A highly active alpha particle emitter, Polonium-210 is a fatal toxin, even at very small doses.
Polonium-210 (210Po) made headlines in 2006 as the poison used to murder former Russian spy Alexander Litvinenko. Litvinenko was a KGB agent who later became an FSB (Federal Security Service) agent when Russia replaced the collapsed KGB in the early 1990s. He was given orders to assassinate an influential Russian business tycoon (whom he knew well), orders he disobeyed and then publicly exposed, among other KGB and FSB activities, on the international stage. His disclosures embarrassed the Kremlin and then-director of the FSB, Vladamir Putin. The Kremlin charged Litvinenko with treason and imprisoned him for nine months. After his release in 2000, in the wake of numerous death threats, Litvinenko and his family fled to the United Kingdom where they were granted political asylum.1
Litvinenko continued to aggressively denounce the Kremlin and Vladamir Putin, whom he accused of drug trafficking and pedophilia, perhaps naively enjoying a false sense of security inside the UK. Then, on November 1, 2006, he was mysteriously poisoned. Litvinenko’s rapid deterioration was chronicled by the international media, and he ultimately suffered for an excruciating 22 days before lapsing into a coma and dying on November 23. The toxin was identified just hours before his death as 210Po, an extremely rare substance. It is one million times more lethal than cyanide, and an amount the size of a grain of salt will kill a human being. Toxicology reports show that Litvinenko ingested more than ten times the lethal dose of the poison, indicating the resolve of his assassin to silence him once and for all.1
210Po—Radioactive and Rare
Polonium, atomic number 84, is a rare earth metal. It was discovered by Marie and Pierre Curie in 1898 while separating uranium from Bohemian pitchblende. The Curie’s found that the unrefined pitchblende was more radioactive than the isolated uranium, meaning it contained another radioactive component. They named this new element polonium, after their native land of Poland. The metal has over 25 isotopes, more than any other known element, and all are radioactive.2
210Po has unique properties that make it suitable for commercial use. The radiation emitted from one gram of the isotope generates 140 watts of heat energy, making it a desirable alternative for powering spacecraft (this is still in the research and development stages). It is currently used commercially to neutralize static electricity in machinery and to remove dust from photograph film and camera lenses.3 Production occurs in a nuclear reactor and is extremely costly, time-consuming, dangerous, and very highly regulated. A mere 100 grams are manufactured annually, mainly in Russia.1
210Po is present in the environment as a byproduct of radioactive uranium and radon decay. Although considered rare, trace amounts are ubiquitous. We are exposed to minute quantities present in soil, air, water, food, and dust.3 It is important to note that polonium itself is not the toxin, but rather the alpha particles it emits during the decay process. Alpha particles are a colorless, odorless, and tasteless form of ionizing radiation. They are very weighty and heavily charged, and can only travel a short distance (a few centimeters in air) before losing momentum. Their energy is released upon impact and therefore incapable of penetrating barriers like paper, clothing, or skin. Thus, 210Po is not dangerous in the environment per se, but is toxic if actually taken into the body.4