Rarity of mineral fibre pleurisy among persons exposed to Finnish anthophyllite and with low risk of mesothelioma

Our plain-English summary of Rarity of mineral fibre pleurisy among persons exposed to Finnish anthophyllite and with low risk of mesothelioma, by G. Hillerdal, A. Zitting, A.H. van Assendelft, et al (Thorax, 1984).

The study

• Authors: G. Hillerdal, A. Zitting, A.H. van Assendelft, T. Kuusela
• Journal: Thorax
• Published: 1984;39(8):608-11
• Cited by: 13 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. 000547).

Abstract

Endemic pleural plaques are reported from many parts of the world. In Central Europe and in Finland no connection with malignant mesotheliomas has been found, whereas this tumour is often encountered in areas in Turkey where endemic plaques also occur. There seem, however, to be differences in the radiological appearances found in these areas. In the present study chest radiographs of 317 persons with pleural plaques from the endemic area of Finland were scrutinized. It was found that 4.7% showed a blunted costophrenic angle unilaterally and 0.9% bilaterally. The prevalence of sequelae of pleurisy is statistically very highly significantly lower than in people with pleural plaques in Turkey. As the risk of mesothelioma appears to be low in Finland, the results are in accordance with the hypothesis that the risk of mesothelioma in a given population is higher if in that population there is a high incidence of benign asbestos pleurisy.

In plain English

This study re-examined chest X-ray films from a 1974 screening survey in two areas of Outokumpu commune in North Karelia, eastern Finland, where anthophyllite asbestos occurs naturally and was mined. The 1090 films from Paloranta and Kuusjärvi Kirkonkylä were compared with 1073 films from a control commune, Raakkylä. In the asbestos areas, 317 people (29.1 per cent) had pleural plaques, compared with 4 controls (less than 0.4 per cent). Plaques became more common with age and were similar in men and women. Most (82 per cent) were bilateral and calcified. Among the 317 people with plaques, 4.7 per cent showed signs of past pleurisy (a blunted costophrenic angle) on one side and 0.9 per cent on both sides. The authors reported that these figures were significantly lower (p less than 0.001) than those found in an earlier study of Turkish erionite villages, where mesothelioma risk is very high. This study did not count mesotheliomas itself. The authors concluded that the results fit the hypothesis that mesothelioma risk is higher where benign asbestos pleurisy is common.

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: Radiological study re-examining chest radiographs from a 1974 general mass miniature radiography survey, with a control area
• Who was studied: 1090 chest radiographs of residents of Paloranta (503) and Kuusjärvi Kirkonkylä (587), the two westernmost areas of Outokumpu commune, North Karelia, Finland, surveyed in 1974. They were compared with 1073 radiographs from the commune of Raakkylä, about 60 km south east, used as controls.
• Exposure: Non-occupational (environmental) exposure to naturally occurring anthophyllite asbestos in an area with former asbestos mines. Paloranta contained the Maljasalmi mine, which operated from 1944 to 1952. Exposure was not measured individually.
• Main results:
  • Pleural plaques were found in 317 of 1090 people (29.1%) in the asbestos areas: 137 of 587 (23.3%) in Kuusjärvi Kirkonkylä and 180 of 503 (35.8%) in Paloranta. In the control area, plaques were found in 4 of 1073 people (less than 0.4%).
  • There was no significant sex difference in plaques. In Kuusjärvi Kirkonkylä, 23.5% of men and 23.1% of women had plaques; in Paloranta the figures were 37.6% and 33.9%. Plaques increased rapidly with age.
  • Of the 317 people with plaques, 260 (82%) had bilateral calcified plaques, 33 (10.4%) had unilateral calcified plaques and 24 (7.5%) had bilateral hyaline plaques.
  • Among the 317 people with pleural plaques, 4.7% had a blunted costophrenic angle (a sign of past pleurisy) on one side and 0.9% on both sides.
  • The only difference between the asbestos areas and the controls in blunted costophrenic angles and visibility of the minor fissure was a low-grade significant difference (p less than 0.05) in bilaterally blunted angles: 20 of 1090 (1.8%) in the asbestos areas versus 8 of 1073 (0.7%) in controls. The excess was among people without plaques.
  • The authors compared their figures with an earlier study of people with bilateral pleural calcification in Turkish erionite villages. In that study, 23.2% had a unilateral blunted angle and 9% a bilateral one. The authors reported that the Turkish figures were very significantly (p less than 0.001) higher than the 4.7% and 0.9% found in this Finnish series.
• The authors' conclusion: The authors concluded that, since mesothelioma risk appears to be low in Finland, the low rate of pleurisy after-effects among people with plaques there agrees with the hypothesis that a population's mesothelioma risk is higher when benign asbestos pleurisy is common in that population. They also stated that the radiological features seen in populations exposed to different mineral fibres are not the same. They added that this relationship does not apply to bronchial carcinoma.
• Limitations the authors state:
  • In most cases only front (posteroanterior) chest views were available, so lateral views were disregarded.
  • The authors stated that comprehensive reports of how often mesothelioma occurs among people with non-occupational pleural plaques in Finland were still lacking.
  • The authors stated that much more data are needed before any conclusions can be drawn about mineral fibre pleurisy and bronchial carcinoma.

Mines named here

Asbestos mines this study is about. Each mine's page says who ran it, when it worked, and what it produced.

• Paakkila mine, Finland

All asbestos mines

Topics

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

Medical terms in this study, explained in our Lexicon: Pleurisy, Anthophyllite, Mesothelioma, Endemic, Pleural Plaques, Chest X-Ray, Costophrenic angle.

Related studies

• Four cases of mesothelioma among Finnish anthophyllite miners — A. Karjalainen, L.O. Meurman, et al. (1994)
• Acute pleurisy in asbestos exposed persons — G.K. Sluis-Cremer, I. Webster (1972)
• Malignant mesothelioma in a patient with anthophyllite asbestos fibres in the lungs — J.I. Phillips, J. Murray (2010)
• Pleural plaques and exposure to mineral fibres in a male urban necropsy population — A. Karjalainen, P.J. Karhunen, et al. (1994)
• Rat model demonstrates a high risk of tremolite but a low risk of anthophyllite for mesothelial carcinogenesis — D. Aierken, Y. Okazaki, et al. (2014)
• Combined effect of asbestos exposure and tobacco smoking on Finnish anthophyllite miners and millers — L.O. Meurman, R. Kiviluoto, et al. (1979)

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