Frank Cluff, Safety Advisory Group, NV BIKINI EXPOSURE CALCULATICHS Following our discussions on the plane and in Honolulu I agreed to 411485 make & quick check of the predictions of exposures that may be associated with the diet on Bikini. Gustafson’s calculations which develops the long-range exposure potential for the Bikinians, begin to produce the key results when he eume the contributien of various items of the diet for several important radionuclides end wakes comperisons with etandaris for the individual end for the general public. See Table VI of his May 1968 report. In Attachment 1 I have gone through a portion of thie exercise for 13Tces, with which I em wore familiar, and then with 90g and >Fe. As you will see, the values check vith Gustafeon's persissible intake mmbers for 137cs and for 9%sr (depending on the calcium intake) but I get a auch higher allowable daily intake for 55Fe. Also I obtained a somewhat lover 5 year }37cs dose for adults, 230 mrad versus 536 mrad, and about the same 5 year 137Cs dose for the worst case for children, 276 mrad versus 268 mrad. There is one additional summary report that was an appendix to the material going to the Comission that you may not have seen. See Attachment 2. You will find that Table 3 of thie appendix is gimilar to Table VI except certain items have been omitted from the table such as Pandanus ani crebs. This makes a significant reduction in the ar ana '3’cs 1evels in the diet but changes the ©9Fe intake not at all. This is why I had more concern for 2Fe Predictions gince I could see no way of reducing that exposure short of placing restrictions on intake of fish. The sample computations in the Attachment for 13og and 22Fe indicate that Gustafson's predicted five year total whole body dose number may be a little high. For exemple, the 5 year contribution to vhole vedy dose from 9’Fe of 27 mrad plus 230 wred from 137cg plus 750 urad external is about 1 rad instead of 1.4 rad as in Table VIII. the spleen dose of 30 mrad/yr from 99Fe, I'll say more later. As to There is one additional consideration. The pandanus will be out of the diet when the natives firet return since the sinrveys have indicated no edible variety of this food is available much less a sufficient quantity of the edible type to meet the needs of the returning natives. BEST COPYAVAILABLE we bd eee ‘ut = - RSRAYS