Polonium subjects were chosen because experimenters wanted persons who had not been exposed to polonium either through work or accident. All subjects had incurable diseases. Excretion of polonium was followed, and an autopsy was conducted at that time on the deceased patient to determine which organs absorbed the polonium. Patients' ages ranged from 'early thirties' to 'early forties'. The experiments were described in Chapter 3 of Biological Studies with Polonium, Radium, and Plutonium, National Nuclear Energy Series, Volume VI-3, McGraw-Hill, New York, 1950. Not specified is the isotope under study, but at the time polonium-210 was the most readily available polonium
Polonium trioxide that polonium trioxide may be formed by heating polonium dioxide and chromium trioxide together in air. It is very difficult to oxidize polonium beyond Po(IV); for example, the only hexahalide of polonium is the hexafluoride, PoF, and fluorine is already the most electronegative element (though polonium hexaiodide was once reportedly formed in the vapour phase, it immediately decomposed). However, the difficulty in obtaining polonium trioxide and polonates (containing the anion, analogous to sulfate, selenate, and tellurate) by direct oxidation of Po(IV) compounds may be due to the fact that polonium-210, while the most easily available isotope of polonium, is strongly