Radiation doses and cancerrisks in the Marshall Islands @ S. L. Simon ET AL. 107 Table 1. Nuclear tests estimated to have deposited measurable fallout in the Marshall Islands. Operation Test site atoll Local date (mm/dd/yyyy) Total yield (Mt)* Fusion yield (Mt)* Yoke Dog Item Mike King Bravo Romeo Sandstone Greenhouse Greenhouse Ivy Ivy Castle Castle Enewetak Enewetak Enewetak Enewetak Enewetak Bikini Bikini 05/01/1948 04/08/1951 05/25/1951 11/01/1952 11/16/1952 03/01/1954 03/27/1954 0.049 0.08 0.05 10.4 0.5 15 11 0 0 0 4.7 0.25 6 3.7 Yankee Nectar Zuni Flathead Tewa Cactus Castle Castle Redwing Redwing Redwing Hardtack I Bikini Enewetak Bikini Bikini Bikini Enewetak 05/05/1954 05/14/1954 05/28/1956 06/12/1956 07/21/1956 05/06/1958 13.5 1.7 3.5 0.37 5 0.018 4.5 0.85 2.25 0.18 2.7 0 Hardtack I Enewetak 05/13/1958 1.4 0.7 Test name Koon Union Fir Koa Maple Redwood Cedar Castle Castle Hardtack I Hardtack I Hardtack I Hardtack I Bikini Bikini Bikini Bikini Bikini Bikini 04/07/1954 04/26/1954 05/12/1958 06/11/1958 06/28/1958 07/03/1958 0.11 6.9 1.4 0.21 0.41 0.22 0.04 2.3 0.7 0.07 0.14 0.07 “UNSCEAR(2000). In the month after the Bravotest, '*'l, an important radionuclide in fallout, was measured in urine collected about two weeksafter the Bravo event from adults exposed on Rongelap, Ailinginae, and Rongerik (Harris 1954; Harris et al. 2010). Those measurement data have proved to be of significant value for reconstruction of internal dose for those groups. For example, Brookhaven National Laboratory used the activity measurements in urine as well as other data and assumptions to estimate internal thyroid dose for persons exposed on Rongelap, Ailinginae, and Utrik (Lessard et al. 1985). Internal doses from long-lived radionuclides on Rongelap and Utrik also were estimated by Lessard et al. (1984) using whole-body and bioassay data collected years after the Bravotest. The U.S. Governmentthrough Brookhaven National Laboratory and otherinstitutions has provided decades of medical care, health surveillance, and documentation of health effects among the highly exposed Marshallese from Rongelap/Ailinginae and Utrik (see for example, Conard et al. 1970, 1980; Cronkite et al. 1997), but only two epidemiologic studies have ever been conducted, one of benign thyroid disease (Hamilton et al. 1987) and one of benign thyroid disease and thyroid cancer (Takahashi et al. 1997, 2001). To date, there has not been a broad epidemiologic study of the Marshallese to determine the total numbers of cancers and other serious illnesses resulting from exposure to radioactive fallout. Nor has there been reliable diagnoses and recording of cancers among the general Marshallese population over the years since the nuclear testing ended that would now permit comparing their cancer rates with rates at other locations worldwide. In 2004, the Senate Committee on Energy and Natural Resources asked the National Cancer Institute (NCDforits “expert opinion” on the estimated numberof baseline cancers* and radiation-related illnesses from nuclear weaponstesting in the Republic of the Marshall Islands. The Division of Cancer Epidemiology and Genetics (DCEG)of the NCI was tasked with developing a response because of its robust research program in radiation epidemiology and many years of experience in reconstruction of fallout-related doses and in cancerrisk estimation. For that purpose, we developed unrefined estimates of radiation doses and numbers of radiationinduced cancers (DCEG 2004), based on: (1) 1954 measurements of '*'I in the urine of adults exposed on two atolls, Rongelap and Ailinginae, collected after the test Bravo in 1954; (2) measurements made in 1957— 1977 of the contents of '°’Cs and other radionuclides in the bodies of inhabitants of Rongelap and of Utrik who returned to their atolls in 1957 and 1954, respectively; and (3) measurementsof total '*’Cs and plutonium in soil from eachatoll obtained forall atolls from the Marshall Islands-sponsored radiological survey completed in 1994 (Simon and Graham 1997). We combined those elements using a simple analytic approach to develop crude estimates of the numberof cancers likely to be radiationinduced among those living in 1954. This was, to our knowledge,the first time radiation doses and numbers of radiation-induced cancers had been estimated in a systematic manner over the entirety of the territory of the * Cancers that presumably would have occurred in the absence of exposure to radioactive fallout.