Measurement of uranium in total diet samples: Daily intake for Japanese

Diet samples were collected by a duplicate portion study of Japanese adults in two districts, a newly-rising town and an established seaside village, of Ishikawa Prefecture, which faces the Sea of Japan. Uranium concentrations in a total of 80 diet samples were determined by -spectrometry after chemical separation. No marked differences between the two districts were found regarding characteristics of food consumption in thirteen categories and in daily intake of²³⁸U per person. The daily intake of²³⁸U per person ranged from 1.1 to 40 mBq with a geometric mean value of 9.6±2.1 mBq. The²³⁴U/²³⁸U activity ratios ranged from 0.7–1.5, with most being from 1.0–1.2. The internal dose estimation system (IDES) was completed with Japanese physical parameters and other parameters of ICRP Publication 30, and then the annaul effective dose equivalent was estimated as 3·10^–7 Sv for²³⁸U in a Japanese adult.