Britain’s pilots are calling for a major investigation into the causes and effects of contaminated air in aircraft passenger cabins and cockpits and are co-ordinating the first international conference on this issue.

The British Airline Pilots’ Association (BALPA), which represents more than 8,000 of the nation’s 10,000 airline pilots, has already stressed to pilots the need to record in the aircraft technical log and air safety reports whenever cabin air becomes contaminated for any reason. Currently, almost all commercial aircraft draw the air for the cockpit and passenger areas from the engines. This is known as ‘bleed air.’ The contaminant of particular interest is engine oil.

‘There has been concern in the civil aviation industry for a long time about contamination of cabin air,’ said BALPA chairman Captain Mervyn Granshaw. ‘Now we are determined to get to the bottom of it.’

BALPA has joined forces with University College, London, and Imperial College, London, and others and submitted a detailed research proposal to the UK Aviation Health Working Group, which is part of the Department of Transport.

Also backing the proposal are cabin crew, represented by the Transport and General Workers’ Union and Amicus, and the Occupational Health Research Consortium in Aviation in North America.

To date there has been no successful measurement of cabin air quality during a ‘contaminated air event’. Of particular concern is the fact that there is no published research into the effects of repeated low-level exposure to the products of pyrolysis of fluids likely to be present in hot bleed air and its subsequent effects via inhalation on pilots, cabin crew and passengers.

Doctors treating crews and passengers following exposure to contaminated air currently have little, if any, guidance on treatment.

Although contaminated air events are generally infrequent, the contaminated cabin air issue has been of concern to some for over 20 years. For this reason it will now take centre stage at an international Contaminated Air Protection Conference being co-ordinated by BALPA and held at Imperial College, London, on April 20 and 21.

In 2004, the organophosphate TCP, PAN and other potentially toxic compounds were discovered in the cockpit air of military aircraft using the same engine oil as used in commercial aviation (Exxon Mobil Jet Oil II). It was later found in the air conditioning ducts of some commercial aircraft in the UK. This alerted the industry to the potential for long-term low-level exposure to such compounds to be harmful.

‘This gives urgency to our call for an investigation,’ said Captain Martin Alder BALPA’s Flight Safety Group chairman. ‘Evolving medical and scientific evidence supports our call for a research programme to thoroughly investigate this area of concern. Our detailed proposal offers a cost effective way of sampling ‘contaminated air events’ as they happen, suggests a medical protocol for dealing with affected crew members, and will give us a clear idea of the scale of the problem we may be facing.’