bimodal activity ingestion rate distribution for 906, in the Rongelap populnotion. Data for 40 Atoll residents. “Co and 65 “Zn were not eufficiene for analysis for the Utiri! Values for K, observed at Rongelap were assigned to Utiril males and females and body burden histories for population subgroups were reconstructed using Eq. 1 or'2. Figures 7 and 8 illustrate the derived mean adult body burdens for all significant nuclides studied on Rongelap and Utirik, This method provides a best Fit of the data shown in Figures 2 through 6, and provides a body burden history during the early years post return at Utirik, a time when body burden measurements were not made. Actual data points are also plotted co demonstrate the fit, The curves shown for 55 Fe in Figures 7 and 8 were obtained by setting Ke equal to gero. future ones, This underestimated the initial body burdens and overestimated Since 355 contributed less than 1.0% to the total dose equiv: lent, an arbitrary assignment of Ke based on observed values for the other iclides was not attempted, During 1974, another series of blood samples was obtained from Rongelap and Utirik (Co75). reported. Analysis for 5356 hss yet to be A recalculation of 3356 body burden and its impact on early dose equivalent rates will be conducted when the data is made available. A substan- tial change in dose equivalent is not to be expected. Figure 4 and Figure 6 illustrate the observed adult histories of 905, and L376 mean urine activity concentrations. adults were plotted. Figure 7. Mean values for adult males or al! Measured values for 137¢, body burdens were also shown in A much smoother curve was plotted in Pigure 7 and it was determined that the collection and analysis technique for urine samples introduced the addi. o, tional variations. . . . 137 : On the basis of this observation for Cs, a smooth tady 17