The statewide investigation revealed that in communities previously denied mortgages based on race, there is a stronger connection between pollutants and emergency room visits.
It is well-known that air pollution adversely affects mental health, but recent findings indicate that its effects may be particularly severe in areas that were historically redlined.
Researchers from the University at Buffalo examined 17 cities across New York State where long-standing federal housing practices had denied mortgage access to neighborhoods populated by people of color. Although the practice was abolished in 1968, the study indicated that elevated air pollutant levels in these communities correlate more with increased emergency room (ER) visits for mental health issues.
“We found a strong connection between exposure to air pollutants and ER visits across various neighborhoods in these cities, most notably in the redlined communities, which continue to affect the vulnerable populations residing there,” stated Eun-Hye Enki Yoo, PhD, an associate professor of geography in the UB College of Arts and Sciences.
Yoo is the principal author of the study, which will be published in the October 20 edition of Science of the Total Environment.
Linking pollution to ER visits
Redlining originated from government-insured mortgages during the New Deal era. The Federal Housing Administration (FHA) classified communities’ lending risks using grades from “A” to “D,” where “D” indicated the highest risk and was shaded red on maps. These D-rated or redlined neighborhoods predominantly contained non-white residents, as the FHA argued that homes near Black residents could depreciate in value.
Studies have shown that these D-rated neighborhoods still experience poorer air quality, attributed to their closeness to industrial areas and highways, along with worse mental health among various other negative health outcomes.
“This led us to investigate whether these mental health issues arise partly from harmful environmental conditions,” explained the study’s collaborator, John Roberts, PhD, an associate professor of psychology and associate director of clinical training in the UB Department of Psychology.
Higher levels of air pollutants are known risk factors for anxiety, depression, schizophrenia, substance abuse disorders, and dementia. To establish a direct link, Yoo and Roberts analyzed deidentified patient records from the New York State Department of Health covering the years 2005-2016 and compared this data with daily air quality forecasts generated by machine learning models. Their focus was on the 17 cities marked by federal redlining maps, including Buffalo, Niagara Falls, Rochester, Albany, and various boroughs of New York City.
The analysis revealed that in neighborhoods rated “D,” an increase of fine particulate matter and nitrogen dioxide led to a rise of 1.04% and 0.44% in mental disorder-related ER visits, respectively, within two days. In contrast, neighborhoods rated “A,” which were considered the least risky by the FHA, showed no correlation between elevated pollutants and increased ER visits.
Researchers also acknowledged that while the sample size for A-rated neighborhoods was limited, they compared the aggregated data of A- and B-rated neighborhoods with that of C- and D-rated areas. Both groups exhibited a significant relationship between particulate matter levels and ER visits, although in the A and B neighborhoods, nitrogen dioxide—a gas released from burning fossil fuels—did not demonstrate the same effect.
“There are numerous factors, including social determinants of health, influencing ER visit frequency in different locations. However, utilizing case-crossover design methods, we can account for preexisting conditions and socioeconomic factors,” Yoo explained. “Thus, our findings strongly indicate that redlined neighborhoods suffer significantly from air pollution-related mental health issues.”
The research also revealed that the connection between increased pollutant levels and ER visits was only observable during moderate temperatures, specifically between 40 to 70 degrees Fahrenheit, and that children under 18 and adults aged 35-64 showed heightened sensitivity to air pollutants affecting their mental health.
“These findings imply that outdoor exposure plays a significant role in pollutant exposure since individuals are more likely to be outside during pleasant weather, and younger individuals typically spend more time outdoors than older adults,” Yoo noted.
Future studies in Buffalo and beyond
Yoo has received a grant totaling $499,963 from the U.S. Environmental Protection Agency to place 30 air quality monitors throughout Buffalo’s East Side, an area with a predominantly Black population experiencing disproportionately adverse health outcomes. This project aims to yield more precise and localized air quality information compared to the predictive models utilized in this study.
In addition, Yoo is partnering with Oregon Health and Science University to investigate the relationship between air pollution and mental health in historically redlined neighborhoods nationwide.
“New York may not be indicative of the entire United States, so we are eager to broaden the scope of this research to include national data,” Yoo remarked. “We hope that more direct evidence will prompt policy changes to address this critical issue.”
