[ RadSafe ] New Scientist reports Radioactive element found in blood of Russian ex-spy

[Fred Dawson]

New Scientist reports

http://www.newscientist.com/article/dn10659-radioactive-element-found-in-blood-of-russian-exspy.html


Radioactive element found in blood of Russian ex-spy

Traces of radioactive polonium have been found in the blood of the deceased 
Russian ex-spy Alexander Litvinenko, the UK's Health Protection Agency (HPA) 
said on Friday. His urine also tested positive for radiation.
"This is an unprecedented event in the UK," said HPA chief executive Pat 
Troop. "It is the first time someone in the UK has apparently been 
deliberately poisoned with a radioactive agent."
The agency is now assessing the health risks posed to members of the public 
who may have come into contact with Litvinenko, including family members and 
hospital staff who cared for him during the weeks he spent in hospital. They 
are also trying to decide the safest way for pathologists to conduct an 
autopsy of his body, and indeed whether such a procedure is safe enough to 
be performed at all.
Litvinenko, aged 43, died on Thursday of heart failure after claiming he had 
been poisoned in a London restaurant. He was formerly an agent of the 
Soviet, then the Russian, security service. He specialised in investigating 
organised crime and its involvement with corrupt officials.
High levels of radiation have been discovered in a central London hotel that 
Litvinenko frequented, and at the sushi restaurant where he said he ate on 1 
November 2006. The restaurant has now been closed, said the HPA.
"Tests have established that Mr Litvinenko had a significant quantity of the 
radioactive isotope polonium-210 in his body," the HPA announced on Friday. 
"It is not yet clear how this entered his body. Police are investigating 
this."
Dissolvable salt
Litvinenko was not admitted to London's University College Hospital until 17 
November. His symptoms, reported to include hair loss, dehydration, vomiting 
and a very low white blood cell count, are consistent with poisoning by a 
radioactive material.
To poison someone, polonium would most likely have been chemically combined 
in some type of dissolvable salt, for example polonium nitrate, experts told 
New Scientist. In this form the material could easily have been added to his 
food and ingested.
Polonium is a radioactive element that is used industrially as an 
anti-static material. It is difficult to get hold of and not used regularly 
by research scientists, but very small traces of it occur naturally. The 
metal is usually made by bombarding the element bismuth with neutrons.
"To poison someone, large amounts of polonium-210 are required and this 
would have to be manmade, perhaps from a particle accelerator or a nuclear 
reactor," said Dudley Goodhead at the UK's MRC Radiation and Genome 
Stability Unit. "Polonium has a half-life of 138 days. This means that if 
that was the poison it will still be in the body and in the area - which 
makes it relatively easy to identify."
Knocking out electrons
Polonium-210 decays to lead-206, which is stable. During the decay it emits 
alpha particles - two neutrons combined with two protons. These are not able 
to penetrate most materials, including skin. This means that Litvinenko 
would have had to ingest the polonium or have it enter his body through a 
wound or by inhaling it, said Roger Cox, director of the UK's Centre for 
Radiation, Chemical and Environmental Hazards.
"Alpha particles are ionising. When they strike tissue they knock electrons 
out of molecules. Such damage can in serious cases wreck cellular machinery 
resulting in cancer, radiation sickness, or worse," said chemist Andrea 
Sella at University College London.
But the short-range action of alpha particles decreases the risks faced by 
people who may have come into contact with Litvinenko. Normal hygiene 
practices would reduce the risks still further, since people would have to 
ingest or breathe in his bodily fluids or faeces to be at risk, Cox added.
Many details are still unknown, such as how much of the material may have 
been given to Litvinenko. Cox was only able to say that a fatal dose would 
have to be something greater than 5 grays (a gray is a measurement of the 
amount of radiation absorbed by body tissue).
Organ malfunction
Determining the amount of polonium originally given will involve a 
"backwards analysis", taking into consideration the radiation currently in 
his body, the days that have passed since it entered his body, and the 
half-life of the isotope.
In low doses over a long period of time, radiation poisoning produces few 
symptoms, but an increased risk of cancer. In high doses - as in this case, 
apparently - organs begin to malfunction within a few days to a few weeks, 
Cox said.
Radioactive poisoning was once used against dissidents by the Stasi, the 
former security service of East Germany. The Stasi favoured the element 
scandium (see Cold war, hot secret).
Litvinenko left Russia after reportedly falling out with President Vladimir 
Putin over a failure to crack down on corruption. His job is said to have 
made him many enemies. Those enemies, he claimed, poisoned him at a meal in 
a London restaurant on 1 November 2006. He was reportedly a close associate 
of exiled Russian billionaire Boris Berezovsky, himself a politically 
controversial figure in Russia.
On Friday, the British Home Secretary John Reid stated that police have 
called in experts "to search for any residual radioactive material at a 
number of locations".

Fred Dawson
fwp_dawson at hotmail.com