Following the Great Depression, the federally sponsored Home Owners’ Loan Corporation (HOLC) drew neighborhood maps of American cities that characterized their attractiveness for mortgages. Many neighborhoods with black and immigrant communities received the worst rating, limiting access to federally backed loans and favorable mortgage terms. Now the researchers who report in ACS’ Environmental Science and Technology Letters found that these “highlighted” areas have higher air pollution levels 80 years later.
In the United States, people of color, especially black and Hispanic Americans, at all income levels, are exposed to higher than average amounts of air pollution. The reasons are complex and partly rooted in historical patterns of discrimination, experts say. Beginning in the 1930s, the HOLC rated neighborhoods in American cities on a four-point scale: “A” (most desirable), “B” (still desirable), “C” (certainly in decline), and “D”. (dangerous for mortgages). Evaluation ; “framed in red”). Historical records indicate that many neighborhoods received the “D” characterization because they had black and immigrant communities. This designation limited residents’ ability to create wealth through home ownership, and it also influenced later government decisions on land use to place hazardous industries in or near neighborhoods. “D”. Joshua Apte of the University of California, Berkeley and his colleagues wanted to examine associations between historical levels of redlining and air pollution in 2010, which had the most recent census data available at the time of the study. .
The researchers focused on two main air pollutants – nitrogen dioxide (NO2; a short-lived gas emitted by traffic, industry and other sources) and fine particulate matter (PM2.5; longer-lived tiny particles found in dust, soot, smoke and other emissions, and also formed in the atmosphere). The team compared HOLC maps from the 1930s with 2010 air pollution levels and census demographics for 202 US cities that are home to 65% of the urban population. They found that pollution levels were consistently related to HOLC grade, especially for NO2, which was 50% higher in “D” neighborhoods than in “A” neighborhoods. Nationally, disparities in air pollution were greater by HOLC level than they were by race and ethnicity. However, within each class, racial and ethnic disparities were observed, with lower NO exposure levels2 and PM2.5 for white people than for people of color. Overall, the authors point out that current disparities in air pollution partly reflect decisions made generations ago.
The authors acknowledge funding from the US Environmental Protection Agency.