The impact of air pollution on mental health: Evidence from Texas

I estimate the impact of air pollution on mental health employing a comprehensive population-level outpatient diagnosis dataset and a quasi-experimental design. This study uses wind direction as an instrumental variable (IV) to address endogeneity concerns associated with exposure to fine particulate matter (PM2.5), ensuring a robust analysis of mental health outcomes. The results indicate that a 1 μg/m3 increase in PM2.5 concentration leads to a significant increase in principal diagnoses for mental health illness in general, and specifically depression, anxiety, and stress, by 9.6, 5.3, 2.6, and 1.7 cases per 100,000 individuals, respectively. In addition, the study highlights sex-specific effects, with women more susceptible to stress and men more affected by anxiety. The findings suggest that principal diagnoses are particularly sensitive to increases in PM2.5 exposure. These results provide valuable insights for the development of public health strategies addressing the environmental determinants of mental health, particularly as air pollution levels continue to rise. In conclusion, this study presents strong empirical evidence linking PM2.5 exposure to increased mental health diagnoses, underscoring the need to consider mental health when designing policies to address air pollution.