Look closely at the paper money in your wallet or purse. You can't see what lies just beneath the surface. But under a scanning electron microscope, there could be a surprise. Tiny flecks of cocaine. While it was known previously that some paper money contained cocaine, studies have now shown that its presence is surprisingly widespread.
Cocaine can easily spread to money, which changes hands quickly.
For law-abiding citizens, the minuscule amount of the drug on their bills is harmless. Money from both Miami and Houston tended to have higher amounts. Law-abiding citizens need not be concerned with the minuscule amount of the drug found on most bills. But the study findings do pose a challenge to current methods used in prosecuting drug cases, where officials are allowed to seize money used in drug transactions. The presence of the cocaine in so much money is partly a reflection of the penetration of cocaine use into American society.