ISSUES IN ASSESSMENT OF POTENTIAL RADON HAZARD AT BUILDING SITES

Abstract

High concentrations of radon in the premises leads to a risk of lung cancer for the population. In this regard, in the production of design and construction works, an assessment is made of the potential hazard of radon in the construction sites. At the present, the unified approach to methodology of assessment is not developed. Abroad, various categorical and numerical values, such as radon potential or radon index, are used as criteria for radon hazard. In different countries, these criteria are determined using various parameters: uranium / radium concentration, radon volumetric activity in soil air and premises, gas permeability of soils, geological structure of underlying rocks, dose rate of gamma radiation. Studies conducted abroad show that the parameters used, as a rule, do not correlate with the amount of radon entering buildings during its operation. In the Russian Federation, the radon flux density measured on the soil surface is used to estimate the potential radon hazard of a building site. Applied today method of potential radon hazard assessment has one general drawback. It is low reliability of results. Such a quality of assessments obtained by measuring the radon flux density is due to the variability in the values of this value and to the measurement of the surface of the soil. The paper discusses the results of measuring the radon flux density obtained by the methods of «accumulation chambers» and «carbon adsorbers» in the summer periods of 2014, 2016 and 2017. It was confirmed that the strongest influence on the values and variability of radon flux density is exerted by precipitation. The paper presents the results of radon flux density measurements on the soil surface, as well as on the surface of dense loams lying at depths of 0.5 m and 1.5 m. It is shown that the radon flux density measured on the soil surface is two to three times smaller than the values of this value measured on the surface of dense rocks. It is important to note that the lowest variability of the results (20%) was observed in 2014, when measurements were made on the surface of dense loams during dry, stable weather.