Toward improved public health outcomes from urban nature

Shanahan, D.F., Lin, B.B., Bush, R., Gaston, K.J., Dean, J.H., Barber, E., & Fuller, R.A. (2015). Toward improved public health outcomes from urban nature. American Journal of Public Health, 105(3), 8. http://dx.doi.org/10.2105/AJPH.2014.302324

Shifting attention from whether nature influences health to how it does so could lead to better health outcomes for diverse communitiesThis article builds on the understanding that while urban green spaces provide settings for an impressive range of physical and mental health benefits, little is actually known about how specific elements of nature deliver particular health outcomes. This limited understanding, the researchers note, makes it difficult to design health-promoting green infrastructure in a cost-effective way. What’s needed, they say, are ecologists and health scientists working closely together to identify causalities and pathways through which nature provides health benefits to the human population. Needed too, they note, are strategies for assessing the degree of the dose-response relationship between nature and health under different conditions.

The authors, while recognizing the complexity of identifying cause and effect in the relationship between nature and health, offer a framework for examining how specific elements of nature lead to specific health benefits. They also present some possible direct and indirect pathways connecting the natural environment with human health outcomes. Direct pathways are presented as instances in which specific elements of nature influence the physical characteristics of the environment in a way that produces a measurable health outcome. For example, tree cover may improve air quality, resulting in improved respiratory health of neighborhood residents. Indirect pathways – which are more common — represent instances where nature influences the likelihood a person will display positive health behaviors or where nature reduces the impacts of other risk factors in a person’s life. For example, people may be more likely to exercise in environments with natural features. This increase in exercise behavior then positively influences cardiovascular or mental health outcomes.

It’s time, the authors state, for research to shift attention from whether nature influences health, to how it does so. This new direction, they suggest, will provide the foundation for guidelines and strategies that will help policy makers shape urban nature to deliver better health outcomes for communities. This, they note, could ultimately help reduce health inequalities, as policymakers would have the necessary information to tailor nature-based interventions to meet the health needs of diverse urban communities.

The Bottom Line

Shifting attention from whether nature influences health to how it does so could lead to better health outcomes for diverse communities