Association between greenspace morphology and prevalence of non-communicable diseases mediated by air pollution and physical activity

Abstract

Neighborhood greenspace is a recognized roborant, yet limited is known regarding the influence of greenspace spatial morphology on the prevalence of non-communicable diseases. Evidence is also scarce as to whether such associations are generalizable. Using census tracts, we examined these relationships in Los Angeles and explored the generalizability of the discovered associations in New York City, San Antonio, Seattle, and Miami, all major metropolitan areas in the US. We used high-resolution satellite imagery to generate greenspace maps, and calculated metrics to measure the average size, fragmentation, connectedness, aggregation, and shape of greenspace. The prevalence of poor mental health, heart disease, stroke, diabetes, COPD, and lack of leisure time physical activity was examined. Conditional spatial autoregression models were used, controlling for geographic, demographic, and socioeconomic factors. Neighborhoods with more connected, aggregated, coherent, and complex-shaped greenspace morphologies had a lower prevalence of non-communicable diseases. Such associations are mediated by air pollution and physical inactivity. A one-interquartile increase in greenspace aggregation in Los Angles was associated with a decreasing prevalence of poor mental health, heart disease, stroke, diabetes, physical inactivity, and COPD by 1.19%, 0.53%, 0.44%, 1.63%, 3.53%, and 0.62%, respectively. A one-interquartile increase in greenspace average size, shape complexity, cohesion, aggregation, and decrease in fragmentation associated with a decreasing prevalence of poor mental health in New York City by 0.12%, 4.29%, 0.68%, 0.44%, and 2.87%, respectively. We offer evidence that the location, shape, and connectivity of urban greenspace have a significant and independent effect on health at the neighborhood level above and beyond that meliorated by sheer amount. The spatial morphology of designed urban greenspace should therefore be incorporated into routine environment-based health planning.