German authorities said today that they had found traces of the radioactive substance polonium in a car and two homes in Hamburg used by a Russian business associate of the murdered ex-K.G.B. agent Alexander V. Litvinenko a few days before the men met in London...
The confirmation that traces of polonium 210, a radioactive isotope, were found in Hamburg as early as Oct. 28 is critical because the British police have so far found no evidence of polonium contamination in London earlier than Nov. 1...
To refresh your memory, Kovtun is the Russian "businessman" who accompanied Lugovoy to the hotel bar on November 1. The fact that he had the stuff on him days before it made its way into Litvinenko's system is obviously hugely incriminating. But I think the NYT is wrong about there having been no polonium found in London before 11/1. According to the Times of London, there's good reason to think it was present in and around the city in mid-October:
Traces of polonium-210 has been found at Parkes Hotel, Mayfair, it was confirmed last night. It means that radiation has been found at all three hotels where Mr Lugovoy had stayed since flying to London on October 16. The Parkes was the first he stayed at.
The radioactive isotope has also been found at Risc Management, a security firm in Cavendish Place, visited by Litvinenko with Mr Lugovoy and Mr Kovtun on October 17.
Assuming ToL is right, Kovtun had already been exposed to the substance long before he got to Hamburg. Back to the NYT:
Police in Hamburg have assembled a detailed picture of Mr. Kovtun's movements after he arrived from Moscow on an Aeroflot flight on Oct. 28. He appears to have begun spreading polonium soon after he stepped off the plane. Traces were found on the seat of a car that met him at the airport...
Ms. Sweden said the traces found in the car, a BMW, are intriguing because they suggest that Mr. Kovtun could have been carrying polonium 210 outside his body, rather than leaving traces from his own body.
"If you're sitting in the passenger seat of a car, you're not likely to be sweating enough to leave traces of it that way," Ms. Sweden said. "It's possible he got poisoned by handling the stuff."
The other traces of contamination — at the apartment of Mr. Kovtun's ex-wife, the house of her mother and in the immigration office — could have been deposited through sweat or saliva, Ms. Sweden said.
This gets us back to the question I asked last night: how resilient is this stuff? British cops discovered today that two of their own have radiation poisoning, one of them from the barest contact:
On the Health Protection Agency's website the agency says that polonium-210 is "not a radiological hazard as long as it remains outside the body" and that "most traces can be eliminated through hand-washing, washing machines and dishwasher cycles for clothes, plates, etc".
However, the only contact one of the contaminated detectives had with the poison was when he removed items such as clothing from Litvinenko's home. Evidence of the substance was reportedly found in a tea cup at the Millennium Hotel more than a month after Litvinenko was killed and countless washes. Seven bar staff who had minimal contact with Litvinenko all show evidence of exposure.
British police are now hastily updating their protocols for dealing with what's quickly becoming a nightmare scenario — a terrorist dirty bomb in the heart of London.
The likelihood of an attack this Christmas? According to Home Secretary John Reid, "very high indeed."
Update: Pretty resilient.
SCOTLAND YARD HAS HAD ONE BIG BREAK IN the case: polonium, once released, is like a persistent, invisible dye that marks whatever it touches. Someone who ingests even small amounts will leave an unmistakable trail through sweat and even fingerprints.

 http://hotair.com/archives/2006/12/10/jackpot-polonium-linked-to-kovtun-days-before-litvinenko-poisoning/