Carbon dating problem
Between 1945 to 1980, testing atomic bombs in the atmosphere was a dangerous experiment in spreading carcinogens literally to the four winds.
But little noted outside science, the radioactive elements created in the tests became radiologic calendars waiting to be used in any organism that incorporates carbon.
Carbon-14 was one of the many radioactive isotopes formed during the instant of nuclear fission and fusion.
An atom of C-14 has two more neutrons than the common C-12.
Because both isotopes are chemically identical, they enter the same biological reactions.
And since C-14 decays over time, the level in the sample can be traced back to the high level of C-14 in the air during the atom-bomb tests.
The result shows when a living animal was eating food contaminated with bomb fallout.
This technique, called carbon dating, was traditionally used to date archeological sites from long before the nuclear era.
A study published this week shows the potential for carbon-dating teeth and ivory tusks from elephants.Thure Cerling, a professor of geology, geophysics and biology of the University of Utah, an expert on carbon dating, was interested in dating ancient bone and ivory samples from Kenya.To explore how carbon had entered the material, Cerling and graduate student (and now Ph. In collaboration with Wildlife Kenya, Cerling says, “We were putting GPS collars on the elephants, and I had tools to help them understand what the elephants were eating, using isotopes as traces.” In the mid-2000s, after an animal they were tracking died, Kenya Wildlife gave permission to examine the tusks.“We weren’t really thinking of ivory poaching,” Cerling says.
“We were interested in how the molar teeth and ivory incorporate isotopes, but as we were doing the study, poaching got worse, and it was quite clear that this could also address the poaching problem.” By the 1990s, market restrictions, international law and social attitudes had brought a steep decline in the demand for ivory in the principal markets of North America and Europe.
“It very quickly became socially unacceptable to have ivory,” says Cerling .” Now that people in China and Southeast Asia can afford ivory, elephant killings, corruption and illegal export are booming.