Distribution of natural radionuclide along Main Central Thrust in Garhwal Himalaya

Study of natural radionuclide is important to assess the radiation level in a particular area. Radionuclide present in earth's crust is different for different geological areas because of the variety of soil and rocks present in a particular area. In present study, the estimation of natural radionuclides have been carried out along the Main Central Thrust (MCT) in Uttarkashi, Budhakedar, Ukhimath and Healang regions of Garhwal Himalaya, India. The large variations in the radionuclide distribution have been estimated along the Main Central Thrust. The 226Ra, 232Th and 40K contents in MCT area varies from 8 ± 1 Bq.kg−1 to 285 ± 28 Bq.kg−1 with an average of 64 Bq.kg−1, 7 ± 1 Bq.kg−1 to 136 ± 15 Bq.kg−1 with an average 69 Bq.kg−1 and 115 ± 18 Bq.kg−1 to 1588 ± 162 Bq.kg−1 with an average 792 Bq.kg−1, respectively. The radon exhalation rate and radon concentration in the soil of study area varies from 2.20 × 10−5 Bq.kg−1h−1 to 3.2 × 10−5 Bq.kg−1h−1 and 287 Bq/m3 to 417 Bq/m3, respectively. It was observed that the distribution of natural radionuclide in the soil of study area is not uniform and concentrated along geological active region. These values of radionuclide and radon mass exhalation rate may be used as baseline data for further study in the area.