Aerotoxic Syndrome: Five cases in Germany

Background: German physicians have to document cases of poisoning (§16 Chemicals Law) to the Federal Institute for Risk Assessment (BfR). Based on good cooperation with physicians, hospitals, Poison- and Environmental Centres, the BfR also receives data on rare or extraordinary cases, such as the case reports of “Aerotoxic Syndrome” (AS). AS is not an officially recognized health impairment entity in aviation medicine. The syndrome describes alleged short-term and long-term ill-health effects that are attributed to exposure to contaminated cabin air in relation to fume events in which the ingredients of engine-oils such as tricresyl phosphate (TCP) could possibly be toxic to humans. In particular in the mass media, radio and television spectacular AS-stories (e.g. near air crashes) have been published. Methods: The German AS-cases were investigated and documented at the BfR. Individual reports as well as cases reported so far under §16e were analysed, evaluated and recorded in the form of standardised case reports. The existing data were evaluated and assessed regarding possible risks for fume events associated with TCP-contaminated cabin air. The categorisation of the health impairment followed the Poison Severity Score (PSS). The causality (exposure vs. symptoms/signs) was assessed by the BfRstandard “Three-Level-Model”. Results: Between 2009 and 2012 the BfR documented 5 cases of AS. All were adults and flying personnel of different airlines (three stewardesses/ two pilots). All claimed smell events but no real fume events. The stewardesses especially had symptoms and signs which Prof. Michael Bagshaw (UK, 2008) described in a paper as similar to those known as Chronic Fatigue syndrome, Gulf War syndrome, Lyme disease, chronic stress and chronic hyperventilation. On the other hand, the two pilots developed symptoms and signs which could not be clearly classified (extreme fatigue, prickling, tingling, numbness etc). Both pilots landed the aircraft with an oxygen mask being afraid of an air-crash. In all cases the analysis of cabin-air contaminants (incl. TCP) was negative. Conclusion: The BfR-assessment of the 5 cases could not find causality between possible inhalational exposure and the health impairment that occurred. TCP poisoning is unlikely.