A new study of eight major California cities, published in The Lancet, has found that the “redlining” of poor neighborhoods in the 1930s is associated with higher rates of hospital visits due to asthma among African Americans today.

Current rates of emergency room visits due to asthma – a respiratory condition that disproportionately affects people of color in the United States – are around 2.4 times higher in areas that were “redlined” or dereprioritized for mortgage investment in the 1930s, researchers found.

It’s well-documented that asthma rates are higher among people of color, affecting 10.1 percent of non-Hispanic African Americans versus just 8.1 of white non-Hispanics in 2017, according to the US Centers for Disease Control and Prevention.

When it comes to asthma-related deaths, the disparity is even starker: African American adults were almost three times more likely to die from asthma-related causes than white adults in 2014, according to the US Office of Minority Health, and African American children had a death rate ten times that of non-Hispanic white children in 2015.