Evaluation of Natural Radioactivity in Soil Samples Collected from the Khasa River Banks in Kirkuk, Iraq

The natural radioactivity in soil samples collected from the Khasa River, which flows in the Kirkuk city of Iraq, was studied using a high-purity germanium (HPGe) detector and a spectroscopy system. The activity concentrations (Bq kg⁻¹) of ²¹⁴Pb, ²²⁶Ra, ²¹²Pb, ²²⁸Ac, and ⁴⁰K varied from 10.1 ± 0.6 to 27.5 ± 3.2, from 23.4 ± 2.8 to 44.1 ± 6.1, from 13.2 ± 0.7 to 26.4 ± 1.8, from 12.5 ± 0.9 to 28.1 ± 4.3, and from 206.5 ± 12.8 to 332.2 ± 7.2, respectively. The results have been compared to the average worldwide values. The hazard indices have also been calculated. The average of radium equivalent activity (Ra_eq) was 81.2 Bq kg⁻¹; the absorbed gamma dose rate (D) was 42.8 nGy h⁻¹; the annual effective dose rates (AEDE) outdoor and indoor were 0.05 and 0.2 mSv year⁻¹, respectively; the external hazard (H_ex) was 0.2; the internal hazard (H_in) was 0.3; the gamma radiation representative level index (I_γ) was 0.5. Our results for some sites were found to be higher than the worldwide values.