Pleural changes and exposure to fibrous minerals

Our plain-English summary of Pleural changes and exposure to fibrous minerals, by G. Hillerdal (Scandinavian Journal of Work, Environment & Health, 1984).

The study

• Author: G. Hillerdal
• Journal: Scandinavian Journal of Work, Environment & Health
• Published: 1984;10(6 Spec No):473-9
• Cited by: 8 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. 000546).

Abstract

The pleura is a main target for various reactions related to asbestos exposure. However there are great radiological and clinical differences between the various reactions, and there is also increasing evidence that they have different prognoses. The main reactions are pleural plaques on the one hand and acute pleurisy and diffuse pleural fibrosis on the other. In a population with a low mesothelioma risk, the anthophyllite-exposed population of Northern Karelia in Finland, there are very few reactions of the second type, while plaques are very common. In Turkey, where the exposure is to erionite, the mesothelioma level is extremely high, and reactions of type two are very common in the exposed population. Thus it seems that careful discrimination of the various pleural changes can have prognostic value. There are also indications that plaques do not have any relation to a disturbed immunologic system, while pleurisy and diffuse pleurisy have.

In plain English

This article was a review. It drew mainly on the author's own earlier studies, done with other researchers, of pleural changes seen on chest X-rays in people exposed to mineral fibers. The author separated two kinds of non-cancerous pleural reactions: pleural plaques, and "mineral fiber pleurisy with remnants" (fluid around the lung followed by scarring such as diffuse pleural thickening). The author noted that not all researchers accepted these definitions. Data came from Finland, from an area where anthophyllite asbestos occurs in the ground. They also came from Turkey, from villages that used asbestos to whitewash houses and from a village exposed to erionite. The Swedish data came from Uppsala, where most subjects had been exposed at work, mainly to chrysotile. In the low-mesothelioma Finnish population, pleurisy-type reactions were very few and plaques were very common. Where erionite was the exposure in Turkey, mesothelioma levels were extremely high and pleurisy-type reactions were very common. The author reported that mesothelioma risk seemed to correlate with how often pleurisy remnants occurred, and said further studies should confirm this.

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: Review drawing mainly on the author's own earlier radiological studies (with collaborators) in three countries, plus other literature
• Who was studied: Populations in Finland (endemic anthophyllite area first described by Kiviluoto), Turkey (villages using asbestos for whitewashing and a village with erionite), and Sweden (Uppsala, people whose chest radiographs showed findings), with reference villages without mineral fiber exposure. Exact counts in Table 1 are not legible in the scanned text.
• Exposure: Anthophyllite asbestos in the ground (Finland); asbestos used for whitewashing houses, and erionite (Turkey); mainly occupational chrysotile with some amphibole exposure (Sweden)
• Main results:
  • In the anthophyllite-exposed Finnish population, which had a low mesothelioma risk, pleurisy-type reactions were very few and pleural plaques were very common
  • In the erionite-exposed population in Turkey, mesothelioma levels were extremely high and pleurisy-type reactions were very common
  • Across the populations in Table 1, the risk of mesothelioma seemed to correlate fairly well with how often remnants of pleurisy occurred
  • In an earlier prospective Uppsala study cited by the author, patients with only pleural plaques had erythrocyte sedimentation rates in the normal range, while those with bilateral remnants of pleurisy had a pathologically high mean value, with high statistical significance
• The authors' conclusion: The author interpreted the sedimentation rate finding as another indication that immunologic factors are involved to a larger extent in pleurisy and its remnants than in changes among people who have only pleural plaques
• Limitations the authors state:
  • The definitions of the two types of pleural reaction were not generally accepted by all researchers
  • The correlation between mesothelioma risk and pleurisy remnants needed to be confirmed by further studies
  • Only limited epidemiologic data were available on different mineral fibers and radiological pleural changes
  • Confirming results were hard to find in the literature because other reports rarely described clearly what they meant by pleural changes
  • Pleurisy remnants were often found without a fluid episode ever having been diagnosed, so a prior episode was assumed but difficult to prove
  • The mechanism behind the raised sedimentation rate was unclear

Topics

The National Library of Medicine indexes this study under subjects our site covers: Crocidolite.

Medical terms in this study, explained in our Lexicon: Pleura, Asbestos Exposure, Pleural Plaques, Pleurisy, Fibrosis, Mesothelioma, Anthophyllite, erionite.

Related studies

• Pulmonary changes after exposure to vermiculite contaminated with fibrous tremolite — J.E. Lockey, S.M. Brooks, et al. (1984)
• The pulmonary response to fibrous dusts of diverse compositions — P. Gross, R.T. deTreville, et al. (1970)
• Prospective clinical and radiologic study of zeolite-exposed Turkish immigrants in Sweden — M. Ozesmi, G. Hillerdal, et al. (1990)
• Lung function and radiographic change in chrysotile workers in Swaziland — M. McDermott, M.M. Bevan, et al. (1982)
• A comparison of the effects of exposure of baboons to crocidolite and fibrous-glass dusts — B. Goldstein, R.E. Rendall, et al. (1983)
• Fibrous minerals in the lungs of mesothelioma patients: comparison between data on SEM, TEM, and personal interview information — T. Tuomi (1992)

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