Mapping of Terrestrial Gamma Radiation in Soil Samples at Baghdad Governorate (Karakh Side), Using GIS Technology

The radioactive field is one of the most important areas in human health. It must be studied to see the changes in the doses of human exposure. In this study, 46 soil samples were collected from different locations of Karakh side at Baghdad Governorate. The specific activity of natural radionuclides (terrestrial gamma radiation) 238U, 232Th and 40K for soil samples were measured using gamma-ray spectroscopy with NaI(Tl) ("3×3") detector in low-background. Moreover, ten radiological hazard parameters, which include radium equivalent activity (Raeq), absorbed gamma dose rate (Dγ), external hazard index (Hext), internal hazard index (Hint), representative gamma index (Iγr), annual effective dose equivalent (AEDE) that includes the indoor and outdoor effective dose rate, and ELCR were calculated. It has also used GIS technology for mapping specific activity and radiological radiation parameters for all the samples under study. The results show that, the average value of specific activity of terrestrial gamma radiation 238U, 232Th, 40K, 238U+232Th+40K and 235U were 16.47±0.94 Bq/ kg, 9.72±0.43 Bq/kg, 367.95±11.13 Bq/kg, 394.15±11.90 Bq/kg and 0.76±0.043 Bq/kg respectively. While, the average value of radiological radiation parameters such as Raeq, Hex, Hin, Iγr , Iα, Exposure, Dr, AGED, AEDEindoor, AEDEoutdoor, AEDEtotal, and ELCR in present study were 58.7183±2.017 Bq/kg, 0.1586±0.00546, 0.2032±0.00768, 0.4523±0.0151, 0.08237±0.0046, 3.367±0.113 μR/h, 28.8309±0.968 nGy/h, 207.1078±6.86 mSv/y, 0.1415±0.00475 mSv/y, 0.03541±0.00119 mSv/y, 0.177±0.00594 mSv/y and 0.6192 ±0.0208 respectively. The results indicate that the effective dose from terrestrial gamma radiation is everywhere across the area within the acceptable level, subject to the inherent spatial averaging of the measurements.