The effects of outdoor air pollution on University students’ mental health: a within-group repeated-measures study

BACKGROUND: Air pollution is regarded as one of the greatest public health threats worldwide and has been linked to mental disorders. Therefore, studies on the effects of air pollution on mental health are highly important. OBJECTIVE: This study aimed to examine the effects of outdoor air pollution on the mental health of university students. METHOD: A pretest- posttest repeated-measures within-group design study was conducted with 365 students enrolled in the faculties of a university in a region of Türkiye characterized by a low air quality index during the 2023-2024 academic year and who consented to participate. Data were collected using a demographic information form and the Brief Symptom Inventory (BSI). Descriptive statistics and paired-sample t-tests were used to analyze the differences between repeated measurements. RESULTS: The mean scores of depression, anxiety, and the global severity index-the BSI subscales- differed between the initial measurement, conducted when air pollution was moderate, and the final measurement, conducted when air pollution was unhealthy and poor. The average scores at the final measurement were higher than those at the initial measurement, and the difference was statistically significant (p < 0.05). CONCLUSION: This study concluded that when outdoor air pollution was unhealthy, students' depression, anxiety, and general psychological distress levels increased significantly. Therefore, long-term follow-up studies are warranted. CLINICAL TRIAL NUMBER: Not applicable.