Estimation of dietary intake of Sr-90 in Japan after the Fukushima Daiichi Nuclear Power Plant accident: market basket study, 2013-2018

Radionuclide contamination in foods has been a public concern in Japan after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. To estimate time and regional trends of daily intake and annual committed effective dose of strontium-90 (Sr-90) after the accident, we analysed Market basket samples using a low background 2 pi gas-flow counter. Samples were collected from six regions, once a year from 2013 to 2018. There appeared to be little variation in estimated daily intake and annual committed effective dose of Sr-90 across the time periods and regions. The estimated maximum annual committed effective dose of Sr-90 was 0.00076 mSv/year, a value sufficiently lower than the intervention exemption level, 1 mSv/year, in foods in Japan. There was no noticeable difference between the range of estimated daily intake of Sr-90 in this study compared with daily intake measured before the FDNPP accident. These results suggested that no obvious increase in dietary intake of Sr-90 was observed after the FDNPP accident, and that the effects on commercial foods from Sr-90 due to the FDNPP accident were negligible.