Study: Historic federal housing discrimination led to millions of Black, Latino Americans breathing dirtier air today

March 11, 2022

The historic practice of federal housing discrimination, known as redlining, has led to millions more Black and Latino Americans breathing in dirtier air than White Americans over decades, according to a new study.

The study, published in the journal Environmental Science & Technology Letters, found that redlining and other discriminatory policies have led to racially segregated communities that disproportionately exposed and continue to expose more Black and Latino Americans to nitrogen dioxide and fine particulate matter from vehicles and nearby industrial sources.

The study looked at the health effect of redlining in 202 U.S. cities, including several in Indiana, finding “substantial intraurban air pollution disparities” historically and worse present-day local environmental quality and health outcomes.

Nitrogen dioxide can irritate airways, aggravate respiratory diseases, contribute to the development of asthma and increase the susceptibility to respiratory infections, like those triggered by COVID-19.

Exposure to particulate matter can cause heart attacks, decreased lung function and premature death in people with heart or lung disease. Long-term particulate matter exposure has also been linked to an increase in the severity of COVID-19 health outcomes, including a higher mortality rate.

“Of course, we’ve known about redlining and its other unequal impacts, but air pollution is one of the most important environmental health issues in the U.S.,” Joshua Apte, a co-author of the study and an assistant professor in the School of Public Health at the University of California at Berkeley, told the Washington Post. “If you just look at the number of people that get killed by air pollution, it’s arguably the most important environmental health issue in the country.”

Beginning in the 1930s, the Home Owners’ Loan Corp., a federally sponsored corporation created during the New Deal, graded neighborhoods on a four-point scale. The scale was used to calculate the financial security of neighborhoods. The higher the rating, the more likely the HOLC was to grant a loan.

The HOLC used discriminatory criteria to establish ratings, with many neighborhoods receiving the worst grade due to the presence of Black and immigrant communities or known environmental pollution sources.

According to the report, HOLC agents were told that “infiltration of foreign-born, Negro, or lower-grade population” were cause for lower grades, and thus typically ineligible for federally backed loans or favorable mortgage terms.

The ratings also informed the decisions of local zoning officials, who would work with businesses to place pollution sources, like industrial plants and major roadways, in the lowest-rated areas, which were often populated by people of color.

1937 HOLC map of Indianapolis archived by the University of Richmond.

The legacy of historical redlining can still be felt in Hoosier cities today, like Indianapolis, where areas redlined in the 1930s are still zoned for industrial use. Some redlined areas still have significant populations of people of color and low-income White people today.


The area of the city including Military Park, Indiana University Purdue University Indianapolis, the Roudebush VA Medical Center, Eskenazi Hospital and other facilities was given a “D” rating in 1937, the lowest possible, due to it being a “blighted area” and the “infiltration of Negro” families, namely the construction of low-cost apartments for “negroes.”

The site is currently a Superfund site now known as the “0153 Ground Water Contamination Site,” a plume of chlorinated volatile organic compounds near the Riverside and White River Municipal Wellfields, water sources for Indianapolis residents.


The area known as West Indianapolis, long a manufacturing hub in the city, was redlined due to its proximity to factories, railroad yards, flood risks and the presence of Black residents and “very low class native whites.”

West Indianapolis today is surrounded by Superfund sites and federally recognized hazardous waste sites, like the Southside Sanitary Landfill Superfund site, the Carter Lee Lumber Co. Superfund site, the Rolls-Royce Corp. RCRA site, the Blue Lake, Inc. RCRA site and former General Motors stamping plant RCRA site.

Much of West Indianapolis is zoned for commercial and industrial uses, including hazardous materials or objectionable substances, resulting in residents living next to pollution sources.

The neighborhood north of the Vertellus chemical manufacturing plant.

Hundreds of residents live next to the Reilly Tar & Chemical Corp. Superfund site, an area contaminated with arsenic, benzene, cyanide and other harmful pollutants. The Superfund site is currently the home of the Vertellus chemical manufacturing plant, which manufactures toxic pyridines and picoline and has had multiple pollutant compliance violations in the past year.


The Martindale-Brightwood area of Indianapolis was redlined in the 1930s due to its large Black population. The area is not currently zoned for hazardous materials, but area residents still face much lower life expectancy than other parts of the city that were not redlined.

A 2021 study by researchers at Indiana University’s Fairbanks School of Public Health found a large gap in life expectancy between different zip codes in the Indianapolis metro area, especially in redlined communities.

Hoosiers living in redlined areas can expect, on average, to live at least five years less than people living in the non-redlined parts of the city.

According to the researchers, people living in the Martindale-Brightwood neighborhood had a life expectancy of 68 years, the lowest in all Indianapolis metro area, including other redlined areas with a hazardous material history.

Study: Historic federal housing discrimination led to millions of Black, Latino Americans breathing dirtier air today