Cohn, Robertson, Conard ESTIMATED BODY BURDEN ISOTOPES -RONGELAP PEOPLE 7 1954 , a | i CS-137 O86 i $f-90 (7) ft CS-1S? OOF (OH) | 1957 , 2R-€5 C281.944' POST REDWING $r-90 .080: _ t pe ce-144 (7 ie 1 RETURN TO RONGELAP 091.68) , 1.0 q 1.5 q 2.0 uc Ficure 6. Estimated body burden of isotopes in Rongelap people; 1954-1958 (from Woodward et ai, 1959). Miller (1957) determined an effective half-life of 110 days for the elimination of Zn® which gives a biological half-life of 200 days. The mean body burden of Zn®, estimated from the 1958 whole-bodycounting data, following the return of the Rongelap people to their island, was 8 times the 1957 whole-body measurement. The estimated intake of Zn% of 2 to 4 mpc/day (Woodward et al, 1959) was derived from the fish in the dict. Zn®Jevels in Rongelap fish muscle were 0.1 muc/g in 1956 (Weiss et al, 1956). The directly measured mean body burden of Zn** for Rongclap people in March 1958 (0.36 ye) is about 60 per cent of the estimated equilibrium value of 0.6 yc. The estimates of body burden of S19, Cs!3* and Zn® (1954-1958), derived both indirectly by urinalysis and directly by whole-body gamma counting, are presented in figure 6. The values in the parentheses are those obtained by wholebody gamma spectrometry, while the other values were obtained by extrapolation from urinalysis data. The body burden for Cs!8? of 11 mye (direct measurement} in 1957 indicates that the Rongelap people were exposed to a continu326 gud Ze uu aad 4 i" a D4 :