Asta a tet nie NN eerieee i el platelet counts were done. The hematocrit levels wereslightly increased overlevels of3 years ago, possibly indicating a better state of nutrition. None of the mean counts were very different from those of the unexposed comparison population (1965 counts) except for leukocytes, which were somewhathigher in the Utirik people. Appendix 10 showslevels of blood elements at various times since exposure. T ° eo . e . e 1965 “TT T HEMATOCRIT Yo por mp FEMALES tet td a T o ! oO x l oO Qo l a o a - Qo o po Ww nm Qo 30 oO T °o T TTT so AGE (YEARS) Figure 63. Hematocrit values of Rongelap exposed females plotted against age. Solid line represents mean level] of unexposed female population, 1965. 50; = c * -ee ee HEMATOCRIT % “sh TT e » T | e T MALES 1965 1 7 ° +L Children of exposed parents born sincethe fallout showed levels of peripheral blood elements about the same as those of children of unexposed parents of the same age range. Leukemia Survey No evidence of preleukemia or leukemicstate wasdetected in any of the people examined, either from the blood picture or from physical examination. Counts of 4000 white cells for percent basophils revealed no abnormally high levels (see Appendix 13). Subject No. 3, a 13-year-old boy, continues to show about twice the numberof basophils (1.13%) noted in other Rongelapese. He has developed marked hypothyroidism during the past 2 years but showsno evidenceof incipient leukemia. Statistical Analysis of Rongelap Blood Data In the last report’” a factorial analysis of variance of Rongelap blood data over the previous 4 years indicated that the slight depression of blood elements (leukocytes and platelets) of the exposed population over this period was highly significant. However,a similar analysis of the 1965 hematological data showsthat at this time there was no significant difference (at the 5% level) of platelets, 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 evidencethat the leukocyte and platelet levels of the youngest age group in all populations werehigherthan in adults. No sex differences could be demonstrated in any of the 1965 data. The percentdifference in blood levels between exposed and unexposed groupsis e presented in Table 24 and Figure 65. It can be sol seen that at 11 years there is no substantial dif- ference between the groups. - . - r . 35h L 30: Children of Exposed Parents L 20 po 30 40 Lo 50 60 AGE (YEARS) 70 Lg 80 30 Figure 64. Hematocrit values of Rongelap exposed males plotted against age. Solid line represents mean level of unexposed male population, 1965. 9008339 _ CHROMOSOMESTUDIES Since chromosome aberrations have been demonstrated in cultured blood cells from various groups of people exposed to radiation, even vears 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 Na- tional Laboratoryfor the statistical analysis of these data.