Beneficial Health Outcomes of Natural Green Infrastructure in Cities

Abstract

We examined recent literature on the human health impacts of natural green infrastructure (NGI). NGI refers to green space that requires less maintenance than traditional formal urban green spaces such as city parks. Where declining cities have excess land and fewer funds for land maintenance, NGI is globally emerging as a cost-effective way to convert abandoned land into useful green space producing ecosystems services. Our goal was to determine if recent studies show that NGI provides human health benefits. Much previous work shows that urban green infrastructure in general has human health benefits but we ask the question whether this specific kind of green infrastructure also provides human health benefits. We found 29 studies reporting positive human health impacts from NGI. Most reported mental health benefits but wellbeing, crime reduction, obesity, and recreation were also reported. These studies also reveal the specific characteristics of NGI that contribute to the positive health impacts: forests, trees, wilderness, biodiversity, and tranquility. We also found an additional 13 studies of low-maintenance greening projects on urban vacant land that all report health benefits including crime reduction, mental health, and pro-social behavior. These 42 studies utilize a variety of different research designs and metrics. The recent literature indicates that NGI may be a low-cost way to convert abandoned land in declining urban areas into green space that provides health benefits to people who often lack access to green space. NGI provides benefits of mental health, wellbeing, and crime reduction that are comparable, if not better, than other, more costly urban green infrastructure.