I guesstimate the deal is not negligible.
Input to my intuition:
a study identified over a hundred different strains of bacteria on dollar bills
Traces of cocaine can be found on almost 80 percent of dollar bills.
(source http://theconversation.com/atms-dispense-more-than-money-the-dirt-and-dope-thats-on-your-cash-79624 )
A powder called Glo Germ, meant to visualize germ spread, was still visible to the naked eye after 8 handshakes (but not 9) in an informal experiment by YouTuber Mark Rober. ( https://youtu.be/I5-dI74zxPg?t=346 )
I guesstimate the deal is not negligible.
Input to my intuition:
(source http://theconversation.com/atms-dispense-more-than-money-the-dirt-and-dope-thats-on-your-cash-79624 )
A powder called Glo Germ, meant to visualize germ spread, was still visible to the naked eye after 8 handshakes (but not 9) in an informal experiment by YouTuber Mark Rober. ( https://youtu.be/I5-dI74zxPg?t=346 )