healthHealth and Medicine

Decades-Old Discriminatory Practice Could Be Causing Asthma In Minority Communities Today


HOLC ratings of Oakland, Berkeley, and Alameda neighborhoods in California, with green indicating “best,” blue indicating “still desirable,” yellow indicating “definitely declining” and red indicating “hazardous.” Mapping Inequality Project

The remnants of racial discrimination may mean detrimental health effects for minority communities living in some of California’s most populated cities. Rates of asthma and air pollution today are significantly higher in neighborhoods that were segregated immediately following the Great Depression, according to new research presented at the 2019 American Thoracic Society conference.

In response to skyrocketing foreclosure rates, Congress formed the Home Owners Loan Corporation (HOLC) in 1933 to stabilize the real estate market. As part of its lending practices, appraisers were hired in more than 200 American cities to assign neighborhoods a risk level, determined in part by racial demographics. Red neighborhoods were deemed as the highest risk – hence “redlining” – while green neighborhoods were ranked Green. Ultimately, this practice served as a way to deny home loans and other investment opportunities to certain communities. Although redlining has been illegal for some 50 years, it has shaped modern America’s neighborhood demographics with many “redline” neighborhoods still being considered as low-income and with a higher proportion of black and Hispanic populations.


“Redlining maps that were drawn 80 years ago, partially on the basis of race, are still predictive of not only who lives in a neighborhood, but also what kind of health problems they are experiencing,” said Anthony Nardone, a medical student at UC Berkeley who participated in the research, in a statement. Nardone obtained historical maps from the University of Richmond’s Mapping Inequality project of eight California cities and compared them against census records, asthma emergency room visits, and environmental pollutants obtained from CalEnviroScreen3.0.

The map on the right shows census tracts in the cities of San Francisco and Oakland categorized according to their Home Owner’s Loan Corporation rating. The map on the right shows the rate of asthma-related emergency room visits per 10,000 residents for those same census tracts. Anthony Nardone/UC Berkeley

People in redlined neighborhoods were more than twice as likely to visit the emergency room for asthma-related symptoms than others. These neighborhoods also saw significantly higher diesel particulate matter levels in the air given their proximity to less desirable infrastructure like highways.

“The persistence of the legacy of redlining, in terms of its current effect on asthma healthcare utilization, was striking,” said study advisor John Balmes, adding that pollution in these areas isn’t the only factor. Psychosocial stress associated with living in these areas could also negatively influence health, from poverty and high crime rates to lack of access to secure jobs, housing, or medicinal equipment.

The team notes that improving air pollution would, in part, benefit these communities, but better living conditions and social structures need to be addressed to improve health.


“Our study shows that, even though a policy gets eliminated or is recognized to be a poor choice, its effect can have impacts even many decades later,” said researcher Neeta Thakur in a statement. “We need to use that information to help us inform our current policies and thinking about what potential ramifications are down the road.”

Future research is aimed at examining historical factors that contribute to these communities’ asthma risk, as well as analyzing disadvantaged neighborhoods for potential intervention in the future. 


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