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
Isotopes of polonium Isotopes of polonium Polonium (Po) has 33 isotopes, all of which are radioactive, with between 186 and 227 nucleons. Po with a half-life of 138.376 days has the longest half-life of naturally occurring polonium. Po with a half-life of 125 years has the longest half-life of all isotopes of polonium. Po and Po (half-life 2.9 years) can be made through the alpha, proton, or deuteron bombardment of lead or bismuth in a cyclotron. Po is an alpha emitter that has a half-life of 138.376 days; it decays directly to stable Pb. A milligram of Po emits as many alpha particles