Why we need access to nature

While access to nature is an established social determinant of health with clear benefits to physical, mental, and social health, it does not receive as must attention by health care providers or health systems as other social concerns, according to a new piece by a Penn Medicine physician published today in the American Journal of Preventive Medicine.

"I think changing how people interact with their neighborhood environment, and changing the environment directly, is perceived as being hard and, perhaps, out of bounds of what is possible from health care," said Eugenia South, MD, an assistant professor of Emergency Medicine "We don't learn about environmental contributors to health in medical school, and it is not part of traditional biomedical care," South said. "And yet, changing the neighborhood, including increasing nature access, has the potential to have a huge health impact on a lot of people. It is worth pursuing."

Social determinants of health are the social, economic, or political factors that affect people's lives and shape the health of individuals and their communities. These could include whether or not people have access to healthy food or stable housing, whether there are higher rates of violence in their communities, what physical infrastructure is in their neighborhood, and what job opportunities are available to them. Many of these factors tie back to recent national conversations about structural racism, and there has also been elevated attention, due at least in part to requirements set forth by the Affordable Care Act. This has led to interventions from health systems, such as through investment in affordable housing. 

But access to nature and greenspace is often not given as much consideration when it comes to addressing the inequities that play into people's health. This is in face of a multitude of studies that show that time in -- and even just the presence of -- nature can improve a community's health, such as through a reduction in diabetes rates and stress-related conditions like heart disease. Moreover, other studies have shown that a lack of access to nature is tied to poorer outcomes, such as research that tied tree loss to increased cardiovascular and respiratory deaths.

South believes that this evidence demonstrates that health systems and health care providers should make more of an effort to increase greenspace access, or "prescribe doses" of it, to potentially boost community health as a result. 

"Now, we need to specify how much of nature, or how accessible it needs to be, for people to get positive benefits - and negate any deficiencies," South wrote in the journal.

A way that health care can be adjusted to factor in nature is to have clinicians incorporate assessments of a person's access to it during patient encounters. This could be done by adding simple questions gauging a person's feelings toward nature, how much time they are able to spend in it, and where they are able to access it. Possible interventions could be as simple as a primary care physician looking up parks or trails nearby so that they're aware of what is accessible. Clinicians could also refer patients to community groups working on increasing green areas.

South pointed out that even if there is an embrace of "prescribing" nature, it can't be a one-size-fits-all approach, much the same as any other prescription. Factors such as a person's mobility or whether they have a condition like asthma may affect how they can interact with certain green spaces. Racial minorities may feel unwelcome in public green spaces, which must also be discussed. 

And while she said any person involved in a health system can provide guidance for nature exposure, South suggested that community health workers, who already live and work in the areas where these interventions would take place, might be best suited. Their knowledge of and relationships with people in the area would inform the best practices for health systems to address deficiencies in access to nature.

Over the last two years, health systems have spent more than $2.5 billion addressing social determinants of health. As such, there is the capacity and the infrastructure in place for them to also address nature access, South explained. That could come in the form of something as simple as vacant lot greening, which has been demonstrated by South and colleagues to reduce violent crime, increase social cohesion, and reduce feelings of depression for nearby community members. Health systems could merge different initiatives to address social determinants of health, like investing in affordable housing that also has access to green space.

"There may be an economic argument to make for investing in greenspace," South said. "I am conducting a study now to see if vacant lot greening reduces emergency department visits for stress-related conditions. Tree canopy coverage is another example: Trees reduce urban heat islands, and high heat on summer days is associated with worse outcomes for people with chronic disease."

As of late, there has been renewed interest in the outdoors due to stay-at-home orders and social distancing. Reddit data shows that toward the beginning of the outbreak, many were questioning whether they could safely go outside. South's paper was written before the COVID-19 outbreak, but its points are especially timely. 

South said she's seen people in cities are spending time outside like never before, and she hopes healthcare providers will "jump on this wave" to discuss its benefits with their patients. But just like other social determinants of health, South sees lack of access to nature correlating with differences in COVID-19 infections.

"Layered on top of a lack of access to greenspace, economic and educational inequities, the criminal justice system and housing, you have a system of structural racism that has worked to create the disparities we see in COVID today," South said.