39 row examinationswill be carried out in both these Bone Marrow Examinations The differential counts of bone marrow aspira- tions on 6 individuals, 4 exposed and 2 unexposed, are listed in Appendix 18. The differential counts showedthat in 3 of 4 exposed persons there was an alteration in the myeloid-erythroid ratio manifested by an increased numberof red cell precursors. In addition to hyperplasia, abnormalities of chromatin material with double nuclei and increased numbersof mitotic figures were seen in the normoblastic series (Figures 50 and 51). One of the exposed (No. 63} and one of the unexposed (No. 948) showedincreased lymphocytosis of 33% and 27% respectively. This was reflected in the peripheral blood counts in which the total number of leukocytes was normal but the lymphocytes were increased to 51% and 56%. The significance 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 number of 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 weight as a criterion, it appeared that 15 of 23 subjects, both Marshallese and Caucasian, showeda significant reduction in red cell mass and/or plasma volume. In orderto 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 madeofred 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. WT.,kg TBW,!1 TBW,% FAT,% LBM,kg RCV,1_ BVY,!1 RCV/LBM, ml/kg BV/LBM, ml/kg 822 832 836 838 841 873 881 882 885 895 916 928 932 938 942 “959 960 1007 1043 1501 Jeton 54.54 46.36 56.36 66.13 66.81 61.36 68.63 54.77 61.81 55.90 63.63 57.27 46.30 40.00 57.72 60.00 38.63 71.36 41.81 66.81 63.18 38.1 25.0 35.3 41.7 31.9 43.2 32.8 39.9 41.0 29.0 32.6 29.4 26.2 22.0 27.6 32.2 24.8 41.2 26.4 43,3 39.8 33.5 68.8 53.0 61.7 62.2 47.0 69.4 47.1 71.8 65.3 51.5 50.4 50.5 55.7 54.1 47.1 52.8 63.1 56.9 62.3 64.0 61.9 44 26.4 14.3 13.6 34.7 3.6 34.6 0.3 9,3 28,5 30.0 29.9 22.6 24.9 34.6 26.7 12.4 21.0 13.5 11.2 14.0 52.1 34.1 48.3 57.1 43.6 59.1 44,7 54.6 56.1 40.0 44.5 40.2 35.8 30.1 37.8 44.0 33.9 56.4 36.2 59.3 54.4 1.402 0.849 1.428 2108 1.150 1.670 1.996 1.131 1.760 1,070 1.091 0.927 1.274 0.886 0.860 L151 0.774 1.620 1.066 1.843 1.310 1.303 3.260 2.358 3.320 4.053 3.196 3.631 4.247 3.426 3.825 2.488 3.031 2.505 2.963 2.331 2.150 2.877 2.150 4.155 2.664 3.840 2.675 3.102 26.9 24.9 29.6 36.9 26.4 28.3 44.7 20.7 31.4 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 62.6 69.2 68.7 71.0 73.3 614 95.0 62.7 68.2 62.2 68.1 62.3 82.8 774 36.9 65.4 63.4 73.7 73.6 64.8 49.2 68.2 Ay Av RCV (1) AVBV(D) TBW(12039) PBW 22-022