You don't need to be told that airports are pretty dirty places. One trip to the bathroom is all the confirmation you need.

But what, if anything, could possibly be dirtier than an airport toilet? According to a 2018 study, self-check-in kiosks far surpassed toilets as the dirtiest surface in the airport, with an average of 253,857 colony-forming units (CFU) per square inch, compared to an average of 172 CFU found on toilets. That's a huge difference!

The study, conducted by InsuranceQuotes.com, tested six surfaces across three major U.S. airports, including Atlanta Hartsfield where one kiosk was found to contain over 1 million CFU.

Coming in at 2nd place, the armrests at the gate measured an average of 21,630 CFU, followed by the water fountain push-button with 19,181 CFU.

Things aren't much better once you board the plane, with lavatory flush buttons measuring 95,145 CFU, tray tables with 11,595 CFU, and seat belts with 1,116 CFU.

To put those numbers in perspective, the average household toilet handle has an average of only 30 CFU.

Before you zip up your hazmat suit, it's worth noting that not all of the bacteria that turned up in these tests were bad. Some are exactly the type our bodies need to keep our natural defenses in check. But that's only a small percentage and certainly excludes check-in kiosks, which were revealed to contain the largest collection of bacteria most likely to make us sick.

So the next time you find yourself standing in front of a streaky germ-laden kiosk touchscreen, you might consider pulling your sleeve over your hand or opt for checking-in directly with an agent. Whatever you do, better bring a lot of hand sanitizer.