Associations of cooking solid fuel use and long-term exposure to PM1, PM2.5, PM10 with depression among Chinese adolescents: A follow-up study

The association of adolescent depression with air pollution remains unclear. This study of 1673 adolescents explored the independent and combined effects of cooking fuel use and long-term exposure to particulate matter (PM) on depression. The statistical analyses included Cox proportional hazard regression models and restricted cubic spline analysis. The participants’ mean age was 13.48 ± 2.27 years. Cooking solid fuel use was positively associated with depressive symptoms. The depression risk among adolescents from households that switched from solid to clean fuel was significantly lower compared with those using solid fuel throughout. PM exposure was linked to an elevated risk of depression (hazard ratio HR = 1.16; 95% confidence interval CI 1.04, 1.29 for PM 1 ; HR = 1.20; 95% CI: 1.08, 1.34 for PM 2.5 ; and HR = 1.17; 95% CI: 1.05, 1.31 for PM 10 ). Similarly, the combined effects of cooking fuel use and exposure to the different PM sizes were associated with an increased risk of depression. Subgroup analyses revealed a significant difference in residence regarding the association of exposure to different PM sizes and cooking fuel use with depressive symptoms. Both the independent and combined effects of cooking solid fuel use and PM exposure were significantly associated with incidence of adolescent depression. Transitioning from solid fuel to cleaner alternatives may reduce the risk of incident depressive symptoms among adolescents. • Few studies examine indoor/outdoor air pollution effects on adolescent depression. • Indoor/outdoor air pollution independently and jointly worsen adolescent depression. • Shifting household fuel structure effectively reduces depression risk in adolescents.