Acute effects on pulmonary function in young healthy adults exposed to traffic-related air pollution in semi-closed transport hub in Beijing

Objectives: Transport hub is an important part of urban comprehensive transportation system. Traffic-related air pollution can reach high level because of difficulty of diffusion and increase of emission in transport hub. However, whether exposure in this semi-closed traffic micro-environment causes acute changes in pulmonary function of commuters still needs to be explored. Methods: Forty young healthy adults participated in this randomized, crossover study. Each participant underwent 2 h exposure in a designated transport hub and, on a separate occasion, in an appointed park. Personal exposures to fine particulate matter (PM_2.5), black carbon (BC) and carbon monoxide (CO) were measured. Forced expiratory volume in 1 s (FEV₁) and peak expiratory flow (PEF) were assessed pre-, during and post-exposure. Mixed linear models were used to analyze the pulmonary effects of traffic-related air pollutants. Results: Participants had significantly higher exposures to PM_2.5, BC and CO in the transport hub than in the park. Exposure in transport hub induced significant reductions in FEV₁ and PEF compared with the park during exposure 1 and 2 h. The reductions were significant associated with traffic-related air pollutants. For instance, per 10 μg/m³ increment in PM_2.5 was associated with −0.15 % (95 % CI −0.28, −0.02 %) reduction in FEV₁ during exposure 2 h. However, effects became attenuate after 2 h exposure. Conclusions: Short-term exposure in transport hub had acute reduction effects on pulmonary function. More attention should be paid to the health effects of exposure in the semi-closed traffic micro-environment.