A recent study published in the Proceedings of the National Academy of Sciences (PNAS) shows that urban inequality in the United States is more complex than previously understood. While the historical practice of redlining — a discriminatory housing policy from the 1930s — played a major role in creating long-term poverty and segregation, it doesn’t fully explain today’s patterns of privilege and disadvantage. Researchers from Emory University and Washington State University, who led the study, focused on the Portland, Oregon, metropolitan area. They found that modern factors like gentrification and displacement are now key drivers of urban inequality, reshaping the landscape of privilege and hardship in new ways. Redlining began in 1935 when the Federal Home Loan Bank Board instructed the Home Owners' Loan Corporation (HOLC) to create maps that color-coded neighborhoods based on their perceived investment risk. Green areas were considered safe and desirable, while red areas — often home to Black and other minority communities — were labeled high risk, making it harder for residents to get mortgages. This practice limited opportunities for homeownership and wealth building among minority populations, contributing to long-term disparities. In their analysis of Portland, the researchers examined socioeconomic data and over 100 environmental and health indicators, comparing modern maps with the original HOLC maps. Their findings revealed stark contrasts: affluent, mostly white neighborhoods — whether redlined or not — generally have cleaner environments, more trees, better healthcare access, and lower disaster risk. However, these areas also often suffer from high levels of air pollution, especially in the city center. In contrast, poorer neighborhoods, often located outside the old redlined zones, face the worst environmental conditions, including limited access to nature, aging infrastructure, higher pollution, greater disaster risk, and higher rates of diabetes, obesity, and disability. Gentrified areas, which were once redlined, now have more transit and community resources but also face hotter streets, less tree cover, and more pollution. While wealthier newcomers may benefit from these changes, longtime residents often do not. Meanwhile, communities that have taken in families displaced by gentrification tend to be greener and less polluted but lack essential services like healthcare, quality schools, and reliable public transportation. This lack of access can threaten the long-term well-being of these communities. The researchers stress that understanding urban inequality requires looking beyond historical redlining to consider a wide range of socioeconomic and environmental factors. They hope their study will inspire similar analyses in other U.S. cities, helping to identify where environmental and health inequities persist or are changing. Their goal is to guide policies such as tree-planting initiatives, housing improvements, health programs, and disaster-risk reduction efforts to make the most significant impact on reducing urban inequality.