Verification of a dose rate-responsive dynamic equilibrium model on radiation-induced mutation frequencies in mice

Purpose: We have proposed a mathematical model (WAM model) expressing increment of the dose-rate dependent mutation frequency caused by artificial radiations. In this model, it is defined that the pool of mutant cells in dynamic equilibrium in organisms. We verified the accuracy of the WAM prediction of mutation frequency in mice. Materials and methods: The theoretical values calculated by the WAM model were compared with the experimental values obtained from the large mouse genetics program at the Oak Ridge National Laboratory (ORNL). Results: Most of all the theoretical values in acute and chronic irradiation conditions nearly coincided with the experimental values. However, the theoretical value of the chronic conditions at the dose-rate of 0.8 R/min was significantly higher than its experimental value. This discordance was able to be minimized in the WAM assumption, when the period from the end of exposure to start mating was two weeks longer. Conclusions: As a result of comparison between experimental and theoretical data, the certainty of the WAM model was confirmed in mice and it was shown that the genetic influence varies depending on the dose-rate.