Northern Marshall Islands Aerial Radiation Survey Preliminary Data Summary (Continued) Rongelap Atoll Average Terrestrial Exposure Rate * (y R/h at 1 meter) Island Number Frame Number Marshallese Total Name Gross Count 137s Component §°Co Component F-29 172 Enybarbar 3.5 3.0 0.3 F-30 172 Bigannuo 6.2 6.5 0.5 F-31 80 5.1 5.3 0.5 F-32 80 Erapuotsu I.1 7.2 0.5 F-33 80 Eniaetok F-34 200 - - F~35 200 - - - F-36 200 - - _ F-37 200 - - - F-38 200 2.8 2.6 0.3 F-39 196 - - - F-40 196 - - - F-41 196 Bokujarito - - - F-42 216 Rongelap 3.8 3.6 <0.3 F-43 72 Arbar 2.7 2.3 <0.3 F-44 72 Bikien - - - F-45 50 Eniroruuri - - - F-46 50 Eniran 2.9 2.4 <0.3 F-47 50 Tufa 3.7 3.0 <0.3 F-48 56 Arugaren - - - F-49 56 Burokku 5.9 5.2 0.3 - - - F-50 | . Pokoreppu * Extrapolated from aerial data obtained at an altitude of 38 meters (125 feet) An additional 3.3 u R/h due to cosmic ray contributions must be added to obtain the total external exposure rate.