Internal doses from radionuclides and their health effects following the Fukushima accident

Ishikawa, Tetsuo*; Matsumoto, Masaki*; Sato, Tatsuhiko   ; Yamaguchi, Ichiro*; Kai, Michiaki*

The current knowledge on internal dose estimation and its health effect were reviewed in this paper. The goals were to discuss the uncertainty of current dose coefficients, to compare the effects of external and internal exposures, and to review recent epidemiological studies. Radionuclides focused on in this study were caesium-137 (Cs), caesium-134 (Cs), and iodine-131 (I), which primarily contributed to internal effective thyroid doses after the Fukushima Dai-ichi Nuclear Power Station accident. Current knowledge suggests that the risk of internal exposure could be generally the same as or less than that of external exposure, when they are compared at the same effective dose.