Comparative Analysis of Radon Accumulation in Public Buildings of Different Class on the Example of Several Sogd Region Cities of Tajikistan

The article presents data and a comparative analysis of the accumulation of radon in public buildings (preschool, school and medical institutions) located near radioactive tailings, deployed in certain regions of Northern Tajikistan (Istiklol, Buston). Most of the preschool and school educational institutions buildings in Istiklol are two-storey and according to the type of building materials – brick, concrete and stone. It has been revealed that the average value of radon volumetric activity in indoor air in public buildings located in Istiklol city (formerly Taboshar) reaches up to 175 Bq/m3 and in Buston city (formerly Chkalovsk) to 26 Bq/m3. The values of radon equivalent equilibrium volumetric activity in indoor air at investigated objects are in the range of 10-330 Bq/m3 in Istiklol and 8-19 Bq/m3 in Buston cities. The range of the annual effective dose is from 0.3 mSv to 7.1 mSv. Toron has been measured in selected public buildings (schools, kindergartens and hospitals) in Istiklol city and its levels have been established between 20 and 160 Bq/m³. Indoor gamma dose values measured in schools and kindergartens fixed in the range of 0.1–1.3 mGy/h and the lowest reading determined less than 0.2 mGy/h. It has been discovered that building materials are the main source for radon intake. But the geology of the region also plays an important role. The data obtained from radon monitoring will be used in preventive measures to protect children from the effects of a radioactive factor. It is noted that the issue of protecting future generation from the harmful effects of ionizing radiation requires a comprehensive study and assessment. For preventive purposes, it is necessary to recommend mandatory periodic ventilation of preschool and school institutions.