Green Space, Social Determinants of Health Spur Health Disparities

April 29, 2021 - Green space, an increasingly recognized social determinant of health, has been linked to lower racial health disparities related to the novel coronavirus, according to researchers from the University of Illinois Urbana-Champaign.

These findings offer another view of the racial health disparities seen during the pandemic. Thus far, most investigations into COVID-19 racial health disparities have looked at the role of income, job type, residence in a multigenerational or crowded house, and other sociodemographic factors.

This latest data, published in partnership with researchers from the University of Hong Kong and City University Hong Kong, showed that environment and particularly the amount of green space in a given county could also play a factor in public health outcomes.

Previous data has shown that green space is associated with better mental health, like better cognitive function, reduced stress, lower sense of impulsiveness or restlessness, and higher perceived sense of safety. Green space can have community benefits, with links to lower crime rates, higher rates of physical activity, and more social cohesion, the researchers said.

The researchers looked at the 135 most urbanized parts of the US, which encapsulates over 132 million people, or 40.3 percent of the total US population. Using data from relevant county health departments from between January and July of 2020, the team tracked COVID-19 infection rates. The team controlled for factors like income, pre-existing conditions, and urban density.

The assessment established that there were, in fact, racial health disparities in the studied counties. Black patients were just about twice as likely to become infected with the novel coronavirus as White patients, 988 infections per 100,000 people versus 487 infections per 100,000 people, respectively.

The team also analyzed the amount of green space in a given county and found the more prevalent the green space, the less stark the racial health disparity. Particularly, green space accounted for about 18 percent of the racial health disparities the team observed. Open space in developed areas, forest, shrub and scrub, and grassland and herbaceous areas were particularly linked to reductions in racial health disparities.

The researchers posited that more green space creates more equitable access to green space, which has proven health benefits.

"In many, many counties, Black folks have less access to green space than white folks do. In counties with more green space, that disparity may be less, and it may help account for some of the positive benefits we're seeing," William Sullivan, a landscape architecture professor at the University of Illinois Urbana-Champaign, said in a public statement.

Specific to the COVID-19 racial health disparities, the researchers posited that access to green space encouraged safer gatherings. The virus is transmitted through aerosol droplets and can be more easily spread indoors. Access to green space may have encouraged more outdoor gatherings, reducing the risk people contract the illness. When there is an abundance of green space, all people have the option to safely gather outdoors, which could have mitigated at least some disparities.

There are also the general benefits of green spaces, which could have boosted overall wellness in residents and staved off serious COVID-19 risk or illness. Because green space encourages physical activity and reduces stress, people living in areas with abundant natural spaces may have had higher baseline health, potentially making it less likely they would become sick with the virus.

"We did not measure these things, but we know from previous research that all these things are tied to green spaces and have implications for health and well-being," Sullivan added.

This evidence could pave the way for further investment in green space as a key social determinant of health, Sullivan said.

"One of the things the pandemic has helped us understand is that the built environment has real implications for the spread of disease and for our health. The design of landscape in cities, in neighborhoods, in communities also has really important ways it can contribute to or detract from health and well-being," he explained.

"There is a lot of competition for investment of public dollars. Lots of times, investments in parks and green spaces are prioritized lower. People think it makes a place look pretty and it's a place to go for walks. What we're finding is these kinds of investments have implications for health and well-being."

Green space is an oft-overlooked social determinant of health, but as noted by the researchers, can have a big impact on community wellness. Previous research has linked green space with community walkability, food security, job creation, and youth engagement, all of which have an impact on overall health and wellness. Equitable access to green space could be yet another link in the work toward health equity.