Air on planes is so polluted that it can make frequent flyers sick – thanks to engine oil and de-icing fluid leaks

AIR inside the plane cabin is already full of germs - which is why you often catch a cold after a flight.

But it turns out the air quality is bad enough to make people really sick.

have shown that cabin air can often be polluted with engine oil.

The air inside the aircraft is a combination of recycled air and “bleed air,” which comes from outside the plane and can contain engine oil, hydraulic fluid and even deicing fluid.

Because pilots and cabin crew are those who fly most regularly, researchers conducted two studies to measure the effects of bleed air on the health of 274 British pilots over several years.

According to the first study, almost 65 per cent [of pilots] reported specific health effects, while 13 per cent had died or experienced chronic ill health.

The second study looked at maintenance reports from plane, which showed when there had been incidents like oil leaks.

It also looked at reports of health issues among people on board these planes, such as dizziness, breathing problems and visual problems.

The study revealed that: “Symptoms ranging from in-flight incapacitation to impairment were reported in 93 per cent of events, with the majority (73 per cent) involving pilots and 33 per cent including full or partial incapacitation of two pilots.

"What we are seeing here is aircraft crew being repeatedly exposed to low levels of hazardous contaminants from the engine oils in bleed air, and to a lesser extent this also applies to frequent flyers.

Even though these studies are new, issues with cabin air affecting health have been reported for a number of years.

Back in 2013, two flight attendants on an Alaska Airlines flight claimed they had become unwell as a result of dirty air.

They sued Boeing, claiming that their illness was due to dirty air that caused them to vomit and pass out.

The Public Health Panorama previously published a study on more 200 cabin crew which showed similar results.

Researchers from Stirling University found a clear pattern of acute and chronic symptoms, ranging from headaches and dizziness to breathing and vision problems.

Dr Susan Michaelis, Stirling University's occupational and environmental health research group, said: “This research provides very significant findings relevant to all aircraft workers and passengers globally.

“There is a clear cause-and-effect relationship linking health effects to a design feature that allows the aircraft air supply to become contaminated by engine oils and other fluids in normal flight.

“This is a clear occupational and public health issue with direct flight-safety consequences.”

The study, published in the World Health Organisation journal Public Health Panorama, was the first of its kind to look in-depth at the health of aircrew.