Frequent flyers accept that exposure to germs is unavoidable. But they also know there are some things you can do to minimize your risk at 30,000 feet.

Armrests tops the list of things to avoid.

Also on the list of things you should avoid touching: tray tables. A 2007 study revealed four in six tested positive for MRSA bacteria and noroviruses.

Rounding out the list of things you shouldn’t touch on a plane: The inside door handle of the restroom, the restroom faucet handles, the toilet flushing button, blankets and the toilet seat.

Let’s quantify just how gross things really are!

Meanwhile, another study from quantified just how gross things are on an airplane and at the airport.

Germs are the worst on the tray table, according to the TravelMath research. In fact, tray tables are 8 times more filthy than the air vent above you and 9 times dirtier than the toilet flush button!

The cleanest thing of all on an airplane? The seatbelt buckle!

In the airport itself, the dirtiest thing is the button on the drinking fountain. It is 18 times more germy than the lock on the bathroom stall in the airport terminal! To put that in context, the average kitchen counter is about 5 times more germy than the stall lock in the airport.

Notice the common denominator there: Areas involved with consuming and/or preparing food are much nastier than even the bathroom. Who would have thought that?