T TT T —=— ---~ & counts 8 males exposed at <5 vrs oid —— Count on No. 34 exposed at | yr old (AML 1972) ' | 65 —~-— Unexposed males of same age WBC x 10-4 interesting that radiochemical analvsis of bone samples showed 99Sr levels about the sameas in people living in New York. - Lymphocytes x 10-4 Retrospective study ofhematological data. The hema- s 1 = x ** + 2 eof : 7 ~ 2 | Ly 1 2 61 4 8 12 16 f}— Months —+————- Years + Time after exposure sr T | T a TT q TT * T yy? TF Te F qT t Tr OF —-+— Unexposed males of same age o&E 7777 MX counts on 8 males exposed at <5 yrs old 4 = x 9 «+ iL = Jra = 2- ‘ 2 = 1 J Counts on No. 54 exposed at | yr old (AME 1972) goo, 4 a 24 : a eee 4 Le 4 ate post-exposure period and in subsequentyears. The least difference appeared to be in the erythropotetic system. Morphological] studies of peripheral blood smears revealed no significant abnormalities until the development of leukemia; unfortunately no bone marrow examinations had been made before. Since the Marshallese children are pronetofre- quentinfections associated with granulocytosis,it was of interest tocompare this response in the sub- ject with leukemia andin the other exposed bovs. The records showed that the white cell count ex- ceeded 10,000 a total of 36 times in 131 counts (27%) in the other 8 exposed boys and only once Ob in 18 counts (3%) in subject No. 54. However. if 45+ = 40> 35 30 L ati. |i | 2 61 4 aoe 8 { 12 atu 16 i Months +-—.__-_-____ Years —_________ Time after exposure 347 tological data gathered over the 18-year period on the subject with leukemia (No. 54) were compared with the meanlevels of 8 other Rongelap boys exposed at <5 vears of age and of 8 unexposed bovs in the same age range (Figure 52). The percentage differences in mean peripheralblood levels between subject No. 54 and his exposed peers are given tn Table 36 for the first year and for the subsequent years. The subject with leukemia showedgreater depression of neutrophils both during the immedi- T q ue 3 o! , 1 | 254 T T T q T TT vO Ty Tr aon X of maies exposed at <5 yrs old . No. 34 exposed at | vr old (AML 1972) io Unexposed males of same age | | i 2 5 this indicated a reduction in marrowreserve in this boy, the reduction apparently was insufficient to result in any illness serious enough to require hospitalization. Other data related to leukemia were generally negative in subject No. 34, including alkaline phosphataselevels of neutrophils, basophil counts, Australia antigen, and blood proteins (except for a slightly elevated gamma globulin level, which is commonin the Marshallese). Chromosome stud- ies of the peripheral blood made 12 years after exposure and of the bone marrow during his terminalillness did not show aneuploidy or structural changes of the chromosomes. However, increased chromosome breakage (11% of thecells) was noted » terminally, which may have been related to radia- z. tion exposure to chemotherapy, or possibly to his disease. aot 261 {Months— a ta + 8 Years Time after exposure 12 6 i o- Figure 52. Mean levels of WBC, Ivmphocytes, neutro- phils, platelets, hematocrit, and neutrophil /lymphocyte ratio for subject with leukemia (No. 534. solid line in each case) compared with those of exposed (-—-) and unexposed {—-- —) boys in same age range, over 18 years since €Xposure. Discussion. It is possible that radiation exposure was involved in the etiology of leukemia in subject No. 54. Radiation exposure has long been associated with the development ofthis disease (in physicians, particularly radiologists,147:148 in pa-