Assessment of radiological hazards due to natural radioactivity in groundwater from Al Masaraat aquifer, Oman

Evaluating radiological health risks of drinking water by analyzing radionuclides is essential for public health studies, as it provides insights into population exposure levels. This research presents the first comprehensive evaluation of the quality of groundwater in Al Dhahirah Governorate, Oman, which is the major source of drinking water source. This investigation evaluates the risks of contamination from naturally occurring radionuclides (²³⁸U, ²³²Th, ⁴⁰K) using a Hyper Pure Germanium detector (HPGe). Additionally, determine both internal and external radiation hazard indices (H_ex and H_in) to determine whether the groundwater meets safety standards, providing essential data to guide public health protection and environmental sustainability. The findings indicated that the water is slightly alkaline, with moderate levels of dissolved salts, as evidenced by electrical conductivity (EC) and total dissolved solids (TDS) readings. Radionuclide concentrations (²³⁸U, ²³²Th, and ⁴⁰K) in all samples were below the World Health Organization (WHO) permissible limits for drinking water. The calculated annual effective doses (AEDs) for two age groups were also well below the WHO-recommended threshold of 0.10 mSv/year, indicating that the residents living in these areas are not at risk from radiological exposure due to groundwater consumption. Furthermore, hazard indices (H_ex and H_in) were below reference levels, indicating no significant health risks from radiation. In conclusion, groundwater is chemically and radiologically suitable for domestic and irrigation purposes. Based on the findings, the groundwater from the study area can be used for drinking and agricultural purposes with practically insignificant radiological health risks towards the local population. Conversely, routine monitoring of radionuclide concentrations and indicators of water quality parameters is crucial to ensure sustainability of the water safety, especially where there may be impending geological or anthropogenic changes that might influence groundwater composition.