This paper presents preliminary results of quasi-integral measurements of the average for 4 days volumetric activity of radon-222 in the indoor air of residential and public buildings of Tobolsk city and adjacent districts – Tobolsk, Vagaysky, Uvatsky, obtained for March – August 2023.The lowest level of volumetric activity of radon-222 was found in residential nine-storey buildings of the Soviet period (years of construction: 1970–1990) up to 20 Bq/m³. Exceeding the level of volumetric activity of radon-222 over 400 Bq/m³ was not revealed in the studied residential and public premises of Tobolsk and adjacent districts – Tobolsk, Vagai and Uvat. The distribution of values of average for 4 days volumetric activity of radon-222 in the air of premises of Tobolsk city and adjacent districts, as well as in subfloors and basement floors is not normal, as p<0,01. The distribution of values of average for 4 days volumetric activity of radon-222 obtained in residential and public premises is visually insufficiently coincided with lognormal, as there are values more than 200 Bq/m³, which agrees with the data of other researchers. In the investigated wooden dwelling houses the presence of a basement and lack of air exchange creates conditions for accumulation of radon-222 in the air, the presence of vents in the foundation prevents accumulation of radon-222 in living rooms.

Tokareva Alena Yur´evna, Research Associate, Chemical-Ecological Laboratory, Tobolsk Complex Scientific Station UB RAS, 15, Academic Yuri Osipov st., Tobolsk, 626152, Russian Federation, e-mail: aytokareva@list.ru

Alimova Gulsem Salimovna, Candidate of Sciences (Technics), Head, Chemical-Ecological Laboratory, Tobolsk Complex Scientific Station UB RAS, 15, Academic Yuri Osipov st., Tobolsk, 626152, Russian Federation, e-mail: gulsem76@mail.ru

Utkina Irina Aleksandrovna, Senior Laboratory Assistant, Chemical-Ecological Laboratory, Tobolsk Complex Scientific Station UB RAS, 15, Academic Yuri Osipov st., Tobolsk, 626152, Russian Federation, e-mail: utkina.67@bk.ru

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