Dose Rate Effect on Survival of Mice During Continuous (23-24 Hr/day) Gamma Ray Exposures

Abstract

Mice were exposed continuously (23–24 hr/day) to gamma-rays at 10 dose rates (0.5–24.0 rad/hr) for the duration of life. Life span declined with increasing dose rate. The critical dose rate at which effects changed rapidly from chronic to acute was approximately 3 rad/hr. Dose rate effect (reduced life span) seems to have a similar function whether the total daily dose is delivered in acute fractions or continuously.