Comparative Lethality Responses of Neutron- and X-Irradiated Dogs: Influence of Dose Rate and Exposure Aspect

Abstract

Previous studies in this laboratory with neutron n/y2or y-irradiated mice indicated no significant effect of dose rate on acute mortality responses when LD50(30)'s obtained at 40 to 100 rads/min and at 105 to 106 rads/min were compared (1, 2). Similar findings with n/y-irradiated mice have been reported by Spalding et al. using dose rates of 10 to 14 rads/min and -2 X 108 rads/min (3). In the course of extending the n/y dose-rate studies to dogs, it was necessary to determine the influence of exposure aspect (unilateral versus bilateral) on LD50(30); and the results led to further comparisons involving X-irradiated dogs. The data presented in the present report permit evaluation of (1) the influence of radiation dose rate, (2) the influence of exposure aspect, and (3) the potency of n/7-radiation relative to X-radiation for the production of acute radiation lethality in dogs.