High levels of BPA found in paper currencies

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 new study in the ACS' journal Environmental Science & Technology.

Kurunthachalam Kannan and Chunyang Liao point out that manufacturers use BPA to make polycarbonate plastics used in some consumer products, including water bottles, sports equipment, and household electronics. Studies indicate that BPA acts as an endocrine disruptor - meaning it mimics the action of the sex hormone estrogen. Exposure to BPA has been linked to a variety of health problems. Although a recent study found traces of BPA in U.S. currency, nobody knew until now about BPA in paper money worldwide.

The scientists' analysis of 156 pieces of paper money from 21 countries found that all contained traces of BPA. The report notes, however, that "estimated daily intake from paper currencies were 10-fold lower than those reported from exposures due to [indoor] dust ingestion in the United States." The highest BPA levels were in paper money from Brazil, the Czech Republic and Australia, while the lowest occurred in paper money from the Philippines, Thailand, and Vietnam. Levels in U.S. notes were about average.

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.