Polonium is a chemical element with the symbol Po and an atomic number of 84. It was discovered in 1898 by Marie and Pierre Curie and named after Poland where Marie was born. They removed uranium and thorium from pitchblende ore and discovered that the ore became more radioactive. Polonium was the first new radioactive element they discovered in the processed ore.
Polonium is metallic and related bismuth and tellurium in the periodic table of elements. All the compounds containing polonium have been created in laboratories. It can be combined with hydrogen, oxygen, the halides, carbon, nitrogen, sulfur and other elements.
Polonium has no stable isotopes, all 33 of its isotopes are radioactive. They range in atomic weight from 188 to 220 with half-lives varying from 115 nanoseconds for Po-205m4 to Po-102 years for Po-209. Most of the isotopes decay to lead by emitting an alpha particle. Rarely, polonium isotopes decay to bismuth via beta particle (positron) emission.
Polonium is very rare because of the rapid decay of most of its isotopes. Approximately one tenth of a milligram will be found in one metric ton uranium ore. Po-210 with a half-life of 138 days is the most common isotope.
Polonium can be extracted from uranium ore but it is difficult and expensive. Commercial polonium is created by bombardment of other elements in nuclear reactor which then decay to polonium. One of the major uses of polonium is in static eliminators. Foils which contain polonium are used in production equipment for materials whose production is accompanied by the generation of static electricity. It is also used to remove particles in clean rooms for the production of computer chips. Polonium is combined with beryllium to make sources of neutrons. Polonium has been used in thermionic power generators for satellites.
Polonium which is ingested or inhaled is eliminated from the human body via feces. A small amount of inhaled polonium remains in the lung. About half of the portion which remains in the body tends to accumulate in the spleen, kidneys and spleen. The rest is found in bone marrow and distributed throughout the body in the blood and lymphatic fluid. The alpha particles emitted from polonium can disrupt cell structures, tear DNA strands, damage DNA and cause the death of cells. Ultimately it can injure major organs, the immune system and cause death.
There is no real danger from naturally occurring polonium. Proper handling will minimize the danger associated with commercial use. But there is a unique danger from man-made polonium because it has been used as an assassin’s weapon for eliminating political enemies. A piece of polonium the size as a grain of salt can kill an adult human. By mass, polonium is about 250,000 times more poisonous than hydrogen cyanide, a well known poison. A lethal dose would never be tasted or smelled when ingested or inhaled. Since it is hard to diagnose if you are not looking for radiation poisoning and the illness takes time to develop, it may escape detection.
Alexander Litvinenko was a officer in a Soviet security service who fled to England and received political asylum. He cooperated with the British intelligence services and wrote books about conditions in Russia. In 2006 he suddenly fell ill and eventually die. It was determined that he had been poisoned with polonium by Russian agents.
The theory had been advanced that Yasser Arafat of the PLO was killed by polonium poisoning. Traces of this rare element have been found on his personal effects and there have been requests for an exhumation of his body so that an autopsy can be performed. If his death was murder, there are several suspect organizations which would have benefitted from his death.
Alexander Litvinenko picture from codkaxorriyadda.net:
