Cohn, Robertson, Conard Sr/Ca ratios were highest «over 1,000 yc Sr®. g of calcium) in portulaca, coconut meat and milk and pandanus (Weiss et al, 1956). Portulaca had a particularly high $r9°/Ca ratio. ranging from 6,000 to 25,800 pyc Sr®/g of calcium, Average Sr*¢'Ca ratios in common foods collected at 3 and 4 vears are discussed later in considering the dietary estimatc of bodv burdens in the exposed Marshallese. Water Ocean and lagoon water samples were collected initially off several islands in addition to the samples collected from cisterns and wells on the islands. Water from the cisterns and a well on Rongelap had high levels of activity (1 ye/liter) at 30 days. The predominant radsonuclide present in the water at this time was Sr8*_ Cistern water contained varving levels of contamination, depending on the orginal contamination, nature of watershed areas, etc. The occan water salnpies contained very smail umounts of beta activity, presumably denved from activity washed off the islands. The radiochemical composition of ground water, Tapir 4. Average relative composition of nuclides in plants, soil and water, March 1956 (from Weiss et al. 1956) Relative composition {per cent) 5 Piant ource No. of samples Part averaged T ota! rare Cs’ earths Sr® Ru” 1 48.9 39.2 ] 79.8 17.8 2.5 3 2 2 1 2 98.2 96.9 99.5 99.6 8.3 1.1 0.05 0.4 0.2 86.5 OF 100 one uu. O.2 0.4 ee 5.1 Plants Portulaca Le a ae. Whole Papava beste ect ceases a fruit busk meat COCO oe ceceees sectssssstssseeteeceteee shel] milk leaves Pandanus |... keys 2 92.6 cu ee . leaves 2 727 88.9 ATTOW TOOE ioe cece eee fuber leaves } ] Soil Depth, O12 im. le 55 10.3 5.1 0.8 8.9 75.4 11.7 16.8 83.9 1.0 3.0 6.8 1.4 0.34 83.8 5.6 10.0 CISCO os ects eerie Wel oc ccccccccccceseetcee ceecotesvesnensce Fe 64.4 100 OCEAN ccccceetctetetees cette sce 100 air root 2 Water 10: 314 | 2.2 Gh 2 10 wT} a in fee cect 13.3 VW.8 94.5 35.6 Dae Bette 0