BUDGET TITLE Dose Reassessment and Utirik for Rongelap CONTRACTOR NAME Associated Universities, 20a. REPORTING DATE PREPARED CODE HA-0~-ol-01-O CODE Inc. AND WP NUMBER 03/31/80 TASK NO. REV. NO. BNL o Facility Requirements. It is anticipated that work for this proposal will use existing Laboratory facilities and site utility services. 20b. Publications. Data generated in this study has been used in other reports. 20C. Purpose. between the incidence of thyroid nodules in the To look for correlations inhabitants of Rongelap and Utirik Islands (Marshall Islands) and the reassessed dose estimates. This study will fuse together all available information on fallout from the BRAVO test and using advanced analytical techniques (now available) derive realistic dose estimates to the inhabitants of Rongelap and Utirik. The results should provide information towards assessment of the risk coefficients for radiationinduced thyroid disease. 20d. Background. Incidence of thyroid nodules, benign and malignant, in the exposed Populations of Utirik and Rongelap has indicated critical differences in correspondence between nodule incidence and thyroid dose for the populations. The estimated extsrnal dose received from the time fallout began to the time of evacuation shows that the Rongelap population received an external dose (175 rads) which was about 13 times that for the Utirik population (14 rads), and the thyroid dose was about 10 times larger, whereas the incidence of thyroid nodules in the two populations were not significantly different. A preliminary study has indicated that the critical area of investigation is the period starting from the beginning of fallout to the completion of evacuation for both the islands. In addition, the fact that the Utirik population returned within 120 days following evacuation, whereas the Rongelap population returned only after three years, requires that we look closely at the Utirik population in terms of a longer exposure period, both internal and external. Further studies would, therefore, have to concentrate on the re-examination of all available data in reports issued by .~arious agencies during that period, consultations ~ith scientific personnel invol”cedat that time, identifying the areas of uncertainty, and using appropriate camputer programs to analyze the data. The ecd result will enable us to look fcr correl~td.ons between the incidence of thyroid zcdcles .md the reassessed dose estimates.