Cranfield University has concluded that on-board contaminant detection systems are vital for the safety of aircraft, and work to eliminate toxins from the cabin environment should be accelerated.

This follows a workshop review of measures to deal with contaminated cabin air and appears to counter recent Cranfield research carried out for the UK Department for Transport, which suggested any toxins were at low levels.

Cranfield nanotechnology head Jeremy Ramsden, who chaired a recent seminar on inhalable toxic chemicals in cabin air, said of the earlier study: "This report actually found significant concentrations of organophosphate neurotoxins and other noxious substances in cabin air, even under normal flying conditions."

While he acknowledged the results of the earlier study - that there was no evidence for target pollutants occurring at levels exceeding health guidelines - he added that the study "failed to achieve measurement of a 'fume event', even though that was one of its principal objectives".

"Even for 'normal flying conditions' the purported conclusion is irrelevant because no standards are available for some of the most problematical substances," Ramsden added.

"Despite the fact that this 'conclusion' is neither sound nor justified by the actual work carried out, it has been carelessly and uncritically quoted... and widely used to infer that there is no safety and health problem."

Ramsden said the most obvious solution is to eliminate the source of the worst neurotoxic contaminants, namely engine oil additives. However, since the additive is a highly-effective anti-wear ingredient, he suggested a more realistic method would be the retrofitting of contaminant-detection systems and bleed-air filtration.

Effective treatment of crew and passengers who have suffered neurological damage might now be practical, he added. "Highly encouragingly, successful biochemical treatments are being developed and are already available," said Ramsden.

But treatment can only be provided if the patients are informed of contamination events because, as Ramsden points out, misdiagnosis is frequent.

Ramsden said the Boeing 787 will be free of this problem because it does not use engine bleed air for cabin ventilation and pressurisation.

For other aircraft types, he said: "The mandatory inclusion of a health warning on air tickets, as on cigarette packets, would seem to be the alternative in the face of technical inaction."

Source: Flight International