Polonium is actually very stealthy. It's an alpha emitter which is not detectable by most equipment, and it was very nearly not detected even by the UK govern

Polonium is actually very stealthy. It's an alpha emitter which is not detectable by most equipment, and it was very nearly not detected even by the UK government. https://en.wikipedia.org/wiki/Poisoning_of_Alexander_Litvinenko#Poison https://en.wikipedia.org/wiki/Poisoning_of_Alexander_Litvine...