Natural radioactivity levels in soil samples from some areas of Himachal Pradesh, India using γ-ray spectrometry

226Ra, 232Th and 40K analysis has been carried out in soil samples collected from some areas of Himachal Pradesh, India using γ-ray spectrometry. The measured activity in soil ranges from 42.09 to 79.63 Bq kg−1, 52.83 to 105.81 Bq kg−1 and 95.33 to 160.30 Bq kg−1 for 226Ra, 232Th and 40K with the mean values of 57.34, 82.22 and 135.75 Bq kg−1, respectively. The measured activity concentration of 226Ra and 232Th in soil samples collected from these areas is higher and for 40K is lower than the world average. The radium equivalent activity in all the soil samples is lower than the safe limit set in the OECD report (370 Bq kg−1). The value of the external exposure dose has been determined from the content of these radionuclides in soil. It has been observed that on the average, the outdoor terrestrial gamma air absorbed dose rate is about 83.28 nGy h−1. The study yields an annual effective dose in the range of 0.07–0.13 mSv. The average value of annual effective dose lies in the global range of outdoor radiation exposure given in United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) [(2000). Effects and risks of ionizing radiations. UN, NY]. The activity concentration of 238U has also been determined using fission track technique and the values range from 3.26 to 7.71 mg kg−1 with a mean value of 4.38 mg kg−1.