Aerotoxic Syndrome is discussed in this article from Aircraft Interiors International with Dr. Craig Lawson/ Cranfield University (12 December 2020).
‘Many crew have had careers cut short and they have attributed this to the so-called aerotoxic syndrome. Research so far has not got to the bottom of this issue.’
“Anecdotal evidence needs to be backed up by robust scientific research to gain a full understanding of what these toxins are, quantities and frequencies of exposure, and their effect on health. Then we can engineer solutions to prevent aerotoxic events. Since cabin air is taken from the engine, engine fluids are likely to be the root cause, which could be filtered out with better understanding. Another solution is to use atmospheric air to pressurise the cabin, like the B787 does.”
Source: https://www.aircraftinteriorsinternational.com/features/improving-cabin-air-quality.html
A few points we would like to raise from above article:
• Aerotoxic Syndrome is not a medically recognised illness hence it still being labeled as ‘so called Aerotoxic Syndrome’. This is due to the reluctance of many parties within Governments, health organisations and agencies/institutions including the NHS in the U.K. to acknowledge its existence and grant an ICD-10 classification code. https://www.who.int/standards/classifications/classification-of-diseases
• Those suffering from Aerotoxic Syndrome have to accept partial diagnosis or possible misdiagnosis of their injuries until Aerotoxic Syndrome becomes fully acknowledged & recognised and a complete, robust NHS Care Pathway is created in the U.K. which would include toxicology testing.
• Exactly what ‘research so far’ is Dr. Craig Lawson referring to? Does he mean the research recommended in the House of Lords enquiry in 2007, most of which still has not been actioned to date?
• P34 - House Of Lords Enquiry 2007.
Recommendations:
4.49.We recommend that the CAA carries out an awareness campaign aimed at airlines and pilots to highlight the importance of reporting contaminated air events and encourages airlines to follow the spirit as well as the letter of the rules on reporting these events.
4.50.We recommend that the AHWG-sponsored research to identify the substances produced during a fume event be completed urgently. It should be followed up by an epidemiological study on pilots to ascertain the incidence and prevalence of ill health in air crew and any association there might be with exposure to the chemicals identified in the AHWG-sponsored study, paying particular attention to the synergistic effect of these chemicals.
4.51.We recommend that the Government works with manufacturers, airlines and the regulator to take effective action in preventing oil and hydraulic fluid leakages into the aircraft cabin.
4.52.We recommend that a protocol should be made available to health professionals, in particular Authorised Medical Examiners, on how to deal with air crew who suffer contaminated air events. We recommend that airlines, the regulators and the Government work together to improve the support given to pilots claiming to suffer ill health following a contaminated air event.’
https://publications.parliament.uk/pa/ld200708/ldselect/ldsctech/7/7.pdf
• However, there has been much research since 2007, most of which has been ignored by the Aviation Industry and U.K. Government. Here are a few examples:
https://www.gavinpublishers.com/articles/review-article/Nanomedicine-and-Nanoscience-Research/is-a-cumulative-exposure-to-a-background-aerosol-of-nanoparticles-part-of-the-causal-mechanism-of-aerotoxic-syndrome
https://www.fortunejournals.com/articles/a-series-of-three-aircraft-emergency-public-health-alerts-at-an-international-airport-over-a-six-week-period-due-to-suspected-cont.html
https://www.euro.who.int/__data/assets/pdf_file/0019/341533/5_OriginalResearch_AerotoxicSyndrom_ENG.pdf
https://www.researchgate.net/publication/346642206_Cabin_Air_Contamination_Events_Teaching_Paper
http://fdx.alpa.org/portals/26/docs/053116_ESC%20Counterpoint.pdf
https://scholars.unh.edu/cgi/viewcontent.cgi?article=1425&context=risk
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3839637/
http://bleedfree.eu/wp-content/uploads/2016/01/18DA14R.pdf
There are many more studies listed here https://www.aerotoxicteam.com/science.html
Dr. Craig Lawson (Cranfield University/U.K.) states that they need ‘a full understanding of what these toxins are, quantities and frequencies of exposure, and their effect on health.’ Here you are Dr. Lawson: EASA published their findings of so far 127 substances, check here: https://www.aerotoxicteam.com/easa-list.html
Information is readily available online (for anyone who wishes to find it), on the harm caused to human health from these toxic chemicals. Here are just a few examples of some of the chemicals found in samples of body fat taken from of aircrew:
Toluene:
‘Toluene can cause irritation to the eyes, throat, lungs and skin. Toluene can be absorbed through the skin and pass into the blood stream although this is rare. Breathing in vapours from toluene can cause irritation to eyes, nose, throat and airways. Once in the blood system it can cause drowsiness, dizziness, headache, sickness and memory problems. Exposure to large amounts of toluene (e.g. from glue-sniffing) can cause permanent damage to the nervous system, coma, heart problems and even death.’
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/659914/Toluene_general_information.pdf
Benzene:
‘Long-term exposure to lower concentrations of benzene can result in:
• bone marrow suppression leading to serious blood disorders such as anemia;
• cancer – forms of leukemia and other white-blood-cell cancers.’
https://www.hse.gov.uk/pubns/indg329.pdf
Xylene:
‘Xylene can also be absorbed into the body following inhalation, ingestion or skin contact. This can cause headaches, dizziness, vertigo and drowsiness. If larger amounts of xylene are absorbed this can result in breathing problems, damage to the liver and kidneys, cause a loss of consciousness, heart failure and death.’
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/775526/Xylene_general_information_2019.pdf
Trichloroethane:
‘Inhalation is the most important route of exposure, and 1,1,1-trichloroethane is readily absorbed from the lungs. The odor threshold for 1,1,1-trichloroethane is 44 ppm, which is about one-eighth of the OSHA PEL. Odor is an adequate warning of hazardous concentrations. The vapor is heavier than air and can collect to toxic levels in poorly ventilated or low-lying spaces. A one hour exposure to 1,000 ppm can cause dizziness and loss of coordination. Central nervous system (CNS) depression generally begins at 5,000 ppm. Levels of 10,000 ppm or higher can cause sedation, hypotension, cardiac dysrhythmia, coma, and death.’
https://www.atsdr.cdc.gov/MMG/MMG.asp?id=427&tid=76
N-Heptane:
The following acute health effects may occur immediately or shortly after exposure to n-Heptane:
* n-Heptane can irritate the eyes, nose and throat.
* Exposure can cause headache, lightheadedness, dizziness,
*lack of coordination and loss of consciousness.
* Loss of appetite and/or nausea may occur.
Other Long-Term Effects
* Repeated exposure may cause skin rash, dryness and redness.
* n-Heptane may affect the nervous system.
This chemical has not been adequately evaluated to determine whether brain or other nerve damage could occur with repeated exposure. However, many solvents and other petroleum-based chemicals have been shown to cause such damage. Effects may include reduced memory and concentration, personality changes (withdrawal, irritability), fatigue, sleep disturbances, reduced coordination, and/or effects on nerves supplying internal organs (autonomic nerves) and/or nerves to the arms and legs (weakness, "pins and needles").
https://nj.gov/health/eoh/rtkweb/documents/fs/1339.pdf
While we are here, let’s talk also about the highly dangerous organophosphate - Tricresyl Phosphate - for which there is no simple human bio-monitoring test currently available to confirm exposure.
"The Hunt for Tricresylphosphate (TCP)" Professor Dr. Johannes Ludwig /AnsTageslicht.de. https://www.anstageslicht.de/Tricresylphosphate/
Open Access Journal Of Toxicology- Review Article by Professor C V Howard - February 2020:
https://juniperpublishers.com/oajt/pdf/OAJT.MS.ID.555634.pdf?fbclid=IwAR2VwPvuKEkmUxP71M_s77xv3H2A04THfg69gs4uBWPUuYbAOkL07r-jGPs
‘The leakage of tricresyl phosphate-containing engine lubricants into aircraft cabin air, either from worn or defective engine seals or under normal operating conditions, is a serious concern for both the health and safety of the cabin occupants, since the oil contains one to five percent tricresyl phosphate (TCP) esters, known neurotoxins. The exposure of pilots is a particular concern since their impairment can affect their safe operation of the aircraft.’ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3839637/
https://nj.gov/health/eoh/rtkweb/documents/fs/3130.pdf
https://www.healthvermont.gov/sites/default/files/documents/pdf/1330_78_5%20Tricresyl%20phosphate.pdf
Current information provides details of each toxin individually as there has been very limited research on the synergistic effects of these chemicals which are heated at very high temperatures within the aircraft engines and enter the aircraft cabin in aerosol or vapour form through the environmental control system (ECS) in bleed-air aircraft.
‘In toxicology, synergism refers to the effect caused when exposure to two or more chemicals at one time results in health effects that are greater than the sum of the effects of the individual chemicals.’https://www.ccohs.ca/oshanswers/chemicals/synergism.html
Tracing Contaminants in Aircraft
There have been calls for monitoring of toxins onboard aircraft for many years. The technology is available but aircraft manufacturers and airlines are reluctant to install it. Yet many airlines have this technology which is used by their engineering departments to analyse the chemicals following incidents of fumes onboard:
This video was published on 5th September 2014:
https://m.youtube.com/watch?time_continue=6&v=7If1F5SipkQ
‘The aerotracer is used to support the ground maintenance staff of airlines and to detect Oil smell in cabin / cockpit (fume events). It is a joint product between the companies ©AIRSENSE Analytics and Lufthansa Technik (©source Aerotracer). It can perform:
• Analysis of leakages and liquid inclusions in various parts of the aircraft
• Location of the origin of a substance
• Reliable identification and quantification of oil smells in the cabin and determination of the root cause
• Detects various fuels, hydraulic fluids, shock strut fluids, glues, lubricants, glycol, corrosion inhibitors and many more
• Unique combination of different detectors
• Online and offline analysis
Find more information here: http://www.airsense.com/en/products/a
Note the emphasis on ‘Saving manpower resources and costs’, which is clearly a much higher priority than the health of airline pilots, cabin crew and passengers.
If airline manufacturers and airlines have this diagnostic technology - why doesn’t Dr. Craig Lawson of Cranfield University know about it?
https://www.cranfield.ac.uk/people/dr-craig-lawson-749315
https://www.cranfield.ac.uk/themes/aerospace
Are Cranfield University too engrossed in the future of air travel (electric aircraft) to be concerned with the (decades old) issue of people being poisoned in present (bleed air) aircraft?
https://www.cranfield.ac.uk/press/news-2019/cranfield-announces-uk-government-grant-for-the-development-of-electric-flight
Useful resources for anyone wishing to research the subject of contaminated air in aircraft:
Professor Dr.-Ing. Dieter Scholz (Aeronautical Engineering HAW/Hamburg) provides engineering and technical information about CACE=Cabin Air Contamination Events on his website:
https://www.fzt.haw-hamburg.de/pers/Scholz/CabinAir.html#Papers
Professor Dr. Johannes Ludwig / Anstageslicht.de explains the problems of fume event underreporting and the reasons for industrial denials
https://www.anstageslicht.de/themen/english/fume-event-files/underreporting-fume-events-perception-trap-and-safety-in-aviation/?fbclid=IwAR2ReXEKQlTwmOy6TNCA6ukmifBt9ouwykBOKkNnbYTHIvkMf7GG0jrP8uc
Bleedfree.eu - This website contains very useful investigative research and documents:
http://bleedfree.eu/
Aerotoxic Team - provides information, testimonies, a medical protocol and much more:
https://www.aerotoxicteam.com/