23 



Analysis of Mammalian Radiation Injury 

 and Lethality 



AUSTIN M. BRUES AND GEORGE A. SACHER 



Biology Division 



Argonne National Laboratory 



Chicago, Illinois 



The first man who asked some authority for an authoritative answer 

 to the question, "How much radiation is safe?" started, quite unwit- 

 tingly, a trend in mammalian biological thinking which is of great inter- 

 est and significance. It has forced the development of a primarily theo- 

 retical and holistic approach in mammalian toxicology which, like its 

 theoretical analog in the physical sciences, can become a powerful di- 

 rective influence for research in certain baffling (and generally avoided) 

 problems such as, in this instance, senescence. This trend has obvious 

 similarities to cybernetics, population genetics, and some of the newer 

 tendencies in the social sciences, and, indeed, has a social motivation; 

 it leaves us in the present position of having to explore constantly for 

 new techniques of research and thought which will serve to fill certain 

 vacua in our minds regarding the nature of growth, longevity, and cancer. 



The question is, at first sight, an irritating one to the biologist, since 

 it implies an authoritarian answer such as one customarily asks of phy- 

 sicians and safety engineers. When the physician retires to his labora- 

 tory, it is not always clear whether he does so to answer such questions 

 or to avoid them. When a physician is asked whether he would recom- 

 mend a certain drug for treatment of some common pathological state 

 (implying a judgment of safety), he may study the effects of the drug 

 in experimental animals, but he must still extrapolate his findings to 

 human beings. This extrapolation takes place through a statistical ob- 

 servation of the occasional drug reactions occurring in human beings, 

 and through other clinical data. 



What makes the comparable radiobiological question different is the 

 quite proper general determination to solve the human problem with- 

 out recourse to significant observations on detrimental human effects, 

 together with the fact that the effects which concern us may be observ- 

 able only after a period corresponding to the human life span. Although 



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