Natural radioactivity concentration in soil samples of Yelagiri hills, Tamilnadu, India

The natural radioactivity of soils at Yelagiri hills has been studied. The radio activities of 25 samples have been measured with a NaI(Tl) detector. The radioactivity concentrations of 238U, 232Th and 40K ranged from BDL to 53.23, 13.54 to 114.75 and from 261.11 to 2207.3 Bq/kg, respectively. The measured activity concentrations for these radionuclides were compared with world average activity of soil. The average activity concentration of 232Th in the present study is 1.61 times higher than world median value while the activity of 238U and 40K is found to be lower. In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity (Raeq) and the external hazard index (Hex) have been calculated and compared with the internationally approved values. The study provides background radioactivity concentrations in a Yelagiri hills. (author)