Invited Perspective: Forging a Way Forward Amid the Enduring Impacts of Redlining

The practice of redlining in the United States, begun by the Home Owners’ Loan Corporation (HOLC) in the 1930s,¹ has enduring effects on current-day American society. The four-level HOLC grade system used to classify neighborhoods within U.S. cities, with “redlined” communities graded as “hazardous” to lenders, led to subsequent disinvestment by financial institutions and eventual declines in neighborhoods with a high percent of Black residents.^2,3 Although no longer officially practiced,⁴ redlining’s adverse effects on communities have continued.⁵ Studies show that this practice contributed to disparities across multiple sectors in the United States, including homeownership,³ wealth accumulation,³ income,³ educational opportunities and attainment,^6–8 and exposure to air pollution,⁹ heat,¹⁰ and greenness.^11,12 In addition, redlining is “nearly universally” linked to adverse health outcomes, particularly between groups that have been historically advantaged and those that have been disadvantaged.³ The divide created by redlining typically manifests along the lines of non-Hispanic White persons compared with racially minoritized persons, where the latter communities usually experience worse outcomes.

In their analysis published in this issue of Environmental Health Perspectives, Tsai et al. examined the potential impact of redlining on the association between neighborhood greenness and depressive symptoms among 3,555 Sister Study participants in 192 U.S. cities.¹³ Consistent with prior work, depressive symptoms were more prevalent among individuals residing in areas graded lower by HOLC, including redlined areas, vs. the most desirable of the 4 HOLC grades. Tree coverage declined by HOLC grade, with the lowest amount in formerly redlined locations. Higher present-day neighborhood greenness (specifically, tree cover) was associated with reduced odds of depressive symptoms, and increases in greenness were more strongly associated with decreased depressive symptoms in formerly redlined areas than in other HOLC-classified locations.

The focus of Tsai et al. on tree canopy—an “ecosystem service” with potential for reducing exposure to heat and air pollution and for fostering physical activity¹⁴—points toward interventions to mitigate the increasingly clear adverse impacts that are associated with redlining. Tsai et al. mention the benefits of tree planting as an example of remediation efforts, and other studies document success of such interventions.^15,16 They also note the importance of including community members in such undertakings.

Looking at the map of Sister Study participants in U.S. cities included in their analysis, we note a substantial number from Detroit, Michigan. A recent study in Detroit reported higher concentrations of various potentially harmful environmental exposures, notably noise and air pollution, in formerly redlined areas.¹⁷ Another evaluated social and physical exposures and their role in associations between race-based residential segregation and mortality.¹⁸ These locally focused studies illustrate the many social and physical determinants of health patterned by structurally racist policies.

We agree with Tsai et al. that research using community-engaged approaches and incorporation of community knowledge is an essential next step in considering ecosystem service interventions—actions that can offer myriad benefits, including mitigating climate-related health impacts. Engaging communities can integrate residents’ insights into research and intervention design.

Our own experiences of working with and learning directly from Detroit community partners and residents have enhanced the value and relevance of our research by ensuring appropriate questions are asked and the appropriate context is incorporated into interpretation of the result.¹⁹ For example, our interviews with individuals to discuss their perceptions and actions related to heat waves illuminated concerns facing people shown in epidemiological studies to be at increased risk.²⁰ Some were reluctant to go to cooling shelters due to concerns about leaving pets behind, having culturally appropriate food available, or personal safety, and some seniors preferred wearing warm clothing such as sweaters, even in hot weather.²⁰ Additionally, we evaluated the role of tree canopy and other factors in reducing indoor temperatures during hot weather, and direct measures in Detroit residents’ homes were invaluable for understanding potential beneficial effects of trees.²¹ Similarly, our ability to estimate and interpret associations between indoor temperatures and health indicators among low-income Detroiters was enhanced by insights and access provided by our community-based collaborators.²² We applaud funding opportunities by the National Institutes of Health that require incorporating community members as research collaborators (e.g., https://grants.nih.gov/grants/guide/pa-files/PAR-22-210.html; https://grants.nih.gov/grants/guide/pa-files/PAR-08-075.html)²³ and resources being invested in training junior researchers in community-engaged work for health equity, e.g., Agents of Change (https://agentsofchangeinej.org/), the JPB Environmental Health Fellows program (https://ehfellows.sph.harvard.edu/), and NIEHS-supported training for pre- and postdoctoral students in environmental and social sciences, run jointly by the Social Science Environmental Health Research Institute at Northeastern University and the Silent spring Institute (https://www.northeastern.edu/environmentalhealth/resources-for-prospective-students/niehs-research-training-program).

The work of Tsai et al. on greenery, depressive symptoms, and modification of this association by historical redlining in the United States highlights a new dimension of environmental injustice that can inform future investment and interventions. Their work on redlining further highlights that this practice, born from structural, systemic racism, has enduring impacts decades after it was instituted. Moreover, they demonstrate how health benefits of environmental improvements may be enhanced among formerly redlined neighborhoods. These findings underline the need for sustained and far-reaching actions and investment to rectify the injustices still being experienced by many.

Refers to https://doi.org/10.1289/EHP12212