Authorities in Western Australia continue to search for the missing tiny radioactive capsule despite the slim chance of finding it.

Mining company Rio Tinto issued an apology on Monday, saying it supports the state government’s efforts to recover an 8- and 6-millimeter capsule of caesium-137, a highly radioactive substance used in mining equipment.

The capsule, no larger than a small coin, is believed to have gone missing in mid-January somewhere along the vast wilderness of the Great Northern Highway in Australia’s largest state.

Rio Tinto says it swept all roads to and from the Gundai Dari mine in the far north of Western Australia, where the device was located, before the contractor headed to the state capital of Perth and picked it up.

According to experts, a capsule emitting gamma and beta radiation fell from the back of a truck that was driving along a 1,400 km highway. Because of its tiny size, the authorities believe that the chances of finding the lost radioactive object are slim.

How dangerous is the capsule?

Now there are fears that the capsule has sailed beyond the search area, and will pose a health hazard to anyone who “falls on it” in the next 300 years.

Experts warn that caesium-137 can cause serious health problems in people who come into contact with it: skin burns and other health problems from radiation – even the risk of fatal cancer, especially for those unknowingly exposed to caesium-137 over a long period of time.

According to radiation protection consulting firm Radiation Services WA, stand at a distance of one meter from the capsule for an hourwould result in a radiation exposure of approximately 1.6 millisieverts (mSv), which is equivalent to the cumulative radiation of approximately 17 chest x-rays.

The company said in a statement that if someone touches the capsule, the object will cause “serious damage” to the fingers and surrounding tissues.

Ivan Kempson, associate professor of biophysics at the University of South Australia, explained that in the worst case scenario, “a curious child takes the capsule and puts it in his pocket.”

“It’s unlikely, but it could happen and it has happened in the past,” Kempson warned. “People found things like this and suffered from radiation poisoning, but they were much stronger than this lost capsule.”

“We are all constantly exposed to radiation from the things around us and the food we eat. but the main concern right now is the potential health impact on the person who finds the capsule.”

What if it’s never found

The half-life of caesium-137 is about 30 years, which means that after three decades the radioactivity of the capsule will be halved, and after 60 years it will again decrease by 50%.

At this rate, the capsule will remain radioactive for the next 300 years, according to an expert from RMIT University. Under normal conditions, the substance is sealed, and if the capsule does not break, it will not contaminate the soil or the rest of the environment. If the remains are left in some isolated location, Kempson assessed, “the likelihood of a serious impact is extremely low.”

Rio Tinto is one of the world’s largest mining giants with 17 iron ore mines in the Pilbara in Western Australia. His mining activities have provoked backlash in the past: in 2020, he destroyed two ancient rock shelters in the Jukan Gorge, sparking outrage. Then-CEO Jean-Sebastien Jacques apologized and subsequently resigned.

Source: CNN