Assessment of Radioactivity Levels in Soil of Koya District in Kurdistan Region-Iraq Using High-purity Germanium Detector

Abstract: This study has been conducted to assess the 226Ra, 232Th, 40K and 137Cs radionuclides concentrations, through (5-10 and 15-25) cm-depth layers of the Koya district uncultivated soils, Erbil governorate, Kurdistan Region-Iraq, for 90 samples in 2018, using high-purity germanium detector (HpGe). As a result, the 5-10 cm layer concentrations have ranged from ‎3.8 ± 1.0 to 21.3 ± 0.3‎ (Bq.kg-1), 3‎.9 ± 0.3 to 36.2 ± 1.2 (Bq.kg-1), 95.0 ± 2.2 to 597.3 ± 8.9 (Bq.kg-1) and 0.0 to 42.7 ± 0.4 (Bq.kg-1) for 226Ra, 232Th‎, 40K and 137Cs, respectively. ‎In contrast, the 15-25 cm layer activities have shown lower values, where they have ranged from 2.6 ± 0.9 to 20.1 ± 0.3 (Bq.kg-1), 3.1 ± 0.3 to 35.3 ± 1.2 (Bq.kg-1), 545.0 ± 8.1 to 92.4 ± 2.1 (Bq.kg-1) and 0.0 to 29.1 ± 0.3 (Bq.kg-1), for 226Ra, 232Th‎, 40K and 137Cs, respectively. Moreover, the radiological parameters; namely, indoor and outdoor gamma absorbed dose rates, annual effective dose rates and excess life time cancer risks with internal and external hazard indices, have been estimated as follows: ‎(56.44, 29.22) ‎(nGy.h-1),) ‎0.28, ‎0.04) ‎‎(mSv.y-1)‎, ‎(0.97, 0.13) x 10-3, ‎0.20 and‎ 0.17, respectively. Fortunately, the results correspond with internationally healthy values. Keywords: Radioactivity, Soil, Effective dose, HPGe, Hazard, Koya.