Radioactivity measurements in the environment of Chamaraja Nagar area, India

Abstract

The knowledge of distribution of radionuclides and radiation levels in the environment is important for assessing the effects of radiation exposure to human beings. Terrestrial radiation is due to the radionuclides present in different amounts in rocks, soils, building materials, water and atmosphere. Radon is the main natural radiation source of exposure of human beings and has been recognized as a carcinogenic gas. Radium ( ²²⁶ Ra) and its ultimate precursor uranium ( ²³⁸ U) are the parent sources of radon. In the present study, radon exhalation rate and radium concentration in soil and rock samples around Chamaraja Nagar area of Karnataka State, India are measured using solid state nuclear track detector's employing "can technique" and LR-115 Type-II detectors. The result from the present investigation shows that radium activity in rock sample varies from 2.9 to 39.5 Bq/kg with a geometric mean of 13.4 Bq/kg. Mass and surface exhalation rate of radon in rock samples varies from 8.0 to 119.7 mBq/kg/h with the geometric mean of 24.8 mBq/kg/h and 93.9-1787.3 mBq/m ² /h with a geometric mean of 562.5 mBq/m ² /h respectively. Radium concentration in soil samples has been found to vary from 3.6 to 34.1 Bq/kg with a geometric mean of 14.7 Bq/kg. The mass exhalation rate of radon in soil samples has been found to vary from 10.0 to 31.4 mBq/kg/h with a geometric mean of 18.6 mBq/kg/h. The surface exhalation rate of radon varies from 142 to 918.4 mBq/m ² /h with a geometric mean of 391.5 mBq/m ² /h.