Germs in the air, germs on the seats, germs in the washroom. But when it comes to the airport, what surface do you suppose is the yuckiest? The plastic trays that you put your carry-ons in at security checkpoints have the highest numbers of viruses of anywhere in an airport, according to new research. Even more than the toilet. Yes, those innocent-looking containers that aren’t unlike a dishpan, where you trustingly set your purse, your phone, probably even your snacks, are covered in pathogens that can cause everything from the common cold and flu to pneumonia.