The Cabin Environment

Air Quality:
In all modern pressurized aircraft, half the cabin air is fresh air drawn in via the engines with the other half recirculated from the cabin. The recirculated air is ducted through an air filter before being reintroduced into the cabin. There is a total air change (filtered recirculated plus outside air) every 2 - 3 minutes or 20 to 30 exchanges per hour. This is far more than for any home or office building and easily maintains cabin contaminants to low levels. Several studies of the past l0 - 15 years have confirmed that the levels of volatile organic compounds (solvents), airborne particulates, carbon monoxide, carbon dioxide, ozone and microbials were well within acceptable health levels of our regulatory agencies. This does not mean the air is 'allergy-safe' by any means--see below.

Humidity:
Aircraft cabin relative humidity is usually less than 20%, which is fairly dry. Although these low levels may be a source of mild discomfort (dry skin and eyes), there is little risk to your health. Minimize discomfort from dryness by

  • Drinking reasonable amounts of water and juices.
  • Limiting consumption of alcohol, tea, coffee, and caffeinated drinks because they cause you to lose fluids.
  • Wearing glasses instead of contact lenses.
  • Applying a skin moisturizer.


  • Motion Sickness:
    For those susceptible to motion sickness
  • Request a seat over the wings.
  • Schedule flights on larger airplanes.
  • Request a window seat.
  • Avoid alcohol for the 24 hours prior to flight and inflight.
  • Keep seat belts fastened while seated.
  • Consult your physician about motion sickness medication if necessary.


  • Space:
    Because of crowding in some aircraft, passengers are frequently uncomfortable and unable to stretch or easily leave their seats. In susceptible individuals, prolonged periods of immobility, can increase the risk for blood clots to form in the legs. This can occur in a train, car, bus, or aircraft. Consequently, it is called travelers thrombosis. There is no epidemiological evidence of a particular link with air travel itself. Travelers' thrombosis can cause pain and/or swelling of the legs during travel or even several days or weeks afterwards. Clots in the legs are not serious in themselves, but occasionally they break off and travel to the lungs causing what is called pulmonary embolism. This is not a common occurrence but when it does happen, it can be life threatening. Nevertheless, a few simple tips might decrease the risk:
  • Wear loose clothing and avoid tight, restrictive garments.
  • Place nothing under the seat in front of you so you can stretch and periodically exercise your feet and ankles.
  • Drink mainly juices and water while minimizing alcohol and caffeinated beverages.
  • Walk about the cabin periodically (every 60 - 90 minutes).
  • Consult your physician if you have underlying illness such as coronary artery disease, cancer, or blood clotting disorder.