Explanation of terms:
The topic of “Contaminated cabin air”, or the poisoning caused by the breathing air provided in the pressurized cabin of aircraft, has been observed with concern for years. These so-called “Fume Events” often lead to serious complications, especially in the case of affected aircraft crews, but also in the case of passengers and ground staff of flight operations. The airlines themselves, the BFU (Federal Office for Aircraft Accident Investigations) and the Employer’s Liability Insurance Association for Transport and Traffic use the trivialising term “Smell Event” for these incidents.
The term “aerotoxic syndrome” has become established as the first medical term in the professional world and appears again and again in the press in connection with these incidents and the diseases caused by them.
It should be noted, however, that this term does not refer to a specific concept of conventional medicine, but merely to various symptoms that occur time and again in patients and have been objectively summarised to form a “syndrome”, i. e. a complex of symptoms. This should facilitate the etiological classification for physicians who are not well versed in this subject area and establish a direct link to the polluter, the aircraft (“aero” = air/aeronautics and “toxic” = poisoning / toxic).
From a medical point of view, however, these documented cases are clearly an intoxication, i. e. the effect of harmful substances (toxins) on the organism caused by gases or aerosols present in the aircraft cabin. These poisonings can be objectified by conventional medicine and doctors are obliged to classify them by means of the so-called ICD-10 (International Classification of Diseases) for diagnostic purposes. Those affected do not suffer from an “aerotoxic syndrome”, but clearly from the consequences of poisoning.
First of all, it does not matter where these noxious organisms originate, which cause these symptoms or diseases, or in what quantity they are present. It is also irrelevant where they originate, whether it is an accidental or a chronic or acute entry caused by technical deficiencies in the aircraft substance. These toxins basically have no place in the breathing air of aircraft.
Every airline is legally obliged to ensure a permanent supply of non-toxic breathing air in aircraft.
Causes of contamination:
There are many reasons for contamination of the cabin air, the most common possibilities are briefly explained below.
- The supply of breathing air in most aircraft is provided by the so-called bleed air, which is fed directly into the aircraft cabin unfiltered from one of the compressor stages of the engines. The engine itself, of course, only works, because of a complex mechanics that floats in a special engine oil, which is only approved for the aviation industry and is enriched with various neurotoxic additives, e. g. different organophosphates. These protect the mechanical components from premature wear and tear, but are extremely hazardous to health. Depending on the design, smaller and larger quantities of this engine oil can regularly enter the combustion chamber due to leaking or defective pressure seals, evaporate there and thus enter the aircraft cabin with the tapping air. This also happens in case of overfilling with engine oils, but above all because of improper maintenance and repair work that has not been carried out in accordance with the manufacturer’s specifications and because the service life of the engines has meanwhile been extended immensely before they are overhauled. The defective compression seals can only be replaced by dismantling the engine, which is correspondingly time-consuming.
- When starting the engines and when taxiing over the apron to the runway, exhaust gases present in the outside air are sucked in and also conducted into the cabin. These are usually originating from aircrafts in front and take-off.
- In winter the planes have to be de-iced. Residues of this de-icing fluid can get into the engines and thus also into the cabin.
- Aircraft are regularly sprayed with hazardous pesticides and insecticides. These are heavy sprays that adhere to the interior, e. g. the carpet, to achieve a long-term effect. These substances emit gases and can pose a health hazard.
- Before landing in certain countries, aircraft crews are required by law to spray the interior of the aircraft with pesticides, above the heads of seated passengers. The empty cans must be shown to the local authorities. These substances are proven to be harmful to health and can even damage the genetic material.
- Interior coverings, carpets and seats are treated with special fire retardant materials and impregnating agents, the carpets are laid with solvent-based adhesives. These substances are released and thus additionally released into the breathing air.
- Special short- and medium-haul aircraft in particular are not equipped with the necessary ozone filters for cost reasons, so that the breathing air is contaminated with the demonstrably harmful gas, which is present in the ambient air at cruising altitude in sometimes high concentrations.
It should be noted that contamination of the cabin air is not a monocausal cause, but that a wide variety of mixtures of substances, which are constantly changing in composition and harmful to health, play a causal role. However, the susceptible tapping air system can be regarded as the main cause.