Survival of Irradiated Rats During Prolonged Exposure to Environmental Cold

Abstract

Groups of rats for control and exptl. temps. were irradiated simultaneously with doses of 250 KVP X-rays varying from 400_900 r. A portion of each group was maintained at 23[degree]C (RH 65%) and the remainder was maintained at 6[degree]C (RH 65%) for 30 days following irradiation. Prolonged exposure to cold air increased the mortality after lethal doses of X-rays. The mean survival time for animals dying during the 30 day post-irradiation period was shortened. Exposure to 6[degree]C resulted in deaths among animals following an X-ray dose (450 r) which was not lethal to animals maintained in the 23[degree]C environment. No deaths occurred among non-irradiated rats exposed to either environment for up to 60 days.