NEW YORK (CBSNewYork) — If you want to stay healthy while traveling through the airport you may want to wash your hands after going through security.

A new study examined a variety of airport surfaces and found that the grimiest of all were the plastic bins used for pushing shoes and carry-on bags through screening machines.

The study, published in the journal BMC Infectious Diseases, found viruses in half of the samples of the trays at Helsinki Airport in Finland.

“Plastic security screening trays appear commonly contaminated,” researchers wrote. “Each security tray is rapidly recycled and potentially touched by several hundred passengers per day… trays are non-porous and virus survival is known to be prolonged.”

While passengers don’t have much of a choice in using the widely-shared bins, air travelers are apparently practicing much better hygiene in airport bathrooms. Fewer or no viruses were found in most toilet areas studied by scientists.