title: Health risk assessment of exposure to TriCresyl Phosphates (TCPs) in aircraft: a commentary.
abstract: Possible exposure to TriCresyl Phosphates (TCPs) has led to concerns among airline crew members. One isomer, Tri-ortho-Cresyl Phosphate (ToCP) is known to be neurotoxic and exposure to ToCP via contaminated cabin air has been suggested to be associated with the alleged Aerotoxic syndrome. The symptoms associated with Aerotoxic syndrome are diverse, including headaches, loss of balance, numbness and neurobehavioral abnormalities such as emotional instability, depression and cognitive dysfunction. Other ortho-isomers are toxic as well, but the non-ortho isomers are regarded as less toxic. In a collaborative effort to increase insight into the possible association between exposure to TCPs via contaminated cabin air and Aerotoxic syndrome, we performed an exposure- and toxicological risk assessment. Measurements in KLM 737 aircraft have demonstrated the presence of non-ortho isomers in low concentrations, though ToCP and other ortho-isomers could not be detected. Based on this exposure assessment, we established a toxicological risk model that also takes into account human differences in bioactivation and detoxification to derive a hazard quotient. From this model it appears unlikely that the health effects and alleged Aerotoxic syndrome are due to exposure to ToCP. Alternative explanations for the reported symptoms are discussed, but evaluation of the current findings in light of the criteria for occupational disease leads to the conclusion that the Aerotoxic Syndrome cannot be regarded as such. Additional research is thus required to unravel the underlying causes for the reported health complaints.
authors.affiliation: KLM Health Services, Schiphol, The Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: de Ree
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: van den Berg
authors.affiliation: Netherlands Center for Occupational Diseases (NCvB), Coronel Institute for Occupational Health, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Teus
authors.initials: T
authors.lastname: Brand
authors.affiliation: Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, The Netherlands.
authors.forename: Gerard J
authors.initials: GJ
authors.lastname: Mulder
authors.affiliation: European Society of Aerospace Medicine (ESAM), The Netherlands.
authors.forename: Ries
authors.initials: R
authors.lastname: Simons
authors.affiliation: KLM Health Services, Schiphol, The Netherlands.
authors.forename: Brinio
authors.initials: B
authors.lastname: Veldhuijzen van Zanten
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. Electronic address: r.westerink@uu.nl.
authors.forename: Remco H S
authors.initials: RH
authors.lastname: Westerink
mesh_terms: D000395:Air Pollutants, Occupational / Q000506:poisoning*; D000401:Aircraft; D006801:Humans; D009784:Occupational Diseases / Q000209:etiology*; D018570:Risk Assessment; D014317:Tritolyl Phosphates / Q000506:poisoning*
chemical_list: D000395:Air Pollutants, Occupational; D014317:Tritolyl Phosphates
keywords: Aerotoxic syndrome; Cabin air; Health risk assessment; Inter-individual differences; Tri-ortho-Cresyl Phosphate (ToCP); TriCresyl Phosphate (TCP)