RESUMO
The natural radioactivity concentration was studied for 40 soil samples of the Churchandpur and Ukhrul districts of Manipur, India, by using gamma-ray spectroscopy. The average radioactivity concentration of 226Ra, 232Th and 40K in Churchandpur was found as 39.9 (range: 30-56), 72.1 (range: 57-93) and 564.1 (range:360-867) Bq kg-1 respectively, whereas, in Ukhrul, average radioactivity for the same was found as 30.3 (range: 16-54), 54.2 (range:24-89) and 637.1(range:103-901) Bq kg-1, respectively. The calculated radioactivity parameters were compared with the world average values. The measured radium equivalent activity (Raeq), absorbed dose rate ($\dot{\mathrm D}$), annual effective outdoor dose(E) and the external hazard index (Hex) were observed as 165 (range: 63.7-234.8) Bq kg-1, 77.6 (36.9-108.0) nGy h-1, 0.11 (0.05-0.13) mSv y-1 and 0.5 (0.1-0.6), respectively. This study aims to provide baseline data for radionuclide present in the Churchandpur and Ukhrul districts of Manipur.
