On the north side of Denver, people have a word for the stench that often drifts through their windows and under their doors: purijuana. It's a combination of the Purina pet food factory up the street, and the many marijuana operations that have made the neighborhood their own. Residents surveyed in 2012 also described smells of “sewer, animal rendering, vehicle exhaust, and death.”

It's no accident that this community has lived for decades with the smokestacks, freeway traffic, and clanging railyards that other parts of Denver can ignore. It and many others across America were redlined starting in the 1930s, marked on government maps as too “hazardous”—as in, too Black or too immigrant—for federal home loans. When zoning officials needed somewhere to put a new factory or freeway, those redlined neighborhoods were like a bullseye that they hit again and again and again.

Researchers from RAND have developed a free online tool that shows the results. It maps those historic red lines against more than a dozen environmental hazards, from air pollution to toxic waste sites to smothering summer heat. It shows, for more than 200 metro areas, where one racist policy continues to shape lives even decades after it was revoked.

“It's meant to start conversations,” said Carlos Calvo Hernandez, an assistant policy researcher at RAND and a student at Pardee RAND Graduate School, who did much of the data work. “Community advocates can just point to the map and say, 'Here is what we've been talking about for years or decades. This is what's been happening in our community.'”

The overall pattern is clear and consistent: more pollution, more hazards, more risk in the redlined communities. On average, for example, communities that the government once labeled “hazardous” still have less than half of the tree canopy coverage even now than neighborhoods the government considered “best.” The pattern seems to be especially strong in some cities, especially those in the Northeast and Midwest, and weak or nonexistent in others.

“We wanted to provide a particularly rigorous way to think about structural racism and how to target efforts to address it,” said Jaime Madrigano, an adjunct policy researcher at RAND and an associate professor at the Johns Hopkins Bloomberg School of Public Health.

“We're not just saying, 'Here are some environmental hazards that exist, and here's how they track with race and ethnicity,'” she added. “It's, 'Here's where there was a racist policy in place, and now here's where the environmental hazards are.'”

Read the full article about environmental racism at RAND Corporation.