Gamma spectroscopy analysis of agricultural soils in Jazan: Radiological safety and environmental impact

The research investigates the levels of radioactivity naturally present in agricultural soils from Jazan region of Saudi Arabia using gamma transcriptional spectrometry NaI(Tl) to measure the activity of uranium -238 (U-238), thorium-232 (Th-232), and potassium-40 (K-40). Analysis of a total of 33 soil samples gathered from diverse agricultural sites revealed average activity concentrations of 35.5 ± 1.26, 22.94±1.35 and 11.20±0.92 Bq/kg for U-238, Th-232, and K-40, respectively. While U-238 levels slightly exceeded the world average, the total radionuclide concentrations remained within internationally accepted safety. The radiation hazard indices, including the external hazard index (Hex=0.18±0.01), the internal hazard index (Hin=0.27±0.01), the equivalent radium activity (Raeq=56.85±1.55 Bq/kg), the average absorbed dose rate (Dab=25.32±0.14 nGy/h), and the gamma index (Iγ=0.46±0.03), were calculated and found to be well below their permissible limits. The results indicate minimal radiological hazards associated with the studied soils, confirming their suitability for agricultural use. The observed differences in radionuclide concentrations and hazard indices across the sampling sites highlight the influence of local geological structure, agricultural practices, and environmental factors on the distribution of natural radioactivity. This research provides a critical baseline for ongoing soil radiation monitoring in the region, contributing valuable data to global efforts in radiation safety assessment and sustainable agricultural management.