How many times have you disembarked from a fight and ended up with a stuffy nose, irritated eyes and spent the next few days tackling a cold, stomach upset, lethargy or worse?
FlyersRights member Cheryl Stevenson penned us an editorial warning about the dangers of toxic fumes in the cabin air:
Is The Air Inside Pressurized Airplanes Sometimes Contaminated?
Before British Airways pilot Richard Westlake died December, 2012, he had repeatedly stated that he was being poisoned by fumes in the cabin. He said he had numbness in his hands and feet as well as vision problems. According to the German TV news program DW Journal on which this report is based, he insisted that upon his death his body be given to research the subject.
An autopsy on Westlake’s body revealed that he indeed did have serious damage to his brain and spinal cord that scientists now associate with the collection of symptoms, known as “aerotoxic syndrome.”
Most aircraft use jet engines to pump air into the cabins. The problem is that jet engine oil contains toxic chemicals, called organophosphates. Leaks sometimes contaminate the air. Water used for coffee and tea also can be contaminated because the water system is pressurized by the engine’s air, and no filters are used for mitigation.
According to aviation expert Tim van Beveren, this problem has been known to the aviation industry for decades even if it is not well known. Over 15 years ago in Australia a Senate hearing determined that the problem was real and that it applied to all airlines.
Sometimes called “the asbestos of the skies,” the problem can be resolved, van Beveren says. Solutions lie first in installing sensors to alert pilots when a leakage is occurring. Planes can be fitted with filters. Finally, we can go back 50 years to the days when the air we breathe was funneled from outside the plane rather than from inside the aircraft. This is exactly what Boeing has done with the production of the Dreamliner. The other major manufacturer has been reluctant to follow.
The airline industry is, as van Beveren says, a closed shop. It has been doing everything it can to keep this problem under wraps. We passengers may well be the major source of pressure on the airlines to solve it.
As if we needed a new fear of flying.
The experience is already arduous – with stressful airports, delays, check-in times hours before flights, intrusive but often useless security checks, DVT
, terrorist activity, aircraft malfunction, pilot error and now we need to be aware of being killed by aerotoxic syndrome?
If this is true, wouldn’t more people be affected?
People are being afflicted, says The Conversation
. The news site explains that airline crew have been reporting for years ill-health
following exposure to contaminated air. Most commonly reported symptoms are: irritation to the eyes, nose and throat; headaches, light-headedness and dizziness; fatigue, weakness; generally feeling unwell; confusion and difficulties in concentration.
For years, flight attendants in the U.S. and Europe have complained about dangerous exhaust in the cabin.
On July 12, 2013, Alaska Airlines Flight 769 made an emergency landing in Chicago with four flight attendants seriously ill after complaining of noxious chemical fumes in the cabin. Two of the flight attendants passed out.
This year, four flight attendants sued Boeing
, accusing the company of knowing about a defect that allows toxic fumes to leak through the engines and into the cabin.
While passengers have occasionally complained of similar symptoms, this is a much rarer occurrence (unsurprising perhaps because of the relative infrequency of travel compared to aircrew). Symptoms may be the result of exposure to the organophosphate known as tricresyl phosphate (TCP)
; a flame retardant additive in jet engine oil and hydraulic fluids. As well as acting as an irritant, these substances are a type of neurotoxic compound, and can interfere
with nervous system functions, resulting in cognitive, emotional and behavioral problems.
Since problems in production of them as nerve gas agents during World War II, it’s been known that organophosphates can cause ill health and death in high doses. However, controversy still surrounds whether low levels are actually harmful. Establishing a link between exposure and chronic ill-health lies in the difficulty we have with establishing an accurate estimation of exposure. The absence of routine air quality monitoring on commercial aircraft make it impossible to determine what chemicals enter the cabin and in what quantities.
But relying on self-reported measures of exposure is notoriously problematic, as it depends on memory and a capacity to detect noxious substances, (both of which vary enormously in reliability). So, before a causal relationship can be determined, our understanding of how exposure might occur, and the level of this exposure, needs to be improved.
How does exposure occur?
Since warm air is needed for engine propulsion and for passengers to breathe, it was decided to combine the two and bring the air through the engine to heat it, then “bleed”
it off and pass it unfiltered into the cabin. It is this ‘bleed air’ that has been the cause of so much controversy.
Every modern jet airliner, except the new Boeing 787, uses the bleed air system. There are seals in the engine intended to keep oil out but unfortunately they require air pressure to keep the seal tight, and at times they allow contaminated air to pass into the cabin. Sometimes if the seal is worn or faulty or if the oil is leaking, large amounts can pass into the air supply and these are known in the industry as ‘fume events.’
The incidence of these “fume events
” is difficult to quantify, as commercial aircraft are generally not fitted with equipment for monitoring on-board air quality. There is also significant under-reporting of exposure: i.e., the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment estimated
that fume events occur on about 0.05% of flights
However, in 2003, a survey of pilots
belonging to the British Airline Pilots Association
suggested that up to 96% of contaminated air events may go unreported. Collectively, the pilots in the survey claimed to have experienced more than 1,674 smoke or fume events but only 61 instances were formally reported to the CAA, possibly due to lack of awareness, commercial pressure and the perception that exposure to such contaminants is normal and part of their everyday job.
Is there any data from military aviation?Transport aircraft are often similar to civilian airplanes and there are well-documented problems for the maintenance crews of the F111. But the exposures were much higher and over sustained periods of time.
This needs looking into on a global scale
The airline industry has long maintained that there is no evidence of long-term health effects from potentially inhaling these fumes, however, pilots recently reported
approximately 167 cases of toxic cabin fumes in just the first four months of 2015. Several of these cases have been so severe that pilots have had to request priority landings, flight diversions, and even an emergency mayday call.
What are the solutions?
In today’s existing modern bleed air aircraft, the quality of cabin air could be improved
and the risk of contamination by engine oil reduced, with these known solutions:
- Activated carbon face masks can offer some protection from toxic oil fumes, but can not provide 100% protection.
- The new Boeing 787 Dreamliner eliminates the possibility of cabin air contamination. Instead of bleed air, cabin air is supplied by electrically-driven compressors taking their air directly from the atmosphere.
- As bleed air is not presently filtered, installation of bleed air filtration systems would eliminate the problem, although a technically efficient system does not yet seem to have been developed.
- A less toxic oil formulation could lead to significant improvement. The French oil company NYCO is continuously developing such oils.
- Chemical sensors to detect contaminated air in the bleed air supplies – instead of human noses – would alert pilots to problems, allowing prompt preventive action.