A recent study suggests 90% of all U.S. currency have traces of drugs on them.

Scientists say the amount of cocaine found on bills is not enough to cause health risks.
Money can be contaminated with cocaine during drug deals or if a user snorts with a bill. But not all bills are involved in drug use; they can get contaminated inside currency-counting machines at the bank. "When the machine gets contaminated, it transfers the cocaine to the other bank notes," Zuo said. These bills have fewer remnants of cocaine. Some of the dollars in his experiment had .006 micrograms, which is several thousands of times smaller than a single grain of sand. Zuo, who spoke about his research at the national meeting of the American Chemical Society on Sunday, found that $5, $10, $20 and $50 bills were more likely to be positive for cocaine than $1 bills. "Probably $1 is a little too less to purchase cocaine," Zuo said "I don't know exactly [why]. It's an educated guess." For years, health agencies have advised people to wash their hands after touching cash for sanitary reasons. Disease-causing organisms such as staphylococcus aureus and pneumonia-causing bacteria have been detected in paper bills. According to a 2002 study published in the Southern Medical Journal, 94 percent of the tested bills had potentially disease-causing organisms.

Bills turned up positive for cocaine in these percentages in certain cities:

100 percent: Detroit, Michigan; Boston, Massachusetts; Orlando, Florida; Miami, Florida; Los Angeles, California.

88 percent: Toronto, Canada.

77 percent: Salt Lake City, Utah.

75 percent: Brasilia, Brazil.

20 percent: Tokyo, Japan; Beijing, China.


Link: http://www.cnn.com/2009/HEALTH/08/14/cocaine.traces.money/index.html?HI_BILLY_MAYS_HERE