Time-series analysis of impact of ground-level ozone exposure on resident mortality in Hohhot City from 2018 to 2023
- VernacularTitle:2018—2023年呼和浩特市近地臭氧暴露对居民死亡影响的时间序列分析
- Author:
Shengjie QIN
1
;
Hairong YANG
1
;
Wulanqimuge
1
;
Yuqing HU
1
;
Ziying ZHAO
1
Author Information
- Publication Type:Investigation
- Keywords: air pollution; ozone; mortality; time-series analysis; non-accidental mortality; circulatory system diseases; respiratory system diseases
- From: Journal of Environmental and Occupational Medicine 2025;42(10):1185-1192
- CountryChina
- Language:Chinese
-
Abstract:
Background Exposure to ozone (O3) is closely associated with an increased risk of mortality in the population, but this association exhibits regional heterogeneity, and relevant research in northern and central-western China is limited. Hohhot, as a typical city in the northern and western region, has seen a significant upward trend in O3 concentrations (an increase of 17.9 μg·m−3 in 2020 compared to 2016). Studies targeting this region can fill the regional research gap. Objective To evaluate the health effects of ground-level O3 exposure on resident mortality in Hohhot from 2018 to 2023. Methods Air quality, meteorological, and mortality data in Hohhot from 2018 to 2023 were collected. A time-series analysis based on Quasi-Poisson generalized additive model (GAM) was employed, controlling for meteorological factors, day-of-week effects, and holiday effects, to assess the impact of O3 on non-accidental mortality, mortality from circulatory system diseases (CSD), and mortality from respiratory system diseases (RSD). Results From 2018 to 2023, the non-accidental, CSD, and RSD mortalities in Hohhot amounted to
89721 ,47394 , and11378 cases, respectively. The daily maximum 8-hour average O3 concentration (O3-8 h) was 90.00 μg·m−3. According to the Class I limit (100 μg·m−3) of GB 3095—2012 Ambient Air Quality Standard, the annual average number of days exceeding the standard was 144 d. For single-day lag effects, O3 had the strongest health impact on non-accidental mortality and CSD mortality on the current day (lag0), with effect sizes of 0.78% (95%CI: 0.33%, 1.24%) and 1.10% (95%CI: 0.50%, 1.71%), respectively. The strongest impact on RSD mortality occurred on the second day (lag2), with an effect size of 1.61% (95%CI: 0.61%, 2.62%). The subgroup analyses showed that for every 10 μg·m−3 increase in O3-8 h concentration, the risk of non-accidental mortality in females increased by 0.70% (95%CI: 0.01%, 1.41%); for CSD mortality, the risk in males and individuals aged ≥65 years increased by 0.73% (95%CI: 0.01%, 1.47%) and 0.76% (95%CI: 0.13%, 1.39%), respectively. During the warm season, statistically significant risks were observed for non-accidental, CSD, and RSD mortalities, with increases of 1.07% (95%CI: 0.54%, 1.60%), 1.31% (95%CI: 0.59%, 2.04%), and 2.27% (95%CI: 1.07%, 3.49%), respectively. In the two-pollutant models incorporating sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), particulate matter with an aerodynamic diameter of 10 micrometers or less (PM10), and fine particulate matter (PM2.5), the effect estimates (excess risk) of O3 remained stable and statistically significant (P<0.05), indicating model robustness. Conclusion Ground-level O3 exposure in Hohhot increases mortalities due to non-accidental causes, CSD, and RSD, with more pronounced effects during the warm season. Females and individuals aged ≥65 years may be susceptible populations. Therefore, relevant authorities should prioritize the potential health risks of O3 exposure, particularly to vulnerable groups, and promote targeted prevention and control strategies.
