TRANSFER OF PLUTONIUM ACROSS THE HUMAN GUT AND ITS URINARY-EXCRETION

The gastrointestinal absorption of Pu-244(IV) has been measured in thr ee male adult volunteers. The plutonium was in citrate solution and wa s taken with food. The work was carried out in two stages. The first s tage measured urinary plutonium excretion up to 8 or 9 d after the ora l intake. The second stage commenced about six months later with an in travenous injection of plutonium citrate and measurements of the urina ry plutonium excretion. Results from the two routes of intake were use d to calculate the fractional absorption (f1) of ingested plutonium. T he f1 values were in the range (2-9) x 10(-4). In theory it should be possible to measure the plutonium in the volunteers' urine throughout their lives. Measurements are continuing and the results show the excr etion pattern up to nearly 2 y for one subject, and 6 months for the o ther two volunteers.