How Old 'Redlining' Policies Still Affect Childhood Asthma Risk

Incidence data from 7 U.S. cities demonstrates the long reach of systemic racism upon new generations growing up in unhealthy neighborhoods, according to study co-authored by researchers from Cincinnati Children's

CINCINNATI, Sept. 24, 2024 /PRNewswire/ -- An old government policy that determined who was eligible to receive government-supported home refinancing based on the race, ethnicity, and immigration status of neighborhood residents known as "redlining" was banned decades ago. Even so, children growing up now in many of the affected neighborhoods are still paying a price in the form of higher risk of developing asthma.

Asthma is the most common form of chronic childhood illness, affecting more than 4.6 million children across the United States. The condition significantly disrupts normal activities, drives thousands of emergency hospital visits and causes more than 150 deaths every year.

For years, studies have shown that asthma's harm is felt most acutely by Black and Hispanic children and in low-income neighborhoods.  

Now, a study analyzing data from Boston, Baltimore, New York, Nashville, St. Louis, Detroit, and Madison, WI, documents how today's ongoing neighborhood-level disparities in asthma outcomes remain linked to housing policies dating back to the 1930s. Findings appear in the American Journal of Respiratory and Critical Care Medicine.

"We found that children who lived in neighborhoods that had been redlined were at increased risk for asthma and that much of this increased risk was related to higher rates of poverty and lower household income," says co-lead author Patrick Ryan, PhD, an expert at Cincinnati Children's who studies how environmental exposures  affect pediatric respiratory health and brain development.

"The health disparities that exist today didn't just happen – there are root causes," Ryan says. "In this study, we show that a systemic racist policy implemented in the 1930s is directly related to asthma disparities today in part because it prevented those neighborhoods from developing through the years with healthy environments."

A CREW of experts dives into history

The study was conducted by members of the Children's Respiratory and Environmental Workgroup (CREW) consortium. Founded in 2016 with funds from the National Institutes of Health's Environment and Child Health Outcomes (ECHO) program, CREW was established to integrate more than a dozen birth cohort studies that have tracked groups of children to study the origins of asthma.

Separately, these groups can lack enough size and diversity. Combined, they can help accelerate understanding of how asthma is affected by interactions between genetics, lifestyle, and environmental exposures, says James Gern, MD, professor of pediatrics at the University of Wisconsin School of Medicine and Public Health and principal investigator for the CREW consortium.

"This study applied new technologies linking addresses to exposures to demonstrate just how important housing and economic factors are in determining the risk for developing childhood asthma," Gern says. "Improving living conditions and addressing structural racism are likely to markedly reduce childhood asthma and have many other health benefits."

"The CREW consortium is significant because it has the demographic diversity of study participants, geographic spread and large sample size that allow us to address the racial and ethnic disparities that might be driven in part by socioeconomic and geographic factors shaped by the legacy of discrimination in the United States," says the study's other co-lead author Antonella Zanobetti, PhD, an epidemiologist and environmental health expert with the Harvard T. H. Chan School of Public Health.

The group gathered information from more than 4,800 children who participated in one of 10 study cohorts based in the seven cities. Cohorts in individual cities ranged from about 80 to nearly 1,400 participants. Then the team mapped family home locations against old redlining maps drawn in the 1930s and followed participants through childhood to identify which children developed asthma.

While not surprising to long-time public health experts, the persistence of the overlap between high-risk asthma locations and the originally redlined neighborhoods is striking.

"Aside from a few small, local interventions that appear encouraging, the factors driving the disparities in asthma cases remain as powerful now as they were nearly 90 years ago," Zanobetti says.

The lingering impact of a "D"

The term redlining began in 1933, when the federal Home Owners' Loan Corporation (HOLC) was created to finance mortgages in order to expand home ownership and prevent foreclosures. The agency assigned letter grades to reflect the potential growth value of various housing areas and the likelihood that residents could repay their debts.

Areas viewed as poor prospects – located overwhelmingly in segregated minority-heavy parts of many cities – received a "D" grade. Maps held by lenders often used red lines to denote such areas.

The Fair Housing Act of 1968 outlawed redlining. But by that time, much damage was done and in many cities attitudes about the attractiveness of neighborhoods became informally locked in. The discrimination by lending agencies further entrenched racial housing segregation and led to decreased investment and wealth of residents.

Redlined neighborhoods continue to have higher levels of air pollution, both from industry and from harmful particulate matter emitted by vehicles, especially diesel-fueled trucks, buses and cars. Low-quality housing in redlined neighborhoods also can be prone to asthma-aggravating mold and dander from cockroaches and rodents. Meanwhile, lower-income families of children with asthma living in these neighborhoods have been shown to struggle much more than wealthier families to gain access to high-quality primary care and proper medications for controlling dangerous asthma exacerbations.

What more can be done?

It may take decades, if ever, to fully eliminate the health threats to children that come with growing up in distressed neighborhoods. But experts say much more can be done to reduce the disparities.

Creating healthier neighborhoods and home environments, improved access to healthy foods and stronger enforcement of existing housing codes are some possible actions that could help prevent some children from ever developing asthma.

Improved health insurance coverage and better access to services for low-income families could further assure that all children with asthma receive effective, evidence-based care.

Continued lowering of permissible pollution levels in the National Ambient Air Quality Standard (NAAQS) also will help prevent new cases and reduce exacerbations for children and adults with asthma.

Some improvements already have occurred that may serve as examples for wider-scale implementation:

• A housing mobility program in Baltimore that provided housing vouchers to help families of children with asthma move into healthier locations helped reduce asthma exacerbations.
• The Cincinnati Child Health-Law Partnership (Child HeLP) program, a long-running partnership between Cincinnati Children's and the Legal Aid Society of Greater Cincinnati has repeatedly achieved healthy housing improvements and helped reduce asthma hospital admissions.
• In California, stricter limits on traffic-related air pollution also have led to fewer new cases of childhood asthma.

"Progress is not impossible. There is no need to rebuild entire neighborhoods or re-locate entire populations to address disparities in asthma outcomes. Once our society stops denying the systemic effects of racist policies like redlining, it will become much more feasible to move forward with achievable policies for zoning, housing and other laws that have health impacts," Ryan says.

About the study

Funding for this study includes several NIH grants (UH3OD023282, UM2 AI117870, HHSN272201000052I, 5P01AI089473-07, UM1 AI114271, UM1 AI160040, and U19 AI104317). Other sources include the Harvard NIEHS Center Grant (P30-ES000002) and Apple, Inc.

In addition to Ryan and Zanobetti, co-authors included experts from Cincinnati Children's, the University of Cincinnati, Harvard University, Columbia University, Vanderbilt University, the University of Arizona, the University of Wisconsin School of Medicine and Public Health, Henry Ford Health (Detroit), the Icahn School of Medicine at Mount Sinai (New York), Augusta University, and Rho, Inc. (Durham, NC).

MORE VISUALS AVAILABLE:

Images of various HOLC maps of the cities mentioned in the study can be downloaded here: https://uwmadison.box.com/s/ip42cqklo01ekq4kje0frh59bpgkn8pd

Please provide the following credit:

• "Mapping Inequality, public domain image"

Also provided are images of the full US, with markers that note cities where the Home Owners' Loan Corporation conducted a city survey. You can visit an online version of this map to access city-specific information for any city noted by a marker, including a full-size city survey map.

If you are using one of the provided US maps in a newspaper or online article, please use one of the following credits:

• "Courtesy of Mapping Inequality"
• "Source: Mapping Inequality"

SOURCE Cincinnati Children's Hospital Medical Center