Isotopes Twenty five isotopes of polonium are known, with atomic masses ranging from 194 to 218. Polonium-210 is the most readily available. Metallic polonium has been prepared from polonium hydroxide and some other polonium compounds in the presence of concentrated aqueous or anhydrous liquid ammonia. Two allotropic modifications are known to exist. Handling Polonium-210 is very dangerous to handle in even milligram or microgram amounts, and special equipment and strict control is necessary.
Damage arises from the complete absorption of the energy of the alpha particle into tissue.