Most of the difference is from the decay of Np-239 and other transuranics and from activation products. g- Integrated Exposure and Whole Body Absorbed Dose The total integrated exposure calculated from Bikini Ash data was 280 R while people were at Rongelap Island. build-up of fallout described previously. at Rongelap Island was included in Fig. 7. This estimate accounts for the A plot of exposure rate versus time Based on the decay exponents derived from Bikini Ash components and the exposure rate survey data obtained by the crews of the USS RENSHAW and the USS PHILIP, exposure rate versus time post deto- nation plots were determined for Sifo and Utirik Islands as well (see Fig. 7). The total integrated exposure at one meter above the surface of Sifo Island was 170 R and at Utirik Island 16 R. Although these exposure estimates differ from those of Cronkite (Cr56), they are in agreement with respect to Cronkite et al whole body and external thyroid absorbed dose calculations. The Marshallese reported no significant deviation from routine living patterns as reported by Sharp (Sh57). In a previous document by Greenhouse and Miltenberger (Gr77), it was shown that external exposure inhomogeneities due to various living patterns (such as fishing in the lagoon, standing on the beach, etc.) could be accounted for by multiplying the island exposure rate by 0.73 to obtain whole body absorbed dose rate. Thus the conservative one to one relationship between expo- sure and absorbed dose assumed by Cronkite et al yields external absorbed dose estimates which are about 12% less than those estimated here. 22