ABSTRACT: The concentrations of natural radioactivity of 226Ra, 232Th and 40K were measured in nuts and seeds samples consumed inSaudi Arabia. A high-resolution HPGe detector was used for the natural radionuclides measurement. The results indicate that 40K was detected in all samples, whereas 226R and 232Th were found only in Brazil nut sample. The average concentration of 40K in the investigated samples was 363.82 Bq kg-1. The estimated annual effective dose due to ingestion of nuts and seeds was 0.068 mSvy-1 lower than the annual dose limit of 1 mSv y-1 for public exposure. This indicates that no risk is expected by the intake of the studied nuts and seeds samples. The radionuclide concentrations were compared with those reported from different countries. A study was carried out to evaluate the association of levels of radioactivity, selenium and aflatoxin in shelled Brazil nuts, which were classified in different sizes, for export. The selenium determinations were performed by inductively coupled plasma optical emission spectrometry (LOQ = 3.0 µg g-1), and aflatoxins were detected by Liquid chromatography-mass spectrometry (LOQ = 0.85 µg kg-1), recovery rates were between 92 and 100%. Radioactivity was measured by high-resolution gamma spectrometry. The selenium mean concentration was (22.7 ± 7.4) µg g-1. (n = 30). Mean activities determined for the following
