The neighborhoods of Chicago share the same skyline, mayor, area codes and police force—yet a new study shows that life expectancy is drastically influenced by where one lives in the city.

recent analysis from the Department of Population Health at New York University School of Medicine, using data from the City Health Dashboard, looked at life expectancies throughout Chicago. It found that in Streeterville, which is predominantly wealthy and White, Chicagoans can expect to live up to age 90. Conversely, in Englewood—which is majority Black and lower-income earning—the life expectancy is just 60.

Researchers determined that this 30-year life expectancy difference is the widest at the city-level nationwide. Based on their data, Washington, D.C. is second (with a gap of 27.5 years) and New York City is third (27.4 years).

According to The Guardian:

The different health outcomes are multifaceted and correlate to almost every socioeconomic factor. The median income in Streeterville is nearly $100,000 a year, according to the U.S. census. In Englewood, smack dab in the center of Chicago’s Southside, it’s a quarter of that. More than 80 percent of Streeterville residents have a college degree, compared with 8.2 percent in Englewood.

In addition to these differences, Englewood is also considered one of the most violent parts of the city. The Guardian reports that between 2000 and 2017, it was home to more than 4,800 shootings.

While violence can clearly impact life expectancy, there is another factor causing harm in Englewood: lead poisoning. According to Chicago Health Atlas, in 2017, the percentage of children in Englewood with elevated levels of lead in their blood were some of the highest in the city. Lead poisoning in children is extremely dangerous. The toxic metal can damage the brain and nervous system, which slows growth and development, leading to learning delays and behavioral problems.

Community organizations, including I Grow Chicago (which has a “peace house” for residents) and Englewood Rising (which participates in door-to-door surveys to match residents with local health services), continue to work toward improving the life expectancy of Englewood residents. But the study highlights the systemic factors that must be addressed by city legislators to improve the health of all Chicagoans.

Says Dr. Marc Gourevitch, the head of the City Health Dashboard project that collected the neighborhood data: “Each city has its own history and challenges that influence how long its residents live. The data on life expectancy gaps are an invitation for city leaders to dig deeper into the conditions that influence health, to better target action to close these gaps and ultimately improve health for everyone. Your neighborhood shouldn’t influence your odds of seeing your grandchildren grow up.”