The effect of peri-urban parks on life expectancy and socioeconomic inequalities: A 16-year longitudinal study in Hong Kong

Exposure to greenspaces has well-established benefits for the health and well-being of urban dwellers. Among these greenspaces, peri-urban parks (PUPs), which are human-modified, large-scale, and public-accessible greenspaces located on the urban fringe, have received increasing attention from policymakers and researchers in recent years, as the limited provision of greenspaces in urban areas barely meet the residents' needs for nature engagement. However, the associations between PUPs and life expectancy and their potential socioeconomic inequalities remain unclear. In this study, we employed a longitudinal, territory-wide death- registration dataset to address such research gaps. The results showed that both the area and greenery of PUP significantly decreased life expectancy loss with standardized coefficients of -0.156 (p = 0.001) and -0.173 (p < 0.001), respectively. The life-expectancy benefits of PUP greenery remain significant throughout 200-8000 m buffer radii. Nevertheless, socioeconomic inequalities were found between PUPs and life expectancy associations. We found that people with higher socioeconomic status (SES) received higher PUP exposure. In addition, contrary to the hypothesis of equigenesis theory, higher-SES populations received greater benefits in life expectancy than lower-SES populations, even after controlling for inequalities in PUP exposure. Our findings uncover a complex relationship between PUPs, life expectancy, and SES, highlighting the need for targeted interventions for people with different SES to ensure equitable health benefits for all.