Urban greenspace exposure and inequality are associated with mortality in cities across multiple countries

Background Urban greenspace is recognized as a key component of healthy cities, yet evidence linking greenspace to mortality remains geographically fragmented, while the association between unequal greenspace distribution and mortality remains poorly understood. We aim to examine associations of greenspace exposure and inequality with all-cause, cardiovascular, and respiratory mortality across cities in multiple countries. Methods We analyzed annual mortality and satellite-derived vegetation data from 624 urban locations across 22 countries during 2001–2020. Greenspace exposure was characterized using the population-weighted Enhanced Vegetation Index, and greenspace inequality using a Gini-based metric. We estimated country-specific associations with all-cause, cardiovascular, and respiratory mortality using negative binomial regression models. Country-specific estimates were pooled using random-effects meta-analysis, and heterogeneity by income level, climate zone, and geographical region was examined. Results A 0.1-unit increase in greenspace exposure was associated with lower risks of all-cause mortality (RR = 0.89, 95% CI = 0.83–0.95), cardiovascular mortality (0.92, 0.82–1.00), and respiratory mortality (0.89, 0.78–1.01). In contrast, a 0.1-unit increase in greenspace inequality was associated with a higher risk of all-cause mortality (1.14, 0.99–1.31), with no significant associations observed for cardiovascular or respiratory mortality. These associations varied across income levels, climate zones, and geographical regions. Conclusion Our findings indicate that both the amount and spatial distribution of urban greenspace are associated with population health, underscoring the need for urban planning strategies that prioritize not only greening but also equitable access.