  We present a novel model to estimate biological effects caused by artificial
radiation exposure, Whack-a-mole (WAM) model. It is important to take account
of the recovery effects during the time course of the cellular reactions. The
inclusion of the dose-rate dependence is essential in the risk estimation of
low dose radiation, while nearly all the existing theoretical models relies on
the total dose dependence only. By analyzing the experimental data of the
relation between the radiation dose and the induced mutation frequency of 5
organisms, mouse, drosophila, chrysanthemum, maize and tradescantia, we found
that all the data can be reproduced by WAM model. Most remarkably, a scaling
function, which is derived from WAM model, consistently accounts for the
observed mutation frequencies of 5 organisms. This is the first rationale to
account for the dose rate dependence as well as to give a unified understanding
of a general feature of organisms.

Biological Physics