Key points:
- A new study shows historically redlined areas have higher levels of air pollution today.
- Areas rated neighborhoods rated the “most risky” had 13% higher levels of NO2 than areas labeled “the least risky.”
- The researchers hope their work helps to identify areas that might be the most improved by remediation programs, such as clean technology incentives.
As part of the New Deal, several governmental programs were created to expand homeownership through mortgages and loans. However, this led to the practice of “redlining,” or denying of loans to those who lived in “risky areas”—most often home to Black or immigrant communities. While obvious redlining is illegal today, the consequences still exist.
According to new research in ACS’ Environmental Science & Technology, those consequences extend to air pollution. Researchers have found that historically redlined areas have higher levels of air pollution than those that received higher ratings, and similar disparities affect many cities across the U.S.
For the study, the team gathered satellite and computer modelling data on nitrogen dioxide (NO2) and airborne fine particulate matter (PM2.5), both of which can be hazardous when inhaled. Combining demographic data from the 2020 census and historical maps from the Home Owner’s Loan Corporation, the researchers found that neighborhoods rated the “most risky” had 13% higher levels of NO2 than areas labeled the “least risky.”
The team chose Denver as their model city. Across Denver as a whole, neighborhoods where the majority of residents identified as non-Hispanic White and Asian or Asian American were exposed to less NO2 and PM2.5 than areas with groups primarily identifying as American Indian and Alaska Native, and Hispanic or Latino.
The researchers also investigated the possible sources of the NO2 and PM2.5 emissions affecting the previously redlined areas. They discovered that diesel-powered vehicles emitted about half of the nitrogen oxides from road vehicles, while additional pollutants, such as benzene, were emitted from other point sources, including nearby petrochemical refineries.
Many major highways and industrial areas in Denver, including Commerce City, are surrounded by diverse communities that typically contain fewer people identifying as non-Hispanic White, even though this group makes up a majority of the city’s population.
The researchers say that this work helps to identify areas that might be the most improved by remediation programs, such as clean technology incentives.