(CNN) — What's the most germ-filled spot in an airport? The bathrooms? Those crowded waiting areas? The passport checking counter?

Surprisingly, none of the above.

A new study from a team of experts from the UK's University of Nottingham and the Finnish National Institute for Health and Welfare, published in the BMC Infectious Diseases journal, has revealed those airport security plastic trays are the biggest culprit for spreading germs in airports.

So next time you're dumping your phone, passport and laptop into the tray -- it might be worth having the hand sanitizer handy.

Revealing study

The team monitored germ levels on a variety of surfaces at Helsinki-Vantaa airport in Finland during the winter of 2016.

Germaphobes who travel will be horrified to find out they found evidence of viruses on 10% of all the surfaces they tested. Other germ hotspots were shop payment terminals, staircase rails, passport checking counters, children's play areas and -- unavoidably -- in the air.

There was evidence of rhinovirus -- the cause of the common cold -- plus some signs of influenza.

Surprisingly, their swabs didn't detect respiratory viruses on the toilet surfaces.

"This study supports the case for improved public awareness of how viral infections spread," said Professor of Health Protection, Jonathan Van Tram, from the School of Medicine at the University of Nottingham, in a statement.

"People can help to minimize contagion by hygienic hand washing and coughing into a handkerchief, tissue or sleeve at all times but especially in public places."

Next time you're dumping your stuff in the security trays, best have that hand sanitzer nearby. Alex Wong/Getty Images North America/Getty Images

His team-partner, virology expert Niina Ikonen from the Finnish National Institute for Health and Welfare, added: "The results also provide new ideas for technical improvements in airport design and refurbishment."

At the end of the study, the team suggest that airports could provide "hand sanitization opportunities where intense, repeat touching of surfaces takes place such as immediately before and after security screening."

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It's also suggested that the trays -- and other frequently touched surfaces -- could be cleaned more regularly.

The study pointed out that handling the plastic security trays is almost inevitable for travelers -- unlike using airport store payment points, for example.

On board

Even if you avoid airport germs, previous studies have shown airplanes are equally as dirty.

2015 study from Travelmath reported that the tray table was the number one offender, with overhead air vents also among the most germ-filled surfaces.

Of course, interacting with these surfaces, whether before you fly or on board, is no guarantee of picking up a virus.