Radiation poisoningArafat may have been poisoned, but what is polonium?
A Swiss forensic report of the exhumed remains of ex-Palestinian leader Yasser Arafat last month suggested polonium poisoning may have been the cause of death – but what is polonium, and why is it so deadly? Polonium is a highly radioactive heavy metal. It is arguably the most lethal known material. Although it has some minor industrial uses it is best known for links with possible assassinations. It is also used to produce neutrons in the core of nuclear weapons. Polonium is element 84 in the periodic table, and all of its isotopes are radioactive. Their half-lives vary between a few millionths of a second to 103 years.
Martin Boland, Research Fellow at Australia's University of Melbourne // Source: theconversation.com
A Swiss forensic report of the exhumed remains of ex-Palestinian leader Yasser Arafat last month suggested polonium poisoning may have been the cause of death – but what is polonium, and why is it so deadly?
First, we need to understand the basics of radioactivity.
Radioactivity is the (term given to the) emission of certain particles or electromagnetic waves caused by the breakdown of nuclei in atoms. Elements can vary so they have different numbers of neutrons within their nuclei; these are called isotopes.
An isotope’s half-life is the time that it takes for half of the starting material in a sample to be converted, or decayed, into another product (after this time half of the starting material is gone). The radioactivity of a material is inversely proportional to the material’s half-life (if something has a long half-life, the amount of radiation it releases per second is lower).
High radioactivity, high lethality
Polonium is a highly radioactive heavy metal. It is arguably the most lethal known material. Although it has some minor industrial uses it is best known for links with possible assassinations. It is also used to produce neutrons in the core of nuclear weapons.
Discovered by Marie Curie, the element was named after her home country of Poland. Polonium is element 84 in the periodic table, and all of its isotopes are radioactive. Their half-lives vary between a few millionths of a second to 103 years.
When polonium is discussed in the media, it is usually in the context of the polonium-210 isotope (210Po). This isotope has a half-life of 138 days, so while the material has very high radioactivity, it is stable enough to be transported (usually from a location with nuclear reactors or other high level scientific equipment).
210Po has been suggested as a method of assassination. The two most famous suspected cases being KGB-agent-turned-journalist Alexander Litvinenko in 2006 and — as mentioned above — Yasser Arafat.
As air reacts with alpha particles, the polonium must be ingested (or be injected) into the assassination target. In the case of Litvinenko it is alleged that was given to him in a cup of tea.
