The cash register receipts that people place near paper money in billfolds, purses, and pockets has led to a worldwide contamination of paper money with bisphenol A (BPA) — a potentially toxic substance found in some plastics, thermal paper and other products.
The amounts of BPA on dollars, Euros, rubles, yuans, and other currencies, are higher than in house dust, but human intake from currency is at least 10 times less than those from house dust. That's the conclusion of a study in the ACS' journal Environmental Science & Technology.
Kannan and Liao also found that the most likely source of the BPA in the currency is the thermal paper used in cash register receipts. They showed that receipts can transfer BPA onto cash when placed next to it or when a receipt is touched before handling currency.
"Although high levels of BPA were measured in paper currencies, human exposure through dermal [skin] absorption appears to be minor," the article notes. - (EurekAlert!, August 2011)