Flight safety could be “degraded” because pilots are breathing contaminated air, a study has warned.
Researchers at the University of Stirling said there was a “clear link” between being exposed to the air on planes and a variety of health issues.
Aircrew who took part in the research reported headaches and dizziness as well as breathing and vision problems.
The air on planes can become contaminated by engine oil and other aircraft fluids.
Unfiltered breathing air is supplied to aeroplane cabins via the engine compressor.
Stirling University said 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 who are suspected of exposure to contaminated air during their careers.
Scientists examined the health of more than 200 aircrew with a “clear pattern” of acute and chronic symptoms.
Dr Susan Michaelis, from the 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 researchers conducted two independent surveys to review the circumstances and symptoms of crew working in aircraft. The symptoms were then confirmed using medical diagnoses.
One test looked at pilots’ health and showed 88% were aware of exposure to aircraft-contaminated air. Almost 65% reported specific health effects, while 13% had died or experienced chronic ill health.
Prof Vyvyan Howard, from the University of Ulster, said the effects could also apply to frequent fliers, though to a lesser extent.
“We know from a large body of toxicological scientific evidence that such an exposure pattern can cause harm and, in my opinion, explains why aircrew are more susceptible than average to associated illness,” he said.
However, exposure to this complex mixture should be avoided also for passengers, susceptible individuals and the unborn.”