Fig. 6.

Combined effects of age at exposure and time after exposure on radiation-induced excess relative cancer risk (ERR). The ERR is calculated at age 70, which is intended to approximate lifetime risk. As discussed in the text, only age at exposure matters if parameter δ = 0, but if δ > 0, time after exposure affects the ERR as well. The parameter values were the same as in Fig. 5, except for T _x and T _y, and a reference radiation dose of 1 Gy