Annual Effective Dose Due to Radon, Thoron and their Progeny in Dwellings of Aligarh City and around a Thermal Power Station in Aligarh District, U.P., India

Abstract

The present study was conducted to measure integrated radon and thoron concentration levels in dwellings of Aligarh city and around the thermal power station situated in Aligarh District. Solid State Nuclear Track Detectors (LR-115, TYPE-II) based twin cup dosimeters were used for this purpose. Radon and thoron progeny concentration levels in terms of Potential Alpha Energy Concentrations (PAECs) and annual effective dose received by the inhabitants in studied dwellings were estimated from observed values of radon and thoron gas concentrations. The evaluated mean values of radon and thoron gas concentration in Aligarh city were 30.3 Bqm-3 (SD =10.6) and 10.2 Bqm-3 (SD =6.1) respectively and around thermal power station 23.6Bqm-3(SD = 5.2) and 7.7 Bqm-3 (SD= 1.9) respectively. The evaluated mean value of radon and thoron progeny concentration were 3.3 mWL (SD=1.1) and 1.1 mWL (SD= 0.7) respectively, in Aligarh city and 2.6 mWL (SD=0.6) and 0.8 mWL (SD= 0.2) around thermal power station. The estimated average value of annual effective dose in studied dwellings was 0.9 mSv (SD= 0.3) in Aligarh city and 0.7 mSv (SD= 0.2) around thermal power station.