platelet counts were done. The hematocrit levels were slightly increased overlevels of3 years ago, possibly indicating a better state ofnutrition. None of Children of Exposed Parents the unexposed comparison population (1965 counts) exceptfor leukocytes, which were somewhathigher in the Utirik people. Appendix 10 showslevels of parents of the same age range. the mean counts were very different from those of blood elements at various times since exposure. Children of exposed parents born since thefallout showed levels of peripheral blood elements about the sameas thoseof children of unexposed Leukemia Survey Noevidence ofpreleukemia or leukemic state was detected in anyof the people examined, either 30 TT rr rs | from the blood picture or from physical examina- T TOOT FEMALES 1965 tion. Counts of 4000 white cells for percent baso- phils revealed no abnormally high levels (see Ap- 45 pendix 13). Subject No. 3, a 13-year-old boy, contines to show about twice the numberof baso- = phils (1.13%) noted in other Rongelapese. He has HEMATOCRIT % developed marked hypothyroidism during the past 2 years but showsno evidenceofincipient leukemia. Statistical Analysis of Rongelap Blood Data In the last report’® a factorial analysis ofvariance of Rongelap blood data over the previous 4 years indicated that theslight depression of blood ele- ments (leukocytes and platelets) of the exposed population over this period was highly significant. 30 20 30 40 50 60 AGE (YEARS) 70 aL 60 However, a similar analysis of the 1965 hemato30 Figure 63. Hematocrit values of Rongelap exposedfemales plotted against age. Solid line represents mean level of unexposed female population, 1965. $0) 1 T T r T presented ig Table 24 and Figure 65. It can be seen that at 11 years there is no substantial difference between the groups. i i to HEMATOCRIT So ru 4 ft at MALES 1965 logical data showsthat at this time there was no significant difference (at the 5% level) ofplatelets, leukocytes, neutrophils, or lymphocytes between the exposed and unexposed Rongelap population.* This wasalso true for the Ailingnae population. The significantly greater platelet level in this group is unexplained. There was evidence that the leukocyte and platelet levels of the youngest age groupin all populations were higher than in adults. Nosex differences could be demonstrated in any of the 1965 data. The percent difference in blood levels between exposed and unexposed groupsis CHROMOSOMESTUDIES — a — sol _ {od 20 30 40 1 #+§$0 #60 AGE (YEARS) L #70 — 4248 90 Figure 64. Hematocrit values of Rongelap exposed males plotted against age. Solid line represents mean level of unexposed male population, 1965. Since chromosomeaberrations have been demonstrated in cultured blood cells from various groups of people exposed to radiation, even years after exposure, it was of interest to see whether any such aberrations were present in the people of — “Weare grateful to Mr. Keith Thompson of Brookhaven National Laboratory for the statistical analysis of these data.