Making rhino horns radioactive and toxic for humans

Researchers at the University of the Witwatersrand have launched the Rhisotope Project. It aims to devalue rhino horns by making them toxic for human consumption and allowing easier detection at border posts.

The team started the project in late June 2024 by inserting low doses of radioisotopes into 20 live rhinoceros’ horns.

Speaking to eNCA, the dean of science at Wits University, Nithaya Chetty, said the radioactive material renders the horns useless to potential buyers.

“The dosage is at a fairly low level, low enough that it will not impact the animal itself in any negative way,” said Chetty.

“Yet it is strong enough to do two things: one is to render the horn totally useless and not consumable by human beings. It is essentially poisonous for human consumption.”

He added that the second and equally important result of the radioactive pellet implants is that the radioactive material will make it easier to detect any Rhino horn or parts thereof at border posts.

Rhino horn is highly sought after on black markets, with its price by weight rivalling that of gold and cocaine.

With South Africa being home to the majority of the world’s rhinos, it is a primary target for poachers.

To this end, the Department of Forestry, Fisheries, and the Environment in February 2024 revealed that 499 rhinos were killed for their horns in South Africa in 2023, primarily in state-run reserves.

This represents an 11% increase over the year before.

Speaking to 702, the director of the radiation and health physics unit at Wits University and lead on the project, James Larkin, explained that the process involves darting a rhino to put it to sleep while the radioisotopes are inserted into its horn.

Larkin said the animal feels no pain during the process, adding that they do not impact its health or the environment in any way.

Injecting a rhino’s horns with harmless radioactive isotopes.

To kick off the project, the team injected radioactive isotopes into the horns of 20 live rhinos.

“This is what we would call a pilot project, so we are now going to watch these animals very closely… for a period of six months, and then bright and breezy early next year, we will say to the world, here we are we’d like to help you protect your animals from predations and from poachers,” said Larkin.

If successful, the project could expand to species like elephants and pangolins.

While the dosage is low, it is strong enough to set off radioactivity detectors installed at border posts worldwide.

Larking noted that the detectors were initially installed to prevent nuclear terrorism. More than 10,000 of these detectors are installed worldwide.

When researchers first tested the concept in May 2021, the team said the technique would be offered to state and private rhino owners in Africa and globally once a proof of concept has been demonstrated.

“The intellectual property as well as training and assistance will be made freely available to conservation organisations who may wish to utilise this process to further protect their animals from poaching,” they said.

Researchers injected two rhinos with amino acids containing the radioisotopes during the initial testing.

The animals were monitored for three months after that, and various samples were taken from them and analysed to determine how the isotope interacted with the horn and the animal.

They then used computer and phantom modelling to identify the appropriate isotopes and concentrations to be used.

CEO of Rosatom Central and Southern Africa Ryan Collyer said the initiative had the potential to save rhinos from certain extinction.

“We believe that science and particularly nuclear science will play a fundamental role in not only protecting the rhino but our planet in general,” he said.