4) ler ioe C837 MALE --- 5-15 YRS ar —— > i6 YRS L a 6 — | cc ea _. 2 ge oa - id - —- 5 4-- So c = 10 14 18 22+ mpc/kg = 10- ~ CoS? a 6+ 7 —_ — 7 LO 14 18 22+ muc/kg — 18 22+ mpc / kg a ee 9 '$8 22 26+ gmekg - 14 ee pee, 18 22 26+ gm / kg RESIOUAL 3AMMA ACTIVITY - — were - - + 34 FEMALE ---5-15 *RS — > 6YRS ~-Lw-f = anne i 0 10 MALE 72+ 5-0'1SYRS — > |6YRS PG = ar aon Qe bee K — Ta !: ae RADIONUCLIDES 7 i r , muc/kg -_- i Se ou 2 16 20+ — 3 x xX 8 myc kg 6 | 5 en 2 16 20 4 a 2 L_ I 28° z & EMITTING --hy ——— 8 GAMMA tN RONGELA.'’ POPULATION MARCH, 196). ro Tt Ul FEMALE --= 5-15 YRS —~>16 YRS \ _ aro a.) ") — — i mp = IO 14 18 22 muc/ kg 4 |i2 20 28+ céms *g 4 12 20 28+ e/m/kg Figure 37. Frequencydistribution of levels of radionuclides in various Marshallese groups. cally significant. Also, females tend to have values lower than those foundin the corresponding male group (Figure 37). No significant difference between the Zn’ concentrations in the exposed and unexposed groups could be determined. The percent variation within each group was approxi- mately the sameas in the case of Cs'*’. Potassium-40 The mean K concentrations for the vounger Total Residual GammaActivity The total residual gammaactivitylevels present after subtraction of the above four spectra are also shown in Table 17. The activity in cpm, kg has no absolute significance. but is of value in indicatiny. first, that there is some activityleft, and, second. the nature ofits distribution by groups. Members of the adult group have considerablyhigher levels of residual activity per unit body weight than do members of the juvenile group. No significant dil- groups were consistently higher than those for the corresponding adult groups. The male adult group averaged 2.13 g/kg body weight and the female adult group 1.63. sex, or between the exposed and nonexposect groups. Cobalt-60 Radiochemical Analysis for Strontium-90 Analyses of the residual spectra obtained after subtraction of the three above-mentioned photopeaks revealed the presence of a fourth photopeak, The estimated 1961 Sr*® mean urinaryexeretion in the Rongelap inhabitants was 7.20.4 wu |. Co". The levels of Co’ were quite low (mean =0.148 mpC,’kg), but were nevertheless readily detectible. No significant differences between the Co™ levels in the exposed and unexposed groups, or on the basis of age or sex, were observed. ferences were observed, however, on the basis «i this represents a 14% increase over the 1959 valuc (6.3 wuC,1). This value is based on theresults ot analysis of a pooled 20.8-liter sample collected from the adult population (see Table 18), This Sr’ urinary excretion expressed in terms of urinars calcium is 30.6+3.9 uwC/g Ca. These values give