low values for the concentration ratios developed from samples collected through March 1980 at Bikini Atoll are listed in Tables 4-6 for "Cs, “Sr, and ?""*Pu, respectively. The 2‘'Am is similar to 2""*2""Pu. The concentration ratios are developed from soil profiles taken to a depth of 40 cm through the root zone of the plants being sampled. This depth is used because we observe that it encompasses most of the active root zone of the subsistence plants we have studied on Enewetak and Bikini Atolls. A report on the root activity of large, mature coconut and banana trees in other tropical ; most of the activity in the 0- to 60-cm depth, although root activity did vary with age and species [38]. The report is consistent with our observations of the physical location of the root zone at Enewetak and Bikini Atolls. Thus, once the concentration ratios are developed from islands where local foods are available, they can be multiplied by the soil radionuclide concentration measured on islands where no local foods are available to estimate the radionuclide concentration in edible foods if resettlement should occur and subsistence food were planted. This predictive method has been used at manyislands where resettlement is being considered but local foods are unavailable for analysis. The concentration ratios are lognormally distributed. Marine Foods The radionuclide concentrations in marine foodsare listed in Table 7 for Bikini Atoll. The details for the radionuclide concentrations in fish at variousatolls are listed and discussed elsewhere [8,39-41]. The data represent the analyses of hundredsof the five or six most common species consumedby the Marshallese. The radionuclide concentration TABLE 7.— Measured and estimated radionuclide concentrations in marine species and birds and coconut crabs at Bikini Atoll. Dietary item mC Fish (reef) Fish (pelagic) Shelifish 0.16 0.14 0.005 Clams" Birds Bird eggs Crabs 0.011 0.055 0.033 48 Concentration (pCi/g wet weight) me meiep, - 0.002 0.002 0.005 3.8 x 10-4 3.8 x 1074 1.7 « 10" 0.04 0.018 8.81 1.3 * 10°“ 13x 10 * 6.8 x 10"" 0.006 * Includes both muscle tissue and hepatopancreas. * Calculated using the fish 7"*?"Pu to “Am ratio of2. © Assumed to be the same as fish muscle. 58 1.4 10° mA 1.9 10-4 1.9 = 10 0.85 x 10-3 0.7x 10°” 0.65 x 10°“ 0.65 x 10°“ 3.4% 10% for most species is very low, and the marine pathway contribertes very small portion of the total estimated doses at an atall Diet The estimated average diet used in the dose assessment is a very critical parameter—doses will correspond directly wit Wy, which ts directly related to the quantity of locally grown food that is consumed. Therefore, an accurate estimate of the average daily consumption rate of each food item is important. Because we have been unable to obtain information on the dietary habits of the people at all of the atolls, the diets used in this dose assessment are those recently developed from the MLSC survey conducted of the Enewetak people on Ujelang Atoll and from the BNI, surveys at Rongelap, Utirik, and Ailuk Atolls. More detailed information on the MLSCsurvey can be found in Refs. 15 and 42 and a discussion of the BNL survey appears in Ref. 43. Briefly, in the MLSC survey there were 144 persons, approximately 25% of the Ujelang population, who were interviewed. Two females failed to complete the dietary questionnaire. The breakdown by age group was 36 adult. males, 36 adult females, 19 children 12 through 17 y of age, 37 children 4 through 11 y of age, and 16 children 0 through 3 y of age. Some people were away from the atoll during the interview, so selection was limited to those households where several people were available. The households were selected at random from the availabl e pool. According to Michael Pritchard of the MLSC, “the househo ld survey met three major needs: it provided in descriptive fashion an account of the eating habits for the entire population of Ujelang; it provided data on certain special diets for certain types of individu als such as pregnant women; and served as a census documen tfor locating individuals for the IMD survey.” The recent BNLreport on dietary information on Rongelap, Utirik, and Ailuk was developed by the authors from personal observat ions while living with the Marshallese and from answers to question naires [43]. The observations and questionnaires were directed more toward estimating the food prepared for a family rather than the amount of food actually consumed. Because food is shared and some food preparedis fed to pigs or chickens, these two are not necessarily the same. In the report the authors state, “the averages which we obtaine d from the interview study are for one reason or another consistently over59