Spat : sts , 34 enae wie a sages eee ek e Ss”a es paiaed Ses Tem Ar apres FALLOUT FROM NUCLEAR WEAPONS TESTS 1333 rate of Cs*37 should have resulted in an equilibrated ¢gt3? burden, with an estimated daily intake sf about 15€0 uuc of csl37 «unfortunately no systematic survey of foodstuffs grown on these atolls has been reported. however Data availeble, show that coconut grown on Roneclap contained about 9 wuc cet 3? per gran, and arrowroot (Utirik) contained about & uuc Csi37 per gram. The daily intake of several hundred grams of either staple would be sufficient to account for the 1957 excretion level in the Utirik group. The Rongelap groups had been resettled for about nine months at the tine of the harch 195@ medical survey, and urinary excretion levels of cst 3? bed increased about one hundred fold over 1957 levels. Mean body burden for the (Tables 3 and 4) Cestun?3? body burden may have equilibrated by late 1998 and predicted burdens vere about 1.3 and 1.6 uc respectively Wade Sag two groups at this tine was 0.9 uc (* 27 percent) and 1 2 uc (+ hy percent) Urinary excretion levels of strontium” are presented in Tables 1, 2, and 3. The strontium? excretion level in 195G was.0.5 uuc/liter as determined in a pooled sample of 57 liters aro Strontiun’> Excretion Levels and Body Burden Figure 2 chows the excretion of $r?? for the three years following fallout exposure. Although there ig considerable variation in the data for the varicus age groups at early times, mean values for all groups Plotted sugpest thet the excretion pattero can be expreesed conveniently ag the sum of two expomential tema The larger portion of 3r?° was excreted with a This is similar to Cowan's (7) urinory excretion atudy of an accident case involving inheled sr??, As wus noted in the March 1953 cat?! levels, the excretion levels of sr°° were also increased tc 3 5-4 O/C.2, or about 20 fold Since cet37 tevets in- creased L200 - 57C0/34, cr about 140 fold, the ratio ie about seven in favor of With the increases in urinery sr?° excretion levels in 1958, it was cee ee SE eestus’? Ree Seea9 egy helf time of about 500 days. ataBch half tine of ehout 45 days, and a smail fraction. 20 percent, was excreted with a