Naturally radionuclides that present in soil such as 226Ra,232Th and 40K contribute in large amount of radiation that population exposed in these areas, the assessment of radiation levels is very important to evaluate radiological hazards due to exposure radiation and comparing these results with the recommended world average values.
In this study we measure the levels of natural radioactivity of some areas from Mosul city, north of Iraq. We used gamma-spectroscopy NaI(Tl) detector and estimated the activity concentration levels of natural radionuclides in soil. Results show that the concentration of radionuclides of 226Ra, 232Th and 40K was ranged from (6.2±0.10-26.51±0.44) Bq/kg with mean value 11.06±0.18 Bq/kg for 226Ra and between (11.33±0.82- 40.78±2.77) Bq/kg with mean value 24.82±1.75 Bq/kg for 232Th, While the concentration radio-isotope of 40K was (82.88±1.53-482.42±7.85)Bq/kg with mean value 228.83±3.93 Bq/kg.
Radiological hazard Indices were determined according to the activity concentration for these radionuclides in the areas under study of Mosul city, the results show that the values of Radium equivalent Req were ranged between (36.89-104.61) Bq/kg with mean 69.98 Bq/kg which is less than the recommended world values that mustn`t exceed 370 Bq/kg. While the values of absorbed dose Dr were ranged between (17.5-48.05) nGy/h with mean 32.21 nGy/h which also less that the recommended world values that equal 60 nGy/h, where the external and internal radiological indices were ranged between 0.099-0.282 with mean value 0.188 for Hex and between (0.118-0.341) with mean 0.219 for Hin ,where these mean values are within the world mean values (not exceed from one) and finally the results show that the magnitude of gamma index (Iɣ) ranged between (0.278-0.766) with mean value 0.522 and also these values are less than the world average (not exceed from one).from this study we can concluded that there is no radiological hazard due to the direct and continuous exposure of radiation on human and organisms that lives in Mosul city.