Analysis of natural radionuclides in soil samples of Purola area of Garhwal Himalaya, India

Naturally occurring radioactive materials are widely spread in the earth's environment, being distributed in soil, rocks, water, air, plants and even within the human body. All of these sources have contributed to an increase in the levels of environmental radioactivity and population radiation doses. This paper presents the activity level due to the presence of ²²⁶Ra, ²³²Th and ⁴⁰K in soil samples of Purola area in Garhwal Himalaya region. The measured activity of ²²⁶Ra, ²³²Th and ⁴⁰K in collected soil samples of Purola was found to vary from 13±10 to 55±10 Bq kg^-1 with an average of 31±2 Bq kg^-1, 13±10 to 101±13 Bq kg^-1 with an average 30±3 Bq kg^-1 and 150±81 to 1310±154 Bq kg^-1 with an average 583±30 Bq kg^-1, respectively. The radium equivalent activity in collected soil samples was found to vary from 47 to 221 Bq kg^-1 with an average of 115 Bq kg^-1. The total absorbed gamma dose rate in this area was found to vary from 22 to 93 nGy h^-1 with an average of 55 nGy h^-1. The distribution of these radionuclides in the soil of study area is discussed in details. (authors)