ABSTRACT
Objective:To establish a simplified anatomical model with the selected rabbits widely distributed in China′s dry region as the reference species and compare the result of internal exposure dose coefficients based on the present mode and ERICA.Methods:A simplified anatomical model based on anatomy and geometry was established for rabbits. Combined with Monte Carlo program, the deposited energy of radionuclide particles in rabbit tissues/organs was obtained, and the internal and external exposure dose coefficient for rabbits was calculated following the empirical formula.Results:Simplified anatomy model-based dose coefficients were 129I 4.81 × 10 -6, 137Cs 4.34 × 10 -5, and 134Cs 3.81 × 10 -5(μGy·h -1)/(Bq·kg -1) for internal exposure and 129I 3.16 × 10 -7, 137Cs 2.39 × 10 -4 and 134Cs 6.22 × 10 -4(μGy·h -1)/(Bq· kg -1) for external exposure. respectively. ERICA-based dose coefficients were 129I 4.44 × 10 -5, 137Cs 1.94 × 10 -4 and 134Cs 2.34 × 10 -4(μGy·h -1)/(Bq·kg -1) for internal exposure and 129I 2.19 × 10 -6, 137Cs 2.52 × 10 -4 and 134Cs 6.95 × 10 -4(μGy·h -1)/(Bq·kg -1) for external exposure, respectively. Conclusions:The simplified anatomical model established is based on the measured data and focuses on the radiation doses to biological tissues/organs, and the calculated result based on the present model are closer to the actual situation, and can provide reference values for the reference biological evaluation of non-human species.
ABSTRACT
Objective:To validate the feasibility of establishing a dosimetric model for insect species by investigating the ecological environment of an inland site in the northwestern China.Methods:For Damalacore, a simplified anatomical model based on anatomy and geometry and a model based on CT scan sequence image were established to produce a voxel model. In combination with the Monte Carlo particle transport process, the deposited energy of the radionuclides in the insect tissues/organs was obtained. The dose rate from 90Sr and 137Cs to Damalacore was calculated on the basis of empirical formula. Results:The dose rate from internal exposure to the simplified anatomical model was 8.58×10 -2for 90Sr and 4.25×10 -3μGy/h for 137Cs, whereas the dose rate from external exposure to the simplified anatomy model was 2.81×10 -2for 90Sr and 2.56×10 -1μGy/h for 137Cs, respectively. The internal exposure to the voxel model from 90Sr and 137Cs was 3.91×10 -2and 2.91×10 -3μGy/h, whereas the external exposure to the voxel model from 90Sr and 137Cs was 2.81×10 -2 and 2.56×10 -1μGy/h, respectively. The internal exposure from 90Sr and 137Cs to ERICA model was 1.46×10 -1 and 1.46×10 -2μGy/h, whereas the external exposure to the ERICA model from 90Sr and 137Cs was 5.79×10 -2 and 2.58×10 -1μGy/h, respectively. Conclusions:The calculated results based on the two models are similar to those based on ERICA model and therefore are proved reliable. With improved model accuracy, the calculated result are more close to the practical situation and feasible.