42 Station 5 1s located 160 miles southwest of Fniwetox and station 55, 90 miles due north of Eniwetok (Fig. 1). Plankton from stations 5 and 55 ylelded similar radiochemiceal analytical results and in addition have almost identical gamma spectra, which are essentially the same as thet of the plankton samples from one of the neighboring stations, 54 (Fig. 11). Station 42 was taken 479 miles west of Fniwetok. The iso- topic. content of plankton from this station was clearly different from that of stations 5, 54 and 55 on the bases of both chemical and ganms spectrum analysis. Comrarisons of the relative activity of the different iso- topes from plankton at stations 5, 55 and 42 as determined by chemical sanalysis with the expected activity based on the Runter and Ballod?curves are as follows; Isotope gr99 90 csi37 Bal37,140 Expected percent * 7.5 <1. <2. Observed percent at stations 5 and 0 0 <1. 55 4o 1.5 0 é1. cont t_ ppt tt 16. 8.2 Triv. R.E. 15. b,5 5.1 Ru, Ru? 6p30 zr?> 5.0 12.5 3.0 28, 3.0 21. C97! 98260 an°? 0 0 3.0 ~w 1 20. s ye 31. 6.0 * Based on an average 8-month interval following detonation. 7 According to the gamma svectrum, Zn65 accounts for approxi- mately 50 percent of the tots] activity at stations 5 and 55. “ae

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