Health and flight safety implications from exposure to contaminated air in aircraft

Abstract

This thesis examines the six-decade use of unfiltered aircraft bleed air, taken from jet engines to supply breathing air in the flight decks and passenger cabins of commercial and military transport aircraft. During this time, numerous flight safety issues and adverse effects from exposure to contaminated bleed air have been reported. The research undertaken in this thesis examined previous investigations into these matters and the consequences of using bleed air on flight safety and crew and passenger health. This research examined: (a) health issues reported by aircrew as a consequence of exposure to contaminated bleed air whilst flying by way of several descriptive surveys; (b) various aviation air monitoring studies previously undertaken were reviewed to assess the knowledge base of the chemicals present during contaminated air events; (c) air sampling data were evaluated for their usefulness in determining any potential adverse health effects; (d) a review was undertaken of the frequency of contaminated bleed air events; (e) a review was undertaken of some of the information known by the aviation industry and others about contaminated bleed air. Analysis of the evidence that bleed air, contaminated by synthetic jet engine oils and hydraulic fluids, is a regular and normal occurrence and far more common than previously accepted and is a consequence of the current bleed air system design. There are significant short and longterm health effects being reported as a direct result of documented exposure events that validate claims of adverse health effects in exposed individuals. 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.