A new interdisciplinary study, published in Science Advances, examines how the features of community design plans (green space, blue space, street trees, etc.) impact residents’ psychological wellbeing. The international team of researchers, representing a variety of disciplines, suggest that innovations in urban planning may counteract some of the risks of urban layouts posing risks to human health.
Bratman and colleagues’ piece outlines their holistic model, drawing from recent research emphasizing synergy between ecosystem layout and whole-person health.
“Many of the contributions of living nature (diversity of organisms, ecosystems, and their processes) to people’s quality of life can be referred to as ‘ecosystem services.’ They include water purification, provision of food, stabilization of climate, protection from flooding, and many others. Worldwide, major efforts are underway to bring ecosystem services and their values into policy, finance, and management. […] However, relatively little attention has been given in the field of ecosystem services to the ways in which nature experience directly affects human mental health […], with a few important exceptions.”
While many environmental features have been connected to healthy development across the lifespan, and overall improved quality of life in research, green space, in particular, has received a great deal of attention.
Results from one recent longitudinal study indicated that proximity to green space in childhood might protect against later development of psychiatric disorders in adulthood. Neighborhood green space has also been linked to community cohesion and reduced crime, reduced stress response, decreased rumination, more advanced cognitive functioning, and more.
Indeed, despite the global expansion of city sprawl, many of the features that characterize cities (dense concentrations of people, heavy industry, many cars, etc.) are detrimental to central aspects of mental and physiological health. Education, healthcare, and many other agencies designed to support human growth are often concentrated in environments with poor air quality, increased stress among residents, and reduced access to green space among residents.
“Controlled laboratory studies have demonstrated beneficial psychological and stress/physiological impacts of nature images and sounds. Experimental fieldwork has also shown the benefits of nature experience by contrasting within-group change across affective, cognitive, and physiological dimensions in participants who walked in natural versus urban environments,” the researchers write. “Cross-sectional and longitudinal research has found that the psychological well-being of a population can be associated, in part, with its proximity to green space, blue space (i.e., aquatic and marine environments), and street trees or private gardens in both urban and rural settings.”
While the size and scope of the impact of experience in nature on mental health require continued exploration, Bratman and colleagues outline three consensus statements characterizing research thus far:
1) “evidence supports an association between common types of nature experience and increased psychological well-being”, 2) “evidence supports an association between common types of nature experience and a reduction of risk factors and burden of some types of mental illness,” and 3) “evidence suggests that opportunities for some types of nature experience are decreasing in quantity and quality for many people around the globe.”
These areas of consensus illustrate the need for the development of creative ways to make cities, in particular, more conducive to human health. To ensure compatibility between decisions made in urban planning and residents’ mental health, and as cities continue to develop, tools are needed to enable planners across a variety of disciplines to anticipate the impact.
To this end, Bratman and colleagues propose a four-step assessment model including 1) the development of an outline of planned natural features, 2) estimation of the level of exposure to environmental features that may be experienced by those expected to interact with the space, 3) projection of how the area that’s been designed will be experienced according to nature of visitor interaction and dose, and 4) consideration of potential short- and long-term mental health effects associated with aspects of design.
Although this model is among the first of its kind, the authors intended for it to be flexible and hope that it will serve to inform a more robust conceptualization of the relationship between space and overall human health in ecosystem service assessments.
“Ultimately, our evolving conceptual model can broaden current ecosystem service models by accounting for the effects of nature exposure on mental health, and identifying where additional green spaces or better access to nature may improve it, or where certain infrastructure, building siting, and other land-use decisions may negatively affect it. Given the large contribution of mental illness to the global burden of disease, these are essential issues to address.”
Bratman, G., Anderson, C. B., Berman, M. G., Cochran, B., de Vries, S., Flanders, J., … Daily, G. C. (2019). Nature and mental health: An ecosystem service perspective. Science Advances, 5 (7). DOI: 10.1126/sciadv.aax0903 (Link)