Association of ambient air pollution with risk of anxiety disorders: an updated systematic review and meta-analysis

Ambient air pollution has become a global environmental health challenge, and anxiety disorders have received widespread attention as a common mental health disorder. This study aimed to explore the epidemiological association between short-term and long-term ambient air pollution exposures and the risk of anxiety disorders through a systematic review and meta-analysis of the existing literature. Based on a comprehensive search and screening of relevant literature by September 1st, 2025, we included 25 studies eligible for the meta-analysis, of which 20, 17, 17, 7 and 9 reported the associations between fine particulate matter (PM_2.5), inhalable particulate matter (PM₁₀), nitrogen dioxide (NO₂), carbon monoxide (CO), and (O₃) and the risks of anxiety disorders, respectively. Based on our meta-analysis, the relative risks (RRs) and 95 % confidence intervals (CIs) of anxiety disorders associated with per 10 μg/m³ increase in long-term PM_2.5, PM₁₀, and NO₂ exposures were 1.738 (95 % CI: 1.191, 2.534), 1.577 (95 % CI: 1.159, 2.146), and 1.186 (95 % CI: 1.144, 1.230), respectively. The RRs of anxiety disorders were 1.012 (95 % CI: 1.006, 1.018) and 1.079 (95 % CI: 1.012, 1.150) per 10 μg/m³ increase in short-term PM_2.5 and NO₂ exposures, and 1.186 (95 % CI: 1.144, 1.230) per 1 mg/m³ increase in short-term CO exposure. The subgroup analysis showed that inter-study heterogeneity may result from the number of cases, study year, and study design. This study supports the impact of ambient air pollution exposure on the risk of anxiety disorders, with a more apparent risk observed for long-term exposure.