The 222Rn and 220Rn concentrations in some dwellings of Mandya city and its surroundings, Karnataka, India

Abstract

The measurement of 222Rn and 220Rn concentrations in air was carried out in 50 dwellings belonging to 20 locations in and around Mandya city, Karnataka. Annual mean values of 222Rn and 220Rn concentrations were found to be 22.4 ± 1.5 and 24.1 ± 1.8 Bq m−3, respectively. The total annual effective dose received by the general public due to radon and thoron was found to be 1.36 ± 0.08 mSv y−1. The doses to different organs and tissues were calculated using the International Commission on Radiological Protection (ICRP) model of the respiratory tract and inter-comparison was made. The flooring, roofing type and age of the buildings were noted and the radon levels with respect to these parameters were analysed and discussed. An attempt was made to predict the indoor radon levels in dwellings using the existing model which was based on the mass balance equation and the results were compared with measured values.