Money laundering has new meaning
VI TAR ENDAST EMOT KORT INGA KONTANTER
“We only accept cards, no cash” reads a sign outside a coffee shop in Stockholm. Sweden often is cited as leading the charge to a “cashless society” with just a quarter of its population using cash at least once a week and fully 85 percent of those between the ages of 16 and 74 doing their banking online.
According to a July 2018 article in Forbes magazine, the Riksbank, Sweden’s central bank, reported that cash-based purchases in the country’s retail sector dropped from 40 percent in 2010 to 15 percent in 2016, and half of the country’s banks no longer allow deposits or withdrawals in cash.
But the Swedes are by no means alone. Last July, the British daily, the Guardian, led off an opinion piece with the quote, “All over the western world, banks are shutting down cash machines and branches.”
Banks commonly market their move away from cash and toward their electronic financial services as a response to customers’ demand for greater convenience — a plastic card and a smartphone instead of a wad of bills. They also tout reduction in cash-related crimes, fraud protection and, almost as an afterthought, “protecting our employees against diseases carried by paper currency.”
Sounds reasonable. What’s actually known about the germs in our wallets?
Firstly, American bills are not paper. They’re 75 percent cotton and 25 percent linen (with a scattering of red and blue security fibers) and their porous surface provides a great hiding place for bacteria and other pathogens — better than the plastic polymer banknotes of Canada and Australia. On the other hand, the low moisture and variable temperatures experienced by a typical bill in circulation are problems for most microbes.
In a 2013 study, researchers from New York University swabbed 40 $1 bills from a Manhattan bank, half in February and half in June. Using the evocatively named shotgun metagenomics method (allowing the identification of organisms by analyzing all the DNA from a sample in one go), they found 397 species of bacteria (385 in winter, 149 in summer), almost all of which belonged to groups found naturally on human skin.
The most abundant of these, in both seasons, was Propionibacterium acnes, the most common bacteria on human skin and, as suggested by its name, one especially frequent on oily skin giving rise to acne.
A 2014 overview of virtually all studies on the biota of money (and there haven’t been as many as you might expect) found that disease-causing bacteria, fungi, viruses and protozoans are not infrequently found on “paper” money. (Interestingly, the copper content of many coins seems to reduce their pathogen loads.)
Although there’s been no clear-cut demonstration that money has actually made people sick, laboratory studies have shown that many of these pathogens can be transferred from hand to hand when cash is exchanged.
Other work has shown that banknotes tend to carry especially high pathogen loads where food handlers and medical staff are slack in their sanitary habits. Unsurprisingly, bills harboring microorganisms causing diarrhea, pneumonia, urinary and reproductive system infections and viruses causing colds and influenza are more commonly encountered in such environments when rigorous hand washing is not practiced.
But to keep things in perspective, it’s important to understand that human skin is remarkably effective at protecting us against invasive pathogens. Most authorities agree you’re generally safe to tuck that twenty in your purse even though it’s passed through thousands of hands during its average 7.9 years in circulation. Just so long as you remember Mom’s admonition: “Did you wash your hands before coming to the table?”
So, what about cash? Is it a totally outmoded medium for transactions that should be eliminated?
Kenneth Rogoff, former chief economist at the International Monetary Fund, long has been a strong advocate for phasing out paper money. In his 2016 “The Curse of Cash,” he recommends beginning with the largest denomination, the $100 bill. Nearly 80 percent of the 1.4 trillion U.S. dollars in circulation, he notes, are $100 banknotes — and of these, almost two-thirds are abroad.
Harvard’s Peter Sands argues it’s not difficult to guess where those bills find their greatest use. “Drug trafficking is the biggest driver of illegal financial flows and a major source of terrorism. And drug trafficking always ends up in cash at some point in the chain.”
A million dollars in $100 dollar bills fits in a shopping bag; the same amount in $10 bills weighs 220 pounds.
But advocates of the greenback and its cousins around the world point out that when all transactions are digitized, all transactions are known. And besides questions of privacy and security, there are important equity issues; what about those too poor, too computer-illiterate or too plain cantankerous to enroll in the cashless society?
Ken Baker is a scientist and a retired biology professor. If you have a natural history topic you’d like the author to consider for an upcoming column, email your idea to email@example.com.