The neighborhood effect of exposure to blue space on elderly individuals' mental health: A case study in Guangzhou, China

Within the urban setting, blue space refers to all visible surface waters, including lakes, rivers, and coastal waters. Exposure to the natural environment, especially blue space, has been consistently linked to better mental health. While previous studies have disentangled the positive relationship between neighborhood blue space and mental health, scant attention has been paid to pathways through which neighborhood blue space affects mental health among Chinese urban elderly individuals. Based on questionnaire data collected from Guangzhou in 2018, remote sensing images, street-scapes, and other such sources, we extracted various blue space indicators. We employed multilevel linear regression modeling, mediating effect modeling to examine bio-psychosocial pathways and mechanisms linking exposure to blue space and elderly individuals' mental health. Propensity score matching method was employed to deal with selection bias. According to this empirical analysis, firstly, neighborhood exposure to blue space was significantly associated with elderly individuals' mental health. Secondly, environmental harm reduction, stress reduction, and social contact facilitation played a separate role in mediating the effect of blue space exposure on elderly individuals' mental health. These findings confirm the mediation pathways in the context of Chinese cities. Our research enriches the empirical research on blue space and public health from the perspective of health geography, and suggests the need for healthy neighborhood and health aging planning in Chinese settings.