As global public health faces unprecedented challenges, Urban Green Space (UGS) is increasingly recognized as a vital instrument for health intervention. However, its efficacy in mitigating infectious diseases remains conceptually contested. Drawing on longitudinal data from 300 Chinese prefecture-level cities (2003–2023), this study employs Spatial Durbin Models (SDM) and threshold regression to unravel the complex spatio-temporal trade-offs between UGS and chronic infectious diseases. Focusing on the mitigation of chronic infectious diseases, our findings challenge linear paradigms by unveiling a non-monotonic “risk-to-resilience” transition. In the nascent stages of greening, UGS expansion may paradoxically create a “pathogenic window” elevating transmission risk through intensified human-wildlife-environment interactions. However, once UGS coverage surpasses a critical tipping point, it serves as a potent ecological shield, significantly curbing the spread and latency of chronic infectious diseases. This suppression is achieved through microclimate stabilization, bio-filtration, and the enhancement of community salutogenesis. Furthermore, our analysis reveals robust positive spatial externalities, demonstrating that protection against chronic infections propagates across administrative borders via ecological corridors. This study identifies a pivotal scale effect in green governance, positioning UGS as a long-term strategic asset for demographic health. Our results advocate for a transition from localized planting to trans-regional collaborative green infrastructure networks, providing crucial theoretical scaffolding for the Healthy China 2030 initiative and the management of chronic infectious risks.
Zheng et al. (Tue,) studied this question.