Element 84 in our International Year of the Periodic Table series is polonium. Polonium is a highly radioactive element which has been used as a heat source for space travel and exploration. It was also the centre of attention in a high-profile poisoning several years ago.
Polonium was discovered by Marie Curie, who named it after her native Poland. Curie carried out her research at a time when the dangers of radiation were still not fully understood – and the elements she researched were significantly radioactive. Today, her laboratory notebooks are still radioactive (largely by radium, the other element she discovered).
Polonium’s radioactivity has seen it implicated in a number of poisonings. The best-known of these is that of Alexander Litvinenko. Litvinenko, a KGB agent who defected to the UK, was poisoned with polonium-210.
Polonium is so intensely radioactive that it has been used as a heat source in moon rovers and satellites. It was used in two Soviet Union moon rovers, Lunokhod 1 and 2.
Small amounts of polonium-210 are found in anti-static brushes used to remove dust from photographic film. This does not pose a significant risk to users unless the polonium is ingested.
Remember, you can keep track of all of the previous entries in this series on the site here, or on the Royal Society of Chemistry’s dedicated page.