In the commercial agriculture areas of JANET and the other northern islands the item of concern is the radioactivity level of coconuts i.e., "Can the Enewetakese sell their copra?" Data in NVO-140 (pg 560-562) indicate that 137 Cs is the principal man-made radionuclide found in coconut meat, with the relationship 137 es (copra) = 1.33 1376, (soil) at 137 66 soil concentrations greater than 4.7 pCi/gm. NVO-140 also indicates that 40. is found in copra at an average concentration of 6.8 pCi/gm. Since 40, is a naturally occurring gamma emitter that has always been present in copra, one way to judge the acceptability of copra grown in Enewetak Islands is on the _ basis of its 13705 content relative to the naturally occurring 40. If the 13766 content in soil is less than 5.2 pCi/em, for example, the 13764 content of the copra produced may be less than its 40, content. One could hold the position that marketability should not be affected if the fission product radioactivity makes less contribution to consumer exposure than naturally occuring radioactivity in the product. Table 10 shows the mean 137 66 soil concentration and soil removal actions that may reduce the 137 ¢6 concentration in copra to values equal to and twice that of the natural 40. for all northern islands (average profile data for PEARL, ALICE, BELLE, and CLARA, plotted in Figs. 8-11 and included in Table 8, were used in the calculations for each of these islands). On JANET, for example, the commercial agriculture area in its current condition should yield copra with an average about three. 1370, ;40 K concentration ratio of Removal of a 6 cm thick layer of soil may reduce this value to two, and removal of 14 cm may result in copra with equal concentrations of 13764 and 40, Note that for islands planned to be used for commercial ’ agriculture, it is possible that only JANET and PEARL have high enough to yield copra with a 137 1 : 37o5 soil values cs /%x ratio greater than 2. -13- Test