Effects of ambient air pollution on the hospitalization risk and economic burden of mental disorders in Qingdao, China

Objective

The aim of this study was to examine the impacts of short-term exposure to air pollutants on hospitalizations for mental disorders (MDs) in Qingdao, a Chinese coastal city, and to assess the corresponding hospitalization risk and economic cost.

Methods

Daily data on MD hospitalizations and environmental variables were collected from January 1, 2015, to December 31, 2019. An overdispersed generalized additive model was used to estimate the association between air pollution and MD hospitalizations. The cost of illness method was applied to calculate the corresponding economic burden.

Results

With each 10 μg/m³ increase in the concentration of fine particulate matter (PM_2.5) at lag05, inhalable particulate matter (PM₁₀) at lag0, sulfur dioxide (SO₂) at lag06 and ozone (O₃) at lag0, the corresponding relative risks (RRs) and 95% confidence intervals (CIs) were 1.0182 (1.0035–1.0332), 1.0063 (1.0001–1.0126), 1.0997 (1.0200–1.1885) and 1.0099 (1.0005–1.0194), respectively. However, no significant effects of nitrogen dioxide (NO₂) or carbon monoxide (CO) were found. Stratified analysis showed that males were susceptible to SO₂ and O₃, while females were susceptible to PM_2.5. Older individuals (≥ 45 years) were more vulnerable to air pollutants (PM_2.5, PM₁₀, SO₂ and O₃) than younger individuals (< 45 years). Taking the Global Air Quality Guidelines 2021 as a reference, 8.71% (2,168 cases) of MD hospitalizations were attributable to air pollutant exposure, with a total economic burden of 154.36 million RMB.

Conclusion

Short-term exposure to air pollution was associated with an increased risk of hospitalization for MDs. The economic advantages of further reducing air pollution are enormous.