Natural radioactivity and radiological risk assessment of soil samples from greater Cairo

This study evaluates the concentrations of primordial radionuclides and the associated radiological hazards in soil samples collected from various locations across Greater Cairo, Egypt. The specific activities of 226 Ra, 232 Th, and 40 K were measured using gamma-ray spectroscopy with an HPGe detector. The results revealed that 40 K exhibited the highest concentration, followed by 226 Ra and 232 Th. To evaluate the potential risks associated with radiation exposure, various radiological hazard indices were computed, such as the radium equivalent activity (Ra e q), external hazard index (H ex ), internal hazard index (Hᵢ n ), gamma index (Iγ), and annual effective dose equivalent (AEDE). The findings revealed that all calculated hazard parameters were below the internationally recommended safety limits, signifying negligible radiological risks to the public. Additionally, comparative analysis with national and international studies demonstrated that Greater Cairo's soil radioactivity levels are significantly lower than those observed in high-background radiation areas. The findings contribute to environmental radiation monitoring efforts and provide crucial insights for future geochemical and radiological assessments in Egypt.