Have you ever returned from a vacation feeling tanned and healthy but a few days after the flight you begin to experience flu-like symptoms which last for days or sometimes weeks?
Many people are quick to blame the air filtration systems in the aircraft cabin for the post flight sickness they often experience however with further investigation this appears not to be the case.
Disregarding the quality of the air and the effectiveness of the filtration systems in screening out bacteria and viruses in addition to re-circulating the cabin air it is still highly likely you may catch any number of airborne infections whilst in proximity to a large amount of people in a narrow, confined space such as that of an aircraft cabin. Buses and trains can be as bad as planes for being a breeding ground for bacteria – in such environments just one sneeze can travel twenty five feet and infect almost as many people if they have not encountered that particular strain before and developed immunity to it.
Airlines claim that the re-circulated air in an aircraft cabin is highly likely to be of better quality than the air in offices and other public buildings where there are certain to be a large volume of people although there have been claims to the contrary in recent years from airline staff stating that their health has been affected due to poor quality air in the cabin. Such claims have been continually refuted by the airlines who state that the cabin crews’ health is more likely affected by their hectic work schedules, unsocial hours and jet lag.
Another factor to consider is that re-circulated cabin air is always drier than normal air and any airline passenger is wise to drink plenty of water before and during a flight to counteract this and avoid dehydration and the inevitable health problems that will follow.
There are ongoing studies into the subject of aircraft air quality to investigate whether there is any danger from toxic fumes entering into the cabin such as ozone from the high altitude air outside or any contaminants from the aircraft engine. It appears that further research is necessary to identify and rectify any problem areas.
The air you breathe on board an aircraft is fifty percent re-circulated and fifty percent from the outside. An aircraft cabin is a totally artificial environment like no other. It would never be possible to fly at altitudes of 40,000 feet without breathing apparatus if it were not for the filtration and air re-circulation systems on board modern passenger airliners such as the Airbus A320 which are designed to exchange the air in the cabin every three minutes.
The environmental control systems (ECS) on jetliners of this nature will filter out ozone from the upper atmosphere whereas smaller planes that never fly as high will not possess this ability. In order to produce breathable air the ECS on a typical passenger aircraft will draw in air from the outside and this air is then mixed with air from the engine compressors before being cooled again to a breathable state. The air is thus not exposed to any combustion from the engines and should not contain any pollutants.
Another system known as HEPA (High Efficiency Particulate Arresting) filters out viruses and bacteria on modern aircraft to ensure that air quality is as good as it can be. In conclusion, a typical passenger may easily experience more toxic fumes from the traffic on his way to the airport than he ever will in flight and need have no fears for his health from the quality of the air in an aircraft cabin.