A new study says that plastic trays that passengers put their hand luggage in at security checkpoints have the highest numbers of viruses of anywhere in an airport, including toilets.
According to the study, the trays are covered in pathogens that can cause everything from common cold to flu, pneumonia, bladder infection, SARS and even brain damage.
The study says that plastic trays are thought to carry high numbers of viruses due to them being rapidly reused, as well as being touched by every single passenger that passes through an airport.
Such trays are also rarely disinfected, with their hard surfaces allowing viruses to survive for up to a day.
The researchers, from the University of Nottingham, collected surface and air samples three times over as many weeks from a variety of sites at Helsinki-Vantaa airport, Finland.
Samples were collected immediately after peak times - 7-9am, 11am-midday and 2-4pm - before the sites were cleaned.
Researchers tested the toilets, including the lid, flush and lock; plastic trays at security checking areas; armrests of chairs in waiting areas; handrails of stairs and escalators; plastic toys in a children's play area; luggage trolley handles; lift and payment terminal buttons; check-in machine screens and desk and glass dividers at passport control
The study saw respiratory viruses beingdetected in 10 per cent of surface and 25 per cent of air samples.
As well as being on plastic trays, pathogens were also detected in the children's play area, payment terminals, handrails and at passport control.
Viruses were not detected in most of the samples collected from toilets, which the scientists believe may be due to people paying particular attention to hand hygiene when in the airport.
The results of the study, published in the journal BMC Infectious Diseases, suggest influenza A, a strain of flu, and rhinovirus, which causes the common cold, are both present on plastic trays at security checkpoints.
Researchers also found adenovirus, which can lead to a sore throat, bronchitis, pneumonia, diarrhoea, pink eye, bladder infections, fever, stomach inflammation and even brain damage.
They even found coronavirus, which has been linked to cold-like symptoms; MERS or 'camel flu', which can cause life-threatening kidney failure; and SARS, which often progresses to pneumonia.
Although such conditions may not affect healthy people, the elderly, young or those with a weak immune system may be vulnerable.