Assessment of environmental asbestos exposure in Turkey by bronchoalveolar lavage

Our plain-English summary of Assessment of environmental asbestos exposure in Turkey by bronchoalveolar lavage, by P. Dumortier, L. Coplü, V. de Maertelaer, et al (American Journal of Respiratory and Critical Care Medicine, 1998).

The study

• Authors: P. Dumortier, L. Coplü, V. de Maertelaer, S. Emri, I. Baris, P. De Vuyst
• Journal: American Journal of Respiratory and Critical Care Medicine
• Published: 1998;158(6):1815-24
• Cited by: 39 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Environmental or domestic exposure to asbestos fibers originating from local soil is responsible for a high incidence of diseases in large rural areas of Turkey. Bronchoalveolar lavage fluids (BALF) were obtained for 65 Turkish subjects originating from these areas and for 42 Turkish controls. Asbestos bodies (ABs) and uncovered fibers (UFs) were quantified by phase contrast light microscopy. Total fiber burden was determined by transmission electron microscopy. The main asbestos types disclosed were tremolite and to a lesser extent chrysotile. AB and fiber concentrations were higher in environmentally exposed subjects (geometric mean [geometric standard deviation]: 5.20 [6.22] AB/ml, 444 [11.6] tremolite fibers/ml) than in control subjects (0.22 [1.45] AB/ml, 12.0 [15.4] tremolite fibers/ml) (p < 0.001). In subjects environmentally exposed in Turkey, AB burdens on tremolite were in the same range as those on commercial amphiboles in subjects occupationally exposed in Belgium. In Turkish subjects, values above either 1 AB/ml, 3 uncovered fiber/ml in light microscopy, or 300 fibers/ml in electron microscopy indicated usually an abnormal alveolar retention reflecting a significant cumulative exposure from environmental or domestic origin. These observations are probably valid for other areas in the world where diseases associated with environmental exposure to soil- derived asbestos fibers occur and for immigrants originating from these areas.

In plain English

The authors analyzed lung-wash fluid (bronchoalveolar lavage) from Turkish patients having diagnostic bronchoscopy in Ankara, 1991 to 1996. Of these 107, 65 were classed as environmentally exposed to soil-derived asbestos, for example through birthplace in affected areas or whitewashed homes; 42 had no known such exposure. Geometric mean asbestos bodies were significantly higher in 64 exposed subjects analyzed, 5.2 per ml (95% confidence interval 2.9 to 8.8), than in controls, 0.22 (0.09 to 0.37). Over 1 asbestos body per ml occurred in 64.1% of exposed subjects and 7.1% of controls. Electron microscopy found mainly tremolite, less often chrysotile; geometric mean tremolite was 444 fibers per ml (234 to 842) in 59 exposed subjects and 12.0 (2.0 to 54.8) in 16 controls. Exposed subjects' asbestos body concentrations were in the same range as those of occupationally exposed Belgians, but closer to Belgians with probable or suspected exposure than to primary asbestos workers. The authors concluded that people exposed to soil-derived fibers are not exposed to low cumulative doses. Patients were those undergoing lavage for clinical reasons, the authors noted.

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: Comparative study of mineral fiber analysis (light and electron microscopy) of bronchoalveolar lavage fluid from environmentally exposed and unexposed Turkish patients, with comparison to previously collected Belgian data
• Who was studied: 107 patients who underwent diagnostic bronchoscopy at Hacettepe University School of Medicine, Ankara, Turkey, between September 1991 and April 1996: 65 with environmental asbestos exposure and 42 controls without known environmental asbestos or erionite exposure. Asbestos body counts were compared with 600 Belgian subjects.
• Exposure: Environmental or domestic exposure to asbestos from local soil, including whitewash or stucco made from asbestos-containing 'white soil'. Subjects were classed as exposed if they were born in endemic areas and/or had lived in a house built with asbestos-contaminated material or with whitewashed walls.
• Main results:
  • Geometric mean asbestos bodies in the environmentally exposed group (n = 64 analyzed): 5.2 per ml (GSD 6.22, 95% confidence interval 2.9 to 8.8).
  • Geometric mean asbestos bodies in controls (n = 42): 0.22 per ml (GSD 1.45, 95% confidence interval 0.09 to 0.37).
  • Asbestos body and uncovered fiber concentrations differed between exposed subjects and controls (p less than 0.001).
  • Concentrations above 1 asbestos body per ml were found in 7.1% of controls and 64.1% of environmentally exposed subjects.
  • By electron microscopy, geometric mean tremolite in environmentally exposed subjects (n = 59) was 444 fibers per ml (GSD 11.6, 95% confidence interval 234 to 842).
  • By electron microscopy, geometric mean tremolite in controls (n = 16) was 12.0 fibers per ml (GSD 15.4, 95% confidence interval 2.0 to 54.8).
  • Total asbestos and tremolite concentrations were lower in controls than in exposed subjects (p less than 0.001). Chrysotile concentrations were not significantly different between the groups.
  • Tremolite made up 81.6% of the cores of 360 asbestos bodies analyzed from 32 environmentally exposed subjects.
  • Among environmentally exposed subjects, asbestos body and uncovered fiber concentrations were higher in men than in women (p less than 0.01).
  • Asbestos body concentrations in environmentally exposed Turkish subjects were in the same range as in Belgian subjects with occupational exposure. Their distribution was closer to Belgian subjects with probable or suspected occupational exposure than to primary asbestos workers.
  • Exposed subjects with mesothelioma and with benign pleural disease had similar asbestos body and uncovered fiber concentrations. Those without asbestos-related disease had lower geometric means, but the differences were not significant.
  • Tremolite fibers in lung fluid had the same chemical composition as tremolite in soil and whitewash raw material samples.
• The authors' conclusion: The authors concluded that tremolite and, to a lesser extent, chrysotile are the main asbestos types involved, and that people with environmental or domestic exposure to soil-derived fibers are not exposed to low cumulative doses. They stated that in Turkish people, levels above 1 asbestos body per ml, 3 uncovered fibers per ml, or 300 asbestos fibers per ml reflect environmental or domestic exposure with high probability.
• Limitations the authors state:
  • Recruitment depended on patients who underwent lavage for clinical purposes, and most exposed patients had asbestos-related diseases. The authors judged the risk of recruitment bias to be limited.
  • Too few amosite, crocidolite and anthophyllite fibers were found to allow statistical analysis of their dimensions.

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Bronchoalveolar Lavage (BAL), Asbestos Bodies, Fiber Burden, Transmission Electron Microscopy (TEM), Tremolite, Chrysotile, Amphibole Group.

Related studies

• Erionite bodies and fibres in bronchoalveolar lavage fluid (BALF) of residents from Tuzköy, Cappadocia, Turkey — P. Dumortier, L. Coplü, et al. (2001)
• Asbestos bodies in bronchoalveolar lavage fluids of brake lining and asbestos cement workers — P. Dumortier, P. De Vuyst, et al. (1990)
• The role of environmental and occupational exposures in Turkish immigrants with fibre-related disease — P. Dumortier, A. Göcmen, et al. (2001)
• The assessment of the malignant mesothelioma cases and environmental asbestos exposure in Sivas province, Turkey — S. Berk, H. Yalcin, et al. (2014)
• Lung diseases due to environmental exposures to erionite and asbestos in Turkey — S. Emri, A. Demir, et al. (2002)
• Asbestos exposure assessment by mineralogical analysis of bronchoalveolar lavage fluid — P. Sartorelli, G. Scancarello, et al. (2001)

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