An unknown quantity of cobalt-60 has been stolen in Mexico. It would be foolish to believe that it wasn't stolen for use in a dirty bomb. A cobalt-60 dirty bomb could be used to prevent access to the release location for years and would be devastating if used to contaminate, e.g., fresh water infrastructure.
Mexico has informed the IAEA's Incident and Emergency Centre (IEC) of the theft of a truck carrying a dangerous radioactive source used in medical treatment.
Mexico's "Comisión Nacional de Seguridad Nuclear y Salvaguardias (CNSNS)" said the truck, which was transporting the cobalt-60 teletherapy source from a hospital in the northern city of Tijuana to a radioactive waste storage centre, was stolen in Tepojaco near Mexico City at around 08:00 UTC on 2 December 2013.