Moderating effects of physical activity on PM₂.₅ - Associated depressive symptom risk among college students

This study aims to explore the relationship between PM₂.₅ exposure and depressive symptom among college students and to evaluate the moderating effects of physical activity.

A cross-sectional study was conducted among college students in 30 provinces of China. Depressive symptom was assessed using the Center for Epidemiologic Studies Depression scale (CES-D), and physical activity was assessed based on the number of days participants engaged in at least 60 min of moderate to vigorous physical activity (MVPA) in the past week. We calculated the average PM₂.₅ concentrations over the preceding 7, 14, 30, and 45 days for each participant using data from the Tracking Air Pollution in China (TAP) database (http://tapdata.org.cn/). Multiple logistic regression analyses were performed to examine the associations. Interaction analysis assessed the modifying effects of physical activity on PM₂.₅ exposure.

PM₂.₅ exposure was positively associated with depression risk, particularly for prior 14 days and prior 30 days durations (OR = 1.014, 95 % CI: 1.001-1.028 and OR = 1.015, 95 % CI: 1.000-1.030, respectively). Physical activity significantly reduced depression risk, even at high PM₂.₅ levels. Interaction analysis revealed a significant interaction between physical activity and PM₂.₅ exposure on depression risk.

PM₂.₅ exposure increases depression risk in college students, while physical activity mitigates its adverse effects. These findings highlight the importance of physical activity in reducing air pollution's impact on mental health.