Late health effects among Hiroshima and Nagasaki atomic bomb survivors

The Hiroshima-Nagasaki inter city differences in the dose-response are smaller for ORNL than that for T65D, but the risk is still higher for Hiroshima than for Nagasaki. The estimated risk coefficients for gamma rays based on a linear model for both gamma rays and neutrons are larger for ORNL than for T65D for each effect, and the ratios of coefficients (ORNL vs T65D) are in the range of 1.2 to 1.7. As the ORNL neutron dose becomes very small even in Hiroshima, estimates of risk coefficients for ORNL neutrons may not be warranted. However, similar estimates as for gamma rays suggest that the risk coefficients are larger for ORNL than for T65D and ORNL-T65D ratios are in the range of 4 to 6. The estimated relative biological effectiveness (RBE) for neutrons using ORNL dose and the linear model indicate that the RBE values for neutrons are larger for the ORNL dose than that for the T65D dose. (orig./HP)