The final report from the Institute of Radiophysics in Lausanne, Switzerland, found abnormal levels of radioactive polonium on Arafat's belongings.

Polonium is a rare and highly radioactive element. It is found naturally in the atmosphere and in the earth’s crust, though in miniscule quantities.

Live from Canberra is George Dracoulis, professor of Nuclear Physics at the Australian National University, who explains in greater detail what polonium-210 is, where it comes from, how it is produced and how it can kill a human being.

Source: Al Jazeera