3. Bone Marrow Although bone marrow examinations at 6 | months post exposure showed no gross abnormalities, smears on four exposed Rongelap people 10 years later showed alteration in the myeloiderythroid ratio in three of them, manifested by an increased numberofred cell precursors. In additon to hyperplasia, the findings included abnormalities of chromatin material with double nuclei and an increased numberof mitotic figures in the normoblastic series (see Figures 14 and 15).1! Oc- casionally, bilobed lymphocytes have been noted in the peripheral blood of some exposed people. 4. Other Hematological Findings Total blood volume andred cell volume were studied 10 years after exposure.11* No differences were found between exposed and unexposed Ron- gelap groups, but it was noted that blood volume and red cell volume tended to be reduced in many Marshallese compared with Americans?® (see Fig- ure 16).12 Several other hematological observa- trons, not related to radiation exposure, were noted. Eosinophilia >5% in more than half the people has been a consistent finding. This could be accountedfor only partly on the basis of intestinal parasitism and maybe related also to numerous fungus infections of the skin and other chronic infections. Other findings possibly related to chronic infections are above-normal sedimentation rates and high gammaglobulin levels (both tending to increase with age). Varying degrees of anemia have beenseen occasionally, particularly in wo-* These studies were done by Dr. L.M. Meyer, Veterans Ad- ministration Hospital, Brooklyn, N.Y., and Dr. W.E. Siri, Uni- versity of California at Berkeley. T T TT Regression lines T T— Siri { BS = 0.91 +.0.090 (TBW) RCV =0.08 +0.0474 (TBW) Nv BY =0.647+0.115(TBW) : foore | RCV . =0.158 +0.05296 (TBW) Marshall BY =0.5337+0.0767(TBW) ATS NESE ( RCV= —0.1749 +0.0441(TBW) Caucasians { BV =1.2101 +0.0792 (TBW) in Pacific RCV =0.19947 +0.0419 (TBW), 7 oe Volume,liters mulative percentage of neutrophils, lymphocytes, and platelets at various times. From these datait appears that hemopoietic recoveryin the exposed groups was incomplete during the first 15 years after exposure. Since that time the levels in the exposed group have been about the sameasin the unexposed group. On the basis of RBC, hematocrit, and hemoglobin determinations, erythropoietic function has been about the sametn the exposed andin the comparison population. The lag in recovery of leukocytes and platelets may represent residual bone marrow injury. The results of bone marrowand chromosomestudies and the developmentof a case of leukemia tend to support this contention. a 5r =4 4f 4 3 4 9 = _ tr ” 0 Total body water,liters 60 Figure 16. men of childbearing age. Price Jones sizing of red cells in these cases showed a slight microcytic tendency.§ Iron deficiency apparently was not the cause since serum iron usually was in the normal range.® Reticulocyte counts have not beensignificantly increased in either the exposed or unexposed population. Macrocytic anemia has not been seen. Vitamin B,2 levels have been unusually high in the Marshallese®; the cause of this is unknown but does not appearto be related to liver disease or leukemia. Thesickling trait has not been seen in the Marshallese examined. D. SUBSEQUENT COURSE OF SKIN LESIONS The residualskin lesions noted in the Rongelap and Ailingnae people since the initial lesions are listed in Table 13. During the first year many of the healed areas, particularly on the back of the neck, showed a roughening (rugosity).and bluishblack pigmentation, which becameless noticeable with time (see Figures 17 and 18). Deeperlesions exhibited early residual scarring and lack of pig-