samples were analyzed for plutonium, calcium-45, strontium-89, ruthenium-103, iodine-131, and barium-140. The I-131 analyses of the pooled urine samples of the servicemen and Marshallese provided the basis for thyroid dose estimates by Dr. Harris and later researchers. Dr. Harris judged that I-13] analysis was the most accurate; it also led to the highest doses to the servicemen (Reference 9). The basic finding of the I-131 analysis of the pooled urine sample was the determination that, for an average individual, the amount of I-13] excreted in urine over a 24-hour period at the time of the urine sample collection (D+17 days) was 4.0 nanocuries. That result is used to determine the amount of 1-131 intake. The amount of a radionuclide excreted in a 24-hour urine sample is related to the amount of the radionuclide initially intaken (that is, inhaled and/or ingested) by A) =Q)° fy * Y(t) Fy where A, @ = the amount (yCi) of the radionuclide in a 24-hour urine sample taken at time t, QF the amount (uCi) of the radionuclide intake, fy = the fractional amount of the radionuclide intake that is transferred to the blood, Y(t) = the ratio of the amount (uCi) of the radionuclide excreted with a 24- hour period to the amount (uCi) of the radionuclide uptaken by the blood, and F = the fraction of the total daily excretion that is present in the urine. 18 Ae