2021
Volume 21, Number 4, pp. 119-124
Adverse synergies between inhaled carbon monoxide and tricresyl phosphate in aircraft cabin air
Jeremy J. Ramsden
Department of Biomedical Research, The University of Buckingham, MK18 1EG, UK
Both tricresyl phosphate (TCP) and carbon monoxide are present in aircraft cabins, albeit at low concentrations. Hitherto, attention has been focused on these toxins individually. In so far as CO directly inhibits the cytochrome P450 enzymes carrying out detoxification of tricresyl phosphate, an adverse synergy will operate between the two substances. The chemical-physiological picture is further complicated by the mild hypoxia suffered by aircrew and passengers in flight. The adverse synergy resolves the puzzle of aerotoxicity even though actual exposures of the toxins individually are below the presumed threshold for pathophysiological effects. Exposure limits should be revised to take the adverse synergy into account.
Keywords: aerotoxic syndrome, cytochrome P450, hypoxia, multiple chemical sensitivity, neurotoxicity, oxidative stress