Respiratory Symptoms in Aerotoxic Syndrome Due to Long-Term Exposure of Contaminated Bleed Air – A Literature Review

Aerotoxic syndrome is associated to the aircraft’s bleed air system which provides air supply in the cockpit and cabin. This system is susceptible to contamination due to the leak of engine oil and hydraulic fluid, resulting in fume events. The contaminated air often contains organophosphates, thus, posing potential hazards to aircrews. Although exposure levels of these substances are considered low, prolonged exposure is believed to correlate with the onset of symptoms in aircrews. Aerotoxic syndrome encompasses a broad spectrum of symptoms that are frequently reported by aircrews, including respiratory symptoms. Prolonged exposure to low-doses of organophosphates has been linked to hyperreactivity and inflammation of the respiratory tract, thereby precipitating both acute and chronic respiratory symptoms. These symptoms could potentially cause sudden incapacitation, which might compromise flight safety, or result in permanent disability for aircrews. Despite the significant impact it can have, there is still ongoing debates within the aviation community regarding the effects of organophosphate exposure during fume events on symptoms associated with aerotoxic syndrome. Furthermore, there is no universally acknowledged medical protocol to guide clinicians in diagnosing aerotoxic syndrome. Consequently, many clinicians might not be aware of the risks associated with aerotoxic syndrome, leading to delays in diagnosis and inappropriate treatment. This literature review aims to raise awareness among the aviation community and clinicians about aerotoxic syndrome. It is hoped that this could spur collaborative efforts across multiple disciplines to better understand the extent of health problems related to contaminated cabin air, especially regarding respiratory symptoms in aerotoxic syndrome.