report. A search for records at DOE headquarters led to the files currently held by Thomas McCraw who has acted as a repository for many Atomic Energy Com- mission documents. Some of these documents related directly to this study and were not easily located anywhere else. An abundance of environmental results have been published by the University of Washington's Laboratory of Radiation Ecology (also known as Applied Fisheries Laboratory). Medical information was published by BNL's Medical Department and by the Safety and Environmental Protection Division. Much of the early and detailed observations on the accidentally exposed Marshallese were recorded in documents published by the U.S. Naval Radiological Defense Laboratory and by the Naval Medical Research Institute. The plan of this report is to document the details of the dose reassessment. Two methods, 1) the estimate of !3!r intake from urine results, and 2) the estimate of particle size and nuclide composition from Bikini ash results, could be related to each other and the known facts about arrival and duration of fallout, external exposure-rate measurements, and gross beta Measurements. A schematic of the approach is given as Figure l. Once the nuclide composition and fallout arrival and duration times were assessed, the composition was normalized to external exposure-rate measurements. Exposure-rate histories and corresponding surface activity histories were then constructed for each island. Estimates of intake of radioiodines and radiotelluriums were based on the /3!1 intake estimate which was in turn normalized to the Rongelap urine results. The time and mode of intake were based on observed diet and living patterns. The population mean and individual thyroid absorbed dose estimates were based on the age and location of the exposed people. Age-dependent values of thyroid absorbed dose per unit activity intake were taken from the scientific literature. The final step was to obtain internal and external thyroid absorbed dose estimates for 251 exposed people. This was related to medical observations and summarized in the finai section of the report. This relationship is presented in terms of thyroid cancer incidence per unit absorbed doseper million person years at risk.