Polonium and political controversy are no strangers

Polonium is a rare earth element. It does not grow on trees. It is in fact very very rare.

From the news reports I understand that traces Polonium 210 (an isotope of polonium) have been found in the now infamous case of Alexander Litvinenko.

You can read the BBC's article here. It will be covered by all papers in the morning.

There are of course some questions which arise. Is Polonium dangerous? Well I suspect it is a bit toxic, quite a lot of rare earth metals are. It is however as rare as rocking horse excrement, if not rarer. Hens teeth would be much easier to get hold of.

You can get it in a number of different ways, all of which involve nuclear power and the technical ability to separate polonium from what ever else it comes with.

Polonium 210 is an alpha emitter. That is to say that when it decays it sends out an alpha particle, which contains 2 protons and 2 neutrons.

There are two other sorts of radiation, beta, an electron, and gamma, a very high energy X Ray.

What makes alpha radiation so safe and deadly at the same time is this: Think of something being hit by an alpha particle as being hit by a 10 ton shell. It is going to do damage. What makes it so safe is that being so large and heavy alpha particles don't go very far. Typically only a few inches in air. In fact you could quite safely keep an alpha emitter on the top shelf and never get any radiation. Schools typically have alpha emitters but kept in lead.

Where it becomes very very dangerous is when it gets inside the body. There is nowhere for the alpha particle to go but some where it is bound to cause damage. It does this normally because it is basically a Helium atom without electrons. As it passes any atom it may steal an electron. This leaves an ion that was not there before, a free radical. These things can and do cause all sorts of problems including cancer. In order to do any of this damage though it does have to be inside of the body.

There will be huge amounts of speculation about who killed Alexander Litvinenko, but the biggest question in my mind is what prat would sign the murder in ten foot high letters of flame by using a chemical so rare that only 100 grams of it are produced a year?

Polonium is of course no stranger to political controversy. The Curries named it after Poland at a time when Poland was occupied in order to highlight its plight.

You can read the already updated to take account of this controversy article on Polonium on Wikipedia here.