177 Acute and chronic intakes of fallout radionuclides @ S. L. SIMoNn ET AL. Table 10. (Continued) Utrik community Rongelap Island community Birth Year RBM Thyroid Stomach Colon RBM Thyroid Stomach Colon <1931 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.8 2.8 2.8 2.8 2.8 2.5 2.5 2.5 2.5 2.5 2.3 2.3 2.3 2.3 2.3 2.9 2.9 1.8 0.017 0.024 0.015 0.019 740 740 740 740 740 740 740 870 870 870 870 870 900 900 900 900 900 1,300 1,300 1,300 1,300 1,300 1,800 1,800 470 6.4 7.2 6.1 3.3 16 16 16 16 16 16 16 18 18 18 18 18 18 18 18 18 18 21 21 21 21 21 31 31 3.7 0.068 0.081 0.073 0.029 180 180 180 180 180 180 180 200 200 200 200 200 230 230 230 230 230 260 260 260 260 260 380 380 32 1.0 1.1 1.1 0.19 25 25 25 25 25 25 25 30 30 30 30 30 27 27 27 27 27 25 25 25 25 25 31 31 16 0.032 0.046 0.029 0.039 7,600 7,600 7,600 7,600 7,600 7,600 7,600 9,700 9,700 9,700 9,700 9,700 10,000 10,000 10,000 10,000 10,000 15,000 15,000 15,000 15,000 15,000 20,000 20,000 5,100 12 14 12 7.2 530 530 530 530 530 530 530 610 610 610 610 610 600 600 600 600 600 690 690 690 690 690 1,100 1,100 150 0.14 0.17 0.15 0.067 2,800 2,800 2,800 2,800 2,800 2,800 2,800 3,100 3,100 3,100 3,100 3,100 3,700 3,700 3,700 3,700 3,700 4,100 4,100 4,100 4,100 4,100 6,100 6,100 480 2.0 2.1 2.0 0.38 were derived from the same thyroid biokinetic model and sets of parameter values used to derive the excretion fractions. Contribution of other radionuclides to the internal doses The 63 radionuclides that have been considered for the estimation of the doses from acute intakes have been selected among those that were systematically reported by Hicks (1984) forall tests, while the five radionuclides considered in the estimation of the doses from chronic intakes are those that were measured in whole-body or from bioassay measurements performed within a few years after the Bravotest. In addition, there are several radionuclides that deserve mention: e ~*Pu and “Pu: The normalized deposition densities of Pu and *°Pu for specific tests were not reported by Hicks (1984) as that information is classified. How- ever, ~°*~°Pu concentrations in the top layer of soil (O—5 cm) were measuredin soil samples collected in 1978 by Robison et al. (1982) and in 1991-1993 by Simon and Graham (Simon and Graham 1997; Simon et al. 1999). In order to estimate the ~’'**°Pu deposition density at the time of fallout, it was assumedthat: (1) all of the *’'**°Pu fallout occurred at the time of large tests in 1954, (2) the deposited activity migrated relatively rapidly downwards from thetop layerof soil during the first year after deposition, then decreased much more gradually with time as the activity became fixed in the soil matrix, (3) the measurements included the contribution from *’'°Pu in global fallout, esti- mated as 0.24 Bq kg', and assumedto haveall been deposited in 1962, and (4) the average density of the top layer of coral-based soil was 1.0 g cm*. The deposition density of *’*~°Pu from all Pacific tests, assumed to have occurred in 1954, and the variation with time after fallout of the concentration of **°*~°Pu in the top level of soil (O—5 cm) are presented in Table 18 for all atolls and reef islands of the Marshall Islands exceptthe test site atolls. Crude estimates of the doses due to acute intakes were obtained using: (1) the deposition densities presented in Table 18; (2) the relationship of 0.031 Bq intake per Bg m* deposited obtained for '°’Cs at Rongelap for the test Bravo, and (3) the committed dose coefficients recommended by ICRP (1996). The doses to bone marrow were much greater than those for the other three organs and tissues that we considered. The highest doses to RBM were