Radiation dose rates now and in the future for residents neighboring restricted areas of the Fukushima Daiichi Nuclear Power Plant

TLDR

The March 2011 Fukushima Daiichi accident poses a potential risk of human radiation exposure. The study evaluated radiocesium dose rates in three areas adjacent to Fukushima’s restricted zones. Dose rates were measured from radiocesium deposits in those three neighboring areas. Annual dose rates in 2012 ranged 0.89–2.51 mSv y⁻¹, and by 2022 they were similar to Japan’s ~2 mSv y⁻¹ background; the additional lifetime dose since 2012 would increase cancer risk by only 3–5 % and is unlikely to be epidemiologically detectable.

Abstract

Significance There is a potential risk of human exposure to radiation owing to the March 2011 Fukushima Daiichi Nuclear Power Plant accident. In this study, we evaluated radiation dose rates from deposited radiocesium in three areas neighboring the restricted and evacuation areas in Fukushima. The mean annual radiation dose rate in 2012 associated with the accident was 0.89–2.51 mSv/y. The mean dose rate estimates in 2022 are comparable with variations of the average 2 mSv/y background radiation exposure from natural radionuclides in Japan. Furthermore, the extra lifetime integrated dose after 2012 is estimated to elevate lifetime risk of cancer incidence by a factor of 1.03 to 1.05 at most, which is unlikely to be epidemiologically detectable.