Health Physics August 2010, Volume 99, Number 2 Table 9. Ratio of '’Cs inventory in 1991-1993 and 1978 esti- Atoll NWRSdata for 1991-1993 (1 SD) LLNL data for 1978 (1 SD) Ailuk Alinginae Alinglapalap Arno Aur Bikar Ebon Erikub Jabat Jaluit Jemo Island Kili Island Knox Kwajalein (north) Kwajalein (south) Lae Lib Island Likiep Majuro Maloelap Mejit Island Mili Namorik Namu Rongelap Island (south part of atoll) Rongerik: Enewetak Island Taka Taongi Ujae Ujelang Utrik Wotho Wotje 1.1 (0.8) 1.0 (0.7) 1.1 (0.7) 1.2 (0.9) 1.3 (0.6) nr& 1.2 (0.7) 0.6 (0.4) 0.9 (0.6) 0.7 (0.6) 0.8 (0.5) 0.8 (0.6) nr 0.8 (0.5) 1.5 (0.7) 1.4 (0.8) 1.2 (0.7) 1.1 (0.7) 1.2 (0.9) 1.5 (0.7) 0.8 (0.4) 0.8 (0.5) 0.9 (0.5) 1.1 (0.7) 0.9 (0.6) 1.1 (0.5) 0.8 (0.5) — — — nr — — — — — — — — 1.3 (na)4 — — 0.7 (0.3) 1.5 (0.8) — 1.0 (0.5) — — — 0.8 (0.2) 1.0 (0.8) 0.8 (0.7) nr 1.1 (0.7) 0.8 (0.5) 1.0 (0.7) 1.1 (0.7) 0.7 (0.4) 1.2 (0.6) 1.1 (0.4) — — 0.7 (0.3) 0.9 (0.4) 0.9 (0.5) — Arithmetic mean (1 SEM) 1.0 (0.043) 1.0 (0.072) Weighted mean* (weighted error on the mean)? 0.93 (0.11) 0.85 (0.12) a?) = — 1969). S/o?) ( (Bevington g ) be b On = 1 \ v/a?) “nr: no reliable measurements; na: not enough information available to estimate uncertainty. “Uncertainty in measurements could not be estimated. Ratio used in arithmetic average but not weighted average. 100 |---| '8’Cs Deposition Density (kBq m”) mated from all available data to measured inventories by the NWRS (Simon and Graham 1997) and LLNL (Robison etal. 1981). The soil sample data obtained for Bikar, Knox, and Taongi were highly uncertain and not suitable for use in the weighted mean calculations. Dashes indicate no sample measurementdata were available for comparison. I {i Ei} CASTLE-BRAVO CASTLE-ROMEO CASTLE-YANKEE 0fesssensanensessenennentensnnens HITTITE 138 Majuro Kwajalein Utrik ATOLL Rongelap Island Fig. 2. Comparison of Bravo, Romeo, and Yankee deposition densities (kBq m~’) of '’Cs at Majuro, Kwajalein, Utrik and Rongelap. Note break in Y-axis between 7 and 18 kBq m”’. southernmost atolls, which includes the capital of Ma- juro, was between 1 and 3 kBq m~. The cumulative deposition at many of the mid-latitude atolls (~10°N) ranged between 3 and 8 kBq m~. Here it should be recalled that global fallout '*’Cs, which is not included in these estimates, was about 0.9 kBq m° across the Marshall Islands implying that the deposition of '’Cs from regional fallout ranged from about the same value as global fallout on the most southern atolls, to about eight times that from global fallout on the mid-latitude atolls (Kwajalein and nearby atolls). Although global fallout deposition was responsi- ble for a large fraction of the '’’Cs measuredin soils at someofthe atolls, this does not imply the doses that were received locally from Marshall Island tests were comparable to the doses received from global fallout since, as discussed in the companion papers by Bouville et al. (2010) and Simonet al. (2010b), most of the dose from Marshall Island tests to residents was from short-lived radionuclides. For purposes of comparison only, mid-latitude con- tinental locations (30—40°N)received much higher '’’Cs deposition from global fallout than did the Marshall Islands. Based on extrapolation from measurements of Sr in fallout collectors (Larsen 1983) at numerous locations worldwide, '°’Cs deposition density from global fallout in the Marshall Islands was only about 15-20% of that in the mid-latitudes. atolls, Majuro, Kwajalein, Utrik, and Rongelap, are compared in Fig. 2. We believe that the deposition densities at these four atolls represent the overall range of deposition from regional nuclear testing on inhabited atolls. The cumulative deposition density of '*’Cs in the A considerably greater amount of '°’Cs from re- gional nuclear testing was deposited at Utrik and at the small uninhabited neighboring atoll of Taka, about 20-30 kBq m~, or about 20 to 30 times the global fallout deposition of '*’Cs. The '*’Cs deposition on a