Activity concentrations of selected natural radionuclides in food samples from the Czech Republic

Activity concentrations of radionuclides from the thorium and uranium series, which contribute most to radiation exposure through ingestion in the existing radiation situation, were measured. Activity concentrations were determined in common foods in the Czech Republic. The determination of the activity concentrations was carried out by a combination of radiochemical separation followed by emanometry, gamma spectrometry, or alpha spectrometry. Between 2020 and 2023, 51 "mixed diet" samples were analyzed for 226Ra and 38 for 228Ra. The average daily intake for adults was 30.8 mBq for 226Ra and 32.9 mBq for 228Ra. The annual committed effective dose for adults from food was 3.15 μSv/y for 226Ra and 8.3 μSv/y for 228Ra, both of which are lower than the doses calculated using the reference activity concentrations from the UNSCEAR (2000) report. Similarly, activity concentrations of 226Ra, 228Ra, 238U, and 234U determined in seven common foodstuffs were lower than UNSCEAR (2000). Additionally, analyses of 210Po in leafy vegetables showed the highest median values in lettuce (62-67 mBq/kg of fresh weight) and the lowest in cabbage (7-14 mBq/kg), both comparable with UNSCEAR reference values.