Ambient air pollution and risk of daily hospital admission for anxiety in 56 Chinese cities

BACKGROUND AND AIM: The potential impact of short-term exposure to ambient air pollution on risk of anxiety remains uncertain, and no study has investigated the association of major ambient air pollutants (including particulate matters and gaseous air pollutants) with risk of hospital admission for anxiety disorders at the same time. METHODS: We performed a detailed evaluation on the association of interest based on data from national insurance databases in China. Daily hospital admissions for anxiety disorders were identified in 2013-2017 from the national insurance databases covering up to 261 million urban residents in 56 cities in China. A two-stage time-series study based on generalized additive models with quasi-Poisson regression and random-effect meta-analyses was conducted to evaluate the associations between short-term exposure to major ambient air pollutants, including fine particles (PM2.5), inhalable particles (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone, and carbon monoxide, and risk of daily hospital admission for anxiety. RESULTS:A total of 57,124 hospital admission cases were identified for anxiety in the included cities. Significant associations between short-term exposures to ambient NO2 and SO2 and risk of daily hospital admission for anxiety were found in the overall analysis. Per 10 μg/m3 increases in NO2 at lag0 and SO2 at lag6 were associated with significant increases of 1.30% (95% CI: 0.09, 2.53) and 1.53% (95% CI: 0.59, 2.48) in anxiety admission, respectively. A 10 μg/m3 increase in PM2.5 at lag5 was associated with a marginally significant increase of 0.45% (95% CI: -0.02, 0.92) in anxiety admission. CONCLUSIONS:Short-term exposure to ambient air pollution is associated with increased risk of anxiety admission, which may provide new insights into the environmental risk factors of mental health and important implications for promotion of mental health in the public. KEYWORDS: air pollution; anxiety; hospital admission; nitrogen dioxide, sulfur dioxide