The capsule, which is less than an inch long, went missing somewhere along the more than 800-mile road between Newman and Perth, the department said. It contains caesium-137, a radioactive material used in gauges for mining, one of the major industries in resource-rich Western Australia.
Despite its size, the capsule is dangerous, the department warned. “Exposure to this substance can cause radiation burns or radiation sickness,” it said, warning people not to touch or move it if they come across it. Anyone who sees the capsule must stay at least five meters away from it and report it, the department said.
Authorities did not close the road, National Highway 95, due to the ordeal, even though the emergency department’s incident map marked the entire stretch of road in red with a radioactive warning symbol.
Workers involved in the search used radiation detectors to find the capsule, said Darryl Ray, acting chief of the emergency department. “We’re not trying to find the little capsule with eyesight,” he said. “The radiation equipment will hopefully lead us there.” The equipment can detect radiation over a 20-meter radius, he said, adding that they were waiting for more specialized equipment to improve the search.
It’s possible the capsule has been missing for a few weeks. It left the mine on Jan. 12 and was supposed to have arrived on Jan. 16, but its disappearance was discovered on Wednesday when it was missing from the package it was transported in, with the gauge inside “broken apart” with screws and a bolt missing, according to the department. Officials said they believe the capsule fell off the back of a truck, according to the Associated Press.
Specialists are targeting “strategic locations” along the route the truck took, Ray said, noting they focused on densely populated areas near Perth.
Cesium-137, the radioactive material inside the capsule, is used for things like detecting fluid flow through pipes and determining the thickness of materials such as metal plates, according to the U.S. Centers for Disease Control and Prevention.
Exposure to the material can cause an increased risk of cancer, radiation burns, acute radiation sickness and possibly death, according to the CDC.