Thyroid dose estimations in the inhabitants of Bryansk, Tula and Orel regions based on the results of radiometry measurements in 1986

Equipment and methods, used for measurements of 131I in thyroid among inhabitants in three regions of the Russian Federation - Bryansk, Tula, Orel, which were most heavy contaminated with radioactive fall-out after the Chernobyl accident, are described in the article. Techniques of estimation 131I activity and dose in thyroid based on measurements are presented. A model of 131I intake in human body is proposed which takes into account applied protective measures and an algorithm for calculating thyroid dose is described. Examples of performed measurements, calculated 131I activity and estimated doses in thyroids in some contaminated areas of Russia are presented. An average thyroid dose in children who lived in the villages was by 2-5 times and in towns by 1.5-12 times higher than that in adults. The mean mass of thyroid glands in adult inhabitants in the Bryansk region was estimated as 27 g, which exceeds the value for a standard man (20 g). This fact was taken into account in the dosimetric calculation.