Radiological Assessment of Gross Alpha and Beta Activities in Groundwater and Associated Health Risks in Central Saudi Arabia

This study presents an assessment of gross alpha and beta radioactivity levels in groundwater samples collected from the Al-Gwaa region in central Saudi Arabia and evaluates the associated radiological health risks. A total of 19 groundwater samples were collected from wells and analyzed using a low-background gas proportional alpha/beta counting system. The measured gross alpha activity concentrations ranged from 0.12 to 1.68 Bq/L with an average value of 0.55 Bq/L, while gross beta activities varied from 0.16 to 2.70 Bq/L with a mean value of 0.86 Bq/L. Several groundwater samples exceeded the World Health Organization (WHO) recommended screening levels of 0.1 Bq/L for gross alpha and 1.0 Bq/L for gross beta activities. Total dissolved solids (TDS) ranged between 312 and 3350 mg/L with an average value of 817 mg/L, indicating elevated mineralization in some groundwater sources. The calculated annual effective dose (AED) and excess lifetime cancer risk (ELCR) values revealed that some sampling locations may pose potential radiological health risks due to long-term groundwater consumption. The elevated radioactivity levels are mainly attributed to naturally occurring radionuclides associated with the geological formations of the aquifer system studied. Continuous radiological monitoring and detailed radionuclide investigations are therefore recommended to ensure groundwater safety in the region.