Air Quality Onboard Airplanes

Some people take getting sick after a flight as an expected occurrence. Especially during cold and flu season, it’s very possible that sitting near an infected person may infect you, too.  But, do the germs transfer to you through the air circulation as so many have claimed? Is airplane air full of dirt, allergens, pesticides, and harmful bacteria?  The truth lies in between the dire claims of those who have become ill and the soft-spoken assurances from airlines that the air is pure.  

First – some facts. 

1. The air on airplanes is cleaner than in most public buildings. The filtration system on modern aircraft captures between 94 and 99.9 percent of germs in the air – much higher than in public buildings.  Additionally, the air is completely changed every two to three minutes through a system that mixes fresh air with re-circulated air. The re-circulated air adds a little more humidity to the mix. 

2. You’re not breathing the same air the entire trip. The fresh air comes from compressor sections of the engines; then it is run through air conditioning units and sent through ducts throughout the cabins. As the air makes its journey around the cabin, it is drawn into the lower fuselage of the plane where half of it is forced out of the aircraft. The remaining half is then mixed with a fresh supply and the circulation continues. While the air may seem smelly or stale to passengers especially at the gates or near the restrooms, the air is actually amazingly fresh considering the number of people who are sitting in close proximity. 

3. There may be allergens in the air.  Cleaning substances and pesticides may volatilize in small amounts but probably much smaller than found in the ordinary home. Pet dander is another matter. Since many airlines allow a limited number of pets to fly inside the cabin in carriers, extremely allergic individuals could be affected. Passengers with extreme pet allergies should notify the airline in advance to make sure there won’t be pets on their flight. 

4. The air is drier.  True. The problem is that humidifiers need water and water adds to the weight of the aircraft. The good news is that germs, fungus, mold, and other airborne pathogens are less likely to be transferred in dry air. Airlines must keep air humidity levels at tolerable levels. Passengers can aid their own personal comfort by staying well-hydrated. 

5. Serious diseases could be passed. We’ve all seen the photos of airlines screening for passengers with fevers or symptoms of epidemic flu’s like the Hong Kong or Avian varieties. If it’s flu season and a person with a compromised immune system is flying, it would be wise for that person to wear a mask. No one with a communicable disease should fly and expose others as droplets of saliva from a sneeze can travel up to 25 feet. 

6. There’s room for improvement.  Even though experts in the aviation industry have recommended higher air standards which include lower ozone levels and lower limits on pesticides, not all airlines have fixed the problem. Public pressure and government regulation are key to maintaining and improving safe cabin air. 

7. There is slightly less oxygen in aircraft air than in regular air. Generally air is pressurized at no more than 8000 feet. A person with compromised breathing who would have difficulty driving over a high mountain pass may need to use supplemental oxygen on board. 

So what’s the bottom line on airplane air quality?  

1. You inhale more toxic fumes from gasoline and road oils while driving than while flying. It really is safer to fly than drive! 

2. Air filtration systems on aircraft are probably better than where you work or shop. 

3. The cold you may contract happens because someone sneezed on you, not because it came through the air vents. You’re as likely to catch a cold from a person next to you in a theater as on an airplane. 

While not perfect, aircraft air is pretty good. The filtration system isn’t going to remove every trace of what a gassy passenger does or of a passenger wearing too much perfume, but it’s probably better than sharing a cubicle at work with the same smelly individuals.   Of the millions of us who travel by air, almost all of us have not suffered ill effects.  So, relax, breathe deeply, and enjoy your flight.