External Gamma Dose Levels In The Soil Samples of HBRAs of Kerala and Tamil Nadu, India
Knowledge on the distribution of these radionuclides in soil is of great importance for radiation protection and measurement. A systematic radiological survey has been carried out in the region of HBRAs in Kollam district of Kerala and Manavalakurichi in Tamilnadu in India to compare the natural gamma-radiation levels. 180 soil samples collected and were analyzed for 238U, 232Th and 40K by NaI(Tl) gamma-ray spectrometry. Heterogeneous distribution of radionuclides in the region may be attributed to the deposition phenomenon of soil in the region. The result of gamma dose rate measured at the sampling sites using survey meter showed an excellent correlation with dose rates computed from the natural radionuclides estimated from the soil samples. From these radioactivity levels, the radium equivalent activity and the external hazard index which resulted from the natural radionuclides in sediments are also tabulated for the analyzed samples and compared with internationally recommended values.