Carbon residue from nuclear bomb testing can be used to help authorities figure out if ivory being sold has been illegally poached.

Carbon residue from nuclear bomb testing can be used to help authorities figure out if ivory being sold has been illegally poached.

Nuclear bomb tests during the Cold War left behind radioactive carbon in the atmosphere that made its way into the tissue of animals, including elephant tusks.

Researchers from the University of Michigan along with a former University of Utah researcher have studied the levels of radioactive carbon in ivory and determined they can date the tusks to see if they were obtained before or after the ivory trading ban of 1989.

The demand for ivory is increasing in Asian countries and that is driving up the number of elephants that are being poached for their tusks.

Daniel Fisher, a paleontologist from University of Michigan who worked on the study said: “Not only can this method help wildlife forensics to combat poaching, but it's also provided conclusive validation of earlier work that had suggested that tusks and many teeth are made of layers that reflect consecutive years in the life of the animal that grew them.”