RANKING OF THE TERRITORY OF THE CITY OF MOSCOW FOR POTENTIAL RADON DANGER

Abstract

Purpose. The identification and hygienic assessment of main sources of natural exposure of the population of the city of Moscow. Ranking areas of the territory of the city according to the potential radon hazard. The elaboration of criteria for the radon hazard of the territory. Material and Methods. There are provided data of the radiation control of the territory of the city (g-spectrometry, the determination of the activity of natural radioactive substances, including samples of the soil and in lithological layers, the density of radon flux (DRF) from the soil), surveys of residential and public buildings for different purposes according to the content of the equivalent equilibrium volumetric activity of radon (EEVAR). Results. There is presented the analysis of materials concerning the evaluation of results of radiation control (the of 226Ra activity in different types of soils, the levels of the DRF from the soil, the concentration of radon in newly constructed and operated buildings, various premises) in administrative districts of Moscow. There was executed the comparison of the spatial distribution of the fields of DRF and EEVAR values in basements and premises of buildings exceeding 200 Bq/m3. There was performed the analysis of criteria of radon-dangerous of areas. Conclusion. There were substantiated criteria and zones of the aggravated radon danger within the city according to following indices: 226Ra content in soils, DRF on soil surfaces, EEVAR in premises, annual dose of the radiation. Performed long-term studies allowed to rank the territory of Moscow into various zones of the radon danger and allocate most dangerous areas (South-Eastern Administrative District, South Administrative District, South-Western Administrative District). There was obtained a map of the interrelationship of the spatial distribution of anomalous DRFs from the soil surface and elevated EEVA values in premises. Ranging of areas for the radon danger permits to significantly optimize the system of radiation control and measures for radiation protection of the population.