Measurement of natural radioactivity and radiation hazards assessment in rock samples of Ramanagara and Tumkur districts, Karnataka, India

摘要

The present study deals with the activity concentration of natural primordial radionuclides, namely Ra-226, Th-232, and K-40 in different rock samples of Ramanagara and Tumkur districts, and has been studied by using gamma ray spectrometry. The average activity concentration of Ra-226, Th-232, and K-40 in the collected rock samples was found to be 41.08 +/- 2.12, 86.26 +/- 2.94, and 869.29 +/- 3.78 Bq.kg(-1), respectively. The average radium equivalent activity (Ra-eq) was found as 225.29 Bq.kg(-1) and these values are well within the recommended limit prescribed for dwellings as 370 Bq.kg(-1). The external (H-ex) and internal hazard index (H-in) values are also less than unity. The mean value of absorbed dose rate in rock samples was found as 107.33 nGy.h(-1), respectively, and is slightly higher than the worldwide average value. The average indoor and outdoor annual effective dose values for rock samples are 0.526 mSv.y(-1) and 0.131 mSv.y(-1), respectively. These values are lower than the average world recommended value of 1 mSv.y(-1).