A nine-month investigation by Al Jazeera discovered rare, radioactive polonium on the ex-Palestinian leader's final belongings. The finding suggests that Arafat was poisoned with polonium, a rare, highly radioactive element. The polonium was found in blood, sweat, urine and saliva stains on his personal effects, and the levels recorded by forensic pathologists in Switzerland - who studied the items - do not occur naturally. Al Jazeera's Clayton Swisher reports.