specific activities cesium in the soil 1.3 parts (Table 3). This is in spite of the fact that total (radioactive plus per million whereas nonradioactive) total amounts to less than strontium amounts to 2000-4000 parts 7 * :4 \ & per million owing to its very much greater natural abundance. a ) 1 Unfortunately for cleanup purposes, cesium-137 is readily taken up by plants, moving in much the same way as potassium, essential element with which it might compete for uptake. activity varies with the in different foods, specific-activity of the but Plants, concentrate cesium 3-6 times over the soil level the concentration ratio (plants/soil) Its specific- in each case will soil. rise especially (6). an and fall fruits, may For strontium-90, in edible fruits ranges from .01 to .5 but in the leaves it may be as high as 10 (Appendix 8). The cesium-137 surface-zone activity (0-10 cm} individual aerial islands survey, of the Bikini Atoll, is given in Table 1. estimates were confirmed determined by a for the comprehensive In the case of Bikini and Eneu, the by terrestrial measurements. These measurements Show that Bikini is among the most heavily contaminated islands, while Eneu is in the lower range. In distributed mean) the fell soil, cesium-137 exponentially with specific-activity depth on both (island islands as illustrated in Figure 4, based on Table 2: where A, is specific activity (pCi/g) at depth Z (cm), activity at zero depth (Bikini, 80.5 pCi/g; Eneu, 5.5 pCi/g). Although the surface activity of Bikini than 10 times that of Eneu, the fractional decline of and A is the ° averaged more activity per centimeter depth (4) was about the same (-.065 per cm vs. -.052 per cm). 5000019. a9