Historical Neighborhood Redlining and Contemporary Environmental Racism.

Area of Science:

• Environmental Science
• Urban Planning
• Public Health

Background:

• The Home Owners' Loan Corporation (HOLC) created color-coded maps during the Great Depression to assess housing lending risk.
• These HOLC maps, largely based on racial segregation, designated neighborhoods A (lowest risk) to D (highest risk), with redlined areas representing the highest risk.
• Historical redlining practices have been linked to persistent socioeconomic disparities.

Purpose of the Study:

• To investigate the association between historical redlining and contemporary environmental disparities across the United States.
• To quantify differences in environmental exposures between HOLC-graded neighborhoods over recent decades.

Main Methods:

• Environmental exposures including air pollutants (PM2.5, NO2), vegetation, noise, and light at night were characterized.
• Proximity to hazardous emission sources and other environmental/social indicators were assessed.
• Data were collected for HOLC-graded neighborhoods and extrapolated census tracts across US cities.

Main Results:

• Neighborhoods with lower HOLC grades (C and D) exhibited consistently higher exposures to adverse environmental factors.
• Significant disparities in exposure to PM2.5 and NO2 persisted between lower and higher graded neighborhoods from 1981-2019.
• The environmental gap between lower and higher graded neighborhoods showed no significant improvement over the study period.

Conclusions:

• Historical redlining, a practice rooted in racial discrimination, is associated with enduring environmental injustice.
• Past discriminatory housing policies continue to shape present-day environmental inequalities.
• These findings highlight the long-term impact of redlining on environmental health disparities.