Assessment of Indoor Radon and Thoron in Dwellings of Nangal Area Using SSNTD

Radon effect on human health need not be overemphasised. In the present study an attempt has been made to measure the concentration of indoor radon, thoron and annual effective dose received by residents of Nangal area of Roopnagar District of Punjab. Radium concentration and Radon exhalation in soil samples are also calculated. Indoor radon concentration varies from 93.1 Bqm−3 to 127.0 Bqm−3 with an average of 95.4 Bqm−3. The value of thoron concentration varies from 5.4 Bqm−3 to 47.2 Bqm−3 with an average of 24.0 Bqm−3. The observed annual effective dose varies from 2.3 mSv to 3.7 mSv which lies within safe limits recommended by ICRP (International Commission on Radiological Protection). Radon gas concentration in soil samples vary from 8.4 to 64.1 Bqm−3 with an average of 31.4 Bqm−3. The mass exhalation rate in samples vary from 0.2 to 2.7 mBq kg−1 h−1 with an average of 1.1 mBq kg−1 h−1, whereas, surface exhalation rate vary from 6.9 to 52.5 mBq m−2 h−1 with an average of 23.6 mBq m−2 h−1. The radium concentration ranges from 0.5 to 3.5 Bq kg−1 with an average of 1.8 Bq kg−1. The observed values of radium concentration in all soil samples are less than the recommended value 370 Bq kg−1 by OECD (Organization for Economic Corporation and Development).