Research findings imminent on the neurological damage allegedly caused by toxic effects of aircraft cabin air
The BAe 146 has been singled out as a possible toxic cabin air offender. Its manufacturer, BAE Systems, has just launched a new cabin air management system (photo: BAE Systems)
Thu 24 Sep 2009 – Researchers in the UK and the US are getting closer in coming up with a definitive answer on the effects of toxic aircraft cabin air on pilots, crews and passengers. The condition, called Aerotoxic Syndrome, has been highlighted over many years but no firm evidence has yet been found to indicate a major problem exists and aircraft manufacturers have denied there is a link between reported neurological health problems and engine faults that could result in dangerous toxins being pumped into cockpits and cabins. Separate findings are due to be published by the University of Washington and Cranfield University within the next six months. Meanwhile, BAE Systems is to introduce a radical new aircraft cabin air management system that claims to eliminate all airborne viruses, bacteria and contaminants.
Half of the air onboard an aircraft is recycled with the remainder drawn through the jet engines, known as bleed air, which is pressurized, cooled and pumped directly into the aircraft through the ventilation system without passing through air filters. It is thought this bleed air can become contaminated with poisonous chemicals from engine lubricating oils, hydraulic fluids and de-icing fluids. Studies have identified toxic chemicals called tricresyl phosphates – or organophosphates – as being of particular concern.
Clement Furlong, Professor of Medicine and Genome Sciences at the University of Washington, believes that these toxins can enter the aircraft cabin if engine seals fail.
Over the past two and half years, Furlong and his team have been analyzing blood samples from 92 individuals, mostly pilots, cabin crew and frequent flyers, who all suffer from unexplained chronic illnesses which they attribute to exposure to toxic cabin air. According to Furlong, the analysis will be completed within the next few months.
Asked by CNN why only a few flyers were affected, Furlong said just a small percentage of people appear to be hypersensitive to the most toxic chemicals, perhaps as a result of genetic disposition, having abnormal expression of proteins that metabolize toxins in the liver or from high enzyme levels that can be triggered by prescription drugs or alcohol. It is a similar condition in which some people are hypersensitive to minute amounts of chemicals including perfume and fragranced products, cleaning and personal care products, vehicle exhaust and cigarette smoke.
The Australian Civil Aviation Safety Authority last year established a committee in conjunction with the Cabin Air Quality Reference Group – an airline, union and industry body – to examine the issue. It is due to report early next year in which recommendations will be made on whether further research is required or other appropriate action should be taken.
It appears there are no accurate figures for the number of so-called ‘fume events’ but it is estimated they occur on around one in 2,000 flights, according to the independent UK Committee on Toxicity.
Dr Peter Julu, a consultant neurophysiologist at the Breakspear Clinic in Hertfordshire, UK, the Royal London Hospital and Aalborg University in Denmark, told the BBC that new evidence of a direct link between fume contamination and neurological damage in pilots has been uncovered. He has tested 18 pilots that show they suffered chronic low-level exposure to organophosphates.
In 2007, the UK’s Department of Transport commissioned Cranfield University to investigate the problem. Professor Helen Muir told the BBC that she expected to report her findings in six months’ time. She said the question is not whether the chemicals are on the flight deck but whether they were in sufficient quantities to cause harm.
“My report will simply be a detailed analysis of what we find. It will be then up to the medical side to determine whether what has been found in the atmosphere that has the potential to cause some of the illnesses that have been reported.”
If the link is scientifically proven, airlines and aircraft manufacturers could find themselves facing compensation claims from pilots, crew and passengers who have suffered from the Aerotoxic Syndrome.
Leading the campaign on behalf of sufferers is the Aerotoxic Association, started by a group of former air crew who say their careers were brought to a premature end as a result of the syndrome. In the US, a website called Toxic Cabin Air is also drawing attention to the issue.
Two aircraft in particular have been singled out as suspect offenders: the Boeing 757 and the BAe 146. In a statement to the BBC, Boeing said: “It is our belief that air quality on airplanes is healthy and safe. This belief is based on a number of studies that show measured contaminant levels are generally low and that health and safety standards are met.”
Similarly, BAE Systems said the air quality on its BAe 146 had been shown by independent studies to exceed international standards.
Coincidentally, BAE Systems announced last week that it had joined forces with Quest International UK to introduce a radical new active cabin air management system. Named AirManager, BAE Systems claims it will “eliminate all airborne viruses and bacteria and will set a new standard for clean air on board passenger and cargo aircraft.”
The company has obtained full safety certification for the installation of the new system on its BAe 146/Avro RJ airliners, and stated trials were already underway on Boeing 757 aircraft. It said designs for other aircraft types would be determined in line with market demand, with initial efforts expected to focus on narrowbody Airbus A320 and Boeing 737 airliners.
Sean McGovern, Operations Director of BAE Systems’ Regional Aircraft business, said: “At a time when there is increasing concern about the transmission of infections on aircraft, together with the continued debate about the quality of air on board aircraft, we are making benchmark technology available to the world’s airlines to allow them to address the widest possible challenges to cabin air quality. Our combined approach has raised the bar to a new level.
“There are also potential fuel savings, as AirManager allows the air conditioning system to operate more effectively. We believe this saving will at least cover the purchase cost in the first year.”
Originally developed for use in the health sector, the patented system uses a revolutionary Close Coupled Field Technology – a contained and safe electrical field that eliminates smells, and breaks down and destroys airborne pathogens, contaminants and toxins.
David Hallam, inventor of the technology and Director of Quest International UK, explained: “The main strength of this technology is its ability to destroy a wide range of contaminants very quickly. It achieves a single-pass kill rate of 99.999% of bio-hazards and removes particles down to below 0.1 micron, equivalent to a single particle of cigarette smoke.”
BAE Systems said that the four-year scientific research programme to verify the technology had included tests on pyrolized engine oils, hydraulic and de-icing fluids. It said the filter system destroyed the tiny amounts of resulting Volatile Organic Compounds (VOCs) in one pass by breaking the compounds down into single harmless anatomical parts.