What’s the risk? Radioactive medical material’s biggest threat is to unwitting thieves

Stolen truck carrying radioactive material found in Mexico 0:29

Plenty of Americans have gone to the hospital for a scan or radiation treatment without ever giving a second thought to the radioactive materials involved. Now, news about a stolen Mexican truck, later found when the thieves stopped for gas, carrying what has been described as "extremely dangerous" radioactive material has raised questions about how such materials are transported and whether they could be used to commit any harm. 

What is the actual danger posed by the material?

None — so long as it is not removed from the medical device, according to the Nuclear Regulatory Commission (NRC).

“This was a medical teletherapy device,” said NRC spokesman David McIntyre. “The cobalt-60 inside was shielded properly, according to the Mexican authorities. As long as the shield stays in place there is no safety hazard. If the shield was removed, it would be a significant health hazard.”

This image released Wednesday Dec. 4, 2013 by the National Commission on Nuclear Safety and Safeguards of Mexico's Energy Secretary (CNSNS) shows a pi...
Photo released by Mexican authorities shows a piece of machinery that is part of the cargo of a stolen truck hauling medical equipment with extremely dangerous radioactive material.

What's the worst case scenario?

The radioactive materials inside could theoretically be used in a dirty bomb, although Mexican officials do not believe there is enough left in the device to harm anyone outside its immediate vicinity. Their big fear is that a thief would unintentionally open the device.

“Either cobalt-60 or cesium-137 (also used in hospitals) could be used in a radiological dispersal device,” said Col. Randall Larsen, USAF (Ret), National Security Adviser at the University of Pittsburgh Medical Center’s Center for Health Security and former executive director of the congressional commission on weapons of mass destruction. “Had a small amount of cobalt-60 been included in the bomb at the federal building in Oklahoma City, it would have been a far greater disaster — not in terms of casualties, but in terms of clean up." For example, a dirty bomb on Wall Street might mean that 10-20 blocks would be evacuated for an extended time, Larsen said.

What if someone dismantles the machine and takes the cobalt-60 out?

Depending on the circumstances, they could suffer pretty significant radiation burns, experts said.

“The major concern would be for that person’s safety,” said Dr. Richard Wahl, a professor and director of nuclear medicine at Johns Hopkins, Baltimore. “There could be a very substantial radiation dose quickly. The people at most risk are the ones taking the thing apart.”

Kei Iwamoto, a professor in the department of radiation oncology at the University of California, Los Angeles, said it depends on how much cobalt-60 is left. “It was being discarded. And cobalt-60 decays relatively quickly — its half-life is about five years or so. But if someone were to open the machine up and put the cobalt-60 in their hip pocket, there is the possibility of whole body burns and even death depending on how long he was exposed.”

Should we be worrying about the devices in hospitals? How secure are they?

Very secure, experts told NBC News.

“Starting in 2001 after 9/11, the possibility that these sources could be used for non medical purposes has been of concern,” Wahl said. “Security is much better now than it was 15 years ago.”

Beyond that, many institutions are turning to devices that don’t depend on radioactive isotopes, both Wahl and Iwamoto said.

At UCLA, “they are quite secure,” Iwamoto said. “The are protected by passwords and only people finger printed with FBI background checks are allowed access. Besides, the material is encased in extremely heavy shielding making it very difficult to steal. I’m sure they weigh a couple of tons.”

Are the trucks carrying medical devices containing radioactive material guarded?

"I can't comment on the particulars of the Mexican shipment, but I can speak in general terms about the type of device on that trucks and how shipment is handled in the U.S," said McIntyre. “This kind of device has to be shipped in a proper container with shielding and in a closed vehicle that would have GPS for tracking,." 

The driver must have at least two forms of communication to call for help if needed and he or she is required to report the progress of the shipment to the shipper at regular intervals. All states through which the shipment is traveling would be notified ahead of time so they can be prepared if they need to respond to an incident. The states have the option of providing an armed escort and some do.

Does anyone keep track of these transfers?

Yes. “The National Source Tracking System has been in place for the past four years,” NRC's McIntyre said. “It keeps track of track of any transfer or movement or sale or new ownership of high risk radioactive sources.”

Have there been any thefts in the U.S.?

“No source like this one has been lost in the U.S,” McIntyre said. “There was a camera stolen in Texas three years ago that wasn’t ever recovered, but the radioactive material it contained decayed in weeks so it was not as significant as this one.”

What about in Mexico?

Juan Eibenschutz, general director of Mexico's National Commission of Nuclear Security and Safeguards, said several trucks with similar material have been stolen in the recent past, but this one had the largest amount of cobalt-60. He believes thieves were interested in the truck, not its contents.

"The risk we run is that someone opens the container out of ignorance," he told NBC News.

Edgar Zuniga, Jr., NBC News Atlanta, contributed to this report