Acute and chromic mtakesof fallout radionuclides @ SL Simow er av ugher uncertamty m the 'Cs deposition density (GSD = 1 8), the overall uncertamty 1s estimated to be characterized by a GSD of 31 For that reason, we assumed that the uncertamty im the thyroid dose received im 1954 by representative persons of the Majuro population and of the populations of other atolls of the mid-latitude and southern regions had the same value (GSD = 3 0), somewhat higher than our estimate for the uncertamty in the thyroid dose from Romeo (GSD of 27) Agam, as for Rongelap and Utrk, we assume that the uncertamty m the dose to other organs 1s comparable to that we estimate for the thyroid Finally, we also assume the same uncertainties for years other than 1954 In summary, we crudely estimated uncertamties of the population-average age-specific annual doses from internalirradiation that were received from 1948to 1970 by lognormalprobability distributions with GSDsof 2 0 for the population groups of the northern latitudes, 2 5 for the Utmk Commumity, and 30 for the population groups of the mid-latitudes and southern latitudes Though all dose estimates we have presented for the Marshallese are uncertam, the models and estimation procedures were developed without knowledge of any specific systematic biases that could be corrected CONCLUSION The methods developed m this work andthe related dosimetry calculations provide a full accountng and disclosure of the doses received by the Marshallese from regional nuclear testmg withm the lmmits of the data known to us The importance of the bioassay-based approach1s clear here, but stands m contrast to methods often used for dose reconstructions relevant to contmental nuclear tests sites where imtakeof fallout activity by the public 1s usually a consequence of mgestion of contammated dairy foods (Health Physics 1990) and where suitable and well-characterized pathway models can be used for dose estrmation The pathwaysleading to acute and chromic intakes by the Marshallese were primarily ingestion of contammation on face and hands, plates, cookmg utensils, and foods drymg outdoors, and probably less importantly, consumption of contaminated water, and over the long-term, consumption of locally grown fruits Because there are no pathway models for this lifestyle that have been suitably quantified, the urmary excretion data of Harms (1954) obtaimed from the highly exposed populations, and, in later years, the whole-body counting data summarized by Lessard etal (1984, 1985), were of particularly great value to estrmating doses There were several unusual and interestmg aspects ofthe exposures in the Marshall Islands in addition to the 191 absence of well-known and well-understood exposure pathways One unusual circumstance was the very lmmited access to fresh water prior to Bravo exposure Coupled with a tropical environment that typically leads to sigmficant losses of water through the skim, urine volumes that were obtamed for bioassay were smaller than m most temperate climate collections on which radioactivity measurements have been based In addition, analyses of the contammation from Bravo andtheintakes of the highly exposed Marshallese mdicated thatparticles m the environment were large (tens to hundreds of microns 1m size) and that the large acute mtakes were a result, almost exclusively, of ingestion, while mhalation played only a very mmorrole (Harms 1954, Lessardetal 1985) In contrast, chronic mtakes at more distant atolls, resultmg im much lower protracted doses, arise from dietary mtakes that occur through mgestion of fruits and crops contammated by root uptake and the consumption of fish (Robison and Sun 1997) Internal contamination of fruits with "Cs, eg, coconuts, whose juice 1s a common water replacement for native residents, 1s higher (per umt soi] concentration) than im almost every contnental location because coral-based soils ofthe atolls are highly deficient in potassium In addition, at least one important conclusion emerged from our analysis of doses on a test-specific basis For many years, the Bravo test has been assumed to have been the single most 1mportant test forall atolls from the pomt-of-view of exposure While this 1s clearly the case for the northern atolls, it 1s not the case for the mid-latitude and southern latitude atolls (see Table 9, Simon et al 2010) As a basis for comparison, the proportions of the thyroid dose contributed by Bravo at Rongelap, Utrik, Kwayalem, and Majuro were >99%, 93%, 47%, and 24%, respectively In contrast, among the mid-latitude atolls (Kwayalem and others), the Yan- kee test was the most rmportant The contributions from Yankee to the thyroid dose at Rongelap, Utnk, Kwaya- lem, and Mayuro were about <<1%, 3 5%, 37%, and 24% Among the southern atolls, the Koon test was the most important contributor to thyroid dose The contributions to the thyroid dose from Koon at Rongelap, Utrik, Kwayalem, and Mayjuro were about 0 2%, 2%, 19%, and 28%, respectively One over-arching findmg from our dose assessment was a distinctive geographic pattern of mternal doses received by residents of the atolls, which, as discussed m Simon et al (2010), was the same as for deposition, external dose, and projected cancer nisk Our data (see Fig 2, Simon et al 2010) clearly illustrate an overall decreasing trend m mternal doses received from more northern latitude atolls to southern latitude atolls (see Table 5 of Simon et al 2010) Moreover, we found that