Exposure to ambient air pollution with depressive symptoms and anxiety symptoms among adolescents: A national population-based study in China.

Background: Air pollution threatens adolescents' physical health and adversely affects adolescents' mental health. Previous studies mostly focused on the effects of air pollution on physical health, but there were few studies on the effects of air pollution on mental health.

Methods: We collected scores of depressive symptoms and anxiety symptoms from 15,331 adolescents from 43 schools in eleven provinces in September and November 2017. The data on air pollution comes from the China High Air Pollutants dataset, which included concentrations of particulate matter with diameters of ≤1.0 μm (PM), diameters of ≤2.5 μm (PM), and diameters of ≤10 μm (PM), as well as nitrogen dioxide (NO). The associations between air pollution and depressive and anxiety symptoms among adolescents were estimated using generalized linear mixed models.

Results: Depressive and anxiety symptoms among Chinese adolescents were 16% and 32%, respectively. In the adjusted model, an interquartile range (IQR) increase from PM was associated with the odds of anxiety symptoms [odds ratio (OR) = 1.01; 95% confidence interval (CI): 1.00, 1.01, P = 0.002]. Also, an IQR increase in PM was significantly associated with the odds of anxiety symptoms (OR = 1.01; 95% CI: 1.00, 1.01, P = 0.029). Compared with the lowest quartile, the adjusted OR of anxiety symptoms for the highest quartile of PM and PM were 1.29 (1.15, 1.44) and 1.23 (1.06, 1.42), respectively. In addition, the association between PM and depressive symptoms was significant. The robustness of the results was also confirmed by stratification and sensitivity analyses.

Conclusions: Exposure values for airborne particulate matter were associated with depressive symptoms and anxiety symptoms in adolescents, particularly for PM and PM with anxiety symptoms among adolescents.