constant (K,=0) was used for Zn, the dose equivalent rate for the average adult was in excess of Federal Radiation Council Guidelines for the first 2 years following the return to Utirik. Internal Dose Equivalents ~ Disintegrations occurring in the total body of an individual during residence following repatriation were determined by several methods. Equation (3), together with personal body burden histories and atoll specific K, rate constants from Table 3, provided an initial estimate of disintegrations between consecutive body burden measurements. The second method used was a log-log plot of the subject's body burden history and an algebraic determination of area between two consecutive measured points. subject's body burden history. The third method used a linear plot of the The area under the curve was cut and weighed and compared to a standard weight of known area. Quality control procedures required that all three methods agree within +10% before a subject was assigned his or her total body disintegrations during residence post return. In general, the methods compared to within +5%. After the total number of disintegrations occurring in a subject's body was assigned, they were apportioned among the body organs according to the fol‘lowing equation Fe fo zLALB: (Z.C;D. + 1n2/A) £.C.D.(Z.A.B. 1121 Raid + In2/A) ’ (5) where F 2 the fraction of total body disintegrations occurring in the organ of interest, A. = organ compartment deposition fraction for the element, 36