The University of Utah (UOU) has developed a radioactive carbon dating method to prevent poachers in Africa from illegally obtaining ivory, according to a press release on the school's website.

The team of researchers' method involves using open-air nuclear bomb tests to reveal how long ago the ivory was taken from the animal. Poachers will kill elephants, rhinos, hippos and other wildlife, taking their tusks or teeth. The carbon dating will tell how long ago the animal died and whether or not the ivory was taken illegally.

"This could be used in specific cases of ivory seizures to determine when the ivory was obtained and thus whether it is legal," says geochemist Thure Cerling, senior author of the study published online the week of July 1 in the journal Proceedings of the National Academy of Sciences.

Geochemist Kevin Uno, the study's originator, performed the research for his PhD thesis at UOU and said each sample cost about $500.

"The dating method is affordable and accessible to government and law enforcement agencies," he said. "It has immediate applications to fighting the illegal sale and trade of ivory that has led to the highest rate of poaching seen in decades."

Cerling, a UOU distinguished professor of geology and geophysics, said the testing method serves purposes other than combatting illegal ivory trade.

"We've shown that you can use the signature in animal tissues left over from nuclear weapons testing in the atmosphere to study modern ecology and help us learn about fossil animals and how they lived," he said.

There was a ban on most ivory trade of Asian elephants in 1975 and African elephants in 1989, but worked ivory (jewelry, other goods) trade in the U.S. is legal. As long as the ivory was imported before 1989 or if the worked ivory was at least 100 years old, the trade was legal.

Until now, traders have not had a way to verify how old the ivory truly is.

"With an accurate age of the ivory, we can verify if the trade is legal or not," Uno said. "Currently 30,000 elephants a year are slaughtered for their tusks, so there is a desperate need to enforce the international trade ban and reduce demand."