Dirty planes

Germs are everywhere. That’s what we were told in school, but how does this connect with our everyday experiences? There is perhaps no better setting to demonstrate this than where people from around the world come together as they travel between cities, states, and countries. To find out just how dirty the airports and airplanes that we rely on for business and vacation really are, we sent a microbiologist to take samples from five airports and four flights.

The general consensus from this study: Airports and airplanes are dirtier than your home (NSF, 2011). Surprisingly, it is the one surface that our food rests on – the tray table – that was the dirtiest of all the locations and surfaces tested. Since this could provide bacteria direct transmission to your mouth, a clear takeaway from this is to eliminate any direct contact your food has with the tray table. It’s also advisable to bring hand sanitizer for any other dirty surface you may touch along your journey.

To summarize, here is a ranking of the dirtiest places and surfaces on airplanes and at airports:

Tray table – 2,155 CFU/sq. in.
Drinking fountain buttons – 1,240 CFU/sq. in.
Overhead air vent – 285 CFU/sq. in.
Lavatory flush button – 265 CFU/sq. in.
Seatbelt buckle – 230 CFU/sq. in.
Bathroom stall locks – 70 CFU/sq. in.


Bathrooms were some of the cleaner surfaces tested, which may be contrary to conventional thought. Regular cleaning schedules mean these surfaces are sanitized more frequently. This is a good thing; while not discrediting the importance of cleaning all major surfaces between flights, bathrooms have the most potential for fecal coliforms to spread.

Airline staff are under more pressure in recent years to quickly deboard arriving flights and board departing flights to maximize profit for their carriers. Boarding times have actually increased since 1970, from approximately 20 passengers per minute down to nine in 1998 (Milne and Kelly, 2014). There are many things that the cabin crew must attend to, so tray tables are often only cleaned at the end of the day. This study demonstrates the need for tray tables to be cleaned between flights. Most carriers set their own cleaning standards since federal regulations through agencies such as the FAA and OSHA are quite minimal in this area (McCartney, 2014). The EPA does occasionally monitor water quality, however (EPA, 2009).

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. Much research is being done on theoretical boarding procedures; however, one aspect that could improve boarding time is encouraging more checked bags and thus reducing carry-on luggage. Boarding delays have been estimated to cost carriers a net $8 billion in 2007 for the United States alone (Ball et al., 2010). This indicates that lost revenues from checked bag fees might be recouped through reduced boarding time, with the added benefit of giving airline staff more time to clean between flights.