[Estimation of doses of irradiation with radon-222 and its degradation products in adults of Tomsk].

The paper presents the results of statistical processing of experimental data on the volumetric activity of radon within the premises of various buildings. The results were used to estimate internal radiation doses of inhaled radon and its short-lived degradation products in the population of Tomsk. The average annual population-weighed value of the effective dose was 1.24 mSv, which is 1.5-times higher than the estimated value for the Russian Federation.

[Factors determining the formation of radon levels inside buildings].

The theoretical and experimental investigation of radon levels inside dwellings of Tomsk was carried out. The statistical analysis of gathered results let us to reveal the significant factors, which define the formation of radon levels inside the buildings and dependencies of radon distribution. The significant factors are: building type (urban or rural), year season, floor level (is significant only for buildings of rural type), daytime and social factor includes habits and life stile of inhabitants. The distribution of mean radon levels in buildings obeys the log-normal law. The distribution of radon level among the floors for urban type of buildings obeys the normal law, for rural type of buildings--exponential law.

[Radiation doses in children of the Tomsk region during inhalation of radon-222]. / Dozy oblucheniia detei Tomskoi oblasti pri ingaliatsionnom postuplenii radona-222.

The paper presents the results of the studies of the levels of radon in the premises of 30 kindergartens and 36 schools of Tomsk and its region, which were conducted in 1989 to 2000. The volume activity of radon in the air of the premises was measured by using passive track detectors of gamma-radiation upon a long-term exposure of 1-3 months. In parallel with these measurements, statistical data required for a more accurate assessment of effective doses were collected. Analysis of the statistical processing of the data on the levels of radon has indicated that the arithmetic mean, geometric mean, and standard deviation are 60, 51, and 33 Bq/m3, respectively, for kindergartens and 50, 38, and 56 Bq/m3 for schools. The mean annual radiation doses obtained on inhalation exposure to radon-222 and its degradation products are 1.06 and 1.08 mZv for preschool and school children, respectively.

[Criteria for the assessment of radon potential risk in territories]. / Kriterii otsenki potentsial'noi radonoopasnosti territorii.

The detailed analysis of criteria used in the different countries for an assessment of radon potential risk in territories was made. Such criteria as radon flux density from earth surface, radon concentration in soil air, specific activity of 226Ra in superficial soils were chosen. The analysis has revealed that the most reliable criterion is the value of equilibrium radon concentration in the soil air. The method of measurement of this value is specified.

[The assessment of the impact of different radon sources into indoor air]. / Otsenka vklada razlichnykh istochnikov radona v atmosferu zhilykh pomeshchenii.

The contributions of different radon sources into total indoor radon level can differ in some times depending on geographical and climatic features of the locality, building characteristics, lifestyle and habits of the population. The revealing of most significant radon sources for examined locality and the assessment of their relative contributions will allow planning expected radon levels during building design stage. The analysis of the factors influencing indoor radon levels and the computation of radon enter to dwellings from different sources were carried out in Tomsk. About 200 dwellings were investigated on the radon presence by solid state track detectors. The results of the comparative analysis of the theoretical and experimental sets are discussed in this paper.

[Role of the number of stories in the radiation-sanitary assessment of residential buildings]. / Rol' faktora étazhnosti pri radiatsionno-gigienicheskoi otsenke zhilykh zdanii.

Upon long-term exposure, the radioactive gas radon-222 and its decay products in increased doses adversely affect human health. Since the human being spends about 65% of his time in the buildings, it is necessary to evaluate air radiation purity in the rooms, which can be obtained by making a sanitary radiological survey of residential buildings. The scope of the rooms in many-storeyed buildings to be examined can be considerably reduced if the regularities in radon distribution are known. This paper deals with searches for regularities in the distribution of radon levels by the floors of many-storeyed buildings in Tomsk. The room air concentrations of radon were measured for 18 residential buildings with tract detectors upon 1-3--month exposure. The findings showed a different pattern in the distribution of radon levels by the floors in relation to the structural features of a building and to the type of a building material. The wooden and slag-concrete buildings show a 2-3--fold increase in radon levels on the lower floors as compared to the upper ones. A statistical analysis of measurements in the bearing-wall and brick buildings revealed no association of the concentration of radon with the level of a floor, the distribution is near-uniform with 15-30% standard deviation, which is within the limits of measurement error.