MIAMI (Reuters) - When 75,000 football fans pack into Dolphin Stadium in Miami for the Super Bowl on February 4, at least a few may want to carry notes from their doctors explaining why they're radioactive enough to set off "dirty bomb" alarms.With the rising use of radioisotopes in medicine and the growing use of radiation detectors in a security-conscious nation, patients are triggering alarms in places where they may not even realize they're being scanned, doctors and security officials say. Nearly 60,000 people a day in the United States undergo treatment or tests that leave tiny amounts of radioactive material in their bodies, according to the Society of Nuclear Medicine. It is not enough to hurt them or anyone else, but it is enough to trigger radiation alarms for up to three months.
Since the September 11 attacks, the U.S. Department of Homeland Security has distributed more than 12,000 hand-held radiation detectors, mainly to Customs and Border Protection agents at airports, seaports and border crossings. Sensors are also used at government buildings and at large public events like the Super Bowl that are considered potential terrorist targets.
At the annual Christmas tree-lighting party in New York City's Rockefeller Center in November, police pulled six people aside in the crowd and asked them why they had tripped sensors. "All six had recently had medical treatments with radioisotopes in their bodies," Richard Falkenrath, the city's deputy commissioner for counterterrorism, told a Republican governors' meeting in Miami recently. "That happens all the time."