Redlined communities face higher mental health risks from air pollution

Air pollution is bad for mental health. That much is clear. Now, new research shows the impact could be even worse in neighborhoods that were historically redlined.

Researchers from the University at Buffalo looked at 17 cities in New York state, where longstanding federal housing policies once kept neighborhoods with people of color from receiving mortgages. Although this practice was banned in 1968, researchers found that elevated levels of air pollutants in these neighborhoods of the state are disproportionately linked to more emergency room (ER) visits for mental disorders.

There was a significant association between exposure to air pollutants and emergency room visits across these cities’ neighborhoods, but it was most pronounced in their redlined communities, negatively impacting the vulnerable population still living there.”

Eun-Hye Enki Yoo, PhD, Associate Professor, Geography, College of Arts and Sciences, University at Buffalo

Yoo is the lead author of the study, which will be featured in the Oct. 20 issue of Science of the total environment.

Linking pollution to ER visits

Redlining originated from New Deal-era government-insured mortgages. The Federal Housing Administration (FHA) has rated the credit risk of communities from ‘A’ to ‘D’, with D considered the riskiest and colored red on color-coded maps. This D-rated; or outlined in red -; neighborhoods, not coincidentally, had a larger population of non-white residents, as the FHA concluded that homes near black residents could lose their property values.

Research has shown that D-rated neighborhoods to this day have poorer air quality, caused by proximity to industry and highways, and poorer mental health, among other poor health outcomes.

“So the next logical question was whether these mental health outcomes are, at least in part, due to harmful environmental exposures,” says study co-author John Roberts, PhD, associate professor of psychology and associate professor of clinical training in the United States. UB Department of Psychology.

Elevated levels of pollutants are considered risk factors for anxiety, depression, schizophrenia, substance abuse disorders and dementia, but to substantiate a direct link, Yoo and Roberts collected anonymized patient records from the New York State Department of Health between 2005 and 2016 and compared them data with daily air quality forecasts by machine learning models. They focused on 17 cities where the federal government drew redlining maps, including Buffalo, Niagara Falls, Rochester, Albany and the boroughs of New York City.

They found that when levels of two pollutants, particulate matter and nitrogen dioxide, were elevated in D-rated neighborhoods, the number of mental disorder-related emergency department visits there increased by 1.04% and 0.44%, respectively, two days later .

Meanwhile, in A-rated neighborhoods, which the FHA once considered the least risky, there was no association between increased pollutants and subsequent increased emergency room visits.

However, the researchers note that the sample size for the A-rated neighborhoods was low, so they also compared the combined data from A- and B-rated neighborhoods to the combined data from C- and D-rated neighborhoods . While particulate matter had a significant effect on emergency room visits in both neighborhood groups, nitrogen dioxide, a gas associated with the combustion of fossil fuels, had no such effect in the A and B groups.

“Of course there are many reasons, including social determinants of health, why there are more emergency department visits in one area than another, but we have methods, such as case-crossover design, that allow us to control for already existing conditions and socio-economic problems,” says Yoo. “So the data showed quite convincingly that the redlined neighborhoods suffered the most from mental health problems caused by air pollution.”

The study also found that the link between increased pollutants and more emergency room visits only occurred at average temperatures, 40 to 70 degrees Fahrenheit, and that

children under 18 and adults between 35 and 64 were more sensitive to air pollutants that affected their mental health.

“Both findings suggest that being outdoors is an important factor in exposure to pollutants, because people tend to spend the most time outdoors during mild weather conditions and younger people are outdoors more often than older people,” Yoo says.

Studies of Buffalo and beyond follow

Yoo has a $499,963 grant from the U.S. Environmental Protection Agency to install 30 air monitors in Buffalo’s East Side, a predominantly Black community with disproportionately negative health outcomes. The goal is to provide even more accurate and localized air quality data than that provided by the predictive models in the current study.

Yoo is also working with Oregon Health and Science University to analyze air pollution and mental health in historically redrawn neighborhoods across the country.

“New York is not necessarily representative of the entire United States, so we are excited to expand the framework of this study to a national analysis,” says Yoo. “We hope that more direct evidence can lead to policy change to address this problem.”