Report by the Rural and Regional Affairs and Transport References Committee of the Australian Senate

Air Safety and Air Quality in the BAe 146 Aircraft

Published October 2000

Background

In late 1999 and during the year 2000 the Australian Senate Rural and Regional Affairs and Transport References Committee undertook an inquiry into air safety with particular reference to the BAe 146 aircraft. Written submissions to the inquiry considered by the Committee, both public and confidential, provide evidence of more than 700 incidents in the last 15 years where fumes have been reported to have entered the cabin and contaminated the cabin air on BAe 146 aircraft operating in Australian airspace.

In the final report many recommendations are made which encompass the issue of cabin air quality on commercial passenger aircraft in general, and it examines whether current regulatory requirements and technical standards are adequate in relation to a range of health standards including cabin air quality.

Summary of main points

• In relation to the BAe 146, there has been for some time a an occupational health effect suffered by a number of aircrew and cabin crew flying the BAe 146.
• There have been recorded incidents, in Australia and elsewhere, involving BAe 146 during which air quality on the aircraft has deteriorated during flight to the extent that aircrew and cabin crew experienced effects such as dizziness, nausea and disorientation.
• The BAe 146 aircraft has been operating in many countries for some 15 years and has, according to available records, been involved in 5 accidents in which lives were lost.
• As well as a record of unpleasant odours … fumes from the lubricating oil used in the aircraft’s engine have entered the aircraft’s cabin.

Toxicity of engine oil additive TCP/TOCP

The ingredient of Mobil Jet Oil II identified as a possible source of neurotoxic effects is TCP. Mobil accepts that it has been known for many years that TCP contains neurotoxic components. Jet engine lubricants can typically contain up to 3% TCP as an anti-wear agent. All engine oils tested to date contain, among other compounds TCP isomers. TCP has been associated with neurotoxic properties. When heated to decomposition it can emit highly toxic fumes of phophorus oxides… The critical effects of TCP include delayed neuropathy and reproductive toxicity ascribed to the TOCP isomer. In reproductive toxicity studies on rats and mice, TOCP has been shown to cause histopathological damage to the testes and ovaries, morphological changes to sperm and decreased fertility.

Professor Chris Winder, Head of the School of Safety Science, University of New South Wales, said:

"I believe that TCP is the particular chemical that causes the neurological problems the staff on 'planes have been exposed to... Symptoms reported by individuals after exposure to fumes... were sufficiently consistent to indicate the development of a discrete occupational health condition."

This condition was described as "aerotoxic syndrome". Professor Winder said: "This syndrome may be reversible following brief exposures, but a picture is emerging of a chronic syndrome following significant exposure".

The inquiry concluded that "The majority of the submissions to the inquiry from medical/occupational health professionals point to components of Mobil Jet Oil II as a source of health problems".

Medical Evidence of Effects of Fumes

Various witnesses indicate that, until this inquiry was given publicity, there had been a series of problems relating to unwillingness to accept that the issue of TCP/TOCP fumes in jet aircraft was an issue.

Professor Winder said:

"The response of airlines to staff showing symptoms of toxicity has shown a lack of understanding of duty of care to employees. Information issued to staff on the issue has attempted to minimise the problem using the language of public relations. The basic approach to injured staff appears to be adversarial. Staff have been bullied and victimised... Workers have been forced to persevere working in conditions that continue to aggravate their health, in some cases to permanent incapacity. Other staff have been offered demeaning duties, and genuine attempts at rehabilitation have been lacking."

To back up this statement there was evidence given by an independent medical professional, Dr Mark Donahoe, in relation to his treatment of a number of Ansett aircrew. In it he says:

"There are political and medical interests that have clouded the nature of inquiring into medical and health problems and into safety issues of the jet. Back in 1988 when I was first contacted by the Chief Medical Officer of Ansett and asked to a meeting, it was the first and only time that I can recall in dealing with employees of a company, that a medical officer has made an attempt to get me to change my views on the health of patients I had seen. At the time I felt that there was a threat - an implied threat more than a direct threat - that it would be in my interests to withdraw statements that I had made about safety on the jets and the health of the people I had seen who had been flying on those jets... Never before, and never since, has any commercial body, where there has been a question of injury to employees, attempted to bring me into a meeting to influence my views and to ask directly for a retraction of my views".

This statement is supported by evidence from aircrew and cabin staff, and one hopes that there would be no repetition of such reactions in the UK.

Dr Robert Loblay, a medical professional, gave evidence arguing that there are no health effects as a result of exposure to fumes. Unfortunately his evidence consisted of attacking the personal and professional integrity and status of other witnesses. He did not supply a written submission to the inquiry.

The report acknowledged the difficulty in collecting evidence of damage to health from fume exposure:

"The majority of the professional witnesses to the inquiry highlighted the absence of clinical testing of flight crew and passengers immediately after their exposure to fumes. In the absence of equipment sensitive enough to detect all potential chemical components present in human tissue following a fume exposure incident, it appears difficult to measure the health consequences of fume exposure".

Symptoms of Illness

There was a commonality within the symptoms reported by affected flight crew exposed to fumes on aircraft which can be summarised as follows:

dizziness, nausea ; vomiting; headaches; head pressure; numbness; tingling; irritations to eyes, nose and throat; breathing and vision difficulties; fatigue; weakness; cognitive dysfunction; concentration difficulties; disorientation; confusion; chemical sensitivities and neurobehavioural difficulties.

Professor Winder listed long and short term symptoms exhibited by affected people he had interviewed who had flown on BAe 146. Symptoms from single or short term exposures included:

neurotoxic symptoms:

blurred or tunnel vision, nystagmus, disorientation, shaking and tremors, loss of balance and vertigo, seizures, loss of consciousness and parathesias;

psychotic symptoms:

memory impairment, headache, light-headedness, dizziness, confusion and feeling intoxicated;

gastro-intestinal symptoms:

nausea and vomiting;

respiratory symptoms:

cough, shortness of breath, tightness in chest, respiratory failure requiring oxygen;

cardiovascular symptoms:

increased heart rate and palpitations.

Professor Winder also listed similar symptoms from long-term low level exposures or long-lasting residual symptoms from exposure events, and in addition he listed lack of co-ordination, sleep disorders, susceptibility to upper respiratory tract infections, skin symptoms such as rashes and hair loss, signs of immunosuppression multiple chemical sensitivity and chronic fatigue, exhaustion, hot flushes, joint pains and muscle weakness and pain.

Conclusions

The Committee noted that:

• "While the BAe 146 is not unique among jet aircraft regarding the entry of oil fumes into the passenger cabins and cockpits, it has been the focus of the majority of complaints made to Australian airlines… the Committee also notes that several other aircraft have been identified during the course of the inquiry as suffering similar problems… including A320s and MD90s".
• "Four Australian pilots gave evidence to the inquiry detailing incidents in which they had been affected by fumes entering the cockpit… and that a serious incident of pilot incapacitation on a BAe 146 was reported in Sweden in November 1999".

Recommendations

The report made the following recommendations (among others):

• The Committee recommends that the Australian Civil Aviation Safety Authority (CASA) should set up a specific national standard for checking and monitoring the engine seals and air quality in all passenger commercial jet aircraft.
• The Committee recommends that incident reports should now be specifically designed so as to reflect the history of the cabin air problem that has been encountered in the BAe 146.
• The Committee recommends air quality monitoring and compulsory reporting guidelines for all passenger jet aircraft operators.
• The Committee believes that development of an appropriate and accurate test for the presence of any chemical fumes in aircraft is essential... and accordingly recommends that CASA liaise with operators to develop a standardised, compulsory monitoring program which provides for testing cabin aircraft air during fume events.
• The Committee recommends that the issue of air quality be reviewed by the National Occupational Health and Safety Commission with a view to including aerotoxic syndrome in appropriate codes as a matter of reference for future workers compensation and other insurance cases.
• The Committee recommends that the Minister for Transport request the Strategic Research Development Committee of the National Health and Medical Research Council to set up and undertake an appropriate research program on the effect of exposure to aircraft cabin air on aircrew and passengers.
• The Committee recommends that the potentially hazardous chemical components of Mobil Jet Oil 11 be referred to the National Industrial Chemical Notification and Assessment Scheme as a priority for review and assessment.
• The Committee recommends that CASA assess how quickly fitting appropriate high-grade air filters can be made mandatory for all commercial airliners flying in Australia, to minimise any deleterious health effects arising from poor aircraft cabin air on crew and passengers. In view of proposed standards currently under consideration in the USA and elsewhere, such a system should be designed to remove at least 99% of particles 0.3micron or larger from recirculated cabin air.