Fig. 4.

Impacts of reducing PM_2.5 concentration, aging, and changes in other factors on the CES-d-10 score. The changes in risk factors (Δx) were evaluated using a fixed group of subjects who participated in all three China Health and Retirement Longitudinal Study (CHARLS) waves; the corresponding coefficients were estimated from the longitudinal model with standard adjustment (Fig. 2) and presented in Table S3; for each variable, the value in 2011 was acted the reference to evaluate the impact attributable to its temporal changes.