Radioactivity of 238U, 232Th, 40K, and 137Cs and assessment of depleted uranium in soil of the Musandam Peninsula, Sultanate of Oman

238 U, 232Th, 40 K, and 137 Cs radioactivities were determined in soil samples collected from the Musandam Peninsula, Sultanate of Oman, using a high resolution gamma-ray spectroscopy system. In addition, total uranium was measured in selected soil samples by inductively coupled plasma optical emission spectroscopy (ICP-OES). The averages of radioactivity levels in the soil for 238 U, 232 Th, and 40K were 14.42 Bq kg −1, 9.95 Bq kg −1 , 158.21 Bq kg −1 , and 2770 Bq m −2 for 137Cs, respectively. The mean of the total uranium in soils was 1578.28 μg kg −1 . As the mean values, radium equivalent was estimated to be 40.84 Bq kg −1 and annual effective outdoor radiation dose was 25.4 μSv. The contributions of individual radionuclides for 238 U, 232Th, 40 K, and 137Cs to the total annual effective dose were 30%, 32%, 32%, and 6% respectively. Selected soil samples were also investigated for depleted uranium (DU) by estimating the percentages of 235U in total uranium and the results revealed that DU concentrations matched its range in natural uranium.