Aerokoj-Eneman Complex: Aerokoj, Aerokojlol Bikdrin, Lele Eneman East Eneman West Eneman Enidrik East Enidrik West Enidrik Lukoj Jelete Oroken Bokaetoktok Bokdrolul Bokbata Aomen-Iroij Complex: Aomen Lomilik Odrik, Iroij 1-10 6-10 1-570 1-10 20-570 3-235 3-30 10-235 60-200 60-130 15-45 10-35 20-50 10-30 5-20 26-330 10-40 6° Co, ©° Co, 137 Cs 1258 sh *No soil sample or field spectra measurements. It should be noted that these are the ranges of our measure- ments. It is quite likely that there are locations where the local exposure rates are higher than the upper limits given in the table. Since “°’Cs has a half life of 30.5 years as compared to half lives of 2.7 and 5.2 years for **°Sb and °°Co, respectively, the exposure rate levels on islands where 137 Cs was the major contributor, most importantly Bikini, can be expected to persist at almost the current levels for some time to come with only slight reductions due to 137 Cs penetration into decay and weathering. Studies of soils usually have indicated that in undisturbed soils with high organic content very little penetration of +37 cas takes