Prospective clinical and radiologic study of zeolite-exposed Turkish immigrants in Sweden

Our plain-English summary of Prospective clinical and radiologic study of zeolite-exposed Turkish immigrants in Sweden, by M. Ozesmi, G. Hillerdal, B. Svane, et al (Respiration; International Review of Thoracic Diseases, 1990).

The study

• Authors: M. Ozesmi, G. Hillerdal, B. Svane, O. Widström
• Journal: Respiration; International Review of Thoracic Diseases
• Published: 1990;57(5):325-8
• Type of article: Case report
• Cited by: 9 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. 003789).

Abstract

Ninety-four persons from the village of Karain, Turkey, now residing in Stockholm, were investigated clinically and radiologically. In this village, environmental exposure to erionite, a fibrous zeolite, occurs, and there is an extremely high risk of mesothelioma among the villagers. Since an earlier investigation of the cohort in 1980, another 4 young persons have fallen ill with malignant mesothelioma in this group, where the incidence thus approaches 1%/year and is the most common cause of death. Solitary pleural plaques were found in 6%, thickening of the interlobar pleura in 4% and other radiologic signs of affection of the pleura in 2%. Thickening of the interlobar fissures were observed in 1 patient as the first sign of mesothelioma which has remained asymptomatic until 1 year later. The comparatively low incidence of pleural lesions in the cohort is probably due to the low mean age (36 years). Further follow-up could give clues to the pathogenesis of malignant mesothelioma.

In plain English

This follow-up survey studied immigrants from Karain, Turkey, living around Stockholm, Sweden. The village has environmental exposure to erionite, a fibrous zeolite. Between February and June 1985, 94 people (47 men, 47 women; mean age 36) were interviewed, examined, tested for lung function and X-rayed. Only 2 had been occupationally exposed to asbestos. All lung function tests were normal. X-rays showed solitary pleural plaques in 6 people (6%) and thickened pleura between lung lobes in 4 (4%). Sixty-four participants reported malignant mesothelioma among close relatives. From 1981 to the end of 1985, 4 new mesothelioma cases occurred among the roughly 150 Karain immigrants in Stockholm, a wider group than the 94; 3 had died before the survey. In one participant, the authors presumed that a thickened fissure seen on her 1985 X-ray before symptoms was the first sign of mesothelioma. For the group of about 150, the authors estimated an incidence approaching 1% per year, and at least half that. They concluded that the low rate of pleural changes was probably due to the group's young age. They noted that the villager list was incomplete and that cases who returned to Turkey may have been missed.

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: Follow-up clinical and radiologic survey of a cohort first examined in 1980, plus short case reports of 4 new mesothelioma cases
• Who was studied: 94 people (47 men, 47 women) from Karain, Turkey, living in the county of Stockholm, Sweden, examined February to June 1985. Mean age was 36 (range 17 to 64). 89 were born in Karain and 5 were married to villagers. They were part of a wider group of about 150 Karain emigrants living in Stockholm.
• Exposure: Environmental exposure to erionite, a fibrous zeolite (a non-asbestos mineral fiber), in the village of Karain. Only 2 participants were occupationally exposed to asbestos.
• Main results:
  • On chest X-rays of the 94 participants: solitary, noncalcified pleural plaques in 6 (6%), thickening of the interlobar pleura in 4 (4%), pleural adherence in 1 and obliteration of the pleural sinus in 1.
  • No tumors or pleural exudates were seen on the X-rays of the 94 participants.
  • All lung function tests of the participants were within normal limits.
  • Among the 63 people who also took part in the 1980 study, no evident progression was seen on X-rays, except a widening of the transverse fissure in a few cases.
  • 64 participants (printed as 65%) reported malignant mesothelioma among close relatives.
  • From 1981 to the end of 1985, 4 new cases of malignant mesothelioma occurred in the wider cohort of Karain immigrants in Stockholm (about 150 people), not only among the 94 examined. All 4 patients died.
  • Three people from the original 1980 list had died of mesothelioma before the 1985 survey.
  • Case 4, a woman who took part in both surveys, had a normal X-ray in 1980. In 1985 she had a thickened interlobar fissure while she had no symptoms, and 1 year later she developed pleurisy and was found to have malignant mesothelioma.
  • In the group of about 150 Karain immigrants in Stockholm there was about 1 case of mesothelioma per year. The authors estimated the incidence approached 1% per year and was at least half that.
• The authors' conclusion: The authors concluded that the comparatively low rate of pleural lesions was probably due to the cohort's low mean age (36 years), and that further follow-up could give clues to how malignant mesothelioma develops.
• Limitations the authors state:
  • The list of Karain villagers in the Stockholm area was not complete, and about 50 more known villagers did not participate. The authors said this should not affect the results because their reasons were not medical.
  • Some patients may have returned to Turkey when they fell ill and been missed.
  • Most of the mesotheliomas reported among relatives had not been confirmed by pathology.

Topics

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

Medical terms in this study, explained in our Lexicon: Zeolite, Karain, Environmental Exposure, erionite, Mesothelioma, Malignant Mesothelioma, Pleural Plaques, Pleura.

Related studies

• The role of environmental and occupational exposures in Turkish immigrants with fibre-related disease — P. Dumortier, A. Göcmen, et al. (2001)
• Is risk of pleural mesothelioma an environmental risk outside Turkey? A study on immigrants to Sweden — S.M. Mousavi, J. Sundquist, et al. (2010)
• Phenotypic characterisation of peripheral blood lymphoid cells in people exposed to fibrous zeolite — M. Ozesmi, A. Karlsson-Parra, et al. (1986)
• Natural fibrous zeolites and their carcinogenicity-a review — K.R. Spurny (1983)
• CT findings in malignant pleural mesothelioma related to nonoccupational exposure to asbestos and fibrous zeolite (erionite) — C. Erzen, M. Eryilmaz, et al. (1991)
• Malignant mesothelioma induced by asbestos and zeolite in the mouse peritoneal cavity — Y. Suzuki, N. Kohyama (1984)

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