[Knowledge of carcinogenic and immunologic findings caused by the zeolite fiber erionite]

Prompted by the unusually high death rate from cancer of the lungs, in 1975 in the Middle-Anatolian village of Karain, later in two other villages, X-ray screening investigations were carried out. These revealed pleural mesotheliomas similar to those seen following exposure to asbestos, although no asbestos was found neither in the village itself or in its immediate surroundings. Minerological tests and examinations of the lungs of the deceased, together with animal experiments involving dust obtained from the village itself, performed in 1980, demonstrated that erionite, a fibrous zeolite is responsible for tumour lesions in the lungs and pleura. Early stages of this tumour located in the pleura were also found in a group of Karain inhabitants working in Sweden. On the basis of the examination results, an immune deficiency that did not correlate with age, sex or duration of exposure was found, and thus cannot readily be classified as an epiphenomenon. Since fibrous zeolites are frequently employed in industry, industrial hygiene and occupational medical consequences need to be drawn.