Malignant mesothelioma due to environmental exposure to erionite: follow-up of a Turkish emigrant cohort.

The incidence of malignant mesothelioma is extremely high in some Turkish villages where there is a low-level environmental exposure to erionite, a fibrous zeolite. The best known example is the village of Karain. However, since epidemiological studies are difficult to perform in Turkey, the incidence and the dose-response curve have not been thoroughly examined. A small cohort of immigrants from Karain who have lived in Sweden for many years were studied. Exposure data, i.e. the time residing in Karain, and hospital records including pathological diagnosis, were recorded. The cohort consisted of 162 people. During the observation time, 18 deaths occurred, 14 (78%) of which were due to malignant pleural mesothelioma. In addition, there were five patients with mesothelioma who were still alive, one of whom had a peritoneal mesothelioma. Thus, the risk of mesothelioma is 135-times and 1,336-times greater in males and females, respectively, than for the same sex and age groups in Sweden. The risk increased with duration of residence.