In case travelers needed another reason to dislike the Transportation Security Administration (TSA), a new study shows that one of the dirtiest parts of the airport can be found in the security line.

Researchers swabbed various surfaces at the Helsinki Airport in Finland, looking for lingering respiratory viruses. The study, reported in the journal BMC Infectious Diseases, found that "plastic security screening trays appeared to pose the highest potential risk" of communicating viral ailments such as the common cold. Viruses appeared in nearly half of the plastic trays, the highest fraction of all the surfaces tested. By contrast, the researchers did not find any lingering respiratory viruses in the airport's toilet bowls.

As the study notes, "handling these [trays] is almost inevitable for all embarking passengers." Although the study was conducted in Finland, the conditions are presumably similar in security lines overseen by the TSA. Thanks to U.S. regulations, handling screening trays is unavoidable for travelers carrying stuff in their pockets, traveling with toiletries, or wearing shoes, belts, hats, or jackets.

We cannot blame the TSA for all of the health risks associated with air travel. A separate 2015 study found that tray tables are the nastiest surfaces on an airplane, with overhead vents a runner-up.

The researchers said the study was aimed at identifying contamination risks in a public area. To help combat the spread of disease, experts recommend preventive measures such as washing your hands and using hand sanitizer.

Bonus links: Germs are not the only TSA-related risk that travelers face. They also may encounter secret but useless surveillance, stalking by air marshals, and some good old-fashioned fondling by total strangers. And for dog lovers, the TSA has an adoption program offering canines that were fired for being "too nice" to work at the agency.