one fraction and iodate carrier to the other, The fodide carrier was oxidized with NaNO. in contact with a CCl, phase to extract iodine as In. The todate carrier was reduced carefully with an equivalent amount of NagS03 in contact with a CCl, phase; after separating the phases, more iodate carrier and then NagS04 were added to the aqueous phases voth fractions were then oxidized with NaNO» in contact with a CCl, phase. The iodine was back-extracted from the three CCl, solutions into the aqueous phase with NaS0,, Comparison of the iodine activity in the three fractions was used as &n indication of the oxidation state of iodine, A third procedure incorporated the use of ion exchange resins. For this procedure the original sampls was placed on a cation resin col- umn at a pH of 5 to 6. Iodine along with other anions and uncharged particles was washed out with de-ionized water. The wash-through was analyzed for iodine. Procedures for the separation d iodide and iodate on an anion resin column resulted in a good elution of iodide from Dowex 1 resin with 3N-HCl. A number of reagents were tried for an elution of jodate but no satisfactory reagent was found at that time; iodate was not removed by 50 column volumes of 3N-HC1. 3.3 e202 3.12. Results The results for the analysis of iodine are summarized in Table The values showing the distribution of total iodine activity in the solid and liquid phase are accurate to within a few per cent. The growth in and decay of the different isotopes of iodine complicate the procedures and the interpretation of the data. The procedures were not as senaitive nor as satisfactory as those for neptunium to show the presence of the several oxidation states. Furthermore, the oxidation atate of iodine in the criginal fallout probably changed before the samples were recovered, The presence of organic bodies, the suscepta- bility of iodine to air oxidation, possiblities of self-nxidation reduction, and exchange with sea water carrier would contribute to the formation of the resultant oxidation state of iodine in the samples at the time of analysis. The gamma spectra of the fodine fractions for Shots 2,3, and 4 showed the presence of q131 7132 | ana 1133, The decay of the early semple on Shot 4 indicated a large amount of 1132 while the gemma spectra showed also the presence of 1131 ana 1133, 34 COMPOSITION OF THE FALLOUT MATERIAL The samples analyzed quantitatively consisted of materials collected from the environment of the shot points prior to detonation and the fallout samples. Three coral samples each from sites Charlie and Tare, two surface lagoon sea water samples, one bottom lagoon sea water sample, and one bottom lagoon coral sample were analyzed, Within the limite of variation of the major elements in these samples their cheaical analysis was used to determine the amount of environmental or background constituents in the fallout samples. Then, if it is assumed thet no great variation in the constituent elements occurred due to fractionation 58