The impact of some factors (building materials, seasonality) on indoor radon content in Chelyabinsk region, Russia

Abstract

This paper reports the results of a study which explores the rate of indoor radon content in four settlements of Chebarkul district in Chelyabinsk region, Russia. A large number of heterogeneous rock formation areas with inclusions of thorium and uranium mineralization is a distinguishing feature of Chelyabinsk region. The natural γ-background in the study area is 110 mSv⋅h-1. The study provides the obtained results of radon content in winter, spring, summer and autumn in rooms in buildings made of wood, brick, concrete panels. Y-background and equivalent equilibrium volume activity were measured in open areas and in premises with ergonometric PAA-10 and "Alpha Guard 2000". The average annual equivalent equilibrium volume activity of radon for all buildings varied greatly depending on the materials used for construction (from 21.5-2.2 to 176.2-15.6 Bq⋅m-3). The highest values were recorded for the premises made of wood. According to the indoor radon content in the premises made of different building materials, the studied settlements were classified into several categories of being radon hazardous (the first, second and third). The range of annual average values of equivalent equilibrium volume activity in different premises was identified in the reducing order which is the following: winter-Autumn-spring-summer. The differences of the mean radon content in different seasons were statistically significant. Conservative estimates of annual doses of radon in all the studied premises ranged from 120 mSv⋅year-1 to 195 mSv⋅year-1, depending on the type of construction.