Objectives This study determined the influence of exposure to environmental tobacco smoke (ETS) in aircraft on measured and perceived cabin air quality (CAQ), symptoms, tear-film stability, nasal patency, and biomarkers in nasal lavage fluid.

Methods Commercial aircrews underwent a standardized examination, including acoustic rhinometry, nasal lavage, and measurement of tear-film break-up time. Eosinophilic cationic protein, myeloperoxidase, lysozyme, and albumin were analyzed in the nasal lavage fluid. Inflight investigations [participation rate 98% (N=39)] were performed on board 4 flights, 2 in each direction between Scandinavia and Japan. Scandinavian crew on 6 flights from Scandinavia to Japan participated in postflight measurements after landing [participation rate 85% (N=41)]. Half the flights permitted smoking on board, and the other half, 0.5 months later, did not. Hygienic measurements showed low relative air humidity on board (2-10%) and a carbon dioxide concentration of <1000 ppm during 99.6% of the cruising time.

Results The smoking ban caused a drastic reduction of respirable particles, from a mean of 66 (SD 56) µg/m3 to 3 (SD 0.8) µg/m3. The perceived CAQ was improved, and there were fewer symptoms, particularly ocular symptoms, headache and tiredness. Tear-film stability increased, and nasal patency was altered.

Conclusions Despite a high air exchange rate and spatial separation between smokers and nonsmokers, smoking in commercial aircraft may cause significant air pollution, as indicated by a large increase in respirable particles. This ETS exposure is associated with an increase in ocular and general symptoms, decreased tear-film stability, and alterations of nasal patency.

Key terms acoustic rhinometry; aerospace medicine; environmental tobacco smoke; eosinophil cationic protein; lysozyme; myeloperoxidase; nasal congestion; ocular symptom; respirable particle; tear-film break up time