RADIATION INJURY AND LETHALITY 



459 



In addition to the quasi-empirical actuarial and kinematic approaches 

 to the problem of radiation lethality, a theoretical statistical approach 

 is being developed (37) based on the fundamental observation that ran- 

 dom fluctuations in physiological state bring an animal into quantita- 



0.01 = 



0.001 



0.000001 



0.0001 = 



0.00001 = 







100 200 300 400 500 600 

 Time after beginning of treatment, days 



700 



Fig. 12. Gompertz diagrams for lymphoma mortality in Carworth female mice; 



control and 3 fractionated doses beginning at 88 days of age. The response rises 



to a peak and then subsides to control levels at about 500 days. 



tively different states from moment to moment, relative to the lethal 

 limit (Fig. 11). In terms of this conception, lethality can be given a 

 mathematicophysical formulation as arising from a rate process. The 

 Gompertz function can be derived theoretically on this basis, and it of- 

 fers another opportunity to correlate physiological variables with the 

 total response. 



Finally, a further note on carcinogenic responses is in order. Two 



