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Cabin fever – Aerotoxic Syndrome: how to stay safe

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If you’re suffering from chronic fatigue, depression or a nervous disorder similar to Parkinson’s disease – and you noticed the symptoms came on soon after a flight – you could be a victim of what has been described as the airline industry’s darkest secret: aerotoxic syndrome.

The syndrome – so named by three scientists in 1999 – is the result of ‘fume events’ in aircraft, which occur when oil from the engines gets into the air that pressurizes the cabin. This can happen when seals become old and worn, and even when the ground crew overfills the engines with oil. The oil contains organophosphate compounds that lubricate the jet engines, but which also attack the nervous system.

Fume events have been recognized by the airline industry since the 1970s, but it maintains they are rare, and that any effects are transitory and will pass in a few days. It certainly doesn’t accept that fume events cause aerotoxic syndrome.

But things could soon be changing after years of denial by the airline industry. British Airways (BA) and the Civil Aviation Authority (CAA) have been ordered to provide a report before the end of this month (April) as to how they intend to reduce fume events in aircraft. The demand comes from Sheriff Stanhope Payne, the senior coroner for Dorset, who has been reviewing the sudden death of BA pilot Richard Westgate, who died in 2012 at the age of 43. Mr Westgate had been convinced he was a victim of aerotoxic syndrome after being exposed to numerous fume events in his cockpit just before takeoff.

Mr Payne has also called on BA and the CAA to take “urgent action to prevent future deaths” in a landmark judgment – the first time a coroner has admitted that aerotoxic syndrome is real and can be lethal.

In his prevention-of-future-deaths report, Mr Payne raised five major concerns for BA and the CAA to address, including the fact that “organophosphate compounds are present in aircraft cabin air,” that “the occupants of aircraft cabins are exposed to organophosphate compounds with consequential damage to their health” and that “impairment to the health of those controlling aircraft may lead to the death of occupants”.

An immediate remedy could be the introduction of a monitoring device that can gauge when organophosphates have been released into the cabin, a simple solution that campaigners have been proposing for years.

Mr Westgate suffered from pain in the head, ataxia (a neurological condition that affects balance and coordination), memory loss and severe fatigue. Blood tests were taken before and after his death, and three scientists – including a pathologist – who examined the samples concluded that he died of ‘organophosphate-induced neurotoxicity.’ His lawyers are continuing with his legal claim against BA for breaching health and safety guidelines by not monitoring cabin air quality.

Passengers too

Although pilots and cabin crew are at greatest risk, aerotoxic syndrome can also affect frequent flyers and any passengers who are chemically sensitive. Dee Passon, a former British Airways flight attendant, believes her own ill health is the result of aerotoxic syndrome and has heard of cases where passengers have suffered long-term health problems after experiencing just one fume event.

Sometimes a fume event is obvious because the cabin fills with smoke or there’s a visible haze, but usually there’s just a smell that’s been likened to smelly feet, the inside of trainers, vomit or a wet dog. “Before we knew anything about fume events, we just thought a passenger had taken off his shoes, and we would be running up and down the aisles looking for the culprit,” said one air hostess.

The danger times are when the jet engines are working harder, such as at takeoff or when climbing, and usually when the engines are starting from cold. They also seem to be more commonplace in two types of aircraft, the Boeing 757 and the BAe 146.

In a fume event, organophosphates – which are neurotoxic – enter the cabin and attack the central nervous system. Effects can be short-lived or chronic (long-lasting) and can start immediately or a few days after the flight. Some of the most common symptoms are fatigue, blurred vision, shaking, loss of balance, seizures, memory problems, headache, tinnitus and breathing problems.

There’s a further hazard: pilots could be affected by aerotoxic syndrome and not know it, so endangering the lives of everyone on board. Their judgment and ability to fly may be impaired by frequent exposure to fume events, says Prof Jeremy Ramsden, formerly of Cranfield University, but it’s something that may be kept under wraps. “If individuals flag up their health problems, their pilot’s licence may be withdrawn, and if the problem becomes more widely known to the public, plummeting passenger numbers and liability suits may force airlines into bankruptcy. This in itself raises a safety issue, for it implies that there are currently pilots flying with damaged central nervous systems, who might be well able to cope with routine flights, but adversely challenged by any sudden emergency,” he says.

Pilots who unwittingly have aerotoxic syndrome might be the explanation for those mysterious air crashes, says Mr Westgate’s lawyer, Frank Cannon. “There are many crashes where we suspect the only plausible explanation is that the crew were suffering from cognitive dysfunction.” Mr Cannon added that he has been contacted by two frequent flyers, who are convinced they are suffering from aerotoxic syndrome, within hours of the coroner’s report being made public.

Who’s counting?

Nobody really knows how many fume events happen on flights because no one is monitoring them. The UK Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) estimates that one in 100 flights experiences a fume event, while another estimate is lower at a figure of one in 1,000 flights and other UK estimates have halved even that.

The British CAA has said there are at least five fume events a week on UK flights so severe that the cabin crew has to wear oxygen masks – although it’s a protection that isn’t offered to passengers. In any case, the drop-down oxygen masks would be ineffective as they’re using the same air that’s already been contaminated.

Even taking the most conservative estimates, this still means there are fume events on 18,750 flights around the world in any given year (based on the International Air Transport Association’s figure of 37.5 million flights in 2012) and, based on US National Oceanic and Atmospheric Administration data, over 5,000 of them over US soil. Right now, a fume event is reported on just 3.6 percent of flights, but this could be because cabin crew don’t know what a fume event is or wouldn’t recognize one even if it happened. Nevertheless, even if that’s the true statistical picture, it means that 1,967 flights in the UK alone are having a fume event each year. Assuming a modest passenger load of 100 per flight, this suggests that more than 196,000 people in the UK alone are inhaling organophosphates on flights each year. Using the 100-passengers-per-flight calculation across the globe, around 1.87 million people a year are being exposed to a toxic fume event.

Researchers in the US have come up with similar levels. In 2003, the US Congress passed legislation that directed the Federal Aviation Administration (FAA) to fund research into cabin air quality. But despite this, not one American airline has permitted flight attendants to carry a portable air sampler on board, so independent researchers have had to bring their own on board when they traveled. They analyzed 55 samples, and 10 of them tested positive for at least one form of organophosphate. The samples were taken on standard flights where there hadn’t been an obvious fume event such as smoke or a strange smell.

With this level of potential claims for damages, it’s not s
urprising the airline industry has been flatly denying the existence of aerotoxic syndrome. Yet, despite its denials, the now-defunct East-West Airlines was forced by an Australian court to pay damages to a flight attendant who suffered respiratory problems after a fume event on an internal BAe 146 jet flight. Described as a “significant global precedent”, the New South Wales Court of Appeal awarded damages of A$139,000 to flight attendant Joanne Turner in 2010 when she suffered respiratory damage after the event.

BA has also been making ‘hush-hush’ payments to staff whose health has been impaired following a fume event, says Dee Passon.

A secret email passed on to WDDTY suggests that airline manufacturers have similar concerns. In it, George Bates, at Boeing’s environmental controls division, says that one flight every two weeks in the US is being diverted or returned to base because of a serious fume event. Crews have reported seeing blue smoke, and visibility has sometimes been so poor that attendants couldn’t see more than halfway up the cabin.

“Bottom line is I think we are looking for a tombstone before anyone with any horsepower is going to take interest,” he concludes, suggesting there will have to be a number of deaths before anything changes.

The industry is also quietly walking away from the controversy, judging by the latest technology. Boeing’s new 787 Dreamliner, which was introduced in 2007, is the first major commercial aircraft to not take its compressed air from the engines. The technology has been bought by virtually every major airline, including BA.

Not many dead

But those tombstones are already popping up, as a group of pilots and cabin crew has discovered. Leading the campaign are Dee Passon, who has set up the Toxic Free Airlines group, and former pilot John Hoyte, who has created the Aerotoxic Association and written an ebook about his findings, Aerotoxic Syndrome: Aviation’s Darkest Secret. Both believe their chronic health problems are the result of aerotoxic syndrome, and Dee’s own doctor has even acknowledged it as the cause of her incapacity.

The third major campaigner is Tristan Loraine, another former BA pilot, who was forced to take early retirement because of ill health just a year after he completed the Iron Man triathlon. Mr Loraine has sunk all his savings, and his payout, into making several films that have highlighted the dangers of fume events. His latest thriller, A Dark Reflection, was released this year (2015).

Dee has been collating the number of deaths among BA aircrew since 2006. According to her report, which she calls Angel Fleet, 23 serving crew died in 2013 – the youngest was 28 – and overall there have been 412 deaths in serving crews between 2006 and 2014, some of whom were in their 20s and 30s. “The Metropolitan Police has half the death rate of airline staff,” says Dee. BA has now stopped publishing these deaths.

She’s not suggesting that every death is the result of aerotoxic syndrome, but she believes it is a factor that contributes to the rate of premature deaths among cabin crew.

Cabin crew also seem to have more than their fair share of health problems. Dee Passon has organized an international crew health survey which, in 2011, collected data from 1,020 pilots and cabin crew from 24 countries; based on these, 37 percent said they were suffering from peripheral neuropathy – the national average is no more than 8 percent – while 48 percent have breathing problems (national average: 0.1 percent), 22 percent suffer from depression (national average: 10 percent), 7 percent have chronic fatigue syndrome (CFS; national average: 0.3 percent) and 5.9 percent have cancer (national average: 0.5 percent).

Dee estimates that around 1,000 BA cabin crew, out of a workforce of 15,000, are on sick leave at any time. She was also passed an email from a BA insider that announced that 500 cabin crew were sick over the last Christmas holidays.

Dr Peter Julu at the Breakspear Medical Group has seen similar patterns of neurotoxic damage in 19 pilots he has examined. All were complaining of memory loss, tremors, lethargy and poor cognitive function, and he discovered damage in areas of the brain that control vital bodily processes, which mirrors that seen in farmers exposed to organophosphates through sheep dip.

Not surprisingly, flight attendants are in the third most hazardous profession, well ahead of drill operators in the oil and gas industry, who are ranked eleventh, while airline pilots are just one place below them at twelfth, according to statistics from the US Department of Labor database. The database, prepared by the Occupational Information Network, looked at the dangers faced by 974 occupations, including exposure to contaminants and hazardous conditions.

Although airlines are still in denial, their position is not shared by some scientists and doctors who are convinced by the evidence that aerotoxic syndrome is a very real condition. One recent study accepts that organophosphates, especially tricresyl phosphate (TCP), are entering the aircraft cabin from engine oil, and affecting the health of the cabin crew and possibly those who are more chemically sensitive.1

Prof Ramsden has also concluded that aerotoxic syndrome is a genuine condition, and that the neurotoxins from fume events are a health hazard for flight crew and frequent flyers. He estimates that fume events happen in around one in a thousand flights.

However, what happened next to Prof Ramsden, after his report was published, is perhaps even more telling. He lost his position at Cranfield University and was locked out of his office. The report was sponsored by the Department of Transport, but he doesn’t know if it was government officials or the university’s own executives who took such umbrage at his conclusions.

But it might not have been his conclusions that were the issue; in the body of his report, he refers to the “Aircraft Cabin Air Sampling Study”, which denied there were any air-quality problems on flights. “It is most unfortunate that the study was commissioned to be carried out by an organization (Cranfield University) that has a strategic alliance with one of the members (BAE Systems) of the Aerospace and Defence Industries Association of Europe,” he wrote.2

Frequent fume events

It’s estimated that, every year, there are fume events on 18,750 flights around the world and on about 5,200 flights in US skies. This suggests that more than half a million US passengers – and 1.87 million people around the globe – are inhaling noxious organophosphates on flights each year.

Detox yourself

If you suspect you might be a victim of aerotoxic syndrome, there’s a standard protocol to follow that would apply in any case of poisoning, which is essentially what has happened to you.

Dr Sarah Myhill advises that heating the body by any means – such as with exercise, a sauna or bathing in Epsom salts – is the best way to ‘boil off’ poisons and get them to the skin’s surface, where they can be washed away.

She especially advocates the use of far infrared (FIR) saunas. She has also collected fat biopsies from 27 poisoned patients who have followed her ‘thermal protocol’ and reduced their toxic load.

Products and resources

• An activated charcoal mask can filter out some organophosphate compounds involved in a fume event. Look for National Institute for Occupational Safety and Health (NIOSH)-approved masks rated N95 or higher.

• Portable FIR saunas are available from FIR-Real (, Ideal Sauna ( and others.

• The Aerotoxic Association website:

Is there a doctor on board?

Compared to the general population (represented by the turquoise bars), cabin crew (represented by the yellow bars) have higher rates of peripheral neuropat
hy (damage to the nervous system), breathing problems, depression, chronic fatigue syndrome and cancer.

How does it happen?

A supply of warm compressed air is necessary to allow passengers and crew to breathe at high altitudes. The air is supplied from the jet engines and known as ‘bleed air’. It’s mixed inside the cabin with recirculated cabin air at a 50/50 ratio. All of the cabin air, including recirculated air, originates from the jet engines.

Bleed air comes from the compressor section of the jet engine, which has to be lubricated. Jet engines have ‘wet seals’ to keep the oil and air separated. However, these seals slowly wear and their effectiveness declines. The wear can happen more quickly when the engine is working hard, such as while climbing or at full throttle. The seals can also fail suddenly, allowing large amounts of oil into the very hot, compressed bleed air, resulting in fumes or smoke entering the cabin. This is known as a fume event.

Jet engine oil uses synthetic chemicals and organophosphate additives as antiwear agents, and other aromatic hydrocarbons as antioxidants. Some of the oil is partially chemically decomposed (pyrolyzed) because of the high temperatures.

When a fume event occurs, the cabin fills with a bluish haze or smoke, whereas a slight leakage can only be detected by smell (terms such as sweaty socks, wet dog, vomit and sweet oily smell have been used to describe this). Such slight leakages, when only a smell can be detected, happen on around a quarter of all flights, the Aerotoxic Association estimates.

Dee’s story

Dee Passon, 56, first became a flight attendant in 1979. In January 1996, she joined British Airways and did short-haul flights out of Heathrow Airport. In September that year, she was called up as an emergency replacement on a flight where the previous crew had all been taken to the hospital with breathing difficulties.

“A passenger on this flight told me he was a paramedic and could smell something that smelled like CS gas [a type of tear gas]. I wasn’t aware of the smell, but after this flight, I developed a persistent cough that would not go away. Over the next 12 years, my health steadily declined. My medical notes record frequent bouts of gastroenteritis, swollen lymph glands, sore throats, chest infections, abnormal lung sounds, fatigue, high blood pressure, high cholesterol, anemia, mood swings, hot flashes, chest and neck pain. Three tests for glandular fever [mononucleosis] were negative.

“In 2005 I was diagnosed with high-grade breast cancer. It is recorded in my notes from the Royal Marsden Hospital that during the time I was being treated for cancer and had eight months away from flying, I felt well.

“The first time alarm bells began to ring about my occupation was when I was greeted by the oncologist at the Royal Marsden. When he found out what I did for a living, he told me, ‘You are my eighth lady from BA this week’.”

On one flight, Dee was convinced she experienceda fume event although, at the time, she had never heard of the term.

“I felt very strange, with pins and needles in my face and lips, and felt light-headed and dizzy. I rang the crew members working at the rear of the aircraft and asked them how they were feeling. They described all the same symptoms. I looked in the mirror and saw my lips were blue.

“I reported this to the captain several times but, each time, I was assured that the oxygen and pressurization were fine. Eventually a cabin crew member collapsed in the cabin and had to be put on oxygen; only then did the captain agree to fill in an air-safety report. On disembarkation, a passenger told me he had done many flights, but had never felt like that before, and he believed there was something wrong with the air on that flight.

“On another flight back from Accra [Ghana] on a 767, a passenger vomited in the aisles, unable to make it to the toilet; then more also felt ill, and someone projectile-vomited all over the rear galley. Eight passengers became unwell on that flight and I too became ill after I got home. I spoke to all eight; some had not eaten so I thought the only thing they had in common was the water. “I did an incident report and asked for the water on the aircraft to be tested for contaminants. Later, when I found out about contaminated air, I tracked down that report. It had been edited to make it sound like the passengers were suffering from air-sickness and stamped ‘Further investigation not required’.”

Dee was forced to retire on health grounds. She has been diagnosed with obstructed lungs and asthma, breast cancer, cardiac dysfunction and ventricular arrhythmia, osteopenia of the spine, chronic fatigue syndrome, multiple chemical sensitivity, hypothyroidism, adrenal fatigue and peripheral nerve damage. A medical certificate signed by her doctor confirmed that Dee is suffering from chronic fatigue syndrome – and aerotoxic syndrome.

Main article



Chemosphere, 2015; 119 Suppl: S58–61


J Biol Phys Chem, 2011; 11: 152–64

Article Topics: Flight attendant
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