Aerotoxic syndrome: evasion after evasion

I've written four previous articles about aerotoxic syndrome, the physiological effects of engine lubricants and other pollutants on cabin air quality in airliners. Flight Global reports that some progress is being made, in that the problem is officially receiving recognition and attention: but its effects are still being denied and/or played down.

Government departments in the UK and USA seem to be on the verge of making a U-turn on whether heated oil fumes in aircraft cabin air can severely damage crew and passenger health. Having previously denied it, now they seem to be preparing to admit the possibility.

Meanwhile, some airlines are fitting air treatment systems to clean up engine bleed air supplied to the cabin and teaching pilots handling techniques to reduce the number and severity of fume events.

Lufthansa CityLine is in the vanguard among airlines tackling the problem in its BAE Avro RJ85 fleet. The RJ85 is one of the BAe 146 series aircraft with a poor record of fume events, a fact established by the Australian Senate in 2000. CityLine has devised engine-operating techniques to reduce the number of incidents.

Lufthansa Cityline Avro RJ85 (image courtesy of Wikipedia)

Cargo carrier DHL also provides its crew with similar instructions for its Rolls-Royce-engined Boeing 757 fleet, which too has a relatively poor record with fume events. But whereas Lufthansa encourages reporting of incidents, DHL has advised its pilots that the occasional fume event is "normal".

DHL Boeing 757 (image courtesy of Wikipedia)

The "fume" or "smell" events occur when oil seeps from faulty engine oil seals into the compressor bleed air used to ventilate and pressurise the cabin. The air is heated in the compression process, turning the oil into aerosol particulates and fumes that are inhaled by crew and passengers. Anti-wear additives in aeroengine oil contain organophosphates that are neurotoxic if heated and inhaled. Organo­phosphates that could come into contact with humans are banned in other industries for health and safety reasons.

But although government agencies now admit that neurotoxins - for example isomers of tri-cresyl phosphate - are present in these fumes, they claim their quantities pose no threat to health. But they admit they do not know in what concentration or form (vapour or droplets) the chemicals are present.

In a re-released frequently asked question list about "cabin air quality" on its website, the UK Department for Transport now says: "The evidence available did not establish a link between cabin air and pilot ill-health, but nor did it rule one out."

It adds: "Some pilots who have experienced these events report a variety of short- or long-term symptoms or ill- health. But it is not certain that these symptoms are work related." This avoids mention of the hundreds of pilots all over the world, recorded by the Global Cabin Air Quality Executive (GCAQE) and the Aerotoxic Association with symptoms of serious long-term sickness from organophosphate poisoning that went undiagnosed for years because pilots and most doctors did not know about it. The DfT does not mention cabin crew, who have also suffered.

Explaining its current inquiry, the DfT says: "The Committee on Toxicity and the House of Lords Select Committee on Science and Technology have identified a knowledge gap. We are now trying to fill that gap. No-one has previously captured samples of cabin air during normal conditions and fume events and analysed them to see what substances they contain and in what concentrations."

Meanwhile, as the principal researcher for the GCAQE Susan Michaelis points out, there is a massive body of scientifically gathered evidence available to the DfT, but it is selective about the information it chooses. Michaelis was refused entry to a recent Aviation Health Working Group meeting.

Since then the Aerotoxic Association has called for the resignation of the chairman of the UK AHWG Sandra Webber, on the grounds that she has been colluding with British Airways' health services head Dr Nigel Dowdall to "counter the impact of lobby groups" on the fume and health issue. Dowdall also holds a senior position at the DfT. Flightglobal has seen Dowdall's letter to Webber, but BA has not replied to an invitation to comment.

There's more at the link.

I'm frankly disgusted by the attitude of the authorities, airlines and manufacturers. I can only assume that the reason for their intransigence is that they fear massive lawsuits from those affected (particularly cabin crews). I suppose they think that if they deny there's any health-related issue, they can't be sued. I suspect they'll find out in due course that they're flat-out wrong about that . . . the evidence is becoming overwhelming. Meanwhile, those of us who fly on commercial airliners would be well-advised to select aircraft (and airlines) with a minimal history of this sort of problem.

Peter