EFFECTIVE ARRIVAL TIME (HOURS) 0 6 f @ i | 9 TO 10 { UW T 12 Y 13 4 14 15 16 17181920 To ToT 100 " GROUND 8 T Tr BIKAR 5 300 ATOLL 1000 000 3300 3: ~ RONGELAP. a13085229 _z30 oseSoHOS ; “Cool ff sae 170 200 BIKINI ATOLL “ UTIR OOO =320_ 104 738 —-175 —_—_—_ RONGERIK ATOLL TAKA ATCLL { K aTou > pAILINGNAE ATQLL | Ld to Li tt L { 1 i 0 1020 40 60 & 100 120 140 160 180 200 270 240 260 280 300 320 340 DISTANCE FROM GROUND ZERO (MILES) Figure 1. Approximate gamma dose cates (roentgens per hour) at 3 feet above the ground, one day after the detonation. 2. From Glasstone (40). Residual Radiaticn To assess potential effects of low-level residual radiation persisting on Rongelap, Utirik, and Bikini, periodic monitoring of the inhabitants of these atolls as well as samples of native flora, fauna, soji, and marine life were performed. These studies are discussed in Section X and Appendix II. E. Data Evaluation Reevaluations of dose estimates are planned or under way using more sophisticated technology and computer methods currently available, and it is possible dose estimates may be increased. In the meantime the dose calculations previously developed will continue to be used. While quantitative variations in dose estimates have an obvious impact on dose/effect correlations, other considerations are equally important in thete studies, especially regarding radiation induction of thyroid neoplasms (caveats regarding thyroid dose estimates are discussed in Section IX and Ap- pendix II). Risk probabilities for development of neoplasms secondary to radiation have classically been derived for malignant tumors of specific organ systems. eaNeeat ee en ane