Distribution and Excretion of Plutonium Administered Intravenously to Man

This is the final report on a medical study in which doctors injected plutonium into hospital patients to learn where it goes in the human body and how fast the body gets rid of it. It is a joint report from the Los Alamos Scientific Laboratory and the Atomic Energy Project at the University of Rochester School of Medicine and Dentistry. The work began under the supervision of the Manhattan Engineer District and was completed under contract for the Atomic Energy Commission. Twelve cases are reported here, correlated with Chicago and Berkeley cases for a total of sixteen.

Subjects were chosen for short life expectancy. As a rule they were past forty-five and ill with chronic disorders such that survival for ten years was highly improbable, which the authors say would avoid late radiation effects and allow post-mortem samples within months. Ten of the twelve were past forty-five. One was eighteen years old. Each person received a single injection of 4.6 to 6.5 micrograms of plutonium as plutonium citrate into an arm vein, on dates from April 10, 1945 to July 16, 1946. Ten of the twelve stayed on a metabolic ward at Strong Memorial Hospital, where urine, feces and blood were collected on a schedule.

Bone and liver took up most of the plutonium. Using bone samples and a 70 kg standard man, the authors estimate 65.7 per cent of the injected dose sits in the skeleton. Liver figures ran higher than animal work predicted, around 20 to 40 per cent of the dose in the first year, with a retention half-time in the liver of a year or more for man against 40 to 60 days for rats. Blood cleared quickly, from 35.7 per cent of the dose at four hours to 0.3 per cent at thirty days. Urine still carried 0.0011 per cent of the dose per day 1610 days after one injection.