Why greenbacks make good drug money

Where there's money, there's cocaine.

 This aphorism doesn't just indicate the extent to which modern culture has embraced mood-altering drugs it's a fact. Fully 78 percent of the $1 bills circulating in Miami carry traces of cocaine, a federally funded study has found. So do similar shares of singles in Houston and Chicago. The only difference is that Miami's currency tends to carry more of the white powder.

 In conducting the analyses that established those numbers, Jack Demirgian of Argonne (Ill.) National Laboratory (ANL) and his colleagues handled hundreds of cocaine-tainted bills some bearing as much as 1 milligram each. Yet while the chemists' skin readily absorbed cocaine from other contaminated items, it never picked up the drug from dollars.

 To figure out why, Demirgian enlisted the help of Benjamin S. Tani, also of ANL, to study the bills with scanning electron microscopy. They saw no cocaine on the bills' surface; instead, they found it wedged in the nooks and crannies below.

 Magnified, the currency's linen fibers "look almost like hacksaw blades," Demirgian notes. "We think that cocaine particles on the surface become fractured by the natural bending of the bills" and fall into the irregular holes formed by the money's fibers. British paper currency, which his team examined this summer, has more rounded fibers and far smaller holes none apparently large enough for the cocaine crystals to enter.

"I think this study showed that [U.S.] money does like to hold onto the drugs that it comes into contact with," says Kent Lunsford of the Office of National Drug Control Policy in Washington, D.C. The finding, he says, seems to undermine the argument many lawyers had been tendering: that clients caught with cocaine on their hands had innocently picked it up from money.