Cabin Air Quality – Cutting Through the Information Smog

1. Cabin Air Quality – Cutting Through the Information Smog Assoc. Prof. Bhupi Singh Acknowledgements: Capt. Susan Michaelis. Editor, Aviation Contaminated Air Reference Manual 2007 Flight International Crew Management Conference, 05-06 Oct 2007, Brussels, Belgium

2. Contamination of cabin/cockpit Combustion products of engine oils/lubricants via ECS. Unfiltered Engine ‘Bleed Air’ used for cabin pressurisation and ventilation Oil/lubricants Produce complex hydrocarbons on being heated Many of these HCs are highly toxic (OPs, TCP) Symptoms Passengers – health concerns Aircrew – health concerns & flight safety implications Exposure Standards The Cause-and-Effect relationship What to do? The Problem

3. More common than is generally realised Under-reporting is the norm Incidence of In-flight Smoke & Fumes Events • Events considered by many as non events, nuisance, or a necessary evil • Often has NO visible fumes • Usually has a faint smell, but not always • Often seen as the ‘normal aircraft smell’ • No universal reporting system • Lack of adequate awareness

4. Incidence of In-flight Smoke & Fumes Events: Civil Aviation • Simply unknown • Anecdotal reports – plenty • FAA Bulletin 8300.10 provides guidance for reporting, but not all operators are reporting • No universal, standardised reporting system • No reliable data overall • Most comprehensive data is in ACARM

5. ACARM: Michaelis 2007 15 events/1000 flights(1 in 66) – APH 2000 3.88 incidents /1000 flights - NRC 2002 46 fume events in 3 months - 1 UK airline (2007) 1050 contaminated air events - UK database Incidence of In-flight Smoke & Fumes Events: Civil Aviation

6. Incidence of In-flight Smoke & Fumes Events: UK Airlines

7. A robust reporting system (Aviation Safety Occurrence Reports – ASORs) Mandatory reporting for ALL safety critical events Incidence of In-flight Smoke & Fumes EventsAustralian Defence Force

8. Incidence of In-flight Smoke & Fumes Eventsper 1,000 flying hours (1997-2007)Australian Defence Force Aircraft

9. All ADF 0.559 Royal Australian Air Force 0.651 Australian Army 0.235 Royal Australian Navy 0.641 Incidence of In-flight Smoke & Fumes Events per 1,000 flying hours (1997-2007)Australian Defence Force Aircraft S&F events last 10 years = 67 per year

10. Incidence of In-flight Smoke & Fumes Events per 1,000 flying hours – ADF AircraftYear-wise: 1997 - 2007

11. Incidence of In-flight Smoke & Fumes Events per 1,000 flying hours – ADF Aircraft Aircraft-wise: 1997 - 2007 Kaman SH-2G Seasprite 2.475 Westland Sea King Mk50 1.668 Lockheed P-3C Orion 1.633 General Dynamics F-111 1.284 British Aerospace HS748 1.083 Eurocopter ARH Tiger 0.967 CT4B Basic Trainer 0.806 DHC4 Caribou 0.742 Dassault Falcon 900 0.620 Boeing 707-338C 0.572 BAe Hawk 127 0.550 Lockheed Hercules C130 0.550 Bell UH1H Iroquois 0.547 Sikorsky S70B2 Seahawk 0.435 Pilatus PC-9/A 0.403 Kingair B200/350 0.340 DHC-6 Twin Otter 0.336 AS350B Squirrel (Navy) 0.326 Sikorsky S70A Blackhawk 0.315 Boeing F/A-18 Hornet 0.276 Bombardier Challenger 604 0.108 Boeing CH47D Chinook 0.087 Bell 206B1 Kiowa 0.085 AS350B Squirrel (Army) 0.042

12. Incidence of In-flight Smoke & Fumes Events No aircraft type is immune No operator is immune

13. Loss of Cabin Pressure VsSmoke & Fumes Events Loss of cabin pressure 8.2/100,000 hrs Smoke & Fumes 56/100,000 hrs Smoke & Fumes Incidence: 680% higher

14. Constituents of Smoke/Fumes • Combustion products of oil/lubricants • Complex hydrocarbons, organophosphorus compounds • VOCs and particulate • Many of these are highly toxic • Most investigated: Tri-Cresyl Phosphate (TCP)

15. Tri-Cresyl Phosphate (TCP) • Ortho-, Meta-, and Para- isomers • Tri Ortho-Cresyl Phosphate (ToCP) has known neurocognitive effects • Di– and Mono- Ortho Cresyl Phosphate are more toxic TOCP toxicity = X DOCP = 5X MOCP =10X

16. TCP Toxicity • Toxic by inhalation/ingestion/skin absorption • Irritant of skin, eyes, respiratory tract • Cholinesterase Inhibitor • Synergistic effect of chemicals • Sensitisation with repetitive low level exposures (hypersensitivity type reaction)

17. Respiratory tract Irritation, sore throat, dry cough Shortness of breath Burning-like discomfort Sneezing, runny nose Eyes Irritation, pain Discomfort with lights Gritty sensation Blurred vision Dryness/watering/redness Systemic Confusion/drowsiness/headache/dizziness Disorientation/Vertigo Tingling or numbness Difficulty concentrating Impairment of Short term memory Tremors Nausea/ vomiting/abdominal pain Common Symptoms

18. Animal (rats) studies 1995, sponsored by USAF Armstrong Laboratory, Dayton, OH Microscopic lesions in brain, spinal cord within hours of exposure A single exposure – nerve cell damage/death (axonal degeneration) after 8-10 days Significant suppression of enzyme neurtoxic esterase (NTE) Organophosphorus Induced Delayed Neuropathy (OPIDN) Lipscomb J. Inhalation toxicity of Vapour Phase Lubricants. USAF Armstrong Laboratory Report AL/OE-TR-1997-0090 Laboratory Evidence of TCP Toxicity

19. NTE InhibitionSevere Spinal Cord damage 77-99% 100% 61-71% 90% 51-63% 15% 31-41% 7.5% 15-21% 0 Lipscomb J. Inhalation toxicity of Vapour Phase Lubricants. USAF Armstrong Laboratory Report AL/OE-TR-1997-0090 TCP Toxicity

20. Long term effects are controversial, may include: Neurological effects CNS,PNS: Jamal 1997. Jamal, Julu… 2002, 2005 Autonomic nervous system. Jamal, Julu… 2002, 2005 Working memory / cognition. Coxon 2002 / Mackenzie Ross 2006 OPIDN. Abou-Donia 2004 Respiratory disorders: Burdon 2005 Immune system effects, fatigue, chemical sensitivity etc.. Blood pathology disorders Strong occupational link: Cone 1983,1999 / Harper 2005 TCP: Chronic Toxicity

21. Short and long-term health effects Effects seen are supported by published data 2007 BAe 146 pilot health survey: preliminary data (n=242) 86% acknowledge exposure to contaminated air. 57% report short, medium or long-term health effects. 25% report medium to long-term health effects. >8% early medical retirement or loss of medical. Crews being diagnosed / misdiagnosed with MS, Parkinsons, CFS, MND, Alzheimer's, depression, PTSD, bipolar disorder… Aerotoxic Syndrome Health Concerns

22. Neuronal & Glial Antibody Test Results in 13 Pilots After Exposure to Fumes(Donia A – Duke University, 2005) Antibody Reference level = 100

23. C-130 Hercules navigator, healthy 34 yo Exposure Inhalation of cockpit fumes Symptoms Headache, dizziness, incoordination, postural instability Nausea, vomiting, sweating, Symptoms disappeared in 24 hours Signs Depressed tendon reflex, unequal pupils Effects still present 9 months after exposure The aircraft had a history of cabin contamination Cabin ToCP levels up to 175ppm Montgomery MR et al. (Pulmonary Disease Unit VA Hospital, University of Minnesota). Clinical toxicology 11(4), 1977:423-6. A case Report

24. TCP Detected in B747, B777, B767, B757, B737, A330, BAe146, MD80 Flight deck & cabin walls/roof top filters, HEPA filters Aircrew clothing Aircraft ducting (CAA 2004) Cockpit/cabin (RAAF 1988, 2005) Honeywell (1997,2000) Allied Signal (1997) Many other contaminants identified TCP in Cockpit & Cabin Air

25. ToCP in Cockpit & Cabin AirRAAF Studies APU on, Engine off 1.0 g/m3 1.1 g/m3 2.9 g/m3 APU off, Engine on 0.01 g/m3 ToCP Exposure standard: • TWA concentration of 0.1 mg/m3 = 100 g/m3 • No exposure standard for other isomers

26. Pilots require High level cognitive skills Reaction times, short term memory, decision making Highly vulnerable to chemical insult Many OPs and HCs have neurocognitive effects even on extremely low doses More pronounced at critical phase of flying Some aircrew may become sensitized due to repetitive exposures Potential flight safety hazard Flight Safety Implications

27. Cause and Effect? • Exposure events well documented • Symptoms consistent with known effects of the chemicals • Temporal relationship between exposure and symptoms • Long-term & irreversible effects reported • Effects reported are occuring below individual exposure standards • Synergistic effect • Individual sensitisation • Evidence of microbiological effects in exposed aircrew • Strong occupational link

28. Mortality among US commercial pilots and navigators in comparison with general population (1984-1991) Results - US pilots and navigators have significantly higher mortality rates due to: cancer of the kidney and renal pelvis prostate cancer brain cancer colon cancer and cancer of the lip, buccal cavity, and pharynx motor neuron disease Mortality was significantly decreased for 11 causes. Health outcomes are related to occupational exposures? Large epidemiological studies required. Nicholas J et al (Medical University of South Carolina). Journal of Occupational & Environmental Medicine: Volume 40(11) November 1998 pp 980-985 Cause and Effect?

29. Aviation environment is largely artificial. A number of stressors: Cabin air quality Cosmic radiation Magnetic fields generated by the aircraft system Mild hypoxia Reduced atmospheric pressure Low humidity Circadian disruption Noise Vibration Cause and Effect?

30. Aviation environment is largely artificial. A number of stressors: Cabin air quality Cosmic radiation Magnetic fields generated by the aircraft system Mild hypoxia Reduced atmospheric pressure Low humidity Circadian disruption Noise Vibration Cause and Effect?

31. Temporal Relationship: exposure precedes disease Strength: Statistical Correlation Dose-Response Relationship Consistency: replicable results Plausibility: consistent with known pathophysiology Alternate Explanations Experiment: laboratory studies Specificity: single specific cause Coherence: consistent with current state of knowledge Hill’s Criteria of Causation (1965)Austin Bradford Hill 1897-1991 (no paradigm shift in reasoning required)

32. Ethical question Easy to answer What would we do if it was our health, our life Why take a chance Err on the safe side Precautionary principle Do the best we can, ALL we can, to avoid exposure Legal question Difficult, but perhaps more important Enforceable Recent legal/legislative changes What to do?

33. Significant changes in OHS legislation Lower tolerance to occupational hazards EU Article 137 (Feb 2007) Transfer of burden of proof re testing & risk evaluation of chemicals from authorities to industry Individual responsibility Reasonable steps to protect the public Substitution with safer alternatives Canadian Bill C-45 (31 Mar 2004) Australia – National OHS Strategy 2002-12 OHS Legislation

34. The burden of proof on the victim is rather light The victim is only required to prove that the event COULD HAVE contributed to, or exacerbated, the condition The burden of proof is heavy on the employer The employer must prove that the exposure did not cause the condition But…debate can continue Let’s get on and do what can be done Duty of Care

35. Recognise Exposure is occurring, aircrew being adversely affected Toxic fumes a strong candidate as causative agent Strong cause-and-effect link, debate only academic Minimise exposure, Preventive measures Alternate technologies for ECS, filters Substitute - alternate oils/hydraulics Protocols for inflight management Protocols for medical management (FAA, OHRCA) Administrative – regulate compliance Public awareness - demand high quality cabin air More research Epidemiological studies Tests of exposure Aviation specific exposure standards What to do?

36. ToCP Exposure Standard ToCP Exposure standard: • TWA concentration of 0.1 mg/m3 of TCP = 100 g/m3 of TCP • No exposure standard for other isomers TOCP toxicity = X DOCP = 5X MOCP =10X Exposure standards outdated/inappropriate

37. Exposure Standards • ACGIH & OSHA Standards • Developed in the 40s and 50s • Based on animal studies and on morbidity/mortality • Cockpit/cabin are unique workplaces • Complex tasks, require high level of cognitive skills, • Neurocognitive skills are more sensitive insult Existing industrial standards inapplicable to aviation

38. Exposure Standards What should be the correct standard? • Perhaps nobody knows • Perhaps need to be lowered by a factor of 100 • Best to avoid ALL exposure until we know better

39. Protocols for in-flight management Quick detection of events (indoctrination) Prevention of exposure (protective equipment) Protocol for medical mgmt Robust reporting system Follow up RAAF Management of Toxic Fumes

40. Passengers Acute, short-term Invariably by inhalation Minor impairment may be significant Short-term, neuro-cognitive effects No standards Aircrew Undetected, low level, repetitive, chronic long-term effects, chronic effects Inflight Exposure

41. 100% Oxygen (closed system), or filter Below 10kft Depressurise, ventilate Above 10kft Depressurise, ventilate Twin problems (hypoxia, decompression) Descend Divert, Land ASAP Medical management Documentation & Reporting Management of an Incident

42. Time of Useful Consciousness 71±16sec TUC, seconds Altitude, feet

43. Respiratory and eye protection Compatible with the aircraft comm system Compatible with spectacle use Flame retardant On/off switch Demand system Flow rate of 35L.min-1 Endurance requirement 25 minutes’ (ASIC) 15 minutes’ (FAR) Protection Against Smoke & FumesSystem Requirements

44. Available Systems • Passengers • Emergency Passenger Oxygen System (EPOS) An ideal system for all situations does not exist • Cockpit crew • Full-face mask • plumbed oxygen • Mobile aircrew • Portable Oxygen System (POS)

45. Expectation of workplace safety A known problem, with increasing awareness Constant search for cause-and effect link Best to get on with it - avoid all exposure Not unlike the problem of climate change There will always be sceptics In the meanwhile, are we abdicating our responsibilities to the crews/travelling public? Summary

46. Royal Australian Air Force Institute of Aviation Medicine RAAF Base Edinburgh 5111 South Australia Thank You, and G’day