Suitability of Japanese wild boar tooth enamel for use as an Electron Spin Resonance dosimeter

The objective of this study was to determine the suitability of Japanese wild boar tooth enamel to evaluate lifetime radiation doses using Electron Spin Resonance Dosimetry (ESR). The opportunity to utilize tooth enamel of Japanese wild boar as a dosimeter is of particular interest due to their importance in the ecosystem within the Fukushima Exclusion Zone. Relevant characteristics were investigated which included the degree of linearity and variability in dose response of wild boar tooth enamel in the range of 1.2-12 Gy. The tooth enamel was found to have a linear dose response in this range. Teeth harvested from the same boar exhibited a variation in dose response ranging from 3.4 to 79.9%. Tooth enamel from deciduous teeth of young boar exhibited greater uniformity in radiation dose response than permanent tooth enamel taken from old boar. This finding suggests that the additive dose method would be more appropriate for performing precise dose reconstructions using tooth enamel of old boar. Preliminary results for retrospective doses varied between 0.2 and 1.4 Gy. Critical level and decision level doses were calculated for the samples used in this study, and values suggest that this methodology would be best utilized for wild boar with estimated absorbed doses exceeding 1 Gy. Information obtained during this study will be used with data collected in future studies to determine the suitability of wild boar tooth enamel for use with ESR dosimetry.