Short-term ambient ozone exposure increases the risk of hospitalization with depression: a multi-city time-stratified case–crossover study

Abstract

Background

Depression, the most common mental illness worldwide, has been studied and air pollution has been found to increase the risk of depression hospitalization, but research results on ozone (O₃) remain limited. In this context, we investigated the relationship between short-term O₃ exposure and depression-related hospital admissions (HAs).

Methods

The 10,459 records of HAs for depression from medical institutions across in 9 cities, China, were collected between 1 January 2017, and 31 December 2018. Air pollutants and meteorological data was obtained from provincial ecological environment monitoring stations in the study area. Conditional Poisson regression was employed to estimate the association between O₃ and hospitalizations for depression, with data stratification by sex, age, weather, and economic level.

Results

Short-term O₃ exposure was positively associated with the number of depression-related hospitalizations (Relative risk: 1.04 [95% CI: 1.02, 1.05]). O₃ had a significant effect on the risk of depression-related hospitalizations on warm days (P = 0.021, Relative risk: 1.05 [1.03, 1.08]). The high gross domestic product group was more likely to be affected by O₃ exposure-associated depression-related hospitalizations (P = 0.005, Relative risk: 1.03 [1.01, 1.05]).

Conclusions

Short-term changes to O₃ exposure may increase the risk of depression related hospitalizations, especially on warm days.

Keywords:

• Air pollution
• ozone
• depression
• risk of hospitalization

Acknowledgments

We thank the responsible person of local medical institutions, all participants and the staff of data reduction for their cooperation.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Availability of data and material

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Ethics approval and consent to participate

This study was supported by National Natural Science Foundation of China (No. 72174032). There did not contain any studies with human participants or animals performed by any of the authors, no other ethics approval was required.

Additional information

Funding

This study was supported by National Natural Science Foundation of China (No. 72174032).