By safely inserting radioisotopes into the horns of live rhinos, the project will make the sought-after horns detectable by an estimated 10,000 radiation portal monitors that are already deployed and in use at border checkpoints, shipping ports, and airports across the world.
The issue: According to the International Rhino Foundation’s 2024 State of the Rhino report, Africa saw a 4 percent increase in poaching from 2022–2023 and the killing of at least 586 rhinos. There are fewer than 28,000 left in the world, with three of the five species qualifying for critically endangered status—the last stop before extinction—on the International Union for Conservation of Nature’s Red List. IRF estimates that there are fewer than 50 Sumatran and Javan rhinos remaining worldwide.
Antipoaching efforts today range from boots-on-the-ground armed rangers to flooding the market with fake horns. Despite these efforts, the South African Ministry of Forestry, Fisheries, and the Environment reported that 103 rhinos were poached in the first quarter of 2025 alone.
The solution: The Rhisotope Project is the next step in protecting the species by capitalizing on existing infrastructure to massively increase the detectability of trafficked horns.
The insertion of radioisotopes into the horns, while harmless to the rhino, also devalues the product to both the poacher and the end user. “No one wants a radioactive horn,” explained James Larkin, director of radiation and health physics at the University of Witwatersrand, who also hopes that the core methodology of the project can be eventually adapted to protect “other endangered species like elephants or pangolins.”
According to the project’s website, 30 rhinos have been treated so far, with a treatment goal of 180 by the end of 2025.
Quotable: “The Rhisotope Project shows how nuclear science and nuclear security infrastructure can be used in new ways to address global challenges. The IAEA is supporting countries to maximize the benefits of nuclear. By using already installed nuclear security infrastructure in novel ways, we can help protect one of the world’s most iconic and endangered species,” said Rafael Mariano Grossi, director general of the IAEA.
