A study has suggested that the health of pilots and aircrews could be negatively affected by extended exposure to contaminated air within aircraft.

Research carried out by the University of Stirling, which is believed to be the first of its kind, looked in depth at the health of pilots and crew who are suspected to have been exposed to contaminated air during their airborne careers.

The study concluded there is a clear link between being exposed to air supplies contaminated by engine oil and other aircraft fluids and a variety of health problems.

The researchers confirmed that over 200 aircrew had been exposed to various substances via aircrafts' contaminated air. It revealed a pattern of acute and chronic symptoms, including headaches, dizziness, breathing difficulties and problems with vision.

Two different surveys were carried out to look at the various circumstances and symptoms of working in aircraft where the air is pressurised. The symptoms were then confirmed using medical diagnoses.

One test reviewed pilots' health, and demonstrated that 88% were aware of exposure to aircraft contaminated air. Almost 65% reported specific health problems, while 13% had either passed away or experienced chronic ill health.

The other test looked at specific incidents such as oil leaks. 80% of these involved fumes only and all of the events took place when the aircraft was being prepared for, or actually in-flight.

Two-thirds of the incidents involved further reports of fumes. Over 90% involved symptoms ranging from in-flight impairment to incapacitation. Over 70% included situations where symptoms affected more than one crew member and anywhere between 10 and 23 differing symptoms were reported in connection with 47% of events.

Over 80% of the incidents confirmed oil leakage from the engines during subsequent maintenance investigations.