Assessment of gamma-emitting radionuclides in the total Kuwaiti diet

Activity concentrations of gamma-emitting radionuclides were determined in commonly consumed Kuwaiti foods and beverages using calibrated high-purity germanium (HPGe) detectors. The total annual activity intakes of ⁴⁰K, ²¹⁰Pb, ²²⁴Ra, ²²⁶Ra, and ²²⁸Ra were estimated at 103,481 ± 4,889, 243 ± 55, 9.6 ± 0.7, 21.9 ± 9.0, and 13.4 ± 1.5 Bq y⁻¹, respectively. ⁴⁰K was detected in all samples, with the highest activity concentration in coffee (640 ± 30 Bq kg⁻¹) and the lowest in grains (64.0 ± 3.3 Bq kg⁻¹). In contrast, ²¹⁰Pb and radium isotopes were detected only in coffee and tea, while ¹³⁷Cs and ¹³⁴Cs were below detection limits. The total annual effective ingestion dose was estimated at 823 ± 71 µSv, of which 642 ± 30 µSv (about 78%) was attributed to ⁴⁰K, while radionuclides from the uranium and thorium series contributed about 22%. Although the ⁴⁰K contribution exceeds the UNSCEAR reference value, it does not pose a health risk due to physiological potassium regulation. However, uranium and thorium series radionuclides remain radiologically significant due to their long-term accumulation and radiotoxicity, highlighting the need for continued monitoring, particularly in frequently consumed beverages.