Mesothelioma in Cyprus: the role of tremolite

Our plain-English summary of Mesothelioma in Cyprus: the role of tremolite, by K. McConnochie, L. Simonato, P. Mavrides, et al (Thorax, 1987).

The study

• Authors: K. McConnochie, L. Simonato, P. Mavrides, P. Christofides, F.D. Pooley, J.C. Wagner
• Journal: Thorax
• Published: 1987;42(5):342-7
• Type of article: Case report
• Cited by: 77 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. 000336).

Abstract

There is a chrysotile mine in the central mountains of Cyprus but no other appreciable source of industrial asbestos. Hence the island was thought to offer ideal conditions to seek pure chrysotile induced mesothelioma. The first reported case was a village woman whose lung tissue contained amphibole asbestos fibres, which were later identified as tremolite. This began a search for the origin of her exposure to asbestos. Our studies have shown that tremolite is widespread, being found, along with chrysotile, in domestic and environmental dust samples. Other cases of mesothelioma have been diagnosed, and the pattern of their distribution suggests that the mine is not the major source of disease. Exposure to tremolite is equally, if not more, important.

In plain English

This study examined mesothelioma in Cyprus, which has a chrysotile mine. The authors reviewed records of 14 reported cases, not all confirmed by a pathology panel, and analysed fibres in human lung tissue, in the lungs of six sheep that grazed near the mine, and in dust from the mine, village roof eaves and dry riverbeds. Tremolite was found in lung tissue from two mesothelioma patients and from a comparison patient with asbestosis, and in the sheep lungs. It was also found in roof-eave dust from two nearby villages, but not in the mine samples. The authors said two cases should probably be excluded: one with a doubtful diagnosis and one man who had opportunity for asbestos exposure in South Africa. Of the remaining 12, seven were confirmed by the panel. Five were asbestos miners, three were miners' wives, two were residents with only environmental exposure and two had no reported exposure. The authors concluded that tremolite may have a role in pleural mesothelioma on the island. They noted that miners were more likely than villagers to be diagnosed, and that human lung samples were hard to obtain.

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: Case series of mesothelioma cases from case records, combined with fibre analysis (analytical transmission electron microscopy) of human lung, sheep lung and environmental dust samples
• Who was studied: 14 reported cases of mesothelioma in Cyprus up to March 1986, not all confirmed by a panel of pathologists; lung tissue from one mesothelioma patient (case 1) and from one Cypriot man with asbestosis; biopsy material from case 2; lungs of six sheep that had grazed for several years around the mine
• Exposure: Chrysotile from the Cyprus mine and tremolite (an amphibole) contaminating the chrysotile ore and occurring naturally on the island. Routes were work as asbestos miners or millers, being the wife of a mine worker, and living in villages near the mine.
• Main results:
  • Two cases should probably be excluded: case 8, whose diagnosis was in doubt, and case 14, who had opportunity for asbestos exposure in South Africa.
  • Of the remaining 12 cases, 5 were asbestos miners, 3 were miners' wives, 2 were residents with only environmental exposure, and 2 had no reports of apparent exposure. The authors said this distribution suggests the mine is not the major source of disease.
  • Of the 12 remaining cases, 7 had their diagnosis confirmed by a panel of pathologists.
  • The lung of case 1, a former asbestos miner and mine plumber with mesothelioma, showed a relevant presence of tremolite.
  • The fibre count of case 1 was compared with lung tissue from a male Cypriot with asbestosis, a former quarry labourer at the mines. Table 1 lists a tremolite count for him as well; the exact figure is garbled by OCR.
  • Tremolite was found in biopsy material from case 2, a woman with no occupational exposure who had lived near the mine, but it could not be quantified.
  • Tremolite, chrysotile and crocidolite were found in varying amounts in human lung samples and in sheep lung samples. The authors said the low crocidolite levels in the sheep had no obvious source and were thought to be background contamination.
  • Roof-eave dust from both villages near the mine contained tremolite.
  • No tremolite was found in mine samples from the 1960s or from more recent sampling. The mine samples contained chrysotile and antigorite. The authors described how tremolite had in the past been separated from chrysotile in the mill and blown away by the wind.
  • Tremolite was found in two of the three dry riverbed sites, but not in the riverbed closest to the mine.
  • The size distribution of the tremolite fibres included long thin fibres, which the authors said resembles crocidolite.
• The authors' conclusion: The authors concluded that their results to date suggest exposure to tremolite, which contaminates chrysotile ore and occurs naturally in Cyprus, may have a role in the cases of pleural mesothelioma reported from the island.
• Limitations the authors state:
  • Mine workers had access to regular chest radiography, so they were more likely than villagers to have their disease diagnosed.
  • Human lung samples suitable for mineral analysis were difficult to obtain, so lung tissue from only one mesothelioma case was compared with lung tissue from one man with asbestosis.
  • Riverbed sampling was non-systematic.
  • Deaths can be certified by various people in a village, and no central record of them is kept.

Mines named here

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

• Amiandos mine, Cyprus

All asbestos mines

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Tremolite, Chrysotile, Amphibole Asbestos.

Related studies

• Biological effects of tremolite — J.C. Wagner, M. Chamberlain, et al. (1982)
• Inhalation studies on the effects of tremolite and brucite dust in rats — J.M. Davis, J. Addison, et al. (1985)
• Radiological survey of past and present vermiculite miners exposed to tremolite — J.C. McDonald, P. Sebastien, et al. (1986)
• Tremolite/chrysotile ratios — G. Scansetti, G. Piolatto (1987)
• Cohort study of mortality of vermiculite miners exposed to tremolite — J.C. McDonald, A.D. McDonald, et al. (1986)
• Chrysotile, tremolite, and malignant mesothelioma in man — A. Churg (1988)

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