Natural radioactivity and radiological risk assessment of Saudi-grown coffee beans

Natural radioactivity in food products contributes to long-term internal radiation exposure and remains an important aspect of radiological food safety assessment. This study evaluates the activity concentrations of naturally occurring radionuclides ( 226 Ra, 232 Th, and 40 K) in coffee beans cultivated in southern Saudi Arabia and compares them with selected imported samples from Ethiopia and China. Seventeen coffee samples were analyzed using gamma-ray spectrometry with a 3 × 3 inch NaI(Tl) detector. Radiological risk was assessed through absorbed dose rate, annual effective dose equivalent, radium equivalent activity, hazard indices, annual committed ingestion dose, and excess lifetime cancer risk. The measured activity concentrations in Saudi-grown coffee ranged from 6.28 to 14.96 Bq kg −1 for 226 Ra, 1.08–5.34 Bq kg −1 for 232 Th, and 48.34–122.06 Bq kg −1 for 40 K. All calculated radiological indices were well below internationally recommended safety limits, indicating negligible radiological risk from coffee consumption. The findings provide the first region-specific radiological baseline for domestically grown coffee in Saudi Arabia and support evidence-based regulatory oversight and long-term environmental monitoring within the expanding national agricultural sector.