TR eR At we neat LE eet net th Conard ie te tata i Aae SaAT TE Effects of Ionizing Radiations 492 mer PERCENT AGING 30}- 20 30 40 50 60 AGE 70 8&0 90 Fig. 2. Combined weighted data (coefficient for age correlation of each criteria used to weight scores before summing). O Exposed, @ unexposed, 0 combined with standard error means. r = 0.99 (correlation with age significant at 1% level), y = 0.51 + 0.38 x + 0.01 x3. though many of these criteria showed good correlation with age, no radia- tion-induced aging effects were detectable since there were no significant differences in the exposed compared with the unexposed groupsin these studies. By combining data on a percentage response basis it was possible to obtain a ‘biological age score’. The lack of correlation with radiation exposure with such scoring in the Marshallese is demonstrated in figure 2. Perhaps these tests were not refined enough to detect aging effects of irradiation since such changes may be too subtle to be detected in this manner. In any event, most of these criteria are probably not associated directly with lethality.