I know it sounds like a quibble, but in these times of scientific mushiness and faith-based policy decisions, it's important to keep straight a few basic scientific facts. An isotope of one element is never a different element. Thus calling Polonium an isotope of Uranium is wrong. It is radioactive and is an isotope, but of Polonium, which is more commonly of the 209 atomic weight.

I just wanted to note that there's an inaccuracy on the first page. Polonium-210 is not "an isotope of uranium" it's an isotope of polonium, and they're two separate elements. Polonium may be produced in nuclear reactions that begin with uranium, but that doesn't make it an isotope of uranium.

My encyclopedia may be a little out of date, we bought it in 1995 (it's hard copy). It goes through the litany about polonium being rare, polonium 210 rarer, but then lists its "industrial uses" among which is drying paper during production.

Are you sure you need to be a nuclear power to make it?

Polonium 210 is commonly used in photographic brushes, which are available at any decent camera store. From Wikipedia:

Some anti-static brushes contain up to 500 microcuries of 210Po as a source of charged particles for neutralizing static electricity in materials like photographic film.

Also from Wikipedia:

The fatal dose (LD50, the dose that leads to 50% risk of death) for acute radiation exposure is generally about 4 Sv. [...] A fatal 4 Sv dose can be caused by ingesting 8 MBq (200 microcurie), about 50 nanogram, or inhaling 1.6 MBq (40 microcurie), about 10 ng.

So it looks like all you need to do is walk into a camera shop, buy one anti-static brush, drop it in the guy's food while he's not looking, and the deed is done. Polonium is entirely non-toxic to handle, so there is virtually zero danger to the assassin. And, no need to suffer a flight on BA.

...and thanks for running it.

The implication here is that we never won the cold war at all and may in fact have lost it.

Polonium 210 is available commercially in the US without a license. I don't know whether it is on the NPT list. Probably not. You don't need to control a nuclear reactor in order to lay hands on this stuff. Take a look at these anti-static brushes, e.g.:

www.optcorp.com/product.aspx?pid=1818

I don't think these guys have a nuclear reactor lying around. Polonium 210 has a number of commercial applications, and is also used for many kinds of scientific research.

We may have abundant cause to think that the Russians were involved in this incident. But, the notion that a state actor is required to explain the presence of polonium is simply wrong.

Obviously, whomever killed Litvinenko wanted others to know what they did, even if they didn't necessarily want them to know how they did it. Personally, I think the sophistication of the method suggests that it wasn't sponsored by the Russian government. Their economic ties to the west are too large and tenuous to risk being blackballed by using a method so beyond the pale. It seems more likely that they would have simply commissioned a more traditional hit--just as effective and about 99% as good of a message, but with a significantly lower potential for backlash.

One of the assumptions that this story is based on is that Large is an expert of polonium biophysiology. Since he says he's not, I would take a good bit of his conjecture with a grain of salt. I trust him when he says that this polonium was produced in a reactor, I do not trust him when he says that it would have to have been inhaled. The former is his area of specialty, the latter is not. A polonium organometalic compound could might be just as easy to transport, but infinitely easier to deliver.

I have to read the letters to get accurate info from your articles? This whole episode already sounds like a LeCarre novel, without you adding more fiction.

I can't find my copy. Does anyone remember what the radioactive poison was in that novel?

Politically speaking, I can't understand why Putin would do this. Litvinenko wasn't making much of an impact on the world's attitude towards Putin BEFORE he died.

And Gaidar had become an academic. Why go after an academic? That's insane. There's no upside to killing Gaidar for Putin at all.

I think it was a miracle that Gaidar was not assassinated when he was working under Yeltsin. But then he had power. He has no power now.

As far as silencing critics -- there is no possible criticism Litvinenko could have leveled at Putin that would have damaged Putin as much as the suspicion for Litvinenko's murder is damaging Putin now.

When they call Litvinenko a "dissident" -- remember this was a guy who willingly joined the KGB during Soviet times and worked in counter-intelligence. Meaning he spied on other spies. That's a job for a particular kind of person. One who is so good at deception, he can deceive professional deceivers.

He's a far cry from traditional Soviet political dissidents like Andre Sakharov or Larisa Bogoraz. I shudder to think how they'd feel sharing this title with a KGB man.

His house in London was purchased for him by billionaire Boris Berezovsky, and if Berezovsky counts as a "dissident," then so does Ken Lay.

This is a very intriguing novel and I hope some day we get to read the end.

Po210 is readily available to the general public in quantities greatly exceeding what is needed to kill a man. Nobody uses it as a nuclear bomb trigger any longer. With a 138 day half-life, one would have to swap out the initiators at least once a year, which would involve disassembling the entire weapon. It was used in the first atomic bombs, but it is not practical for weapons that must be stored for long periods. Nor is it very useful for thermoelectric generators on satellites, the half-life is too short and it is too expensive. Plutonium is usually used these days, as in the Cassini spacecraft. Instead, the most common use by far is in anti-static devices, such as Staticmaster brand brushes, which contain 500 microcuries of Po210. Here is a product that contains a whopping 31 millicuries of the stuff for $225.00:

http://www.ricelake.com/docs/viewProduct.php?productID=91906

That is about ten times what it would take to kill a person. Litvinenko is thought to have been poisoned with five millicuries. Ordinarily these devices are very safe, the polonium is plated onto a strip of gold foil, which is then overplated with more gold, sealing the polonium source inside. One could probably swallow this strip without causing significant injury. However, if one were to dissolve this strip (it is a tiny amount of gold) in a bit of an acid solution called aqua regia, that would transform the metal polonium (along with the gold) into a water soluble salt, readily absorbed from the gut. This would obviously be hazardous to whomever was preparing the poison, but the risks could be obviated by a few simple precautions; a makeshift glove box would probably be adequate if one was careful. The question of whether anyone but a KGB assassin would have thought of this before it happened is open to debate, but the means to do it is available to anyone with $225.00 and a minimum of technical knowledge.

Again, this doesn't mean these devices are dangerous, used properly they are positively benign and very useful. Lots of things can be deadly if misused. A pack of cigarettes contains enough nicotine to kill five men if administered properly.

Too often when someone says something is hard to do, what they mean is that they wouldn't know how to do it, and that is what is going on with a lot of the reporting about this incident. Here is a fact sheet on Po210 toxicity from the Health Physics Society:

http://hps.org/documents/po210_information_sheet.pdf

You can see from this fact sheet that the amounts of Po210 available in a just few anti-static brushes would easily do in your average Russian spy.