272 - R. A. Conard to be sub-lethal, since no deaths occurred which could bedirectly related to radiation exposure. However, it is probable that the dose was in the high sub-lethal range, judging by the degree of haemopoietic depression that VQ TTT §F I -L 4 wm 6 Wd = o oO x - 3xr oO. = 4 FF 4 > J 2 r 4 Oo pot 8 24 40 DAYS Oo aL 56 A 72 6 | 2 3 4 ~=5 MO YEARS TIME AFTER EXPOSURE 5- 499-5 9 Figure 3. Mean lymphocyte counts of exposed people from time of exposure through tive years’ post-exposure. Stars represent mean values of comparison populations. 90 ETT 30+ w + w w T we ~ T ° ” -_—--" he Vee” uy we - MALES (AGE >10) _ 210+ Oo - | 0 8 I 24 ] ! 40 DAYS } ! 56 | 72 fA 6 At | k l l L 2 3 4 5 MO YEARS TIME AFTER EXPOSURE 4449-5 J Figure 4. Mean platelet counts of exposed Rongelap people from time of exposure through five years’ post-exposure. Stars represent mean values for comparison populations. developed. In addition radiochemical analyses of the urine also showed that definite amounts of radioactive material had also been absorbed internally. The changes during the past five years in the mean peripheral blood levels of the more heavily exposed group of 64 Rongelap people receiving approximately 175 r of whole-body radiation are shown in figures 2, 3 and 4. The ae fwd white blood cell levels of the exposed group were depressed to about half the