The hidden toll of air pollution: mental health effects on middle-aged and older adults.

Objective: Depressive disorders are increasingly recognized as a major public health challenge, especially in aging societies. This study aims to explore the impact of air pollution on the mental health of middle-aged and older adults, with a particular focus on identifying the vulnerable subgroups and underlying mechanisms. Methods: We employ micro-level data to empirically examine how exposure to fine particulate matter (PM2.5) affects short-term mental health outcomes, as measured by the Centers for Epidemiologic Studies Depression Scale (CES-D). We also explore the potential mediating channels through which air pollution may influence psychological well-being, including sleep quality, life satisfaction, physical health, and cognitive functioning. Results: Our findings show that the increment in fine particulate matter (PM2.5) increases the scores of Centers for Epidemiologic Studies Depression Scale (CES-D), indicating a deterioration in mental health. The negative effects of air pollution are particularly pronounced among older adults, females, and widowed individuals. Mechanism analysis reveals that air pollution significantly worsens sleep quality, reduces life satisfaction, impairs cardiopulmonary health, and diminishes cognitive competence. Conclusions: This study highlights the substantial mental health burden of air pollution, especially for vulnerable populations. We find suggestive evidence that improving access to pollution information and urban greening can help mitigate these adverse effects. Our findings underscore the urgent need for targeted public health interventions and environmental policies to address the mental health consequences of air pollution, particularly in the context of climate change and population aging.