Behavioral and Correlated Hematologic 



Effects of Sublethal Whole Body 



Irradiation* 



T. C. RucH, Walter Isaac,! and Robert W. LearyJ 



University of Washington School of Medicine, 

 Seattle, Washington 



This study is the second of two sets of experiments deaHng with the effects 

 of radiation on primates. The need for radiation studies on animals closer 

 to man than mice, rats, or dogs is obvious and was recognized by the Na- 

 tional Institutes of Health when they established a committee on radiation 

 studies to encourage such work. 



Both sets of experiments involved single sublethal doses of ionizing radia- 

 tion, 50-400 r in the first set and 300, 400, and 500 r in the second. At the 

 time the study was planned, much radiation research was directed towards 

 lethal whole-body exposure to x-rays and to higher energy radiations. It seemed 

 to us that low level radiation in single doses had considerable importance 

 for civil defense. For example, in an atomic bomb explosion, the number of 

 persons subjected to low level radiation should equal those exposed to lethal 

 and to severe sublethal doses. While the medical problems of low level ir- 

 radiation are not grave, for psychologic reasons they might be magnified by 

 fear, panic, and neurosis. Subsequent international concern over atomic 

 bomb testing has shifted interest further towards the effects of low level 

 irradiation. 



We deliberately chose relatively simple, lightly motivated types of behavior 

 to measure radiation stress or damage. The reflex approach to assaying stress 

 damage is to seek out or devise tests that call for the highest level of cerebral 

 activity and to insure the highest level of performance by employing strong 

 motivation. Common experience teaches us that man is quite capable of 

 extraordinary feats of strength and endurance in crises. Since strong motiva- 

 tion is required to produce these levels of activity, we may actually be testing 



* Aided by a grant from the National Institutes of Health. 

 t Now at Emory University, Atlanta, Georgia. 

 t Now at University of Oregon, Eugene, Oregon. 



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