urine activity concentration.to body burden. Equation 3 ves obtained by integrating Eq. (2). Equations (1) and (2) were used to determine the instantaneous fraction of“. atoms removed or added to the stom uptake per unit time, ke and then the ini- tial daily activity ingestion rate required to produce the measured:or derived body burden. Equation (3) was used to determine the number of disintegrations that occurred in the’ bodyduring the residenceinterval ‘ofanindividual living on Rongelap or Utirik Atoll. ‘ 1 If the mean residence time in the diet is wuch auch longer then the resii lhM dence interval, then constéiitcontinuous“uptakeieachieved. Helepton (1) and —— ‘e ue ” (2) can be converted fo: thg-sonstant gontinuous sauartons by “plein Ke with -h. Single uptake-expressions are obtained by setting ¥ equal,takgero, In some cases only radioactive decay may remove the nuclide trom/dintsy items; for - these cases K, would equal sero. In the case of the fo r/Aibingresidence, the maturing of coconut trees during residence on Bikini Atsltcaused acon tat. tinuously increasing dietary uptake of 1375 Cs, tive value. Thus, mybag fopnil! to have a uege-. . PAY In the case of Ronge lap and’ Utirik, Ky was found to have a positive value for 13708, 6525, 60-,, and 905, This indicated that in addition to radioactive decay, some other removal mechanism decreased the radipactivity in dietary items during the residence interval. Yor the nuclide 5p, only one meas surement was published by the BNL Medical Program (Be72); thus an estimate of Ke was not possible. K, was determined by using Eq. (1) or (2) and the population subgroup mean body burden or urine activity concentration. Portions of these bioassay data are illustrated for adult males and females in Figures 2 to 6. Two consecutive urine or body burden data points were used to eliminate the unknown ingestion Caer me TERRI ONLagree- 1 oem