Radiation levels and radionuclide distributions in soils of the gogi region, a proposed uranium mining region in north Karnataka

Abstract

This paper reports the results of systematic studies aimed at generating a baseline database on the radiation levels and radionuclide distribution in the Gogi region, which has been identified as a prospective uranium mining region. A total of 39 villages in a 0-30 km radius zone of the Gogi region were covered under this study. The ambient gamma absorbed dose rates were measured using portable gamma dosimeters. The activity concentrations of 226 Ra, 232 Th, and 40 K in the soil samples were measured by the HPGe gamma spectrometry method. The ambient gamma absorbed dose rate varied in the range of 126-428 nGy h -1 , with a median value of 143 nGy h -1 . The activities of 226 Ra, 232 Th, and 40 K in the soil varied in the range of 5-176 Bq kg -1 , 9-687 Bq kg -1 , and 81-1493 Bq kg -1 , with the corresponding median values of 36 Bq kg -1 , 85 Bq kg -1 , and 859 Bq kg -1 , respectively. The study showed a highly non-uniform distribution of primordial radionuclides in the soil, with activity concentrations varying significantly within a small area. The results observed in the present study were compared with the literature values reported for other parts of India and the worldwide average values, and discussed.