If you’ve ever fallen sick while travelling, chances are that you should blame your time passing through security, a small study suggests.

The report published by Finnish and British researchers found that 50 per cent of plastic security bins at one airport tested positive for nucleic acids of respiratory viruses. The bins, which all passengers with carry-on luggage are required to use, were the most virus-prone area in the airport.

The research, published last Wednesday in the BioMed Central Infectious Diseases journal, tested various surfaces within Helsinki-Vantaa airport, Finland’s largest airport, over several weeks at the peak of the European country’s flu season.

Researchers collected 90 samples from 13 different surfaces. They timed the testing so that the surfaces sampled would not have had time to be cleaned after being handled by passengers.

Researchers found that bathrooms were among the least likely places to be contaminated. Toilet bowl lids, toilet flush buttons and the locks inside toilet stalls all came back negative for respiratory viruses.

The security area was a different story. Researchers swabbed eight different hand-carried luggage boxes. Four different types of respiratory viruses were detected.

Researchers also tested the air inside the security check area on four occasions. On one occasion, they detected adenovirus, which can cause a range of illnesses, including colds, bronchitis and pneumonia.

The prevalence of contamination could be due to the high turnover rate of the bins, researchers say, or the fact that the non-porous surface allows the virus to survive for a longer time.

The solution could be stricter rules around cleanliness in the security area, researchers suggest.

“Security trays are highly likely to be handled by all embarking passengers at airports; nevertheless the risk of this procedure could be reduced by offering hand sanitization with alcohol handrub before and after security screening, and increasing the frequency of tray disinfection,” the researchers wrote.

Other areas that tested positive included a handrail for stairs, a plastic toy in the children’s playground and payment buttons at an airport pharmacy.

Areas that tested negative included an armrest of a chair, escalator handrails, elevator buttons and the touch-screen of a check-in machine.