Radiation doses and cancerrisks in the Marshall Islands @ S. L. Simon ET AL. particles emitted during radioactive decay. In this analysis, we have not estimated the dose to skin or the number of skin cancers that might be produced as a consequence of exposure to fallout, primarily for two reasons: (1) there are no baseline non-melanoma skin cancer data reported by the Surveillance, Epidemiology and End Results (SEER) program and other U.S. cancer registries, and the baseline risks are an essential part of the calculation to estimate the number of cancers, and (2) the number of personal injury claims awarded by the Marshall Islands Nuclear Claims Tribunal indicates that, among the 2,046 awards made through June 2004, there were 72 awards for skin burns, but only one award for skin cancer (Marshall Islands NCT 2004). Hence, it appears that, despite potentially high doses to the skin to at least a small subset of the Marshallese, there is little evidence that the risk of skin cancer is great among Marshallese. Estimated doses were derived for “representative” persons, that is, for persons who could be described to have habits, lifestyles, diet, and anthropometric charac- teristics typical of the Marshall Islands population for their age and sex (except in the case of military servicemen on Rongerik). Doses were assessed on a yearly basis for exposures occurring from 1948, the year in which the first relevant test took place, to 1970, when the residual environmental contamination had reached negligible levels on most atolls. These estimated annual organ doses were necessary input data for the cancerrisk calculations. The estimated total radiation absorbed doses include 111 Table 4. List of radionuclides considered in estimates of deposition and of internal doses from acute intakes for the 20 tests considered in this study (all are fission products unless otherwise noted). Nuclide Half-life SFe# “Cur TAS 8Br 8Rb Sr St oy 2.7a 13h 39h 2.4h 18 min 5ld 29a 64h LTSb Te 2°Sb Lint By eT; 127 3m 3.9d 70 min 44h 30h 8.0d 78h 2.3h 55 min olmy Str my By 50 min 2.7h 3.5h 10h 135] BIC Ba MOBa 6.6h 30a 83 min 13d MT a Ce PTa 3.9h 33d 91 min 3p Ce Mp USP MNd 14d 280 d 17 min 6.0h lid Sr Zr °Nb he *7™NIb ”Mo mT 1E8RU 103Rh Ru Rh 9.6h 64d 35d 17h 538 66h 6.0h 39d 56 min 44h 35h RU Pd 370d 14h '8Cd 53h ‘Ag Cd Lint e'Sn 3Sb LTSh 3.1h 25h 2.0h 27h 2.8 a 2.1h Nuclide By MoTa '8Ce Pm “Nd Spm 35m 237[ya 40a Homntp 229K? 239+ 240pb Half-life 21h 1.7d 33h 53h 17h 28h 46h 6.8d 14h 7.2 min 2.4d 24,000/6,600 a “ Activation product. > Fuel material. Only cumulative depositions and intakesoverall tests were estimated. three components: (1) doses from external irradiation emitted by fallout deposited on the ground; (2) doses from internal irradiation from acute radionuclide intakes immediately or soon after fallout after each test; and (3) doses due to internal irradiation from chronic (..e., protracted) intakes of radionuclides resulting from the continuous presence of long-lived radionuclides in the environment. Sixty-three radionuclides, listed in Table 4, were considered in the estimation of internal doses from acute intakes of fallout radionuclides from each test. Based on screening estimates, these 63 radionuclides were estimated to account for over 98% of the internal dose to any organ from acute intakes. In addition, five long-lived radionuclides (Fe, “Co, Zn, ”’Sr, and '*’Cs) were considered for the estimation of the internal doses from chronic intakes, including two radionuclides, “Co and ©Zn, that were not considered in the calculation of the doses from acute intakes. Doses from acute and chronic intakes from cumulative deposition of *?***°Pu were also estimated. Risks of radiation-induced leukemia and cancer of the thyroid, stomach, and colon, as well as all other cancer types combined, were assessed for the 25 Marshallese population groups on the basis of the estimated radiation doses. Two time periods were considered: from 1948 through 2008 for the assessment of the radiationinduced cancers that have been expressed thus far, and from 2009 onwards for the prediction of cancers that remain to be expressed. For comparison purposes, the numbers of baseline cancers, that is, those unrelated to fallout exposure, are also reported. SUMMARY OF METHODS AND FINDINGS A brief overview of methods of the study and a summary of the findings are presented here. Detailed information can be found in individual companion papers. Throughout this section and elsewhere, we discuss findings relative to four groups of atolls or communities. Within each group, resident populations were exposed to similar levels of fallout as a consequence of the dispersion patterns of the nuclear debris clouds. The southern atoll group is well represented by Majuro, whichis the