However, data indicate that Pu bound to soil probably has a much lower gut-transfer factor of about 10-4 to 10-5 (Gilbert et al., 1989; Harrison et al., 1989). ICRP also recognizes a different gut transfer factor for Pu that is not organically bound (ICRP, 1990). Consequently, we used a gut transfer factor of 10 for Pu bound to soil. All Am was assumed to have a gut transfer factor of 10-3. It is noted that the 10-3 gut transfer factor is considered to have a considerable margin of safety built in (ICRP, 1986, 1990). The estimated effective dose from Pu based on the concentrations in food, soil, and air are very similar to those calculated by BNL based on the analysis of Pu in urine of the Rongelap people (Sun, 1992). These two very independent methods are in excellent agreement on the Magnitude of the dose from the transuranic radionuclides as shown in Table 17. The estimated average committed effective dose for 30-y residence from Pu based on environmental data and models is 0.26 mSv (26 mrem), or 0.10 mSv (10 mrem), for the 50-y integral effective dose. We have assumed that a person is in a high-resuspension condition (1 h d-! ) everyday of his life, which is probably excessive, and that a person consumes 100 mg of soil every day. The value of 40 mrem committed effective dose from urine analyses is based on the detection limit of the analytical method used for analyzing Pu in urine. The median value for Pu in the urine ofall the people analyzed is below this detection limit value. In other words, the actual median committed effective dose people receive is below _the detection limit value of 40 mrem committed effective dose. People have been living on Rongelap Island for about 28 y subsequent to the fallout from BRAVO. Consequently, both for residence between 30 and 50 y. In the long term, of course, as and 69Co disappear, the radionuclides will be the only sourcg The total estimated effective dose fransuranic of exposure. fgom 239+240Py and 241Am radionuclides, baged on the inhalation and imported food afailable diet scenario discussed previously, is alfout 0.08 mSv (8 mrem) over 30 y, 0.18 mSv (18 } over 50 y, and about 0.33 mSv (33 mrem) over y. From the marine pathway, reef fish in particular, and the pelagic fist, are a key source, and a favorite source, of grotein in the Marshallese diet. It is fortunate and 99Sr concentrations are very marine foods (Tables 5 and 6). Co that the 137Cs low in the ently, the marine pathway is a minor contgibutor to the total estimated dose from} man-made radionuclides, but not necessarily for naturally because there is more 137Cs and in the ground occurring radionuclides. The roof-catchment water [(i.e., cistern water) contributes in a very minpr way to the estimated dose listed in Table If ground water is consumed, then the d will go up water than in the cistern water; ever, ground water generally is used only in c of extreme drought. In our dose calculations, we assume 40% this. The maximum annual intake 9067, 239+240Py and 241Am for Ron Table 17. The average committed effective dose from Pu and Am at RongelapIsland in Method Environmental (LLNL)* Committed effective dose__50-y integral effective dose njSv (mrem) | Urine Analysis (BNL) Committell effective dose Pu . 0.26 (26) 0.10 (10) 0.49 (40) Am 0.23 (23) 0.078 (7.8) Nqd estimate a Twosignificant figures are given only to showthe slight difference between Pu and b Based on the detection limit. The actual mean dose is something below this number.