39 Bone Marrow Examinations row examinations will be carried out in both these The differential counts of bone marrow aspira- tions on 6 individuals, + exposed and 2 unexposed, are listed in Appendix 18. The differential counts showed that in 3 of 4 exposed persons there was an alteration in the myeloid-ervthroid ratio manifested by an increased numberofred cell precursors. In addition to hyperpiasia, abnormaiities of chromatin material with doubie nuclei and increased numbersof mitotic figures were seen in the normoblastic series (Figures 50 and 31). One of the exposed (No. 63) and oneof the unexposed (No. 948) showed increased lymphocytosis of 33% and 27% respectively. This was reflected in the peripheral biood counts in which the total number of leukocytes was normal but the lymphocytes were increased to 31% and 56%. Thesignificance of this finding remains obscure, but repeat bone mar- cases during the 1965 survey. Red Cell Mass and Plasma Volume Studies During the 1961 and 1962 surveys blood volume studies were performed on a group of Marshallese subjects and on a small numberof Caucasians who had beenliving on the islands for one year or longer. Sodium chromate labeled with Cr*' was used to tag the erythrocytes. With body weightas a criterion, it appeared that 15 of 23 subjects, both Marshallese and Caucasian, showed a significant reduction in red cell mass and/or plasma volume. In order to establish the relationship of blood volume to lean body mass tritiated water was administered orally to each of 21 Marshallese subjects during the 1963 survey. In addition, determinations were made ofred cell mass and blood volume by using Cr*'-labeled sodium chromate. Table 20 Total Blood and Red Cell Volume Data (WT. =gross weight; TBW =total body water: FAT =fat as % gross weight; LBM =lean body mass: RCV =red cell volume; BV =blood volume) Subject No. 822 832 836 838 841 873 381 882 885 895 916 928 932 938 042 959 960 1007 1043 1501 Jeon Ay WT.kg 54.34 46.36 56.36 66.13 66.81 61.36 68.63 54.77 61.81 35.90 63.63 37.27 46.30 40.00 57.72 60.00 38.63 71.36 41.81 66.81 «63.18 Av RCV(1) TBW.! 38.1 25.0 35.3 417 31.9 43.2 32.8 39.9 41.0 29.0 32.6 29.4 26.2 22.0 276 32.2 24.8 412 26.4 43.3 39.8 33.5 _ TBW.% 68.8 53.0 617 62.2 47.0 69.4 7.1 71.8 65.3 31.3 30.4 30.5 35.7 54.1 471 52.8 63.1 56.9 62.3 64.0 61.9 AvBV() _ AvTBW1)7239) ASFBW oy 70-09 FAT,% 44 26.4 14.3 13.6 34.7 3.6 34.6 03 93 28.5 30.0 29.9 22.6 24.9 34.6 26.7 12.4 21.0 13.5 11.2 14.0 LBM,kg RCV,1 BV! 52.1 1402 3.260 34.1 0.849 2.388 48.3 1428 3.320 37.1 2108 4.053 43.6 1150 3.196 59.1 1670 3.631 43 1996 4.247 34.6 1.131 3.426 36.1 1.760 3.825 40.0 1.070 2.488 43 1.091 3.031 40.2 0.927 2.305 35.8 L274 2.963 30.1 0.886 2.331 378 ©«0.860——2.150 44.0 115) 2.877 33.9 0.774 2.150 364 1.620 4.155 36.2 1.066 2.664 39.3 1.843 3.840 344 1.310 2.673 1.303 3.102 RCV/LBM, ml/kg 26.9 24.9 29.6 36.9 26.4 28.3 44.7 20.7 314 26.8 24.5 23.1 35.6 29.4 22.8 26.2 22.8 28.7 29.4 31.1 24.1 28.3 BV, LBM, ml kg 62.6 69.2 68.7 71.0 133 614 95.0 62.7 68.2 62.2 68.1 623 32.8 774 36.9 63.4 63.4 73.7 3.6 643 49.2 68.2