SCIENTISTS TRACK ORIGINS OF COCAINE

LONDON (Reuters) - Science is closing in fast on international drug cartels.

U.S. researchers said on Wednesday they had devised an accurate method of
tracing cocaine back to its country of origin, giving drug enforcement
officials a powerful new weapon in their battle against traffickers.

"Science is catching up," James Ehleringer, of the University of Utah, told
Reuters in an interview.

"We can tell who is pushing what."

By examining the so-called fingerprint of cocaine the scientists can tell
where it came from, if a country is in compliance with drug regulations and
whether or not the narcotics originated in the country where they were
confiscated.

The technique will also help officials to reconstruct trade routes, tell if
two samples have a common origin and identity new cocaine producing regions
as they develop.

The manufacturing process that transform the coca leaves into the narcotics
peddled on city streets does not alter the fingerprint.

Much like human DNA fingerprints, cocaine and other drugs like morphine and
heroin have a distinct makeup.

But instead of looking at DNA, the scientists search for environmental
signatures that determine the isotope ratios of carbon and nitrogen in cocaine.

"We've identified a fingerprint but we can't explain how we get the
fingerprint, only that the fingerprint seems to be reliable," said
Ehleringer, whose research is published in the science journal Nature.

He and his colleagues think soil composition, humidity and the length of
the dry season influence the fingerprint.

"All these things are contributing to specific isotopes and basically what
you have is a fingerprint plot, and the combination of environment and soil
appear to be unique for a location," he added.

About 99 percent of the world's cocaine comes from Colombia, Bolivia and
Peru. The scientists, who work closely with the U.S. Drug Enforcement
Agency, can trace cocaine back to specific regions.

"If a piece of material (cocaine) comes in we have a pretty good
probability of what country it originated from," said Ehleringer.