Abstract:

Moscow -- In November 2006, former Russian spy Alexander Litvinenko, an ex-KGB and FSB officer living in London who defected to British Intelligence in 2001, was killed after ingesting radioactive poison laced with polonium-210. 

Only advanced state-level agencies have the resources to manufacture polonium-210. More specifically, analysis of trace elements and decay rates have allowed British Atomic Weapons Establishment investigators to trace the specific polonium-210 used to kill Litvinenko to a reactor in Russia. 

Polonium-210 emits alpha particles at 803 kilo-electron volts (keV). Unlike gamma rays, alpha particles don't penetrate clothing or skin. In some ways, polonium is a perfect poison. It can be carried through airports and even skip past sophisticated radiation detectors. 

Dangerous when breathed, injected or ingested, polonium-210 poisons victims from the inside to produce a slow and tortured death, the exact kind of death one might intend for a defector deemed a traitor to his country by his former colleagues because it serves as punishment and warning. Those in the know, suspect, but unless one is looking for it, polonium-210 poisoning may slip past detection, with the victim's death attributed to industrial-strength rat poison. Investigative agencies are left in a murky fog of conflicting facts and enigmatic radioactive trails. 

While Russian intelligence services certainly had the motive and means, tracing polonium-210 to a reactor in Russia does not create and open and shut case. 

Polonium-210 is specifically manufactured inside nuclear reactors to reduce static electric buildup in components of nuclear reactors, but It also has commercial uses and is a component of products openly available. Static electrical charges allow dust to cling to objects. Polonium ionizes air passing over it, the charged air then binds with and electrically neutralizes dust, allowing it to be easily blown away.  (more)