Canister of Radioactive Material Stolen in Britain Police say it's safe ... if it stays in its lead container By Kevin Spak, Newser Staff Posted Feb 18, 2013 8:33 AM CST 12 comments Comments A canister of the radioactive element Iridium 192 has gone missing. (Shutterstock) (Newser) – Police in Lancashire are asking the public for help and urging them to be careful after a canister containing a small amount of Iridium 192 was stolen from a van there this weekend. The pilfered material—which is housed in a foot-long yellow canister and is used in cancer-fighting radiotherapy, among other uses—is likely safe provided it remains inside that heavy lead container, Sky News reports. But police said that if anyone had prolonged exposure to it outside that packaging, they should "seek medical assistance." That's because it emits beta and gamma radiation that can harm human cells. Police urged the public to contact them with any information. "I would also appeal direct to the people who have stolen this," a police chief inspector said. "They may have no idea what it is that they have in their possession or they may have discarded it somewhere. If that is the case then I would ask them to contact us."