Determination of Whole-Body and Lens Dose Conversion Factors for Japanese Field Mice, Apodemus Speciosus.

The 11 March 2011 Fukushima nuclear accident in Japan resulted in widespread radioactive contamination within the 20 km evacuation zone. Japanese field mice (Apodemus speciosus) living within the contaminated region received radiation doses from external environmental contamination as well as internally deposited radionuclides. Cataract formation in the lens of eyes of these mice is a possible deterministic effect of ionizing radiation; however, determination of actual doses is difficult. Since no dose conversion factors currently exist for the lens of the eyes of Japanese field mice, lens dose conversion factors were created using a Monte Carlo N-Particle simulation and compared to the International Commission on Radiological Protection Publication 108 reference rat whole-body dose conversion factors. Monte Carlo N-Particle simulations included doses to the lens of the eyes from external sources (received while both above and below ground), as well as doses from internal contamination. Although the Publication 108 reference rat is almost twice the average mass of the Japanese field mouse, all dose conversion factor calculations using Monte Carlo N-Particle methods were within approximately 37% of the Publication 108 values for the reference rat.