AN INTERSPECIES PREDICTION OF THE RISK OF RADIATION-INDUCED MORTALITY

Mortality data for B6CF(1) mice exposed to Co-60 gamma rays for the du ration of life were used to make quantitative predictions of age-speci fic mortality observed in comparably exposed beagles. Simple Kaplan-Me ier survival curves for the beagles and their 95% confidence intervals were computed for each dose-rate group observed. A dose-response equa tion was estimated from the mortality data for mice using a proportion al hazard model. The dose-response model for mice was then used to gen erate predicted survivorship curves at dose rates that would recreate the dose burdens observed in the beagle at comparable points within th e life span of the two organisms. When these predicted survivorship cu rves were scaled to adjust for species differences in the life span of control animals, the predictions for the mouse fell within the confid ence intervals observed for the beagle. The successful interspecies ex trapolation of age-specific mortality risks for species as different a s the mouse and dog enhances both the value of studies involving labor atory animals and the potential relevance of the animal studies to the prediction of health effects in humans. (C) 1998 by Radiation Researc h Society.