Incidence of malignant pleural mesothelioma due to environmental asbestos fiber exposure in the southeast of Turkey

Our plain-English summary of Incidence of malignant pleural mesothelioma due to environmental asbestos fiber exposure in the southeast of Turkey, by A. Senyiğit, C. Babayiğit, M. Gökirmak, et al (Respiration; International Review of Thoracic Diseases, 2000).

The study

• Authors: A. Senyiğit, C. Babayiğit, M. Gökirmak, F. Topçu, E. Asan, M. Coşkunsel, R. Işik, M. Ertem
• Journal: Respiration; International Review of Thoracic Diseases
• Published: 2000;67(6):610-4
• Cited by: 49 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Inhabitants of the southeast of Turkey (ST) have been exposed since childhood to inhalation of asbestos, from a material containing tremolite, used for whitewashing. This has resulted in an increased incidence of malignant pleural mesothelioma (MPM).

Objectives: To review the epidemiological features of MPM cases in ST; to calculate and compare the incidence with the previously reported ones.

Subjects And Methods: The study included 176 MPM cases from different places in ST. The incidence of MPM was calculated for those places according to the distribution of the cases.

Results: In the previously identified regions of asbestos (region 1) where the population had been informed of the danger with the soil some decades ago, the MPM incidence was decreased, as compared to the previous reports. The annual incidence of MPM in these places was found to be 42.9 per million in this study while it had been reported to be 105.5 per million in the previous studies. In contrast, the incidence that was reported previously to be 2.75 per million in the regions where asbestos exposure had not been identified before (region 2) was found to be 8.6 per million in this study. In region 2 the incidence of MPM increased even in the second half of the last decade (5.9 versus 11.9 per million).

Conclusions: Use of asbestos-containing soil continues in different places in ST. Even if the use of this soil is abandoned today, MPM will be an important health problem in this region till the third or fourth decades of this century. Informing the villagers of the danger and preventing the use of this soil may result in a considerable decrease in the incidence of MPM.

Copyright 2000 S. Karger AG, Basel

In plain English

This study examined malignant pleural mesothelioma in the southeast of Turkey. There, villagers dug a local tremolite-containing soil and used it as whitewash on house walls and floors. The authors reviewed 176 cases diagnosed at a university hospital between 1990 and 1999 and estimated yearly rates per million people. Of the patients, 100 were men and 76 were women. None had occupational or industrial asbestos exposure. In areas already known for asbestos (region 1), the rate was 42.9 per million. That was lower than the 105.5 per million an earlier study reported there. In areas not previously known for asbestos (region 2), the rate was 8.6 per million, rising from 5.9 in 1990 to 1994 to 11.9 in 1995 to 1999. Electron microscopy found tremolite and small amounts of serpentine asbestos in soil from 4 region 2 places. The authors thought the region 1 decline was mainly due to villagers being told of the danger. They noted the true rate may be higher because of limited health services, undiagnosed cases and migration.

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: Hospital-based case series used to estimate regional incidence (1990 to 1999), compared with rates from earlier studies
• Who was studied: 176 patients with malignant pleural mesothelioma confirmed by histology or cytology, diagnosed at a reference university hospital in southeast Turkey between 1990 and 1999; 100 men and 76 women
• Exposure: Environmental (household) exposure to asbestos-containing soil used as whitewash. Soil samples from region 2 contained amphibole (tremolite) and a small amount of serpentine asbestos. No patient had occupational or industrial exposure. Exposure was recorded as positive for patients from places where environmental asbestos was known to exist.
• Main results:
  • Annual incidence was 42.9 per million in region 1 (previously identified asbestos areas) and 8.6 per million in region 2 (areas where asbestos had not been identified before)
  • Overall incidence of MPM in southeast Turkey was calculated as 22.8 per million
  • In region 2, incidence rose from 5.9 per million (1990 to 1994) to 11.9 per million (1995 to 1999)
  • Region 1's 42.9 per million was lower than an earlier study's figure of 105.5 per million for region 1. The article's abstract gives an earlier figure of 2.75 per million for region 2.
  • Highest town rate was Maden (19 cases), at 77.8 per million for 1990 to 1999. Dicle, a newly identified asbestos place, had 35.9 per million.
  • Electron microscopy of soil from all region 2 places found serpentine (small amount) and tremolite asbestos fibers in only 4 places
  • 60% of patients had a positive history of asbestos exposure. This rose to 68% when patients from the four newly identified places in region 2 were counted. None had occupational or industrial exposure.
  • Female patients were aged 21 to 79 (mean 54.2) and male patients 25 to 77 (mean 52.4)
• The authors' conclusion: The authors concluded that the study reveals the extent of MPM in the region and supports public health concern for more stringent environmental control of this fiber. They thought the decrease in region 1 was primarily due to informing villagers of the danger. Because of the latency period, they said it will take many decades for the effect of such controls to be seen.
• Limitations the authors state:
  • Calculated incidence may be lower than the real incidence because many districts are underserved by health services
  • Some patients with suspected MPM could not be diagnosed by closed pleural biopsy and refused more invasive procedures
  • People frequently migrate from these places to big cities
  • Population data were available only for 1990 and 1997; annual figures were estimated from growth rates

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Tremolite, Asbestos Exposure.

Related studies

• Malignant pleural mesothelioma caused by environmental exposure to asbestos in the Southeast of Turkey: CT findings in 117 patients — A. Senyiğit, H. Bayram, et al. (2000)
• Environmental asbestos-related pleural plaque in southeast of Turkey — G. Ates, T. Yildiz, et al. (2010)
• Malignant pleural mesotheliomas: an environmental health risk in southeast Turkey — K.M. Müller, M. Fischer (2000)
• Assessment of environmental asbestos exposure in Turkey by bronchoalveolar lavage — P. Dumortier, L. Coplü, et al. (1998)
• Lung diseases due to environmental exposures to erionite and asbestos in Turkey — S. Emri, A. Demir, et al. (2002)
• High-resolution computed tomography in cases with environmental exposure to asbestos in Turkey — F. Topçu, H. Bayram, et al. (2000)

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