Fig. 1

Excess relative risk (ERR) of solid cancer in atomic bomb survivors. a [31], L: linear fit, LQ: linear-quadratic fit, C⁺ and C⁻: 95% CI (confidence interval) to L. Assumed ERR is 0.42 at age 70 when people of age 30 were exposed to 1 Gy (a, blue arrow). Inset shows ERR at dose range 0–0.6 Gy. See that only one point is between C⁺ and C⁻, unusually low ERR at 0.4 and 0.6 Gy, and LQ (<2 Gy) comes under C⁻ (green line). b [33], comparison of conventional LNT (black lines) with a Bayesian semiparametric model (red lines). C⁺ and C⁻ are 95% confidence interval for LNT and 95% credible interval for the semiparametric model. As for the definition of non-parametric data (filled circle), see the reference [33]. Inset shows ERR at dose range 0–0.4 Gy. See that LNT has only one point between C⁺ and C⁻, while eight points (ERR at 0.6 Sv is not shown) are located between C⁺ and C⁻ in the Bayesian model, which predicts a threshold and hormesis. Significant increase of ERR is observed over 0.1 Gy. Figures are presented with permission from Radiation Research (a) and John Wiley and Sons (b)