THE UNIVERSITY OF 1 NEW SOUTH WALES Aerotoxic Syndrome by Chris Winder A thesis submitted in fulfilment of the requirements for the degree of Master of Public Health (by Research) The Faculty of Medicine The University of New South Wales August 2010 Thesis Administration 0.1.1 Thesis Cover Sheet PLEASE TYPE THE UNIVERSITY OF NEW SOUT H WALES Thesis/ Dissertation Sheet Surname or Family name: Winder First name: Chris Other name/s: - Abbreviation for degree as given in the University calendar: Master of Public Health (by research) School: Public Health and Community Medicine Faculty: Medicine Title: Aerotoxic Syndrome Abstract From 1992, adverse health symptoms were reported in Australian pilots and flight attendants following "fume events" or "exposure events" of jet oil leaking from the airplane engines into the bleed air system, environmental control system, auxiliary power unit and thence the flight deck and passenger cabin. Examination of various documents circulating within the Australian industry indicates that there was considerable effort expended to minimise this issue, with a formulaic approach of denial, bluster and misinformation. There are a variety of reasons for this, including commercial pressures, fatalism about lang standing and apparently insurmountable engineering problems, operational procedures that focus keeping aircraft flying and a culture within the industry to minimise health and safety risks. lt is concluded that these actions breach the general duty of care mandated in OHS legislation. Reporting of such incidents appears low, with an escalating chain of underreporting, from exposed personnel to airline operators and to regulators. Further, few events reported to regulators are investigated. This project uses a mixed methods approach to study this problem. In 1999, an initial analysis of seven case studies from flight crew and flight attendants in four airlines operating in four countries and in three airplane models, noted that the reported symptoms had a degree of consistency. At the time, these symptoms were given the descriptive name "Aerotoxic syndrome". From review of the ingredients in aviation oils and hydraulics, it is apparent that some contain toxic ingredients. A detailed study of the ingredients in one proprietary jet oil in widespread use indicated that it contained at least two toxic ingredients, one neurotoxic and the other a sensitiser. Ma nufacturer product information such as the Material Safety Data Base (MSDS) understated the risk of the product. Monitoring studies of air quality on airplanes are generally favourable, although most are sufficiently flawed on methodological inadequacies to render their conclusions invalid, few monitor for the hazardous chemicals of concern, and none have been conducted during a fume event. The initial study of seven cases was followed up by a second study in 2001, of fifty pilots and flight attendants. A ra nge of general, neurological, neuropsychological, respiratory, gastrointestinal, reproductive and irritancy symptoms were reported. There was sufficient commonality in reported symptoms to conclude a symptom basis for Aerotoxic syndrome. This is further supported by application of the Bradford Hili criteria for causation to the effects reported in this survey, and by later studies published in the literature. Whether or not Aerotoxic syndrome exists as a real condition remains controversial. The term certainly polarises opinion and this may not be helpful for those affected individuals seeking assistance. At best, the condition can be considered a form of Multiple Chemical Sensitivity (MCS) associated with fume events when exposed by working in the aviation industry. Declarat ion relatin g to disposition of pr oj ect t hesis/dissertation 1 hereby grant to the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all property rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. I also authorise University Microfilms to use the 350 QdY„)11/word abstract of my thesis in Dissertation Abstracts International (this is applicable to doctoral theses only). 30 October 2010 Signature Witness (Name) Date The University recognises that there may be exceptional circumstances requiring restrictions on copying or conditions on use. Requests for restriction for a period of up to two years must be made in writing. Requests for a longer period of restriction may be considered in exceptional circumstances and require the approval of the Dean of Graduate Research. FOR OFFICE USE ONLY Date of completion of requirements for Award: THIS SHEET IS TO BE GLUED TO THE INSIDE FRONT COVER OF THE THESIS Page 2 of 276 0.1.2 Originality Statement I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project's design and conception or in style, presentation and linguistic expression is acknowledged. ~„)JV Chris Winder 30 October 2010 0.1.3 Copyright Statement I hereby grant the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. I also authorise University Microfilms to use the 350 word abstract of my thesis in Dissertation Abstract International (this is applicable to doctoral theses only). I have either used no substantial portions of copyright material in my thesis or 1 have obtained permission to use copyright material; where permission has not been granted I have do not need to apply/applied/will apply for a partial restriction of the digital copy of my thesis or dissertation. ~„)JV Chris Winder 30 August 2010 0.1.4 Authenticity Statement 1 certify that the Library deposit digital copy is a direct equivalent of the final officially approved version of my thesis. No emendation of content has occurred and if there are any minor variations in formatting, they are the result of the conversion to digital format. ~„)JV Chris Winder 30 August 2010 Page 3 of 276 0.2 Table of Contents 0.1.1 Thesis Cover Sheet 2 0.1.2 Originality Statement 3 0.1.3 Copyright Statement 3 0.1.4 Authenticity Statement 3 0.2 Table of Contents 4 0.2.1 List of Figures 8 0.2.2 List of Tables 10 0.3 Acknowledgements 11 0.4 A Personal Note 12 0.5 For the Record: FAR/JAR Airworthiness Standard Section 25.831: Ventilation 14 0.6 Abbreviations Used in this Thesis 15 0.7 Abstract 18 1 Chemical Exposures at Altitude 22 1.1 Air Safety is Important 22 1.2 Air Safety, not Public Safety 22 1.3 Air Safety, not Occupational Health and Safety 23 1.4 Bleed Air 24 1.4.1 The Concept of Bleed Air 24 1.4.2 The Problem of Bleed Air 28 1.5 Industry based information 30 1.5.1 Evidence of Leaks before 1992 32 1.5.2 Early Documentation about Health Problems 43 1.5.3 The August 1992 Meeting at BAe, Hatfield 44 1.5.4 Later Actions so 1.5.5 The Australian Senate Inquiry 58 1.5.6 Discussion: Industry Based Information 59 1.6 Oil Leak Incidents 60 1.6.1 Engine Lubricating Oil and Hydraulic System Malfunctions: Sources of the Problem 63 1.6.2 Regulatory Requirements 64 1.6.3 Reporting Requirements 65 1.6.4 Evidence of Reporting of Defects 66 1.6.5 Under-Reporti ng 69 1.6.6 Discussion: Number of Incidents 70 1.7 Cabin Contamination of the BAe 146 72 1.7.1 The BAe 146 Airplane 72 1.7.2 The BAe 146 Engines 72 1.7.3 The BAe 146 Auxiliary Power Unit (APU) 76 1.7.4 The BAe 146 Environmental Control System (ECS) 76 1.8 Sources of Exposure Events on the BAe 146 76 Page 4 of 276 1.8.1 The impact of physical properties of oil 78 1.9 Control of Chemical Exposures: The Hierarchy of Controls 78 1.10 Discussion 80 1.11 References 81 2 The Aims of this Research Thesis 94 2.1 Aim of this Research Thesis 94 2.2 Research Objectives 94 2.3 Research Questions 94 2.4 Research Methodology 95 2.4.1 Introduction to Mixed Methods 95 2.4.2 The Mixed Methods used in this Thesis 98 2.5 Administrative Matters 99 2.5.1 OHS Awareness and Training 99 2.5.2 Risk Assessment 99 2.5.3 Ethics approvals 99 2.6 References 100 3 The Case Studies 102 3.1 Introduction 102 3.2 Seven Case Studies 102 3.3 Analysis 110 3.3.1 Symptoms from short term exposure 111 3.3.2 Symptoms from long term exposure 111 3.3.3 Symptom duration 112 3.3.4 Symptom severity 112 3.4 Discussion 113 3.5 Conclusion 115 3.6 References 116 4 Chemical Products used in Aviation 118 4.1 Introduction 118 4.2 The Chemical Products Used in Aviation 119 4.3 Case Study: Jet Oils 124 4.4 Mobil Jet Oil II 125 4.4.1 The Ingredients of the Oil 126 4.4.2 Pentaerythritol and Dipenterythritol and their Esters 127 4.4.3 Substituted Diphenylamine 128 4.4.4 N-Phenyl-1-naphthalenamine 128 4.4.5 Tricresyl phosphate 131 4.5 Issues that can Impact on Exposure to Jet Oils 147 4.5.1 The Impact of Altitude 147 4.5.2 Issues Related to Minimal Oxygen Content __ 149 Page 5 of 276 4.5.3 Issues Related to Vapeurs and Particulates __ 150 4.5.4 Issues Related to Combustion and Pyrolysis _ _ 151 4.6 Exposure to Jet Oils in the Occupational Environment 153 4.6.1 Exposure standard 153 4.6.2 Exposure situations 153 4.