Abstract: Objective To investigate the impact of short-term severe air pollution on the nasal function and inflammation status of young healthy residents. Methods Twenty-three young healthy adults living in downtown Beijing were recruited. The self-reported nasal symptoms, nasal patency, upper and lower respiratory tract nitric oxide (NO) and inflammatory cytokines in the nasal secretions of each participant were recorded before and after severe air pollution which lasted for five days. Results At the second visit, different percentage of participants claimed slight symptoms of nasal congestion, irritation, dryness or postnasal drip. Accordingly, rhinometry and rhinomanometry examination showed that nasal airway resistance increased significantly, while nasal cavity volume and minimum cross-sectional area decreased significantly. Both nasal NO and exhaled NO increased after severe air pollution. In nasal secretion, Th2-type cytokines eotaxin, and interleukin-5 (IL-5), chemokine (C-C motif) ligand 7, and pro-inflammatory cytokine IL-8 increased significantly after severe air pollution, Th1-type cytokine interferon-γ (IFN-γ) as well as immunoregulatory cytokines IL-10 and transforming growth factor (TGF-β) decreased significantly. Conclusion By means of promoting the Th2-predominant immune reaction and suppressing the regulatory immune response, exposure to short-term air pollution predisposes healthy adults to nasal inflammation, especially allergic nasal inflammation.

Key words: haze, air pollution, particular matter, nasal inflammation, cytokine