Abstract
The article presents findings on the content of radon isotopes in the air of buildings maintained in Kurchatov t., the dependence of concentrations of radon isotopes in residential and administrative buildings on a season assessed as well as on the type of premises and their purpose. Seasonal variations in radon concentrations in the air were studied by measuring the equivalent equilibrium volumetric activity (EEVA) and the volumetric activity (VA) of radon. For the first time, volumetric activities of radon isotopes in premises of residential and industrial buildings have been determined. Data showed that EEVA and VA values of radon in the air of residential and administrative premises surveyed increase from winter toward summer in the following descending series: summer > autumn > spring > winter, which, is perhaps related to soil freezing and the presence of the snow cover at the winter time. Radon concentration was also proved to decrease in the indoor air with a storey.