VIENNA, Austria – Thieves have made off with a truck in Mexico carrying a dangerous radioactive source used in medical treatments, a material that could also provide an ingredient for a so-called “dirty bomb.” The UN nuclear agency said it had been informed by Mexican authorities that the truck, which was taking cobalt-60 from a hospital in the northern city of Tijuana to a radioactive waste-storage centre, was stolen near Mexico City on Monday. A search was underway in six Mexican states and in Mexico City for the white Volkswagen Worker truck, Mexico's National Commission for Nuclear Safety and Safeguards (CNSNS) said in a statement. It gave phone numbers for anyone with information to call and released photos of the steel-reinforced wooden crate carrying the material. Experts have long warned about the risks posed by the large amounts of radioactive material held in hospitals, university campuses and factories, often with little or no security measures to prevent them being stolen. Such material is highly dangerous to human health if not properly handled. Cobalt-60 “has figured in several serious source accidents including fatalities because the material was obtained and handled by people who were not aware of its danger,” said Mark Hibbs, analyst at the Carnegie Endowment for International Peace. “There are many thousands of these sources worldwide. There is in most countries a regime to keep them safe and secure, but if they are stolen or lost, many people would be unaware that the radioactive contents locked up inside could threaten their lives,” Hibbs said. “If dispersed, cobalt-60 or other radioactive source material could cause radiation poisoning locally,” he said. Apart from peaceful medical and industrial uses, experts say cobalt-60 can also be used in a dirty bomb in which conventional explosives disperse radiation from a radioactive source. The International Atomic Energy Agency (IAEA), which has stepped up calls on member states to tighten security to stop nuclear and radioactive materials falling into the wrong hands, made no mention of any such risk in its statement on Wednesday. The IAEA also did not give details on how much radioactive material was in the vehicle when it was seized. “At the time the truck was stolen, the (radioactive) source was properly shielded. However, the source could be extremely dangerous to a person if removed from the shielding, or if it was damaged,” the IAEA statement said. The IAEA has offered to assist Mexican authorities, who it said were searching for the material and had alerted the public. Cobalt-60 – the most common radioactive isotope of cobalt, a metal – has many applications in industry and in radiotherapy in hospitals. It is also used for industrial radiography to detect structural flaws in metal parts, according to the US Environmental Protection Agency. The EPA said exposure to gamma radiation from cobalt-60 results in an increased risk of cancer. More than 100 incidents of thefts and other unauthorised activities involving nuclear and radioactive material are reported to the IAEA annually, the UN agency said earlier this year. It is rare, however, that it makes any such incident public. Because radioactive material is regarded as less hard to find and the device easier to manufacture, experts say a so-called “dirty bomb” is a more likely threat than a nuclear bomb in any attack by militants. Experts describe the threat of a crude fissile nuclear bomb as a “low probability, high consequence act” – unlikely but with the potential to cause large-scale harm to life and property.
