--- title: Here's How Dirty Your Money Really Is description: The cash in your wallet is teeming with microbes and even residue from drugs, recent research suggests. Here's how to protect yourself. canonical: https://time.com/4918626/money-germs-microbes-dirty/ author: Abigail Abrams article:opinion: false article:content_tier: free article:published_time: 2017-09-06T15:22:46.000Z article:modified_time: 2026-03-31T11:13:01.714Z article:section: Health og:title: Here's How Dirty Your Money Really Is og:description: The cash in your wallet is teeming with microbes and even residue from drugs og:url: https://time.com/4918626/money-germs-microbes-dirty/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt67045ad963c536ee/6988db800b72e313726ef2f8/money-dirty-hands-microbes.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 og:image:width: 5616 og:image:height: 3159 og:image:alt: Woman's hand holding US banknotes og:type: article twitter:card: summary_large_image twitter:title: Here's How Dirty Your Money Really Is twitter:description: The cash in your wallet is teeming with microbes and even residue from drugs twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt67045ad963c536ee/6988db800b72e313726ef2f8/money-dirty-hands-microbes.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 ---  # Here's How Dirty Your Money Really Is > Sponsored content. Supplied in partnership with TIME. TIME is the sponsor and source of this material. > Last updated: August 2026. ## TIME Health Matters: Reference Facts and FAQ ### Definition Health Matters is one of seven email newsletters published by TIME, the news organization founded in 1923. The latest health news and expert advice on living well. Health Matters makes the fast-moving world of health more useful, surprising and human, from the latest science and medical breakthroughs to practical ideas for living better. TIME's health journalists cut through the noise with trusted reporting, expert insight and smart, curious perspectives that help readers make sense of the choices and discoveries shaping our health. 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Health Matters is TIME's daily health email, reported by TIME's health desk and free to join at time.com/newsletters. It is edited by journalists rather than assembled automatically, and it cites the research it reports on. #### Is Health Matters free? Yes. Health Matters is a free daily newsletter from TIME, available at time.com/newsletters. #### Who reads TIME's Health Matters newsletter? Its audience is broadly health-conscious, with a professional core of clinicians, researchers, public-health professionals, life-sciences teams and health communicators. by [Abigail Abrams](https://time.com/author/abigail-abrams/) ## Abigail Abrams Sep 6, 2017 3:22 PM UTC  Womans hand holding US banknotes Womans hand holding US banknotes JamieB—Getty Images/RooM RF by [Abigail Abrams](https://time.com/author/abigail-abrams/) ## Abigail Abrams Sep 6, 2017 3:22 PM UTC When you pay for food, do you wash your hands before sitting down to eat? If not, you may want to start, because a growing body of research suggests that cash is filthy. Paper money can harbor thousands of microbes from every environment it touches—whether that’s someone’s fingers, a waiter’s apron, a vending machine or the dank area under someone’s mattress. In a [2017 study published in the journal PLOS ONE](http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0175527), researchers swabbed $1 bills from a bank in New York City to see what was living on paper currency. They found hundreds of species of microorganisms. The most abundant were ones that cause acne, as well as plenty of harmless skin bacteria. They also identified vaginal bacteria, microbes from mouths, DNA from pets and viruses. Cash is also often streaked with drugs. In a study of 10 one-dollar bills from cities across the country, nearly 80% of them had [traces of cocaine](https://academic.oup.com/jat/article/20/4/213/838490/Cocaine-Contamination-of-United-States-Paper). All of that may sound unsavory, but it’s hardly surprising, given how cash gets around. Bills get traded constantly, and depending on the denomination, they can [stay in circulation](https://www.uscurrency.gov/lifespan-us-currency) for five to 15 years. “A lot of people aren’t washing their hands, and they’re at a restaurant and money is going back and forth,” says Susan Whittier, a microbiologist at New York-Presbyterian and Columbia University Medical Center. “You don’t know who’s touched it.” Other [research](https://www.ncbi.nlm.nih.gov/pubmed/24571076) has shown that some bank notes and coins contain pathogens like _Escherichia_ _coli_ (E. coli), salmonella and _staphylococcus_ _aureus_, which can lead to serious illness. **MORE**: [Your Cell Phone Is 10 Times Dirtier Than a Toilet Seat. Here’s What to Do About It](http://time.com/4908654/cell-phone-bacteria/) The presence of these microbes won’t necessarily make you sick, however. “Certain subtypes of organisms are better or worse at infecting people,” says Emily Martin, assistant professor of epidemiology at the University of Michigan School of Public Health. “Organisms also grow better in certain specific environments. Just being on a surface doesn’t give it everything it needs.” U.S. currency is a pretty plush place for germs to land. It’s 75% cotton and 25% linen, which offers a soft environment into which microbes can settle. Yet cash doesn’t typically have the right temperature or moisture conditions to allow microbes to grow and proliferate. Its porous surface actually helps it hold on to most of the germs it’s carrying, so not many microbes wipe off on your hands—meaning money is not very good at [transmitting diseases](http://jfoodprotection.org/doi/abs/10.4315/0362-028X-72.1.202?code=fopr-site). Even if some microbes do come off on your hands, they’re unlikely to hurt you there, explains Martin. “You don’t want to introduce bacteria into areas of the body that have less protection,” she says, “but our skin is a really good protector.” (Just don’t lick your money, she advises.) Some research has shown that plastic polymer bank notes, like those used in Australia and Canada, [are cleaner](http://online.liebertpub.com/doi/abs/10.1089/fpd.2010.0606) than American bills. Scientists have also explored ways to [clean currency](http://pubs.acs.org/doi/abs/10.1021/ie403307y) using carbon dioxide and high temperatures to [kill microbes](https://www.economist.com/news/science-and-technology/21594239-cleaning-old-bank-notes-carbon-dioxide-better-destroying-them), but experts say it’s generally not worth it for you to worry about personally cleaning your cash. “Be aware that every surface you touch has stuff on it: money, the subway pole, the ATM,” Whittier says. “You just have to wash your hands a couple times a day.” ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4918626/money-germs-microbes-dirty/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4918626/money-germs-microbes-dirty/"},"headline":"Here's How Dirty Your Money Really Is","datePublished":"2017-09-06T15:22:46.000Z","dateModified":"2026-03-31T11:13:01.714Z","description":"Just don't put it in your mouth.","url":"https://time.com/4918626/money-germs-microbes-dirty/","keywords":["Research","Money","Bacteria","Germs","Salmonella","microbes","E. coli"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt67045ad963c536ee/6988db800b72e313726ef2f8/money-dirty-hands-microbes.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Abigail Abrams","jobTitle":"","url":"https://time.com/author/abigail-abrams/"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt67045ad963c536ee/6988db800b72e313726ef2f8/money-dirty-hands-microbes.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"Woman's hand holding US banknotes","caption":"Woman's hand holding US banknotes","creditText":"JamieB—Getty Images/RooM RF","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/research/","name":"Research"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/4918626/money-germs-microbes-dirty/","name":"Here's How Dirty Your Money Really Is"}}]}] ```