Table 5 Total Body Equilibrium Dose Equivalent Rate per Unit Body Burden I, Se mRem y~! yci7! 95 re 2x 10° 606, 6 x 102 657, 30 1 x 10° 90c, 3x 107 1376, 55 2x 102 26 27 38 Figure 15 illustrates the relative contribution to the composite dose equivalent rate for each dosimetrically significant internally deposited nuclide. For the average Rongelap adult, the residence interval begins June 1, 1957; however, many adults were reported to have resettled during the next 3 to 6 months (Co80b). The composite dose equivalent rate indicated that a broad maximum of approximately several hundred millirem per year persisted for several hundred days. Most of the dose rate is attributable to the 1376, component Ce- sium dominated over the entire post return period and would be of prime concern for populations returning to a contaminated environment years after a fission type initiating event. Figure 16 illustrates two possibilities for the Utirik dose equivalent rate resulting from the 65 ~Zn body burden history during the first three years post-return. The higher body burden resulted from use of the two measured 31 65 Zn