FALLOUT FROM NUCLEAR WEAPONS TESTS 1333 rete of Cst37 should nave resulted in an equilibrated csi3? burden, with an estimated daily intake of about 15€0 uuc of Cet3? Unfortunately no systezatic gurvey of foodstuffs grown on these atolls has been reported. Bee ep eo « hovever Data available, show that coconut frown on Ronselep contained about 9 uuc Ca gram, and arrowroot (Utirik) contained about 8 uuc C3137 per gran. 137 per The daily intake of several hundred grems of either staple would be sufficient to account for the 1957 excretion level in the Utirik group. r a ¢ i] f. a Be The Rongelap groups had been resettled for about nine months at the time of the March 195@ medical survey, and urinary excretion levels of cs!3? nee increased about one hundred fold over 1937 levels. Mean body burden for the two groups at this time was 0.9 uc (+ 27 percent) and 1 2 uc (+ 47 percent) (Tables 3 and 4) Cestum? 3? body burden may have equilibrated by late 1958 and predicted burdens were about 1.3 and 1.6 ue respectively Strontium?” Excretion Levels and Body Burden Urinary excretion levels of strontium’? are presented in Tables 1, S & 2, end 3. The strontiun?? excretion level in 195C¢ was 0.5 uuc/liter as determined in a 4 Boo pooled sample of 57 liters 2. years following fallout exposure. * 8 the data for the various age groups at early times, mean values for all groups ‘ a % gt BO of ' Figure 2 shows the excretion of gr2° for the three Although there is considerable variation in Plotted suggest thet the excretion pattern can be expressed conveniently as the sun of two exponential terms The lerger portion of gr? was excreted with a half time of about 4O days, and a smail fraction, 20 percent, vas excreted with a helf time of about 560 dpys. This is similar to Cowan's (7) urinary excretion study of an accident case involving inhaled gr0, - As was noted in the March 1958 Ca 137 512° levels, the excretion levels of S were also increased to 3.5-4 0/6.2, or about 20 fold Since ce!37 levels in- creased 300 - 570 /3h, cr about lho fold, the ratio is about seven in favor of a STTEte, aN iE aany a] With the increases in urinary gro excretion levels in 1958, it was et ll cestuat 3" 900 1108