Terrorists could seize medical equipment that use radioactive isotopes and build dirty bombs that could blanket an area the size of Manhattan, warned a new report from the Defense Science Board.
The board, made up of approximately 40 civilian members who advise the Pentagon on scientific and technical matters, recommended that the Defense and Homeland Security departments invest $200 million over five years to replace current equipment with cobalt sources or electron beam irradiators that are used to sterilize food.
More than 1,000 machines in the United States now use the cesium-137 isotope as a radiation source in medical research and blood irradiation. The irradiation process disinfects blood and is a common practice used to prevent transfusion-associated graft versus host disease, which could kill a patient receiving a blood transfusion.
Replacing the equipment that uses cesium-137 in blood irradiators "would eliminate the most dangerous domestic RDD [radiological dispersal device] threat," said the report, released earlier this month.
Dr. Richard Benjamin, chief medical officer of the American Red Cross, which provides blood products to more than 3,000 hospitals in the United States, said despite the recommendations from DSB, there is currently no other safe and efficient alternative to cesium-137 approved by the Food and Drug Administration for blood irradiation.
Benjamin said he understood the security concerns outlined in the DSB report, and that the Red Cross and blood banks have beefed up security for blood irradiators through careful vetting of personnel and keeping the equipment in a locked, secure environment. The machines weigh "several tons" he said, making them difficult to steal. The isotope itself is encased in the machine and hard to remove.
A November 2008 report from the National Research Council concluded that there are few alternatives today for blood irradiation, and called for more security and tamper-proofing of cesium-137 machines.