Beyond green: how city greenspace shapes health outcomes in China

Urban greenspace is increasingly acknowledged as a vital component of sustainable urban development. While being exposed to greenspace is associated with a lower risk of chronic diseases, the specific health effects of different types and functions of greenspace remain unclear. As a distinct category with clear boundaries, high accessibility, and multiple functions, urban parks may play a particularly important role in promoting health, yet research focusing specifically on urban parks remains limited, and the underlying mechanisms are still unclear. The data were obtained from the China Health and Retirement Longitudinal Study (CHARLS), the China Longitudinal Aging Social Study (CLASS), and the China Urban Construction Statistical Yearbook for 2016, 2018, and 2020. Spatial autocorrelation analysis was applied to identify clustering patterns and hot/cold spots of chronic disease prevalence and greenspace resources (including park area and green coverage). A Multiscale Geographically and Temporally Weighted Regression (MGTWR) model was applied to quantify the influence of green coverage and park area on chronic disease prevalence, supported by geographic information system (GIS) mapping to visualize spatial distributions. Chronic disease prevalence followed an inverted U-shaped trend from 2016 to 2020, peaking in 2018. High-high clustering and hot spot shifted cyclically from the southwest to the northeast and back. Areas with high park greenspace remained consistently concentrated in the Bohai Rim and Pearl River Delta metropolitan regions, while those with high green coverage transitioned from the Yangtze River Delta and Pearl River Delta to the Middle Yangtze River urban agglomeration and finally to the southwestern ecological zone. The MGTWR model indicated a marginal effect: in eastern regions with ample green infrastructure, expanding greenspace yields limited returns, whereas in the less-green western regions, further development produces more significant health improvements. It is recommended to adopt tailored chronic disease prevention strategies, focusing on high-risk areas. Urban planning should prioritize equitable access to greenspace rather than merely expanding their area. Long-term environmental health monitoring is also advised to better capture the lagged effects of ecological improvements. This research provides evidence for transforming green infrastructure into health assets, supporting equitable urban planning to reduce the burden of chronic diseases.