Cocaine Money

HIGHFLYING executives and working mothers, teenagers and little old
ladies: these days everyone's handling cocaine. In most cases, though, they
don't know it. They aren't smoking it and they're not snorting it: they're
spending it. The drug is now so widespread that it has contaminated almost
every banknote in the US.

Of course, the amount of cocaine on each note is so small down in the
nano gramsthat you need sophisticated equipment to detect it at all. But
it's a gift for lawyers defending dealers and pushers. The smart ones argue
that the discovery of cocaine on their clients' cash proves nothing. And
finding cocaine on their hands is just as meaningless: it could simply have
rubbed off from "ordinary" money.

With such widespread contamination, even the skills of sniffer dogs hove
been called into question. In 1994, the 9th US Circuit Court of Appeals
ruled that police officers could not seize suspected drugs money or raid
premises just because a sniffer dog had indicated it was contaminated. They
would need better evidence than that.

Deprived of one of their weapons in the war against drugs, the FBI decided
to track down the source of the problemand find out whether it really
did invalidate the evidence. "The extent of the contamination surprised
everyone early on," says Tom Jourdan, a chemist at the FBl's laboratory in
Washington DC. "How could the bad guys have touched all that money?"

GAMING TABLES

The answer is that they haven't. Someone who has handled cocaine, then
touched money will transfer several hundred nanograms to a bill, says
Jourdan. But as the note circulates, the cocaine is spread around onto
other notes, eventually leaving a background level of a few nanograms on
each. Snorting a line of cocaine will leave as much as a milligram on the
bill. That could contaminate half a million bills with an average of 2
nanograms per bill.

Jourdan and his colleague Deborah Wang have been checking banknotes all
around the country, and from every imaginable source from respectable
banks to the gaming tables of Caesar's Palace in Las Vegas, from innercity
streets to the back routes of rural areas. They have detected cocaine on
every batch of bills examined, but nothing to compare with the amounts
found on real drug money.

In their latest study, they sampled bills ten at a time, covering the
surface with a specially adapted vacuum cleaner. Then they screened the
samples with a portable ion mobility spectrometer, an instrument that
identifies organic vapors at concentrations of less than a nanogram. If the
result is positive, they take a second sample for more accurate analysis in
the lab.

Somewhat surprisingly, banknotes from Miami, the cocaine capital of the US,
gave lower readings than those from Houston. As expected, Manhattan yuppies
had more coke on their money than the people of poor New Hyde Park, but the
bills taken straight off the gaming tables at Caesar's Palace had only a
fraction of the cocaine found on notes circulating in Las Vegas suburbs.

The FBI chemists hove also examined money from more than fifty real drug
cases. Based on their results, they are confident that finding cocaine on
money can be good evidence in court. The mere presence of the drug proves
nothing but the amount of cocaine can be incriminating. Jourdan puts an
upper limit for background contamination at 30 nanograms per bill. By
comparison, the amount of cocaine detected in criminal cases con be
stratospheric. "We have found up to 4000 nanograms per bill," he says.

So, according to Jourdun's findings, real drug money is unlikely to be
confused with innocently tainted cash. But could innocent people end up
with drugs on their hands, as some lawyers have claimed? Not even if you
handle money all day, argues Jourdon. Swabs taken from the hands of bank
clerks after four hours of handling money showed no trace of cocaine. There
is a simple explanation for this, says Jack Demirgian of the Argonne
National Laboratory in Illinois, who has scrutinized banknotes with a
scanning electron microscope. This revealed crystals of cocaine trapped in
the criss crossed fibres of the paper beneath the surface. "The cocaine is
so stuck in the fibres that it doesn't rub off easily."

So how does cocaine spread through the money supply so effectively? The
answer, says Jourdan, is that almost every banknote has been in contact
with the automatic money counting machines installed in every bank and post
office. "The machines spread the coke around," he says and he has
evidence to support this idea. The average amount of cocaine on bills is
much the same whatever the denomination. Perhaps even more convincing, the
fronts are always more contaminated than the backs. Because humans are
creatures of habit, they invariably load the counters with all the bills
stacked the same way, their faces in contact with the machine's rollers.

The casual contact of fingers may not be enough to loosen the cocaine, says
Demirgian, but the action of the rollers in a currency counter is violent
enough to strip off some of the surface fibres of paper, exposing and
picking up the cocaine below.

And what about those sniffer dogs? Is there really so much cocaine about
that they can no longer make an accurate hit? Not according to Ken Furton
at Florida International University in Miami.

In lab tests with wads of money spiked with varying amounts of cocaine, 15
dogs failed to detect cocaine at the levels found on money in general
circulation. Sniffer dogs do not respond to cocaine itself, explains
Furton, but to a volatile breakdown product, methylbenzoate. This does not
form in pharmaceuticulsgrade cocaine, which dogs will ignore even in large
quantities. But streetgrade cocaine generally contains about 10 per cent
methylbenzoate.

None of the dogs responded to less than a microgram of
methylbenzoatesuggesting that it would require far more cocaine than you
would find on "innocent" money to trigger an alert. With money handled in
the normal wayin small numbers of notes at a timethe volatile
component of coke quickly disappears. In large wads of notes, the coke is
trapped and methylbenzoate lingers far longer.

"No one has found methylbenzoate on circulating notes so it's unlikely dogs
will react to ordinary money," says Furton. "If a dog responds then there
must be a significant amount of narcotic odor. Dogs are sensitivebut
only to a degreeso you shouldn't get false alerts."