Evaluation of Natural Radioactivity Levels and Associated Radiological Risk in Soil from Siwa Oasis, Egypt

Thirty soil samples were collected from different locations in Siwa Oasis, Egypt. The activity was measured with a γ-ray spectrometer using a scintillation detector with a NaI(Tl) crystal, 3 × 3 inch. The average activity concentrations of 226 Ra, 232 Th, and 40 K in the soil are 22 ± 2, 12 ± 0.6, and 158 ± 8 Bq kg –1 , respectively. In addition, the radiological hazards were calculated for the investigated samples. The average values of radiological hazards affecting the population were 60 Bq kg –1 , 27.5 nGy h –1 , 33.7 mSv year –1 , 0.16, 0.22, 0.44, and 1.18 × 10 –4 for the radium equivalent activity, absorbed γ-dose, effective dose, external and internal hazard indices, gamma index, and excess lifetime cancer risk (ELCR), respectively. According to the results obtained, all samples would not present significant radiological hazards.