649-54
• Type of article: Review
• Cited by: 55 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 003644).

In plain English

This was a single-author review, not a new study, of epidemiological, pathological, mineralogical and animal research on how different fibres relate to diffuse malignant mesothelioma. The author described evidence indicating that chrysotile was either very weakly carcinogenic or non-carcinogenic in humans. The author noted that the Quebec chrysotile ore linked to 10 mesotheliomas up to 1980 contained tremolite. Crocidolite was described as generally recognised as the most dangerous form of asbestos, and amosite as less carcinogenic than crocidolite by an uncertain amount. Tremolite/actinolite was linked to mesothelioma from both occupational and environmental exposure. Erionite, a fibrous zeolite, was linked to a very high incidence of malignant mesothelioma in certain Turkish villages. The author reported that some 10-20% of UK cases were unrelated to asbestos exposure. The author concluded that chrysotile has a much lower disease potential than the amphibole minerals and that there appeared to be no good reason to ban its use. The author noted that research was hampered by few populations exposed to only one fibre type, long latent periods, diagnostic problems and poor data on airborne fibre levels.

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: Narrative review by a single author of published human and animal research
• Who was studied: Published epidemiological, pathological and mineralogical studies of exposed workers and residents, plus in vitro and in vivo (animal) experiments. No new subjects were studied.
• Exposure: Asbestos fibre types: chrysotile (serpentine) and the amphiboles crocidolite, amosite, tremolite/actinolite and anthophyllite. Also non-asbestos fibres, especially erionite, with brief mention of man-made mineral fibres.
• Main results:
  • The author summarised recent evidence as indicating that chrysotile is either very weakly carcinogenic or non-carcinogenic in man.
  • In cited studies of Quebec chrysotile miners and millers, a total of 10 malignant mesotheliomas had been found up to 1980. The ore contained tremolite (less than 10% of the ore), and lung tissue of affected workers showed a high tremolite content.
  • In a cited report on a Rochdale textile plant, 17 malignant mesotheliomas occurred in 850 men dying more than 20 years after exposure. These were first attributed to chrysotile, but appreciable quantities of crocidolite had also been used at the factory.
  • The author described crocidolite as generally recognised as the most dangerous form of asbestos.
  • In cited preliminary data on 6506 men in crocidolite mining and milling at Wittenoom, Western Australia (1943-66), 31 had developed mesothelioma by the end of 1980. There were no mesothelioma deaths in workers employed 90 days or less; men employed longer showed about a 10 fold increase in mortality.
  • In a cited study of 5969 men at an insulation board factory (Cape Boards, Uxbridge) that used predominantly amosite, there were five mesotheliomas, a doubling of lung cancer risk and nine asbestosis deaths up to 1980. The author stated that amosite is generally agreed to be less carcinogenic than crocidolite, but how much less is not certain.
  • The author described considerable evidence linking malignant mesothelioma with occupational and environmental exposure to tremolite/actinolite fibres. Cited examples included vermiculite workers at Libby, Montana, and residents of areas of Turkey, Corsica, Cyprus and Metsovo, Greece.
  • A cited Finnish study found no cases of mesothelioma in workers exposed to anthophyllite only.
  • The author reported that some 10-20% of malignant mesothelioma cases in the United Kingdom are unrelated to asbestos exposure.
  • Inhabitants of certain Turkish villages built from volcanic material containing erionite have a very high incidence of malignant mesothelioma.
  • In cited implantation experiments, fibres greater than 8 micrometres in length and less than 0.25 micrometres in width were the most potent in producing malignant mesothelioma.
• The authors' conclusion: The author concluded that recent human studies show chrysotile has a much lower potential for causing disease than the amphibole minerals. The author also stated that there appeared to be no good reason to ban chrysotile, and that removing intact white asbestos from public buildings seemed misplaced.
• Limitations the authors state:
  • Few populations have been exposed to only one fibre type.
  • There are long latent periods between exposure and disease.
  • Diagnosis is difficult, and satisfactory data on workers' airborne fibre levels are lacking.
  • Animal studies must not be overinterpreted or readily extrapolated to humans.
  • For the New Jersey amosite factory workers, the absence of lung fibre analyses means crocidolite exposure cannot be ruled out.

Topics

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

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

Related studies

• Mesotheliomas in rats following inoculation with acid-leached chrysotile asbestos and other mineral fibres — G. Monchaux, J. Bignon, et al. (1981)
• Fibre distribution in the lungs and pleura of subjects with asbestos related diffuse pleural fibrosis — A.R. Gibbs, M. Stephens, et al. (1991)
• The Italian Experience in the Development of Mesothelioma Registries: A Pathway for Other Countries to Address the Negative Legacy of Asbestos — C. Magnani, C. Mensi, et al. (2023)
• Development, radiological zone patterns, and importance of diffuse pleural thickening in relation to occupational exposure to asbestos — H. Bohlig, A. Calavrezos (1987)
• A review of carcinogenicity studies of asbestos and non-asbestos tremolite and other amphiboles — J. Addison, E.E. McConnell (2008)
• The relationship between fibrosis and cancer in experimental animals exposed to asbestos and other fibers — J.M. Davis, H.A. Cowie (1990)

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