Daily intakes of naturally occurring radioisotopes in typical Korean foods

The concentrations of naturally occurring radioisotopes (232Th, 228Th, 230Th, 228Ra, 226Ra, and 40K) in typical Korean foods were evaluated. The daily intakes of these radioisotopes were calculated by comparing concentrations in typical Korean foods and the daily consumption rates of these foods. Daily intakes were as follows: 232Th, 0.00–0.23; 228Th, 0.00–2.04; 230Th, 0.00–0.26; 228Ra, 0.02–2.73; 226Ra, 0.01–4.37 mBq/day; and 40K, 0.01–5.71 Bq/day. The total daily intake of the naturally occurring radioisotopes measured in this study from food was 39.46 Bq/day. The total annual internal dose resulting from ingestion of radioisotopes in food was 109.83 μSv/y, and the radioisotope with the highest daily intake was 40K. These values were same level compiled in other countries.