Excess relative risk of solid cancers as a function of dose in atomic bomb survivors.

<p><i>Reprinted with permission from figure 3 of “Studies of the mortality of atomic bomb survivors</i>, <i>Report 14</i>, <i>1950–2003</i>: <i>an overview of cancer and noncancer diseases</i>.<i>”</i> [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140989#pone.0140989.ref008" target="_blank">8</a>]. Estimated excess relative risk (ERR—equal to relative risk minus one) of solid cancer development vs. mean total colon dose for atomic bomb survivors. These estimates represent the risk of solid cancer development by age 70 to a person exposed at 30 years of age after controlling for the influence of gender and city (Hiroshima vs. Nagasaki) using models specified by Ozasa and others [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140989#pone.0140989.ref008" target="_blank">8</a>]. Black points represent central estimates for each exposure group. Vertical bars represent 95% confidence intervals. Linear (L) and linear-quadratic (LQ) dose response models were both fit to the data and appear as labeled. A linear-quadratic model fit to doses below 2 Gy is shown as well (LQ (<2Gy)). The apparent quadratic component of ERR increase with dose is most pronounced for exposures less than 2 Gy. This curvature is presumably a consequence of the relatively lower than expected solid cancer development risks in the dose range 0.3–0.7 Gy for which neither Ozasa and others nor earlier reports offer an explanation.