9 ee a Oo ere mee LsSe sy 410307 a - (Reprinted from Nature, Vol. 223, No. 5209, pp. 925-928, August 30 1969) / 4 i“ ‘ By My Mg eA Bs wok iF t ar € Baeor, 2 ‘ ane we t z ‘ ane a tk < PRE teeth : ama Seek a bog. ee ge hp AR ay 6 Aes ebb External Radiation on Bikini Atoll by - ‘ BURTON G. BENNETT Wide variations in external exposure rates and a large number of Health and Safety Laboratory, US Atomic Ener, Commission, New York, NY l4 on Bikini Atoll. radionuclides were found contributing to the residual radiationfields HAROLD L. BECK ” # A suRvey of the iglands of Bikini Atoll has revealed exposure rates on each island of the atoll. We were able radiation in an area of heavy local fallout several years which have not been detectable in previously surveyed several interesting features of the residual environmental after the initial deposition. Bikini Atoll is the former weapons test area in the mid-Pacific where more than twenty nuclear tests were conducted between 1946 and 1958. Our survey in May 1967 included measurements of the external radiation levels and determiiation of the principal isotopes contributing to the total external to detect many long-lived fission and activation products fallout areas. The pattern of the residual radiation on the atoll can be related to the locations of the ground zeros of various tests, the meteorological conditions affecting local fallout at the time of the tests, and the subsequent weathering and radioactive decay. Bikini Atoll consists of some fifteen islands and two BOKBATA BRAVO 54 TEWA 56 ROMEO 54 FIR 58 UNION 54 ASPEN 58 CHEROKEE S056 SYCAMOR 5B CEDAR 58 POPLAR 58 YANKEE 54 MAPLE 58 REDWOOO 58 BIKINI NAVAHO MH OSG BIKINI ATOLL BOKDROLUL BOKAETOKTOK S, OROKEN a ADRIKAN JELETEA Li " ‘ BOKANTUAK JOMELEN ENEALO DAKOTAS6 EQNJEBI Pearneapsé ROJKERE KOON $4 huTwee $8 MICKORY 58 JUNIPER 58 a ENIDRIK ScaL ABLE 46 EROKOU- ENEU ENEMAN COMPLEX NAUTICAL MILES Fig. 1. Bikini Atol showing locations with code names and years of nuclear weapons teats.