Historic Redlining Practices Continue to Negatively Impact Community Health Risks

By Katie Renzi, NLIHC Research Intern 

A recent article published in the International Journal of Justice and Sustainability examines the enduring impact of historic redlining practices on present-day life expectancy across the United States. Redlining, a discriminatory practice stemming from the 1930s, involved color-grading neighborhoods based on factors like socioeconomic status and racial makeup, leading to the denial of loans and resources in predominantly nonwhite communities. The authors found a significant negative association between historic redlining and modern-day life expectancy, with each increase in neighborhood grade (from 1 to 4, where 4 is the worst) corresponding to a 1.7-year decrease in life expectancy. 

The study used a statistical model to explore how historic redlining might affect modern-day life expectancy, directly or indirectly, through other factors. These factors included air quality (measured through PM2.5 levels) and community sociodemographic characteristics, like educational attainment, homeownership rates, income, and racial composition. The authors also examined how specific health conditions, such as asthma, high blood pressure, and COPD, were associated with redlining, and their relationship to life expectancy. The model used the grades of neighborhoods scored in the 1930’s by the Home Owners’ Loan Corporation (HOLC) to test pathways between redlining and poor life expectancy. HOLC assigned neighborhoods a score from A (or 1; best) to D (or 4; worst or "hazardous") based on perceived creditworthiness. Loan requests for D-scored neighborhoods, which were primarily nonwhite, were often denied and investment discouraged. The color code for neighborhoods with a D score was typically red, resulting in the term “redlining.” 

The researchers observed significant differences in sociodemographic indicators and PM2.5 levels across neighborhood grades. Non-Hispanic Black residents accounted for 36% of the population in census tracts with a HOLC grade of 4, but only 15% of the population in grade 1 tracts. Grade 1 tracts had a significantly higher percentage of residents with a bachelor’s degree (28.9%) compared to grade 4 tracts (14.9%) and double the median household income ($81,491 vs. $40,130). PM2.5 levels were also significantly lower in grades 1 and 2 tracts compared to grades 3 and 4. 

The study found a significant negative association between HOLC grade and life expectancy. Life expectancy decreased by an average of 4.8 years when comparing census tracts with a HOLC grade of 1 (80.5 years) to those with the worst grade of 4 (75.7 years). The study also revealed significant associations between HOLC grade and health conditions. COPD prevalence increased from 5.0% in grade 1 tracts to 7.4% in grade 4 tracts, while asthma prevalence increased from 8.6% to 10.7%. High blood pressure prevalence displayed a similar relationship, increasing from 29.3% in grade 1 tracts to 34.1% in grade 4 tracts. The study quantified the years of modern-day life expectancy lost due to historic redlining via specific health conditions: 0.531 years due to COPD, accounting for 31% of lowered life expectancy; 0.300 years due to asthma, accounting for 17.5%; and 0.233 years due to high blood pressure, accounting for 13.6%. 

These findings indicate the lasting and continuing impact of historic redlining on health outcomes and life expectancy through various environmental, social, and health-related pathways. To address these factors, the authors recommend interventions and strategies like stricter environmental regulations, improving filtration systems in homes and schools, amending local zoning laws to reduce residential racial segregation, increasing educational opportunities, and implementing preventative health programs in historically redlined neighborhoods.  

The full article, "The mediating effects of particulate matter 2.5 (PM2.5) and sociodemographic indicators and health conditions on the relationship between historic redlining and modern-day life expectancy”, is available at: http://bit.ly/44Aan58