Soil samples taken on Bikini showed greater than 95% of the exposure rate to be due to the !37Cs and thus the reduction in exposure rate can be assumed to closely follow the decay of !37Cs, Soil samples from the other islands showed varying amounts of ©°Co and 192MRh in addition to the 137Cs. The reduction in exposure rate due to radioactive decay on these islands should be much more rapid than for Bikini. Comparing the decay curves for these islands with that for Bikini, it can be seen that _within approximately ten to fifteen years only Eneman will have an external background higher than that of Bikini. It is recommended that a re-survey to verify this projection be conducted in about ten years in anticipation of unrestricted use of the atoll. In the meantime, the recommendation of the Ad Hoc Committee that occupancy of the above islands be limited to visits of short duration should be followed. The remaining islands of the atol] are lower in radiation levels than Bikini and should not be restricted against continuous occupancy on that basis. This is particularly true of the Oboe (Aerokoj), Peter (Aerokojlul), Roger (Bikdrin) complex where the lowest levels on the atoll were found. In addition, coconut samples from Aerokoj were lower in !37Cs and 99Sr content than those from Bikini or Eneu. development of these islands should be encouraged. Agricultural While the external levels on Sugar (Lele) are as low as those on the other three islands, the fact that it is contiguous with Tare (Eneman) would make it advisable to restrict the use of this island at the present time. The causeway joining Lele to Bikdrin makes a logical dividing line for indicating this restriction. Sampling of food items presently growing on the atoll indicated mean concentrations of !37Cs and 99Sr which are essentially in agreement with those obtained in 1967. It should be pointed out that the planting of new species of foods on the islands will require additional sampling at the time of their reaching maturity in order to assess the potential internal dose. Internal dose estimates have been performed by Gus tafson'°? utilizing the 1967 data and would appear to be valid for the 1969 data as well. Results of the 1970 survey for plutonium in air are approximately two orders of magnitude below the FRC guide for an individual 43