Since bloggers discovered that Polonium 210 could be bought on the Internet, one of the on-line isotope stores took down its website.

It’s back up today with a new front-page setting the record straight about Polonium. The copy contains this wonderful line: ‘Although it obviously works, Polonium-210 is a poor choice for a poison.’

Reporting hasn’t made much of when Polonium-210 is a good choice. A quick digest from Perfect UK:

Polonium 210, when mixed with beryllium, becomes a source of neutrons and because of this is used to initiate fission reactions (bombs). Compared with tritium initiators (the main alternative) the polonium / beryllium design is simpler; it appears to be first choice in a start-up nuclear weapons programme.

Saturday’s UK ‘Times’ has five pages on Polonium which somehow manages not to mention its prime purpose at all. And when the Express asks the question, Was ex-spy trying to sell dirty bomb? - it is promptly rubbished by respected commentators, like Larisa Alexandrovna.

One can appreciate Larisa’s scepticism, since the Express is another paper that will say anything and hardly makes a case. But it remains nevertheless that Polonium was a poor choice for a poison. Moreover, a highly unusual choice - in fact this is the only recorded case of a death. Polonium is extremely difficult and expensive to obtain. And it’s a method that puts the poisoner at risk as well as the victim.

Speaking of which, Mario Scaramella is thought be an accidental victim and will be giving eight urine samples a day for the next decade. Could Litvinenko be an accidental victim too? We know from the trail that there was a lot more Polonium around than the amount needed for a simple poisoning. According to the Times, Litvinenko himself had 100 times the lethal dose.

So what do we think about dirty bombs, or suitcase nukes? Fruitcase nukes give rise to a fruity scare story every now and then. Problem being though, there isn’t a lot of corroboration for their existence. Litvinenko, however, was reportedly up to many dirty deeds - propaganda, selling secrets and blackmail - so why not a little arms dealing on the side? Certainly he had meetings at Erinys, where more traces of Polonium were found. Or was he just raising a private army?

The annoying part is that intelligence services probably know what really happened. As Eduard writes in the Moscow Exile, Litvinenko would have been under constant surveillance by both British and Russian agents. So we’ll have to enjoy the conspiracy theories while they last. Wackiest of the week from Kirill Pankratov, who links Polonium with Poland - it was named after Poland by Marie Curie - and Polonius from Hamlet - also spelled Polonium in Russian - which all dovetails with Poland’s unfriendly veto at the recent Russia-EU summit. Follow that.

My thought for the day: Britain may want to extradite some of those iffy Russians who visited Litvinenko and Erinys. Will Russia co-operate if Britain finally hands over Berezovsky in return?