RETROSPECTIVE ESR RECONSTRUCTION OF CATTLE TOOTH ENAMEL DOSES FROM THE RADIOACTIVE NUCLEI RELEASED BY THE ACCIDENT OF FUKUSHIMA DAI-ICHI ATOMIC POWER PLANTS.

The method of electron spin resonance (ESR) tooth enamel dosimetry was successfully applied to cattle molar teeth exposed in the accident of Fukushima Dai-ichi atomic power plants. Total of 10 samples from 5 cattle were examined and the doses were retrospectively reconstructed to be up to 1.2 Gy (enamel dose). The dose values are roughly consistent with those estimated from the monitored environmental dose rate and the durations of the exposure. This first successful result on ESR reconstruction of doses in the actual radiation accident indicates that ESR tooth enamel dosimetry with cattle is practically useful in the dose range of ~1 Gy.