Excess relative risk per dose for cancer mortality in nine studies of low-dose-rate, moderate-dose exposures (red symbols), as compared with acute, high-dose exposures (atomic bomb survivors of Hiroshima and Nagasaki) (blue symbols). The error bars indicate 95% CIs for the studies of workers at Rocketdyne, the Chernobyl emergency workers and the Techa River residents, and 90% CIs for all other studies.