India's cobalt-60 poisoning: canary in a coal mine

equipment and blood.

Most medical waste can simply be stored until its radioactivity subsides within a few years, then safely thrown out with the regular trash. Some institutions store their radioactive material in lead-lined safes, behind doors fitted with alarms and covered with yellow-and-black radiation warning signs.

Over the past decade, however, 4,363 radioactive sources in the United States have been lost, stolen, or abandoned, according to a Nuclear Regulatory Commission (NRC) report released in February 2008. Though none of the material lost was rated “extremely dangerous” — meaning unshielded, up-close exposure can cause permanent injury within a few minutes and death within an hour — more than half the radioactive items were never recovered, the NRC said.

Since the 9/11 attacks, owners of dangerous amounts of radioactivity have been told by the U.S. government to take greater precautions, such as having 24-hour surveillance, erecting barriers and fingerprinting employees, regardless of whether the devices are in use or stored as waste.

Yet in 2003, the federal Government Accountability Office (GAO) reported there was not even a record of how many radioactive sources existed nationwide. In June 2008, the GAO concluded that while there has been progress, more must be done to track radioactive material to prevent it from falling into terrorists’ hands and ending up in a dirty bomb, or one that uses conventional explosives to scatter radiation. “I don’t think we’re yet in crisis, but certainly there’s information out there to suggest we may be closer to that than is comfortable for me,” said Gregory Jaczko, a commissioner with the NRC, one of the agencies charged with tracking the material.

In 1987 four people died and hundreds fell ill after looters in Brazil found a cancer-therapy machine in an abandoned medical clinic and sold it as scrap metal. More recently, 19 small vials of cesium-137, implanted for cervical cancer treatments, disappeared in 1998 from a locked safe at Moses Cone Memorial Hospital in Greensboro, North Carolina. The tubes were never found and were believed stolen.

A terrorist would need to gather far more of those vitamin-sized capsules to create a dirty bomb capable of killing anyone within one city block, said Kelly Classic, a health physicist at Mayo Clinic in Minnesota.

For decades, the U.S. federal government urged states to build low-level nuclear waste landfills, either on their own or in cooperation with nearby states. Those efforts have run into strong not-in-my-backyard resistance of the sort