More than 2 million airline passengers in the US and the UK every year could be exposed to toxins and fumes that can cause neurological damage.
'Fume events' - where chemically-laden fumes from engine oil enter the cabin - happen on around 14 flights a day in the US, and on three in the UK. This means that around 200,000 UK passengers and more than 2 million US passengers are exposed to harmful fumes and toxins every year.
Doctors are discovering that 'fume events' are becoming an occupational hazard for pilots and cabin crew, and many are suffering from fatigue, memory loss and muscle spasms. Neurophysiologist Peter Julu from the Royal London Hospital has tested 18 pilots from the US and the UK, and has identified neurological damage caused by chemicals, such as TCP (tricresyl phosphate), a compound used in nerve agents and pesticides.
Fume events occur when oil sealants weaken. A study that involved three Canadian airlines in 2002 estimated that four out of every 1,000 flights had a fume event, while the UK's Committee on Toxicity said pilots reported an event in 1 per cent of flights. This would mean that 28 flights a day in the US suffer a fume event.
Doctors stress that fume event doesn't mean that every passenger will suffer neurological damage. Any effect depends on the individual's immune system, enzyme level, and medical history, including medications.
(Sources: BBC; CNN).