Observations on environmental asbestos exposure in a high risk area

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.

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.

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.

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.