the external dose assessment, is based pandanus fruit and breadfruit, upon the unmodified conditions for the pattern III, for example, the total village island. terrestrial bone dose is 75 rem, of which The largest contribution to the whole-body and bone doses comes For living 74% is derived from the intake of bread- from the terrestrial food chain, the ex- fruit and pandanus, It is important to note, ternal dose pathway is the next highest however, that the large contribution to contributor, and the marine food chain the bone dose via these fruits occurs only and inhalation pathway contribute the when they are grown on northern islands, least. The relative contributions of each Pandanus and breadfruit grown on the less diet component to the terrestrial pathway contaminated southern islands lead to dose is shown in Tables 242 and 243. much lower dose commitments. Table 245 shows the 30-yr integral In general, living on JANET, visiting northern islands, and maintaining dose for the six living patterns for the agriculture on northern islands (living modified soil condition, i.e., where the patterns III, V, and VI) lead to signifi- village area has 5 cm of gravel and the cantly higher doses than if the village and village island is plowed. Table 246 agriculture are located on islands in the shows the 5-, 10-, 30-, and 70-yr dose southern half of the Atoll (living pattern estimates for the same conditions. I), Doses for these same patterns have Table 247 shows the additional effect been calculated for 5, 10, and 70 yr and on the 30-yr integral dose of limiting are shown in Table 244, growth of pandanus, breadfruit, coconut, The most significant contribution via and tacca to the southern islands, while the terrestrial food chain is the dose to Table 248 shows the effect of limiting all bone resulting from 905, uptake via terrestrial foods to the southern islands. The effect of the combination of these preventive measures reduces the dose for ‘As indicated earlier, these dose cal- living pattern III from 11 rem to 1.9 rem culations assume that the Enewetak people will continue their current practice of using catchment rain water for drinking and that the underground lens water supply will not be a part of their diet. An indication of doses that are to be expected from lens water may be obtained from four water samples taken on JANET in July 1971. These samples, two each from each of two 2,5-m-deep holes about 100 m from the lagoon shore, gave average concentrations of 130 pCi/liter for for living patterns I and III relative to the concentrations were scattered (<0.03, 21, when the other major isotopes observed rent purpose, we will assume an average at the Atoll have decayed away; therefore, 90Sr, and 400 pCi/liter for 15%cs, 239py <0,03, and 17 pCi/liter) but, for our cur- value of 20 pCi/liter. for whole body and from 80 to 4.7 rem for bone. A comparison of the 30-yr integral dose average United States external background doseover 30 yr is shown in Table 249, Plutonium isotopes, because of their long half-lives, will still be present Tables 250 and 251 are included to show Using these concentrations, and assuming an average daily intake of 100 ml of lens water, the resulting 30-yr the predicted doses from plutonium to the three major receptor organs (lung, doses would be 0.83 rem due to 9 Sr, liver, and bone) via the three relevant 0.019 rem due to 137%Csg, and 0.00082 rem due to 239py, exposure pathways. II-60