Observations on environmental asbestos exposure in a high risk area

Our plain-English summary of Observations on environmental asbestos exposure in a high risk area, by U. Sahin, O. Ozturk, N. Songur, et al (Respirology, 2009).

The study

• Authors: U. Sahin, O. Ozturk, N. Songur, A. Bircan, A. Akkaya
• Journal: Respirology
• Published: 2009;14(4):579-82
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background And Objective: Environmental asbestos exposure is causally associated with various pulmonary pathologies. In Turkey, one of the most important sources of asbestos exposure is dust originating from the walls of homes whitewashed with white stucco. The main asbestos types implicated are tremolite and, to a lesser extent, chrysotile. This study investigated the presence and effect of environmental asbestos exposure in a small village in Isparta, Turkey.

Methods: Samples of asbestos mine ore, whitewashed plaster from the interior walls of the houses and whitesoil from the outside walls of the houses were analysed. Chest radiographs of 132 villagers aged 30 years and over and living in the village during the study were obtained. Verbal histories from the relatives of people who had died from lung cancer or mesothelioma and hospital records contributed 13 cases to the study population, giving a total of 145 cases under study.

Results: Chrysotile fibres were found in the old asbestos mine sample, and zeolite in the whitesoil sample from the outside walls. Abnormal CXR were found in 19 subjects (14. 4%), the most common being pleural calcifications and/or pleural plaques (n = 14, 10.6%). A further five subjects with pleural calcifications and/or pleural plaques were identified from verbal autopsy and hospital records. Malignant pleural mesothelioma was present in one living subject and four of the deaths. A possible familial clustering of lung cancer and malignant mesothelioma was noted.

Conclusion: While tremolite asbestos is the asbestos found in most white soil in Turkey, in this village chrysotile asbestos was found in the white soil. Familial clustering may indicate genetic susceptibility or increased environmental exposure in some families.

In plain English

This short communication reported a November 2005 investigation of Karağı, a village in Isparta province, Turkey. Mineral samples were analysed, 132 residents aged 30 and over who were born in the village had chest X-rays, and 13 more villagers with asbestos-related disease were identified through interviews with relatives and hospital records, for 145 people in total. A sample from an old asbestos mine contained chrysotile. Plaster from interior house walls contained an amphibole group mineral among other minerals. White soil from outside walls contained zeolite (analcime). Of the 132 X-rayed residents, 19 (14.4%) had asbestos-related abnormalities, most often pleural calcifications and/or calcified pleural plaques (14, 10.6%). Five villagers had malignant pleural mesothelioma: one living and four among the deaths. All five, plus three people with lung cancer, came from one family with no identifiable occupational asbestos exposure. The authors concluded that a high incidence of pleural calcifications and mesothelioma was confirmed and that chrysotile was found in white soil. They said the familial clustering may indicate genetic susceptibility or increased environmental exposure. They noted that about half the villagers had migrated and that some hospital records were lost.

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: Short communication reporting a village field investigation: mineral analysis of soil and plaster samples, chest X-ray screening of residents, plus interviews with relatives of the dead (verbal autopsy) and retrospective review of hospital records
• Who was studied: Residents of Karağı village, Isparta province, Turkey (village population 304), visited in November 2005. The 132 participants aged 30 years and over, all born in the village (62 men, 70 women), were joined by 13 villagers identified through verbal autopsy and clinical records, for 145 in total.
• Exposure: Non-occupational environmental exposure to white soil used as plastering material on house walls in the old settlement (Upper Karağı). Samples came from an old asbestos mine (natural mantle about 10 km from the village) and from interior and outside house walls.
• Main results:
  • The sample from the old asbestos mine contained serpentine minerals, including chrysotile.
  • The plaster sample from interior house walls contained quartz, calcite, kaolinite, smectite group mineral, illite, feldspar, amorphous material and amphibole group mineral.
  • The white soil sample from outside house walls contained feldspar, zeolite (analcime) and ankerite.
  • Among the 132 X-rayed residents, 19 (14.4%) had asbestos-related radiographic abnormalities.
  • Among the 132 X-rayed residents, the abnormalities were pleural calcifications and/or calcified pleural plaques in 14 (10.6%), pleural thickening in 4 (3.0%) and massive pleural effusion in 1.
  • Among all 145 people studied, 19 (13.1%) had pleural calcifications.
  • Malignant pleural mesothelioma was found in one living villager and in four of the deaths. All five were of epithelial type, and their mean survival after diagnosis was 24.2 months.
  • All five villagers with malignant pleural mesothelioma and the three with lung cancer came from the same family.
  • No members of this family had any identifiable occupational exposure to asbestos.
  • Among the villagers with malignant pleural mesothelioma, all the men were smokers and neither of the two women was.
  • The authors said the familial clustering may indicate genetic susceptibility or increased environmental exposure in some families.
• The authors' conclusion: The authors concluded that a high incidence of pleural calcifications and mesothelioma was confirmed in an asbestos-exposed population. They also concluded that a different type of asbestos from that found elsewhere in Turkey (chrysotile) was found in white soil.
• Limitations the authors state:
  • Some cases may have been missed because about half of the villagers had migrated to other regions or countries.
  • Not all verbal autopsy results could be confirmed from hospital records, because some records had been lost or destroyed.
  • The small number of subjects prevented examination of any association between malignant pleural mesothelioma and smoking.

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Tremolite, Chrysotile, Chest X-Ray, Lung Cancer, Mesothelioma, Zeolite, Pleural Calcification.

Related studies

• High risk of malignant mesothelioma and pleural plaques in subjects born close to ophiolites — M. Bayram, I. Dongel, et al. (2013)
• 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)
• Environmental exposure to asbestos: from geology to mesothelioma — M. Bayram, N.D. Bakan (2014)
• Malignant mesothelioma due to environmental exposure to asbestos: follow-up of a Turkish cohort living in a rural area — S. Metintas, M. Metintas, et al. (2002)
• Environmental asbestos contamination: What are the risks? — V.L. Roggli (2007)

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