Drinking fountain buttons are the dirtiest places in an airport, with 1,240 colony-forming units (CFU) per square inch, compared to 172CFU on a home toilet.
Bathroom stall locks in the airports were found to have 72CFU, in a study undertaken by the website Travelmath.
The microbiologists employed by the website surveyed five unidentified airports to come up with the results.
Four airplanes covered in the research showed that the food tray table was the most infected with 2,155 CFU per square inch, followed by overhead air vent (285CFU), lavatory flush button (265CFU), and seatbelt buckle (230CFU).
The study, however, found that the 26 samples collected from the airports and airplanes were negative for the presence of fecal coliforms such as E.coli.
Bathrooms were far cleaner than the food tray tables and other areas in an airplane due to constant sanitisation.
According to the website, the onboard crew has little time to clean and sanitise the airplanes due to a short time gap between deboarding of arriving passengers and boarding of the departing ones.
"Boarding times have actually increased since 1970, from approximately 20 passengers per minute down to nine in 1998.
"There are many things that the cabin crew must attend to, so tray tables are often only cleaned at the end of the day.
"What is needed is a procedure for increased efficiency of boarding and deplaning that gives the cabin crew more time to do a thorough cleaning between flights," Travelmath wrote on its website.