Even many decades later, redlined areas see higher levels of air pollution

The freeway cuts through neighborhoods near the airport. A new study shows links between air pollution and redlining.

Reed Saxon/AP

A new study has found that neighborhoods that were redlined in the 1930s have higher levels of air pollution decades later.

The authors looked at air quality data from 202 US cities and found a correlation between pollution levels and redlining. Their study was published in a journal.

After the Great Depression, redlining was used by the federal government to keep Black and immigrant areas out of the mortgage market. Neighborhoods were categorized into A, best, to D, for hazardous, and colored in red.

The neighborhoods that were redlined by the Home Owners Loan Corporation have worse air quality than those that were graded either A or B, according to one of the paper.

Nitrogen dioxide is a gas associated with vehicular exhaust and industrial facilities, and tiny particles known as PM 2.5. The Clean Air Act regulates them.

We see a clear association between how these maps were drawn in the 30s and the air pollution disparity today, according to one of the paper's authors.

Smokestacks near an oil refinery can be seen in front of the Utah State Capitol. Thousands of Americans are killed by the air we breathe each year.

Rick Bowmer/AP

The study by researchers at UC Berkeley and the University of Washington analyzes air pollution and redlining at the national level. Other studies have shown the negative effects of redlining. NPR has previously reported that historically redlined neighborhoods are hotter in the summer and residents have a range of health issues.

The places with the lowest grades were the places where minorities and immigrants lived. The language on the maps was pointedly racist, with comments about the "heterogeneity" of the neighborhood leading to a lower grade.

Environmental factors are intertwined with power and race. A lower grade would be given to a neighborhood if it already had industrial uses.

More hazardous facilities were allowed to locate in the same neighborhoods because of the federal maps and grades. People of color at every income level in the U.S. are exposed to higher-than-average levels of air pollution.

The researchers found that race is a factor affecting air quality. People of color were more affected by air pollution in 2010 than they were in 2009.

The only thing that is driving the racial and ethnic disparity is air pollution.

There are several reasons for that. White people living in a formerly redlined area might live in a part of the neighborhood that is further away from the highway than the rest of the neighborhood. The places that are more polluted may have more people of color living in them.

The El Porto neighborhood of Manhattan Beach, Calif., is in the foreground of a picture of the Standard Oil Refinery.

Reed Saxon/AP

Air pollution kills thousands of Americans every year. Nitrogen dioxide pollution can cause asthma, heart attacks, strokes, and lung cancer.

The air quality in neighborhoods is different. The D- grade neighborhoods on average experience 50% more pollution than the A- grade neighborhoods. It is more than double in some cities.

We know that these air pollutants have adverse health consequences and that they have consequences for community health.

She says that the solution to improve the average air quality cannot be just improving the emission sources.

Morello-Frosch says that we need to address the persistence of inequalities and exposure to air pollution by race.

She says that future strategies need to take a targeted approach to narrow the racialized air quality gap.