BUDGET TITLE AND REPGRTING CCC)E DATE ??~?A2E2 I I Dose Reassessment for Rongelap Tt. 1< CONTRACTOR NAME Associated 20. a. ~ ilA-02-01-!31 1 .! Detail I.Jniverslries, CODE BNL Inc. I TASK NO. ‘WP NUMBER REV. NO, o I Attachments: Facility ?teauire~encs. It is anticipated that work for this proposal will use existing Laboratory facilities and site utility services. b. Publications. Naidu, J.R., Greenhouse, >;..4., and Knight, J. Diet and Living ?attsrns. BNL 51313, ~Uly, 1980. Xars’nail Islands: A study of Lessard, E.T., Greenhouse, N.A., and >filt~nberger, x.?. A Reconstruction of Chronic Dose Equivalents for Iongelap and Utirik Residents - 1954 ta 19’30, 3~iL jl~j7, ~c:05er, ~9800 The purpose of this rzsearch is to refine the estimated thyroid absorbed doses received by members of the Xongzlap and iltirik Atoll populations in the Nayshall Islands. These doses will be compared to t’nethyroid nodule incidence ta provide information towards assessment of the risk coefficients for radiation induced thyroid diseasz. d. Background. Incidence of thyroid nodules, benign and malignant, in the exposed populations of Utirik and Rongelap has indicated critical differences iz correspondence between nodule incidence and thyroid absor5ed dose for these pcpulatio~s relative Registry Life Spe~ Study or the other poputo that reported by the Japa~ese ~unor lations under study as reported in 31Nt 111. The estinated external dose received Shoh,s ~~.a~ the a~u~~ ~oF.gelz3 from the time fallout bsgan co the :i~e Of evacTJa:ion population received an extarnal absorbed dose (175 rads) w“nichwas about 13 tiaes (14 rads). The thyr~id absorbed doses uere that for the Ctirik pOp~J12tiOn estimated originally to be several times these external doses. A preliminary study has indicated that the important dosimetric area of investigation is che ?eriod starting from the 5egi~ninS of fallout to the compleELon of evacuation for both the islands. In addi:ion, the fact that the Utiri’x ?opulation returned within 120 days followlxg evacuation, whereas the xo~gela~ population returnetiafter three years, requires that the Utirik ?opula:ion be exazized dosizetr<cally i> te~s of a longer zx;osure period, both iat~rza~ and external. Furtker studies vould, therefors, have to concentrate on the reexamination of all availabl~ data i? reports issued by various agencies during that scientific personnel involved at that tiae, identi~yins period, the areas of uncertainty, and ‘usin3zppro?ziare cca?ucer programs to ardyze che data. The end result will e~able comparisons between the incidence of thyroid nodules and the reassessed dose estiaates. consultations ‘wi:’n ,#.Q2 -3--