Determination of Natural Radionuclides and Radiation Exposure Levels in Underground Water in Riyadh city, Saudi Arabia

The purpose of the current study was to determine the radionuclides in ground water in Riyadh (Latitude 24.774N, longitude 46.738E) using High Pure Germanium (HPGe) gamma detector (GMX40POrtec). In addition, the drinking water bottles investigation was comparable to the groundwater used for other purposes by the resident in the area. The water sample analysis results show, the radioactivity concentration average of Uranium-238 (²³⁸U) is: 10.029 ± 3.013 mBq/L, for Radium-226 (²²⁶Ra): 2.224 ± 0.614 mBq/L, for Thorium-232 (²³²Th): 6.69 ± 1.664 mBq/L and for Potassium-40 (⁴⁰K): 55.983 ± 6.349 mBq/L. The radium equivalent (R_eq) assessment was found in the range of 10.021 mBq/L to 20.123 mBq/L, while the internal hazard index (H_in) (i.e. >1) and the external hazard index (H_ex) (i.e. >1). The level of radiation absorbed dose rates is found to be varied from 0.29 mSv/year -1.16 mSv/year. The element's radioactivity in the water compared to the international recommended data shows the lowest of the radiations values of the natural isotopes materials. The factor analysis and statistical is revealed that the ²³⁸U and 40 K concentration variations related to the same source in all samples.