How Intersections of Race, Education, and Socioeconomic Status May Predict Unequal Greenspace Exposure.
How Intersections of Race, Education, and Socioeconomic Status May Predict Unequal Greenspace Exposure
A new study suggests that considering these factors jointly can capture a more accurate representation of disparities in residential greenspace exposure, driven by structural racism and decades of disinvestment in marginalized communities.
Exposure to trees, grass, and other greenspace provides numerous benefits to physical and mental health. Inequities in access to greenspace persist today as a result of structural racism, driven by historical policies such as redlining and segregation, as well as economic and environmental disinvestment in marginalized communities.
While previous research has explored differences in greenspace access by individual factors of race/ethnicity, income, and education, a new study led by School of Public Health researchers sheds light on how these factors also intersect to drive disparities in greenspace exposure, and how these disparities vary by type of vegetation.
Published in the journal Environmental Epidemiology, the study found that intersecting levels of race/ethnicity, education, and neighborhood social economic status (NSES) accounted for more disparities in residential exposure to greenspace than each of these factors individually.
The researchers utilized a powerful multi-level analysis called the Multilevel Analysis of Heterogeneity and Discriminatory Accuracy (MAIHDA) approach, along with street-view greenspace metrics, to quantify unequal distribution of residential greenspace by vegetation type for intersecting combinations of race/ethnicity, education, and NSES. The study group included nearly 6,000 geographically and racially diverse participants enrolled in the longitudinal Multi-Ethnic Study of Atherosclerosis, beginning in 2000. Exposure focused on the percentage of trees and grass among total vegetation in the participants’ neighborhoods.
Overall, White residents of all education and NSES levels had greater exposure to trees and grass compared to Black, Chinese American, or Hispanic residents, but these patterns became more nuanced when residents were grouped by intersecting levels of race/ethnicity, education, and NSES. For example, among those with more education and higher NSES, Black, Chinese American, and Hispanic participants were exposed to a higher percentage of trees (versus other vegetation), while White participants were exposed to a lower percentage of trees. But this trend persisted only for White participants in higher-density—i.e. urban—areas, which have less greenspace overall than lower-density, or rural, areas.
“These findings highlight the importance of viewing greenspace exposure through intersecting factors and by type of vegetation,” says study lead author Tara Jenson, a postdoctoral associate in the Department of Epidemiology. “Differences in exposure to different types of vegetation can have important implications for health outcomes. Research has shown that higher exposure to trees and other non-grass greenspace is associated with better cardiovascular and behavioral outcomes, compared to no benefits for higher grass exposure.”
In total, the team created 36 combinations of intersecting levels of race/ethnicity, education, and NSES (such as Hispanic participants with some college education living in a low socioeconomic area, or Black participants with a college degree living in a high socioeconomic area) and found that trees and grass exposures were higher overall for White participants than participants of other races/ethnicities.
“This study shows that race, education, and NSES are experienced jointly, and considering these factors together allows us to capture a more complex and realistic explanation of greenspace distribution,” says study senior author Marcia Pescador Jimenez, associate professor of epidemiology.
A core aim of epidemiologic studies is to generate evidence that can guide targeted interventions, she says. “Distinguishing between types of greenspace and their relative impacts allows us to better direct intervention efforts.”
It is also important to consider a “greening without gentrification” approach to prevent displacement of the long-time residents and community resources, says Jenson. “Interventions to improve residential greenspace in historically under-resourced areas where marginalized communities are concentrated can inadvertently lead to gentrification as more affluent populations move into the area in response to improved amenities and higher property values. This often results in the original residents, businesses and communities being displaced.”
The team says that further research is needed to better understand greenspace distribution patterns in urban and higher density areas.
“Future work should investigate neighborhood socioeconomic level at a more narrow, granular level than the US Census tract level neighborhood area as an intersecting factor contributing to greenspace disparities,” Jenson says. “This is important as, as each Census level neighborhood can encompass a diverse range of housing types and amenities driven by different patterns and sources of economic segregation, inequalities and gentrification. This research should also incorporate additional area measures of economic segregation and inequality, as well as more nuanced measures of individual and family income, wealth and financial insecurity beyond just individuals’ income.”