The elevation of CS-137 in the Rongelap population indicates increased use of the northern islands and the potential body burden from this source may be anticipated to rise over the next several.years. At Rongelap Atoll, the northern island Naen is some 20 to 30 times more contaminated with CS-137 relative to the inhabited southern island, Rongelap. The mean =posure rate at Naen Island is currently similar to that observed at Rongelap Island shortly after rehabitation in 1957. Assuming the unlikely event of heavy dependence on the northern islands for food, one might anticipate the adult mean body burdens rising to about 18KBq (0.5 PCi) over the n=t year or so. matimum of 53KBq (1.5 l.ICi) might be anticipated in any single indiviudal. A It is more probable that the eastern, southern and northeastern islands will continue to be used for food production and if the northern islands are included, the overall result may be an increase in the adult mean body burden to perhaps llKBq (0.3 uCi). These estimates on the future adult body burdens of CS-137 are based on ~trapolation of direct body burden measurements. This metlmd is not very accurate beyond about a year after the last measurement and is subject to variation which is directly related to the daily intake of radioactive material. Tables Six and Seven contain quality control results related to the precision and accuracy of the whole-body counting system. The accuracy of the whole-body count for CS-137 was estimated to be about plus or minus 10% based on point source counting. The precision was within plus or minus 10% based on replicate counts. Whole body counts for CS-137 above the ninimum detection limit and for K39-41 were used to estimate precision (see Table Seven). The comparison between results fran system one or system two was also determined 5 ___