108 Health Physics Marshall Islands Our unrefined estmates were generally conservative and were intended to avoid under-estimation of the number of cancers that might occur These mitral results were presented durmg joint hearmgsof the House of Representatives Committee on Resources and the Committee on International Relanons m May 2005 (Umited States 2005) Followmg these jomt hearmgs, we improved the models and data analysis to derive more realistic estimates of external and mternal radiation dose by year, atoll, and age, as well as improved estimates of cancer nsks Those estmates and the methods on which they are based are the subject of this Summary paper and 1ts compamion papers The purposeof this group ofpapers 1s to present, m the peer-reviewed Iterature, a summary of the most important data that are available and that are useful for dose reconstruction, a detailed analysis of fallout deposited on each ofthe atolls of the Marshall Islands from nuclear weaponstests at Brkim and Enewetak, improved estimates of radiation doses, and mproved estimates of cancer risks resultmg from exposureto the fallout These estimates are based on a much deeper analysis of the available data than m DCEG (2004) and on models developed especially for this study Although numerous studies have been conducted over the past decades to momitor the Marshall Islands and people, to develop land remediation strategies, and to assess contemporary and possible future doses that might be received by mhabit- ants of certam atolls in the Marshall Islands, the focus was more often on radiological momtoring, and on the northerm Marshall Islands m particular Many of those studies were chronicled m a special issue of Health Physics (Stmon and Vetter 1997) The current study, however,1s the first comprehensive effort to estimate the deposition ofal] the rmportant radionuchdes contributing to dose and to estimate the doses and associated cancer risks to the population of the Marshall Islands Detailed information on the technical aspects of this work and on the results of all parts of the study are provided m the seven companion papers m this volume, including @ the estimation of the amounts of fallout that were deposited on the ground over each atoll] and separate reef island of the Republic of the Marshall Islands (Beck et al 2010), ® the estimation of doses from external irradiation (Bouville et al 2010), ® the estimation of the doses from mternal 1radiation (Simonet al 2010), ® the estimation of the cancer nsks (Land et al 2010), August 2010, Volume 99, Number 2 bioassay data rmportant to mternal dose estimation (Harris et al 2010) and interpretation of mtake-related dosimetric factors (Ibrahim et al 2010), and ®@ a model of atmospheric transport and deposition that was used to provide confirmation of the reliabihty of some of the estmated depositions (Moroz et al 2010) The present paper summarizes the purposes and methods ofthe overall study and the estimated radiation doses and related cancer risks, as well as presents data that are commontoall of the above papers, cluding the nuclear tests, the radionuchdes considered, and the pop- ulation sizes and their movements during the testing period SCOPE OF THE STUDY The overall purposes ofthis study were to derive an mternally consistent set of radiation absorbed doses to Marshallese alive during and after the years of nuclear testmg m the Marshall Islands and to provide a thorough description of methods used in the dose reconstruction, to estimate the numberof cancersthat had already occurred and that could be attributed to radiation exposure, and to estimate the number of radtation-related cancers yet to occur The dose and risk assessment includes all Marshallese population groups and takes mto account the size of the population of each atoll community, the baseline cancer risks (1e, cancers unrelated to fallout exposure), and all of the Bikim and Enewetak nuclear tests that resulted m fallout over the terntory of the Marshall Islands As indicated mm Beck et al (2010), we estimatedthat, ofthe 66 nuclear tests detonated m or near the Marshall Islands from 1946 through 1958, 20 tests deposited measurable fallout m the Marshall Islands excludmg the atolls on which thetest sites were located (Fig 1) These tests were Yoke m 1948, Dog and Item m 1951, Mike and Kimg mm 1952, Bravo, Romeo, Koon, Union, Yankee, and Nectar m 1954, Zum, Flathead, and Tewa m 1956, and Cactus, Fir, Koa, Maple, Redwood, and Cedar in 1958 The characteristics of these 20 tests are presented im Table | Eachofthese 20 tests was taken mto account im the estimation of radiation doses and cancer risks There are 30 atolls and four separate reef islands m the Marshall Islands Ground deposition densities were estimated for 63 rachonuchdes plus ***“"Pu for all the atolls and separate reef islands except the two atolls where the testing sites were located (Bikim and Enewetak) However, some of the atolls were not mhab- ited during all or part of the testing period either because they were historically used only for gathermg food (Ailinginae, Bikar, Enkub, Jabat, Jemo Island, Knox,