In June NBC News reported that four flight attendants have sued plane manufacturer Boeing, accusing the company of knowing about a defect that allows toxic fumes to leak through the engines and into the cabin – fumes that can cause serious illness.
The air we breathe on most commercial passenger jets is provided to passengers and crews from the compression section of the engine in a process known as “bleed air.” The bleed air is not filtered, and if a seal inside the engine leaks, burning oil can mix with the cabin air. The flight attendants’ attorneys said that happens once a day, somewhere in the world.
The lawsuit suggests Boeing has been aware of the danger for decades, citing internal documents including a 2007 email from a Boeing engineer who laments: “Bottom line is I think we are looking for a tombstone before anyone with any horsepower is going to take interest.”
In February in London, the annual conference of the Global Cabin Air Quality Executive heard that at least 3% of airline pilots are flying with degraded physical and mental performance caused by repeated exposure to neurotoxins in the aircraft cabin air, and may actually become incapacitated during flight if their exposure continues.
This assessment was presented to the conference by Dr Michel Mulder, a former KLM airline captain and medical doctor who now specializes in helping pilots whose health has been damaged by their work. He also reported that a KLM internal communication concedes that “incapacitation in the cockpit is a regular occurrence”.
Prof. Clement Furlong, a research professor of genetics and medicine at the University of Washington, Seattle, presented a paper on “Organophosphates: the effect on pilots and passengers” at a Flight International Crew Management Conference. He suggests organophosphates found in cabin air contamination events lead to neurological effects on the brain and nervous system.
Organophosphate neurotoxins from engine oil are present at low levels in pressurized cabin air, and occasionally at high levels when a “fume event” occurs. A 2003 survey of pilots belonging to the British Airline Pilots Association suggested that up to 96% of contaminated air events may go unreported.
Since their use as nerve gas agents in World War II, it is known that organophosphates can cause ill health and death in high doses. As well as acting as an irritant, these substances can interfere with nervous system functions, resulting in cognitive, emotional and behavioral problems.
Medical experts believe that sustained exposure to organophosphates from contaminated cabin air contributed to the death in 2013 of British Airways pilot Richard Westgate. In 2012, a UK study found that a group of airline pilots had a specific pattern of cognitive impairments similar to that seen in organophosphate-exposed farmers.
There have been regular crew reports of airborne incidents in which cockpit and cabin air has been contaminated with engine oil fumes. This is particularly true in Germany, which has a respected system of compulsory safety reporting, but it is a universal issue with reports being filed by pilots in UK and US airlines, among others.
The US’s largest flight attendant union estimates hundreds, perhaps thousands of crew members and passengers have been exposed over the years, but may not realize it. “They may not realize that they’re sick or that it was caused from this contaminated air,” Sara Nelson of the Association of Flight Attendants told NBC. “So they are not getting properly treated for that poisonous fumes that are now in their system.”
(Boeing’s newest plane – the 787 – does not use the engine bleed system to ventilate the cabin.)
After a 16-year legal battle, in 2010 the High Court of Australia upheld a ruling that inhaling contaminated air is harmful. Substantial damages were awarded to an Australian airline cabin attendant for respiratory illness attributed to toxic fumes in cabin air.
So what about he air rage phenomenon that seems common these days?
Air rage is “the single most pervasive security problem facing the industry worldwide,” Stephen Luckey, chairman of the Airline Pilots Association’s national security committee, told a congressional hearing on the topic in 1998.
In a typical commercial passenger plane, the cabin altitude of an aircraft planning to cruise at 40,000 ft is programmed to rise gradually from the altitude of the airport of origin to around a maximum of 8,000 ft.
Consuming one alcoholic drink raises our body’s experience of altitude to 10,000 ft. After three beers you’re cruising at 14,000 ft. Higher altitude plus alcohol equals loss of inhibition. According to Dr Ross Lee Graham at Linkoping University in Sweden, the resulting hypoxia causes “temporary environmental anemia.”
Environmental physician Dr Vincent Mark, M.D., has noted: “Curtailment of fresh air in airplanes can be causing deficient oxygen in the brains of passengers, and this often makes people act belligerent, even crazy. I’m positive about this, and it can be proven with a simple blood test.”
And former flight attendant Diana Fairechild, who lived on Maui, wrote the book “Jet Smarter The Air Traveler’s Rx.” She says most airplane conditions are a “toxic environment” that “contributes to air rage.”
One more factor – dryness and dehydration. At around 12 percent humidity, plane cabins are drier than you will find in most deserts. This is chiefly a by-product of cruising at high-altitudes, where moisture content is somewhere between low and nonexistent.