Hi, here is a jumping pad for those who want to "DYOR" ("do your own research): a quick 15 min search via Google Scholar reveals some relevant papers:
(Link to list and origin doc:
https://scholar.google.com/scholar?c...iodt=0,5&hl=en)
TLDR:
- A. We know that toxic particles exist in cabin air, originating from the bleed air system
- B. We know that pilots and cabin crew self-reported "aerotoxic syndrome" for many years now
- C. However, science was not yet able to conclusively link A and B in a causal relationship. So the blood test might exactly be what we need
Michaelis (2010):
- Abstract: The thesis argues that the precautionary principle, occupational health and safety guidelines and aviation regulations are being ignored by the aviation industry, who continue to claim that cabin air is safe. The systemic misuse of available data is widespread, secondary to commercial objectives, and places passenger and crew health and flight safety at serious risk. The thesis concludes that the use of bleed air on commercial aircraft with no form of contaminated air detection or filtration system present should be discontinued. The risk to health and flight safety is no longer acceptable.
- My take on the study: comprehensive in analysis, but suffering a bit from its method (survey-based data collection) due to lack of more available data - she comments this herself in the work.
- Metrics: PHD thesis from respectable uni
Michaelis (2021): - Abstract: This study identified increases in UFP concentrations associated with engine and APU power changes and changes in air supply configuration. These results correlated with times when engine and APU oil seals are known to be less effective, enabling oil leakage to occur. The concentrations reached in the passenger cabins exceeded those taken in other ground-based environments. UFP exposures in aircraft cabins during normal flight indicates there will be health consequences for long serving aircrew and some passengers.
- My take on the study: has a great practical relevance and identifies air bleed supply changes as the main events during which particles are blown into the cabin air. Still, only 4 flights were studies, suggesting further data collection is needed.
- Study metrics: Paper was submitted in ENV health, with an H-index of >100 this seems to be a good journal in the field.
Howard (2018):
- Abstract: We present strong evidence for the presence of aerosols of Nano-particles (also termed Ultrafine Particles (UFPs) in aerosol science) in the breathing air of pressurized aircraft using engine bleed air architecture. The physical and chemical nature of engine oils and the high temperatures attained in aircraft jet engines (up to 1,700°C in the oil circulation and up to 30,000°C in the bearings) explain why UFPs are to be expected. A discussion of oil seals used in gas turbine engines concludes that they will permit UFPs to cross them and enter the breathing air supply, in conjunction with a complex mixture of chemicals such triaryl phosphates which are neurotoxic. A consideration of the toxicology of Nano-particles concludes that their continual presence over a typical working lifetime of up to 20,000 hours in aircrew will predispose them to chronic respiratory problems and will exacerbate the translocation of neurotoxic substances across the blood brain barrier.
- My take on the study: This seems to be a literature review on the topic rather than original research. Howard references to her previous work (which is widely cited): https://www.sciencedirect.com/scienc...69409X11002328
- Study metrics: The journal in which this paper was published does not seem to be relevant, however, the main researcher is a widely cited scholar in the field. I think I wouldn' use this paper in research but the papers referenced by this one.
Harrison (2016):- Abstract: "Toxicology is a new science, the complexities of which have been highlighted in the papers contained within this special section. Our understanding of the mechanisms through which various chemicals interfere with nervous system function is constantly evolving and research is unable to keep up with the speed with which new chemicals are produced and put onto the market. Thus there are often controversies surrounding the health-effects of commercially available compounds and disagreement around what constitutes safe exposure limits. This article will introduce readers to an emerging concern in this field, the potential risk to health of toxic fumes in airplane cabins. We explore the challenges and methodological issues encountered by researchers who have tried to investigate this issue and highlight the need for further research on this topic. We hope this article will promote discussion amongst academics and clinicians, and lead to the identification of creative solutions to the methodological issues encountered to date."
- My take: seems to be a balanced perspective and highlights method and data gaps
- Study metrics: not journal-published
Summary on the research from Harrison (2016): "Some researchers have suggested chronic exposure to OP compounds (particularly TCP) in engine oil may be to blame (Winder and Balouet, 2002). To reflect this, in 2000 Winder and Balouet proposed the term ‘Aerotoxic Syndrome’ to describe the common symptoms reported by aircrew following exposure to toxic fumes in aircraft cabins, and encompasses both short and long-term effects such as ear/nose/throat irritation, skin conditions, nausea and vomiting, respiratory problems, headaches, dizziness, weakness and fatigue, sensory changes and nerve pain, tremors, chemical sensitivity and cognitive impairment (e.g. Abou-Donia, 2003; Cox & Michalis, 2002; Coxon, 2002; Mackenzie Ross, Harper & Burdon, 2006; Mackenzie Ross et al, 2011; Michaelis, 2010; Montgomery, Weir, Zieve & Anders, 1977). In addition, recent studies have reported evidence of neuropsychological impairment (Heuser, Aguilera, Heuser, & Gordon, 2005; Mackenzie Ross et al, 2006; Mackenzie Ross, 2008; Mackenzie Ross et al, 2011; Reneman et al, 2015) and neurological damage (Heuser et al, 2005); evidence of nervous system degeneration (Abou-Donia, Abou-Donia, El Masry, Monro & Mulder, 2013; Abou-Donia, van de Groot & Mulder, 2014); and altered white matter microstructure, cerebral perfusion and activation (Reneman et al, 2015) in aircrew and pilots. Although these studies have shown those working in the airline industry complain of an array of symptoms and/or show evidence of neurological damage, none of these studies have been able to determine cause. Indeed, without any objective measurement of exposure, it is very difficult to claim that contaminated air is to blame. The only studies published to date that have attempted to explicitly measure and link ill-health with exposure to cabin fumes have relied solely on self-report questionnaires"