FILE - A Friday, May 10, 2002 photo from files showing Alexander Litvinenko, former KGB spy and author of the book "Blowing Up Russia: Terror From Within" photographed at his home in London. Polonium first hit the headlines when it was used to kill KGB agent-turned-Kremlin critic Alexander Litvinenko in London in 2006. This week, Yasser Arafat's widow has called for the late Palestinian leader's body to be exhumed after scientists in Switzerland found elevated traces of radioactive polonium-210 on clothing he allegedly wore before his death in 2004. (AP Photo/Alistair Fuller, File)