Air passengers ‘at risk from lack of oxygen.

More than half of airline passengers are so starved of oxygen at high altitude that their health could be harmed, according to a study.
The drop in oxygen levels in their blood is so severe that, were they in hospital, doctors would prescribe them extra supplies.

Experts say that poor air quality and ventilation is partly due to economies made by airlines to reduce fuel costs and extend the working life of aircraft.

In the study, a team of Belfast researchers measured oxygen saturation levels – the amount of oxygen carried in the blood.

Before take-off, levels averaged 97 per cent but these fell to 93 per cent at altitude.

For 54 per cent of travellers, the fall in oxygen levels was at least 6 per cent – a level at which many hospital doctors would prescribe extra oxygen.

The results were similar for both short-haul and long-haul fliers, according to the research published in Anaesthesia, the official journal of the Association of Anaesthetists of Great Britain and Ireland.

The 84 passengers who took part in the tests were aged between one and 78. None had severe cardio-respiratory problems and no one required permission from their doctor to fly.

Dr Susan Humphreys, anaesthetic specialist registrar, said research showed that a drop in oxygen levels in the blood can lead to an increase in blood clotting, which raises the risk of a deep vein thrombosis even in healthy people.

Illness Link

“We believe that these falling oxygen levels, together with factors such as dehydration, immobility and low humidity, could contribute to illness during and after flights,” she said.

“This has become a greater problem in recent years as modern aeroplanes are able to cruise at much higher altitudes.”

Dr Humphreys said oxygen deficiency can result in impaired mental performance and shortness of breath.

It can also worsen conditions such as angina and breathing problems.

Experts believe that a significant number of passengers travel with medical conditions that could put them at risk.

Farrol Kahn, of the Aviation Health Institute, a medical research charity promoting better health for passengers, said surveys show that around 10 per cent of travellers are unfit to fly.

“Oxygen reduction particularly affects people with pre-existing conditions, the old and very young, as infants can get into difficulty if they have insufficiently developed lungs,” he said.

“Economies play a role because if the altitude pressure is routinely changed on existing aircraft it cuts their working life.

“But passengers can ask for extra oxygen to be supplied to a section of the cabin and cylinders are available for giving individuals supplementary oxygen.”

Mr Kahn said travellers with cardiovascular disease or respiratory diseases such as bronchitis and asthma should have preflight checks, along with the over-50s, to ensure they were fit to fly.

“The conditions on board, especially long-haul flights, put special stress on essential organs such as heart and brain,” he added.

“At the Institute we provide medical advice to GPs who are concerned about whether a patient can fly after a stroke, for example.”

Mr Kahn said ventilation was cut on some flights to save fuel and, by making passengers sleepy, cut down on extra services needed on board.

A report on the risks of flying from the House of Lords select committee on science and technology said there should be display cards at every ticket sale point and in every doctor’s surgery asking intending passengers: “Are you fit to fly?