Abstract
Individual radiation dose received by radiation accidents are obtained from the amount of paramagnetic radicals in tooth enamel by ESR (electron spin resonance) measurements. The tooth enamel is a sensitive dosimeter made of hydroxyapatite, while dentin had not been used for dosimetry. Recently, it was reported1 that neutron doses can be independently obtained when we utilize the difference in the sensitivity of neutron dose relative to that of gamma ray dose between enamel and dentin.
In the present study, tooth enamel and dentin from the victims of JCO accident were measured with ESR. The enamel and dentin were mechanically separated with a high speed diamond saw. They are subsequently crushed to grains of about 1mm in diameter. ESR measurements were done with an ESR spectrometer, JEOL FA-100 at RIRBM, Hiroshima University. The intensities of the dosimetric signal probably due to CO2- were obtained by using a computer program named "New ER"2. The doses equivalent to gamma ray dose were calculated from the calibration line. The obtained doses from enamel ranged from 11 to 13 Gy which are consistent with the previous work3. Unfortunately, the doses obtained from dentin scattered too much to discuss the neutron doses.
1. F. Trompier et al. (in press) Radiat. Protec. Dosim.
2. A. Ivannikov et al. (2001) Health Phys., 81, 124-137.
3. K. Shiraishi et al. (2002) Jour. Raidat. Res., 43, 331-335.
