13/cg, Four persons visited Argonne from Rongelap and, in addition, pooled urine samples from both atolls were analyzed radiochemically for 1370, and 90. Subsequent Brookhaven National Laboratory expeditions by the Medical Department and Safety und Environmental Protection Division utilized whole body counting and radiochemical analysis of urine and blood samples to identify and guantify the radionuclides that were present in the body. The results of these radiological measurements are given in terms of body burden in tables 1 and 2. The aforementioned body burden tables illustrate adult mean values for Ronugelap and Utirik. of age. An adult, as classified here, was a person over 16 years The mean body mass in this age iaterval was 60 kilograms. The observed body mass versus age distribution is shown in figure 1 for Rongelap residents. The same body mass versus age distribution was observed at Utirik. Due to the paucity of measurements at Utirik, information on %o, 6574 and Fe was in some instances derived from the ratio of adult mean body burdens between Rongelap and Utirik. for 65 Zn, A mean ratio of 2.6 was observed in body burdens 90 Sr an d 1376, after they reached their maximum values. The standard deviation of this ratio was 15%. In the following analysis, personal body burden histories and residence intervals, in conjunction with contemporary dosimetric models, are used to estimate internal dose. Dosimetric distributions were constructed from the results and a summary of the derived activity ingestion rates and dose equivalents was provided for various subgroups of the population. Additionally, exposure rate history curves were constructed for each atoll for the period following the BRAVO test. These data, together with appropriate conversion factors and living patt:rn models, provided an estimate of external dose equivalent.