The long-run effects of fetal PM_2.5 exposure on mental health: evidence from China

This paper investigates the long-run effects of PM_2.5 exposure in utero on the mental health of adolescents. Using nationally representative survey data from China, we instrument the PM_2.5 exposure with wind speed to tackle the possible endogeneity problem. Our results show that mothers' PM_2.5 exposure during their pregnancy negatively affects the mental health of their children aged between 10 and 15 years. A 1 µg/m³ increase in PM_2.5 exposure in utero increases the probability of having a severe mental illness for adolescents by 0.6%. Our evidence supports the "fetal origins" hypothesis. We also find that fetal PM_2.5 exposure leads adolescents to be more likely to be absent from school and quarrel with their parents, implying that fetal PM_2.5 exposure may affect individuals' behavior when they grow up.