Terror at 20,000 feet

A new global campaign and film asks whether the air we breathe on commercial flights is as safe as we think it is.

While the pandemic means the prospect of international travel remains very much up in the air (no pun intended), many of us have probably been dreaming of the day when we will be packing our bags and heading to warmer climes.

The aviation industry has always had an uneasy relationship with the environment, especially with the amount of fossil fuel consumed by flights all over the world.

Another issue, which frequently gets overlooked, is the quality of the air passengers breathe onboard

In February, a global campaign was launched by the Global Cabin Air Quality Executive (GCAQE), which called for the mandatory introduction of effective filtration and warning systems, to be installed on all commercial passenger jet aircraft.

According to the GCAQE, there have been 50 recommendations and findings made by 12 air accident departments globally over the last 20 years, directly related to contaminated air exposures on passenger jet aircraft.

However, commercial aircraft continue to fly, with no contaminated air warning systems to inform passengers and crews when the air they are breathing is contaminated.

The issue has also been highlighted in a new film — Everybody Flies — which follows Captain Tristan Loraine, as he uncovers the facts about the air we breathe on commercial aircraft.

‘When I was flying, I would get six or seven chest infections, a year,’ explains Captain Tristan. ‘Some of them would last six weeks. I would go and see my company doctor and say, “look this just isn’t right”. They said it must be must down to where you live or something like a tree fungus, but since I’ve stopped flying I’ve had one chest infection in like 14 years. So, it just goes to show it’s absolutely linked to the air I was breathing.’

Captain Tristan says the air onboard passenger planes is contaminated because of ‘bleed air’, which brings air in through the compression section of the engines, or from the auxiliary power unit, a small engine at the tail of the aircraft. He says it is not filtered and has been known to be contaminated with jet engine oils and other fluids.

‘Bleed air is extremely hot – hundreds of degrees Celsius,’ he tells Air Quality News. ‘And as oil leaks in with it, the oil breaks down into hundreds and hundreds of different compounds. The most hazardous compound in there is the organophosphate tricresyl phosphate. The most toxic chemicals piggyback onto ultra-fine particles which then enter the cabin, and that allows them to get them deep into the lungs or through the blood brain barrier.’

Rightly or wrongly, passengers have always assumed that the chamber of an aircraft is sealed during flight and the air is just recycled, but Captain Tristan says the truth is slightly more complicated.

‘It is sealed, but there is an outflow valve at the back,’ he explains. ‘That allows air to go out of the back of the aircraft. But you need to keep replacing the air in the sealed unit and you do this by taking in the air from the engines. All the air comes in from the engines, and to reduce how much air per second they take, they recirculate half of it. That air does gets filtered for bacteria and viruses inside, but the air that comes from the engine is unfiltered.’

Captain Tristan says there is only one airplane which does not use the ‘bleed air’ system, the Boeing 787 Dreamliner and ‘the crews who work on that plane just say it’s a totally different working experience, they just come off feeling totally refreshed’.

He adds there are also no sensors onboard aircraft to alert pilots to any issues with onboard air quality.

‘Aeroplanes are worth hundreds of millions of pounds and when you fly across the Atlantic, you could be at 36,000 feet, and the plane above you at 37,000 feet is literally right above you. The navigation is precise, virtually to the metre. And yet, they don’t have any sensors to tell you whether the air quality you’re breathing is safe or not.

‘The great irony in this is that in any other enclosed space that man works in – a submarine, spacecraft or a mine – they all have air quality monitoring equipment. So, if you can have it on the space shuttle why don’t you have it on an aeroplane? If you get into a smaller propeller plane, which you learn to fly on, they actually have a carbon monoxide detector, in there. But in a jet, there’s nothing.’

Captain Tristan adds that cancer rates are much higher among those who work in the airline industry than in other sectors.

‘I just think people should be told this is what’s going on and make an informed choice,’ he tells Air Quality News.  ‘We know businessmen that have been on just one flight and have been seriously affected when there’s been a bigger exposure. Eleven million people used to fly every day, and most of them will be fine. Passengers are not told about contaminated air even if they are in a big event. Passengers are also not told what is written on the warning labels of the products they are being exposed to such as synthetic jet engine oils or hydraulic fluids. They state: “do not breathe mist or vapour from heated product; risk of cancer; suspected of damaging fertility” etc…’

The trade union Unite has also been vocal about the issue of air quality on commercial aircraft and is supporting the ongoing High Court claims of airline staff against several of the largest UK airline operators.

Unite has backed calls for airlines to be held accountable for their lack of action in addressing this issue to ensure the health and safety of their staff and passengers on board their aircraft.

‘The aviation industry does not accept bleed air causes injury, particularly a significant neurological injury,’ a Unite spokesman tells Air Quality News.

‘Those staff who raise concerns are framed by the industry as campaigners or troublemakers and are marginalised. As a result, discussion about contaminated bleed air has become a taboo subject amongst airline staff.

‘As a consequence, no study has ever been conducted to properly assess the impact of exposure to contaminated bleed air on airline staff.’

Captain Tristan adds the aviation industry has taken numerous steps to enhance flight safety over the last 50 years, but it has failed on this issue.

‘In the GCAQE’s view, despite knowing about this issue for decades, aviation regulators around the world such as the US Federal Aviation Administration (FAA) and the European Union Aviation Safety Agency (EASA), have on this specific problem, put the corporate interests of the aerospace industry ahead of flight safety and public health,’ he added.

‘They have failed to mandate the installation of effective contaminated air warning systems or ‘bleed air’ filtration systems. They have also failed to require airlines to inform crews or passengers about these exposures. Instead, they claim the air in aircraft is better than in your home and continue to call for more research. The sole result of calling for further research will be to delay having to take mitigating actions which are needed now, to finally resolve this public health and flight safety issue.

‘The regulators say they need to know what chemicals are present during a contaminated air event before they can consider mandating new technologies to mitigate the problem,’ he says.

‘They knew over 20 years ago what chemicals were present, as they have data from the investigation into the total incapacitation of two pilots on a domestic Swedish flight known as the ‘Malmo’ incident. It is unbelievable that they continue to fail to fix this basic design flaw.’

Air Quality News reached out to the Aerospace Industries Association (AIA) on the issue of onboard air quality.

The AIA supplied AQN with a copy of a letter from the world’s top aerospace medical associations in 2017, which rejected a connection between cabin air and exposure to toxins.

‘Over the past two decades several major studies of cabin air have been carried out internationally and none have identified levels of toxic substances approaching clinical significance,’ the letter states.

‘While encouraging thorough scientific research in all areas of aerospace medicine, our review of the available literature leads us to suggest that significant symptoms being suffered by a group of individuals, here labelled as aerotoxic syndrome, are not explained by toxins in cabin air, and that other causes must be sought.’

It also cited two studies on cabin air quality by the European Aviation Safety Agency (EASA) in 2017. The first, conducted by a consortium of the Fraunhofer Institute for Toxicology and Experimental Medicine and the Hannover Medical School, concluded that the cabin/cockpit air quality is similar or better than what is observed in normal indoor environments, like offices or schools.

It found no occupational exposure limits and guidelines were exceeded on eight different types of aeroplane.

The second study, by the Netherlands Organisation for Applied Scientific Research and the Dutch National Institute for Public Health and the Environment, looked specifically at the toxicity of turbine engine oils and chemical compounds released in the cabin or cockpit air.

It concluded that neuroactive products are present in cabin air, but that their concentration is too low to be a major concern.

This article first appeared in the Air Quality News magazine which is available to view here.