Urinary cotinine concentration in flight attendants, in relation to exposure to environmental tobacco smoke during intercontinental flights

Objectives: To measure and compare the urinary cotinine concentration (U-co tinine) in nonsmoking cabin attendants (C/A) working with the Scandinavian Airlines System, before and after work on intercontinental flights with exp osure to environmental tobacco smoke (ETS). Methods: The study material con sisted of 24 cabin attendants and one pilot, all volunteers and all without exposure to ETS in the home, working on 15 intercontinental flights. Infor mation on age, gender and occupation was gathered, as well as possible sour ces of ETS exposure in other places, outside work and during previous fligh ts, during a 3-day period prior to the investigation. Urine samples were ta ken before departure and after landing, on board, and were kept frozen (-20 degrees C) until analysis. Cotinine was analyzed by a previously developed gas chromatographic method, using mass spectrometry (MS) with selected-ion monitoring (SIM). The difference in U-cotinine before and after the flight was compared. Moreover, the change in U-cotinine during the flight was rel ated to occupation (work in the forward or aft galley) and observed degree of smoking during each flight. Results: The median U-cotinine was 3.71 mu g /g crea; 2.4 mu g/l (unadjusted) (interquartile range 2.08-8.67 mu g/g crea ) before departure, and 6.37 mu g/g crea; 7.1 mu g/l (interquartile range 3 .98-19 mu g/g crea) after landing, a significant difference (P < 0.003). C/ A in the aft galley had a significantly higher concentration of U-cotinine after landing than subjects working in the front of the aircraft (P = 0.01) . In C/A working in the aft galley, the median increase of U-cotinine was 3 .67 mu g/g crea; 3.2 mu g/l (interquartile range 0.04-13.8 mu g/g crea) dur ing flight. In contrast, those seven subjects working in the forward part o f the aircraft had no increase in U-cotinine during the flight (median incr ease 0.97 mu g/g crea; 0.5 mu g/l interquartile range 0.27-2.65 mu g/g crea ). Conclusion: Tobacco smoking in commercial aircraft may cause significant exposure to environmental tobacco smoke among C/A working in the aft galle y, despite high air exchange rates and spatial separation between smokers a nd nonsmokers. This agrees with earlier studies, as well as measurements on the aircraft, showing a higher degree of ETS-related air pollution in the aft galley than in the forward galley. The average cotinine concentration i n urine was similar to that in other groups with occupational exposure to E TS, e.g., restaurant staff, police interrogators and office workers. Since smoking in commercial aircraft may result in an involuntary exposure to ETS among non-smokers, it should be avoided.