Neighbourhood greenness and mental wellbeing in Guangzhou, China: What are the pathways?

Rapid urbanization in China has diminished urban residents' opportunities to connect with nature and thereby posed a great threat to their mental wellbeing. While a plethora of studies have disentangled the positive relationship between neighbourhood greenness and mental wellbeing in developed countries, scant attention has been paid to pathways through which neighbourhood greenness affects mental wellbeing among Chinese urban residents. This study aims to systematically explore biopsychosocial pathways linking exposure to neighbourhood greenness to mental wellbeing using survey data collected from 35 neighbourhoods of Guangzhou, China. It uses the Normalized Difference Vegetation Index (NDVI) as the surrogate for residential exposure to greenness, thereby enabling the comparison between China and other countries, Results from Structural Equation Modelling show that exposure to neighbourhood greenness is positively associated with mental wellbeing. Results also suggest that, consistent with what is known, promotion of walking, facilitation of social cohesion and satisfaction with neighbourhood greenspace play separate roles in mediating the protective effect of neighbourhood greenness. However, in contrast to previous findings from developed countries, this study finds no evidence to indicate that reduction in stress and mitigation of air/noise pollution are pathways linking exposure to greenness to mental wellbeing. Our findings suggest the necessity of building sufficient green infrastructure at the neighbourhood scale in promoting mental wellbeing in Chinese urban settings.