Nov 20, 2006
What is Thallium
A former colonel in the FSB (the successor to the KGB) has allegedly fallen foul of chemistry. Alexander Litvinenko, 43, a vocal critic of Russian President Vladimir Putin, fell ill on November 1, after a meeting in a London sushi bar, reports the BBC.
Litvinenko is on life support in University College Hospital having allegedly been poisoned with a potentially lethal dose of the heavy metal thallium polonium. His condition is apparently serious but stable and he is under 24-hour armed surveillance. The BBC claims that his condition could be the work of the Russian Secret Service. Thallium (nor polonium) is certainly not available “over-the-counter” to the general public.
The alleged assassination attempt is revealed just as the British secret services try to exploit the marketing of the new James Bond movie – Casino Royale, starring Daniel Craig in the role of 007 – to recruit new spies. One British agent told BBC Radio 1 listeners that the secret services always work within the law and there is no license to kill. This thallium polonium attack comes in the wake of the gunning down in Moscow of journalist Anna Politkovskaya in October 2006 and perhaps does suggest that someone, somewhere does have a license to kill.
But, what exactly is thallium and why is it poisonous?
Thallium, Tl, is the element with atomic number 81 and lies just below indium in the periodic table (same column as boron, aluminium, and gallium). It’s tasteless, colourless, and odourless and would be undetectable if sprinkled into food or a drink in a restaurant.
Thallium ions have the same charge and are approximately the same size as potassium ions. As such, they can reach most tissues including the tissues of the central nervous system (CNS). Like other heavy metals, it binds to sulfydryl groups in the body disturbing numerous biochemical processes.
If you’re an ex-spy worried about meeting former colleagues in London sushi bars, you might be well advised to carry some D-penicillamine and Prussian blue with you. This combination can act as an effective antidote to thallium poisoning because these compounds have a greater affinity for the metal than the sulfhydryl compounds in your blood.

The Guardian today reports that the medical team treating him still do not know what has led to his present condition, but they have now ruled out thallium poisoning and believe radiation poisoning is unlikely.
Moreover, the paper points out that BBC speculation that the three “objects” are something to do with the alleged poisoning is misguided. Most likely is that the shadowing seen in the X-ray pictures is due to the presence of the chelation agent Prussian blue administered as an antidote to thallium poisoning.
I believe one of the ways the CIA was thinking of debilitating (or killing) Castro was with Thallium poisoning…strikes a chord somewhere…
The toxicology report is still pending lab tests, but a new development in the case of Litvinenko’s condition has emerged. University College Hospital has announced that they have found three objects of dense matter in his intestines. They could only have got there through ingestion, but the Hospital has not confirmed the size of these objects nor said whether or not they are related to the alleged poisoning. Unfortunately, for Litvinenko, whatever these objects turn out to be, his condition has deteriorated and he is suspected to have suffered a cardiac arrest, reports the BBC.
It now emerges that Litvinenko may also have been exposed to a radioactive material, although it is possible the two were one in the same, i.e. a radioactive isotope of thallium.
(An isotopes of a chemical element has the same atomic number and so is chemically almost identical, but it has a different number of neutrons in its nucleus. This difference in neutron to proton ratio in the nucleus can make some isotopes of elements more or less stable or radioactive.)
Claims that the former KGB colonel was poisoned by the Russians have been dismissed by the Kremlin as “sheer nonsense”. Litvinenko is known to have been investigating the death of Politkovskaya.