The Impact of Urban Green Space on Public Health: Evidence from 30 Provinces in China (2012–2023)

The association between urban green space (UGS) and public health represents a core interdisciplinary issue in ecological city construction and the “Healthy China” strategy. However, the underlying mechanisms, contextual constraints, and regional heterogeneity of the impact of UGS on public health at the provincial macro-scale remain insufficiently understood. Existing research primarily examined the health effects of green space at the resident-level micro-scale, with samples often limited to single cities or local urban clusters. Furthermore, limited attention has been paid to the moderating mechanisms and nonlinear threshold characteristics through which green space affects public health. Using panel data from 30 provinces in China from 2012 to 2023, this study empirically investigates the effects, moderating mechanisms, threshold effects, and regional heterogeneity of UGS on public health through two-way fixed-effects ordinary least squares (OLS) regression, moderation models, and threshold regression models. UGS The results show the following: (1) From 2012 to 2023, the overall levels of provincial UGS and public health in China increased, exhibiting a spatial distribution pattern characterized by higher levels in the east and lower levels in the west. (2) The development level of UGSs is significantly and positively associated with provincial public health in China; (3) The health-promoting effects of UGSs exhibit both moderation and threshold characteristics. Environmental regulation, traffic accessibility, and population aging exert positive moderating effects, whereas the level of urbanization exhibits a nonlinear threshold relationship. (4) Regarding regional heterogeneity, the health benefits of green spaces are more pronounced in urban functional zones and coastal regions, whereas key ecological functional zones and major grain-producing areas demonstrate synergies between ecological protection and health improvement. Accordingly, China should strengthen the coordinated advancement of UGS planning and public health protection, optimize the spatial layout of age-friendly green space, improve the supporting environmental regulation systems, and thereby promote the coordinated development of residents’ health and well-being and ecological environmental quality.