Plastic security trays harbour the highest levels of viruses at airports, a study has found.

Pandemic experts found evidence of viruses on 10% of airport surfaces tested – which also included shop payment terminals, staircase rails, passport-checking counters and children’s play areas.

The various surfaces were swabbed at Helsinki airport at peak time as part of a scientific investigation carried out by experts from the University of Nottingham and the Finnish national institute for health and welfare during the winter of 2016.

The research discovered viruses were most commonly found on the plastic trays that are circulated along the passenger queue at the hand luggage X-ray checkpoint.

Experts concluded that hand-washing and careful coughing hygiene are crucial to the control of contagious infections in public areas with high volumes of people passing through.

The University of Nottingham said the most common virus found in the survey was rhinovirus, which causes the common cold, while the swabs also picked up the influenza A virus.

No respiratory viruses were found on toilet surfaces.

Professor of health protection Jonathan Van Tam, from the university’s school of medicine, said: “This study supports the case for improved public awareness of how viral infections spread.

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

“These simple precautions can help prevent pandemics and are most important in crowded areas like airports that have a high volume of people travelling to and from many different parts of the world.”

Virology expert Niina Ikonen from the Finnish national institute for health and welfare said: “The presence of microbes in the environment of an airport has not been investigated previously.

“The new findings support preparedness planning for controlling the spread of serious infectious diseases in airports. The results also provide new ideas for technical improvements in airport design and refurbishment.”