Trays at airport security stations are loaded with microbes. A new study shows they can contain more viruses than toilets.

Air travel is a well known culprit in the spread of infectious diseases, such as the common cold and the flu. We can now add another potential mechanism for the spread of these types of infections, thanks to a new study published in BMC Infection Diseases last month.

Scientists from the University of Nottingham in England and the Finnish National Institute for Health and Welfare swabbed the trays and other airport surfaces after peak travel times, then identified traces of common respiratory viruses that were found in those samples. They looked at a variety of surfaces including toilets, pay machines, hand rails and luggage trays. Of all of the surfaces that they sampled, the luggage trays contained the most identifiable traces of respiratory viruses. Out of the 8 tray samples, 4 of them were positive for respiratory viruses like rhinovirus, which causes the common cold, and influenza, or the flu. Out of the 14 samples from the toilet flush button, zero gave positive results.

We know that objects that are frequently handled or manipulated with our hands tend to be laden with bacteria. Mobile phones, tv remotes and computer keyboards have been identified as having high bacterial counts. It now appears that the same applies to airport trays.

One caveat of the study is that although traces of viral DNA were found on various surfaces, this does not necessarily mean that they were contagious or able to infect humans. However, viruses and microbes have been known to survive for a few days on surfaces.

What can you do to minimize your risk of infection? The best advice still applies:  Wash your hands!