The assessment of the malignant mesothelioma cases and environmental asbestos exposure in Sivas province, Turkey

Our plain-English summary of The assessment of the malignant mesothelioma cases and environmental asbestos exposure in Sivas province, Turkey, by S. Berk, H. Yalcin, O.T. Dogan, et al (Environmental Geochemistry and Health, 2014).

The study

• Authors: S. Berk, H. Yalcin, O.T. Dogan, K. Epozturk, I. Akkurt, Z. Seyfikli
• Journal: Environmental Geochemistry and Health
• Published: 2014;36(1):55-64
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

One of the most significant diseases related to environmental asbestos exposure is malignant mesothelioma (MM). Sivas province is located in the Central Anatolia where asbestos exposure is common. We aimed to study clinical, demographical and epidemiologic features of the patients with MM in Sivas, along with the history of asbestos exposure. In total, 219 patients with MM who were diagnosed in our hospital between 1993 and 2010 were retrospectively analyzed in terms of demographical and clinical features. Rock, soil and house plaster samples were taken from the habitats of those patients and were evaluated with optical microscopy and X-ray diffraction methods. The age of the patients ranged between 18 and 85 years. The male-to-female ratio was 1.4:1. Most of the patients confirmed an asbestos exposure history. The most frequent symptoms of the patients were chest pain (60 %) and dyspnea (50 %). The gap between the start of first symptoms and the diagnosis date was approximately 4 months in average. The plaster materials used in most of the houses were made up of mainly carbonate and silicate minerals and some chrysotile. Ophiolitic units contained fibrous minerals such as serpentine (clino + orthochrysotile) chiefly and pectolite, brucite, hydrotalcite and tremolite/actinolite in smaller amounts. MM is not primarily related to occupational asbestos exposure in our region, and hence, environmental asbestos exposure may be indicted. Yet, single or combined roles and/or interactions of other fibrous and non-fibrous minerals in the etiology of MM are not yet fully understood and remain to be investigated.

In plain English

This retrospective study came from a university hospital in Sivas, central Turkey. It reviewed records of 219 patients diagnosed with malignant mesothelioma from 1993 to 2010 and analyzed rock, soil and house plaster samples from their home areas. Of these, 126 were men and 93 women, aged 18 to 85; 211 had pleural and 8 peritoneal mesothelioma. More than 84% were farmers or housewives. Only 4 (1.8%) had a job with possible asbestos exposure. The text reports one hundred and ninety-six patients (given as 86%) who lived about 40 years on average in houses plastered with asbestos-contaminated soil, but a table lists 190 (86.7%) with asbestos exposure; the article does not reconcile these. Nearly half the patients came from Yildizeli district. Plaster from most patients' houses contained mainly carbonate and silicate minerals and 5 to 10% chrysotile. Local serpentine-bearing rocks also contained other fibrous minerals, including tremolite/actinolite, in small amounts in a few samples. The authors concluded that mesothelioma in their region is not mainly occupational and that environmental asbestos exposure may be responsible. They noted that exposure times were self-reported.

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: Retrospective review of hospital patient records (case series), combined with mineral analysis of environmental samples by optical microscopy, X-ray diffraction and scanning electron microscopy
• Who was studied: 219 patients with malignant mesothelioma diagnosed at a tertiary referral hospital in Sivas, Turkey, January 1993 to December 2010. 207 (95%) were diagnosed by tissue examination and 12 (5%) by clinical and radiological features plus asbestos exposure history. 172 (78.5%) lived in Sivas province and the rest in other provinces.
• Exposure: Environmental exposure from asbestos-contaminated soil (locally called 'white' or 'barren' soil) used as whitewash and stucco on house walls in rural areas. Exposure was measured as years lived in such houses. Plaster from most patients' houses contained 5 to 10% chrysotile.
• Main results:
  • Of the 219 patients, 126 (57.5%) were men and 93 (42.5%) were women, a male-to-female ratio of 1.4:1. Men's ages ranged from 18 to 85 years (mean 58.8, plus or minus 12.7). Women's ages ranged from 34 to 85 years (mean 58.9, plus or minus 13.1).
  • 211 patients (96.3%) had pleural mesothelioma and 8 (3.7%) had peritoneal mesothelioma (Table 1).
  • More than 84% of patients were farmers and housewives who had lived in a rural area all or most of their lives.
  • Only 4 of 219 patients (1.8%) had an occupational history with a potential risk of asbestos exposure: a dozer operator, a painter, a railway worker and a person working with concrete sleepers.
  • The Results text reports one hundred and ninety-six patients, printed as 86%, who had lived in a house containing asbestos-contaminated soil. (Dividing that count by the 219 patients would give 89.5%, not 86%.) They had lived there for an average of about 40 years, plus or minus 20 (range 3 to 70 years). Table 1 instead lists 190 patients (86.7%) with a history of asbestos exposure. The article does not reconcile these figures.
  • Among the patients, the most frequent symptoms were chest pain (60.2%) and shortness of breath (50.2%). The average time from first symptoms to diagnosis was about 4 months.
  • Nearly half the patients (102, or 46.5%) came from Yildizeli district, where 82% of the population lived in rural areas.
  • The youngest patient was diagnosed at age 18 and had no asbestos exposure.
  • Plaster used in most of the patients' houses in the Sivas region contained mainly carbonate minerals (50 to 70%), silicate minerals (10 to 30%), and a smaller amount of chrysotile (5 to 10%).
  • The fibrous minerals in the ophiolite rocks of Sivas province were mainly serpentine (more than 90%). Only a few samples also contained pectolite, brucite, hydrotalcite and tremolite/actinolite (less than 10%).
• The authors' conclusion: The authors concluded that mesothelioma in their region is not primarily related to occupational asbestos exposure, so environmental asbestos exposure may be implicated. They added that the roles of other fibrous and non-fibrous minerals remain to be investigated.
• Limitations the authors state:
  • Exposure time to asbestos was self-reported, so the latency period could have been miscalculated.
  • The study focused on asbestos and excluded other possible factors related to mesothelioma development.
  • The study did not include tissue (histopathological) findings that could show a causal link between asbestos and mesothelioma.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Asbestos Exposure, X-Ray Diffraction (XRD), Dyspnea, Silicate, Chrysotile, Serpentine Group, Brucite.

Related studies

• Assessment of environmental asbestos exposure in Turkey by bronchoalveolar lavage — P. Dumortier, L. Coplü, et al. (1998)
• Turkey National Mesothelioma Surveillance and Environmental Asbestos Exposure Control Program — S. Metintaş, H.F. Batırel, et al. (2017)
• Determination of environmental exposure to asbestos (tremolite) and mesothelioma risks in the southeastern region of Turkey — A. Senyigit, A. Dalgic, et al. (2004)
• Assessment of environmental and domestic exposure to tremolite in New Caledonia — D. Luce, M.A. Billon-Galland, et al. (2004)
• Environmental asbestos exposure in rural Turkey and risk of lung cancer — S. Metintas, M. Metintas, et al. (2012)
• Malignant pleural mesothelioma caused by environmental exposure to asbestos or erionite in rural Turkey: CT findings in 84 patients — A.A. Sahin, L. Cöplü, et al. (1993)

Browse more research in Environmental Geochemistry and Health, or return to medical research.