Pun, Manjourides and Suh examine neighbourhood greenness as a longitudinal exposure capable of modifying psychological stress among older adults. Using a nationally representative U.S. sample and NDVI measures at 250-m resolution and within 1000-m buffers, the study connects environmental vegetation with validated measures of perceived stress, depression and anxiety. Its strongest result concerns stress: greater greenness is associated with lower perceived stress, while physical activity partially mediates this relationship. The study also demonstrates that effects are not socially uniform, varying by race, social support, physical function, socioeconomic status and region. Methodologically, it exemplifies the epidemiological translation of neighbourhood form into measurable exposure while retaining mediation and effect modification as analytical problems. Conceptually, greenness becomes less a visual attribute than a spatially distributed condition whose benefits depend on who inhabits it and through which behavioural and social pathways. The bridge to urbanism lies in recognising environmental support as differentiated rather than universal.
