Doctor of Philosophy / Department of Mechanical Engineering / Steven J. Eckels / Byron W. Jones / Poor air quality in commercial aircraft cabins can be caused by volatile organophosphorus (OP) compounds emitted from the jet engine bleed air system during smoke/fume incidents. Tri-cresyl phosphate (TCP), a common anti-wear additive in turbine engine oils, is an important component in today’s global aircraft operations. However, exposure to TCP increases risks of certain adverse health effects. This research analyzed used aircraft cabin air filters for jet engine oil contaminants and designed a jet engine bleed air simulator (BAS) to replicate smoke/fume incidents caused by pyrolysis of jet engine oil. Field emission scanning electron microscopy (FESEM) with X-ray energy dispersive spectroscopy (EDS) and neutron activation analysis (NAA) were used for elemental analysis of filters, and gas chromatography interfaced with mass spectrometry (GC/MS) was used to analyze used filters to determine TCP isomers. The filter analysis study involved 110 used and 74 incident filters. Clean air filter samples exposed to different bleed air conditions simulating cabin air contamination incidents were also analyzed by FESEM/EDS, NAA, and GC/MS. Experiments were conducted on a BAS at various bleed air conditions typical of an operating jet engine so that the effects of temperature and pressure variations on jet engine oil aerosol formation could be determined. The GC/MS analysis of both used and incident filters characterized tri-m-cresyl phosphate (TmCP) and tri-p-cresyl phosphate (TpCP) by a base peak of an m/z = 368, with corresponding retention times of 21.9 and 23.4 minutes. The hydrocarbons in jet oil were characterized in the filters by a base peak pattern of an m/z = 85, 113. Using retention times and hydrocarbon thermal conductivity peak (TCP) pattern obtained from jet engine oil standards, five out of 110 used filters tested had oil markers. Meanwhile 22 out of 74 incident filters tested positive for oil fingerprints. Probit analysis of jet engine oil aerosols obtained from BAS tests by optical particle counter (OPC) revealed lognormal distributions with the mean (range) of geometric mass mean diameter (GMMD) = 0.41 (0.39, 0.45) [mu]m and geometric standard deviation (GSD), [sigma][subscript]g = 1.92 (1.87, 1.98). FESEM/EDS and NAA techniques found a wide range of elements on filters, and further investigations of used filters are recommended using these techniques. The protocols for air and filter sampling and GC/MS analysis used in this study will increase the options available for detecting jet engine oil on cabin air filters. Such criteria could support policy development for compliance with cabin air quality standards during incidents.

<p>The objective of the dissertation was to study the cabin environment, and identify personal and environmental risk factors, associated with symptoms, and perception of cabin air quality. Another objective was to study if ban of smoking, and increased relative air humidity on intercontinental flights, could have a beneficial health effect. The studies were performed among Scandinavian cabin crew in one Airline Company. Office workers from the same company served as controls. Exposure differed between cruise and non-cruise conditions. Air humidity was very low during intercontinental flights (3-8%). Concentration of moulds, bacteria, formaldehyde, and ozone was low. Tobacco smoking increased respirable particles in the cabin air, from 3 to 49 mg/m3, and increased cotinine in urine. The ETS-exposure was highest in the aft part of the cabin. Symptoms and environmental complaints were more common among flight crew than office workers. We could identify personal factors of importance, and certain conditions that could be improved, to achieve a better cabin environment. There was an association between symptoms and environmental perceptions and work stress, lack of influence on working condition, and a history of atopy. After ban on smoking in aircraft, there was a decrease of ocular and general symptoms, and increased tear-film stability in aircrew. Air humidification reduced headache and ocular, nasal, and dermal dryness symptoms, increased tear-film stability, and increased nasal patency. Our result indicates that ETS and low air humidity are important environmental factors in aircraft, and that atopy, and work stress could be significant risk factors for symptoms and environmental perceptions.</p>

The objective of the dissertation was to study the cabin environment, and identify personal and environmental risk factors, associated with symptoms, and perception of cabin air quality. Another objective was to study if ban of smoking, and increased relative air humidity on intercontinental flights, could have a beneficial health effect. The studies were performed among Scandinavian cabin crew in one Airline Company. Office workers from the same company served as controls. Exposure differed between cruise and non-cruise conditions. Air humidity was very low during intercontinental flights (3-8%). Concentration of moulds, bacteria, formaldehyde, and ozone was low. Tobacco smoking increased respirable particles in the cabin air, from 3 to 49 mg/m3, and increased cotinine in urine. The ETS-exposure was highest in the aft part of the cabin. Symptoms and environmental complaints were more common among flight crew than office workers. We could identify personal factors of importance, and certain conditions that could be improved, to achieve a better cabin environment. There was an association between symptoms and environmental perceptions and work stress, lack of influence on working condition, and a history of atopy. After ban on smoking in aircraft, there was a decrease of ocular and general symptoms, and increased tear-film stability in aircrew. Air humidification reduced headache and ocular, nasal, and dermal dryness symptoms, increased tear-film stability, and increased nasal patency. Our result indicates that ETS and low air humidity are important environmental factors in aircraft, and that atopy, and work stress could be significant risk factors for symptoms and environmental perceptions.