Authorities undertook the daunting task of locating and securing the tiny capsule, which is believed to have fallen from a truck on Jan. 10 during its long journey from a desert mine near Newman to a storage facility in Perth.
Emergency services were first notified last Wednesday, officials said, and alerted the public last Friday.
“DFES and radiation specialists are searching along the Great Northern Highway by driving north and south at low speeds,” the Department of Fire and Emergency Services (DFES) said in a hazmat alert Monday, adding that it used survey meters to determine the find capsule by detecting radiation levels.
The truck arrived in Perth on Jan. 16, DFES said, while emergency services were not made aware of the missing pod until Jan. 25 when a gauge was unpacked for inspection.
“On opening the package it turned out that the meter was broken, with one of the four mounting bolts missing, the source itself and all the screws on the meter missing,” said the emergency services.
While the capsule cannot be weaponized, the health ministry said in a statement Friday, it could have “serious health consequences”.
The capsule’s radioactive source, cesium-137, emits potentially lethal amounts of radiation, nearly equivalent to receiving 10 X-rays in an hour, and prolonged exposure can even cause cancer. It takes cesium-137 nearly 30 years to decay by half.
“It dissipates quite quickly compared to other radionuclides. However, its short half-life means it is quite active,” Hajime Kinoshita, a senior lecturer in materials chemistry at the University of Sheffield in the UK, told NBC News.
“So if someone has it in their pocket or something, it’s not particularly good,” he said, adding that prolonged exposure could damage human cells.
Authorities have warned people to stay at least 5 meters away from it.
“Exposure to this substance can cause radiation burns or serious illness – if people see the capsule or anything resembling it, stay away from it and keep others away as well,” said Andrew Robertson, Chief Health Officer of Western Australia, in a statement. Friday.
“Being very close to or touching the material greatly increases the radiation risk and can cause serious damage to your health, including causing radiation burns to the skin.”
Concerns remained that the capsule might get caught in car tires. But the risk to passengers was low, Kinoshita said, because the organic material of the tires and iron car frame should block the radiation.
Radioactive material is routinely transported through Western Australia, although under strict regulation, and is widely used in medicine, industry, mining and research, Robertson told NBC News in a separate statement Monday.
“It’s extremely rare for a resource to go to waste,” he said, adding that these radioactive resources are usually returned to the manufacturer at the end of their useful life.
Rio Tinto did not immediately respond to NBC News’ request for further comment.
Associated Press contributed.