Air travel is disgusting. If someone sneezes in row two you breathe it way back in row 30. Cabin air is basically a cesspool of recirculated germs. Right?
Actually, airplane air is cleaner than the air in your office or your supermarket. "Air on an airplane is about half fresh and half recirculated, and that whole volume is changed out several times per hour," says Patrick Smith, a longtime pilot and author of Ask the Pilot. Recirculated air passes through the same kind of high-efficiency particulate air filters hospital ORs use—which remove almost all bacteria and viruses. One airline's study found that the only time cabin air quality dipped below excellent was when the plane was sitting on the ground with its doors open.
Airplane design also minimizes airflow in the fore and aft directions, says David Space, an air quality technician at Boeing. That first-class sneezer is breathing entirely different air than you are back in the caboose.
If you do get sick after flying, it has less to do with germs in the air than with touching dirty surfaces like tray tables, lavatories, and shared arm rests.
