Short-term effect of ambient ozone pollution on respiratory diseases in western China

Ambient air pollution has been regarded as an important cause of the morbidity and mortality of respiratory diseases. In the current work, a total of 469,490 respiratory emergency room (ER) visits in Lanzhou, China from Jan 1, 2013 to Dec 31, 2016 were collected. A generalized additive model (GAM) was used to investigate the association between O₃ and respiratory ER visits for the different gender and age subgroups. The results showed that: (a) with per inter-quartile range (IQR) (31 µg/m³) increase in O₃, the greatest relative risk (RR) of respiratory ER visits for the total was 1.014 (95% CI 1.008-1.020) at lag 4 days. Females and 16-to-45-year-olds were relatively more sensitive to O₃; (b) the significant lag effects were found in single-day lag models, with the highest RR values for different groups were observed at lag 3-lag 5 days. The multi-day cumulative lag effects were stronger for the total; (c) in the multiple-pollutant models, the effects of O₃ were generally increased when introducing other pollutants (PM₁₀, PM_2.5, SO₂ and NO₂) for adjustment. This study demonstrated that short-term exposure to O₃ increased the RR of respiratory ER visits in Lanzhou, China.