Health impacts and drivers of long-term ozone and nitrogen dioxide exposure in urban China

Air pollution is a significant global health hazard and a major risk factor for mortality. Like many regions experiencing rapid economic development and urbanization, China continues to face persistent air pollution, with increasing O₃ levels and NO₂ as critical pollutants. This study analyzed the spatiotemporal distribution of O₃ and NO₂ in urban China from 2015 to 2020 using online monitoring data. Concentration-response functions (CRFs) were employed to assess health impacts. The result reveals that, while NO₂ pollution has declined during the six-year period, its level was still above air quality standard, and O₃ levels have escalated. The study identified a 62,100 increase in combined O₃- and NO₂-related deaths in 2020 compared to 2015, with the highest health burdens occurring in Central China. Critically, a major factor increasing health risks from air pollution is population aging, since the elderly exhibit heightened biological susceptibility to pollutant exposure. This underscores a growing challenge not only for China but also for aging societies worldwide. Taking the vulnerability of the aging population into account, new age-sensitive air quality standards and measures to mitigate health consequences of criteria air pollutants become imperative.