By Raymond Fang

Quick, take a guess—how many times do you think you touch your cell phone every day? 50? 100? 200? Wrong. How about over 2,000? That’s right, according to a report from the research firm Dscout, the average American touches their cell phone at least 2,617 times a day. To get this number, the researchers recruited 94 Android users and installed an app on their phones that tracked “every tap, type, swipe and click,” 24 hours a day, for five days straight. Then they divided the total number of touches recorded by the app by the number of days and the number of users to get the average number of touches per person per day—2,617. If you consider the number of times you touch your phone every day in addition to tapping, typing, swiping, and clicking—to pick it up, to put it in your pocket, to check the time, to charge it, and so on—the actual number of touches is probably even higher than 2,617. But why does any of this matter?

To put it simply, cell phones are dirty. Very, very dirty. One study found that cell phones carry 10 times more bacteria than toilet seats. Though most of these bacteria are perfectly harmless because they originate from your skin and your natural skin oils, researchers have still found dangerous bacteria like streptococcus, MRSA, and E. coli on cell phones. Another study found that roughly one out of every six smartphones has traces of fecal matter on it. Yet another study found “between about 2,700 and 4,200 units of coliform bacteria,” an indicator of fecal contamination, on eight randomly tested cell phones. For comparison, in drinking water it’s recommended that the water have less than one unit of coliform bacteria per ml of water. Much of this bacteria accrues either when you touch something dirty with your hands and then touch your phone (such as if you take out the trash and then use your phone afterwards without washing your hands), or when you expose your phone to a dirty environment (such as if you bring your phone into the bathroom with you, since flushing the toilet releases germs into the nearby environment).

So, if your cell phone is potentially harboring all sorts of nasty bacteria, what can you do about it? While some companies sell $60 UV light-emitting-devices that claim to kill 99% of the bacteria on your phone, the best and most economical solution is probably to wash your hands regularly several times a day, leave your phone out of the bathroom, and wipe down your phone with a moist microfiber cloth daily. If you’re really committed to sanitizing your phone, you can also create a 1:1 water and 70% isopropyl alcohol mix, spray it onto a microfiber cloth, and wipe down your phone with the isopropyl-alcohol-dampened microfiber cloth every week. This is the method that is effective for eliminating more dangerous and enduring bacteria like “clostridium difficile (which can cause diarrhea or even inflammation of the colon) and flu viruses” that will not yield to a microfiber cloth moistened only with water. Although Apple’s website warns against using “window cleaners, household cleaners, compressed air, aerosol sprays, solvents, ammonia, or abrasives” to clean your phone, researchers found that the isopropyl alcohol mixture is necessary to eliminate the more pesky and dangerous bacteria. While it may be yet another chore to complete, regular phone cleaning can help provide peace of mind and prevent the spread of germs and disease. Happy spring cleaning!

Raymond Fang, who has a B.A. in Anthropology and the History, Philosophy, & Social Studies of Science and Medicine from the University of Chicago, is a member of the ISLAT team.