120 Health Physics August 2010, Volume 99, Number 2 Table 9. Proportion (%) of total organ dose to adults of each of four communities from the six tests contributing most to the total dose. Majuro residents Nuclear test Kwajalein residents Proportion (%) Thyroid Koon Romeo Bravo Flathead Mike Nuclear test Proportion (%) Yankee Yoke Koon Romeo Flathead 37 21 18 8 5 Bravo Yankee Koon Romeo Fir Cumulative Red Bone Marrow 95 Cumulative 92 Cumulative Koon Bravo Flathead Mike Union Cumulative Stomach 31 19 5 4 3 95 Koon Bravo Flathead Mike Union Cumulative 31 20 5 4 3 96 Romeo Romeo Colon Romeo 3 Bravo 33 Yankee 33 Yankee 31 Yankee Koon Bravo Flathead Mike 30 21 6 5 Cumulative 95 King Yoke Koon Romeo Flathead Bravo Cumulative Yoke Koon Romeo Flathead Bravo Cumulative 2 5 Bravo 36 Bravo 36 Bravo 21 14 11 5 4 91 Yoke Koon Romeo Flathead 22 15 10 5 Cumulative 92 Bravo 4 Romeo Koon Yankee Union Fir Cumulative Romeo Koon Yankee Union Fir Cumulative Yankee Koon Romeo Union Fir Cumulative Proportion (%) 93 3 2 0.8 0.4 0.3 ~100 94 2 1 1 0.7 0.6 ~100 94 2 1 1 0.7 0.5 ~100 95 2 1 1 0.5 0.4 ~100 Rongelap Island community Nuclear test Bravo Romeo Koon Union Yankee Zuni Cumulative Bravo Romeo Koon Union Yankee Zuni Cumulative Bravo Romeo Koon Union Yankee Zuni Cumulative Bravo Romeo Koon Union Yankee Zuni Cumulative Proportion (%) 94 2 2 0.8 0.5 0.1 ~100 83 7 6 2 1 0.3 ~100 85 6 5 2 1 0.3 ~100 90 4 3 1 0.8 0.2 ~100 cumulative exposures were often estimated from historical measurements or from relatively simple conversions from fallout deposition density. We determined that the uncertainty of doses from external irradiation could be characterized by lognormal distributions with geometric standard deviations (GSDs) of approximately 1.2 for exposure on Rongelap and Ailinginae, 1.5 for exposure on Utrik, and 1.8 for exposures on the other atolls —*— Rongelap Island community —*¥— Kwajalein residents ——o— Majuro residents 100 = So (Bouville et al. 2010). As can be seen, the overall GSDs —_ ° Annual Thyroid Dose (mGy) Union 36 21 14 11 5 4 91 1,000 1} ------ —O— Utrik community 0.01 0.001 1954 Nuclear test 29 29 23 6 5 King \ Utrik community 1956 | 1958 l 1960 i 1962 | 1964 | 1966 | 1968 1970 Year Fig. 3. Annual thyroid doses (mGy) to representative children born in 1953 on four atolls (Majuro, Kwajalein, Utrik and Rongelap Island) that are representative of exposures across all of the Marshall Islands: sum of external dose plus internal acute and chronic doses. Rongelap and Utrik estimates account for evacuations and relocations of communities. were smallest for the communities where the greatest doses were received from the 1954 tests. Conversely, the GSDs were largest for communities with the lowest doses from the 1954 tests. In comparison to estimates of external dose, estimates of dose from internal irradiation are substantally more uncertain. Based on an analysis accounting for uncertainties in the most relevant and sensitive parameters involved in the internal dose assessment, we found that the uncertainty of doses from internal irradiation could be characterized by lognormal distributions with GSDs of approximately 2.0 for exposure on Rongelap and Ailinginae, 2.5 for exposure on Utrik, and 3.0 for exposures on the other atolls (Simonet al. 2010). Doses from chronic intake of radionuclides result from a more complex exposure situation and are more uncertain than