Assessment of natural radioactivity levels in beach sand and their associated radiation hazards in the Southwestern coastline of Ghana

The study employed high-resolution gamma-ray spectrometry with a p-type extended range germanium coaxial detector to determine the activity concentrations of 40 K, 238 U, and 232 Th in coastal sand samples collected along the western coast of Ghana. The evaluated mean activity concentrations of 40 K, 238 U, and 232 Th in the beach sand were 349.5 ± 92.8 Bq kg −1 , 21.7 ± 4.4 Bq kg −1 and 19.7 ± 4.3 Bq kg −1 respectively. The measured mean concentrations of radionuclide levels were then used to estimate radiological hazard indices to assess the potential radiological hazards associated with the measured radionuclide activity levels in the study as well as the excess lifetime cancer risk. The estimated radiological hazard indices and corresponding effective dose indicated that the beach does not pose a significant radiological risk to the public. The average Excess Lifetime Cancer Risk value was 0.2 × 10 −3 , within the range of 0.074 × 10 −3 to 0.958 × 10 −3 , which is within the globally accepted limit. The Pearson's correlation analysis established a significant contribution of 232 Th and 40 K to the radiological hazards of the coastal area, whereas 238 U showed a negative or weak correlation with the hazard parameters, suggesting its minimal impact. Support Vector Machine with Radial Basis Function Kernel (SVM-RBF) models outperformed Random Forest in predicting radiation-induced cancer risk (RMSE = 0.038, R 2 = 0.91), with Annual gonadal dose (AGD) as the dominant predictor. Findings highlight the importance of external exposure monitoring and warrant validation in expanded cohorts. Continued monitoring is recommended to track the possible changes in radionuclide contamination due to agricultural and industrial activities. This study provides baseline data for future research and regulatory purposes within the study area and other coastal regions in Ghana.