In the U.S., people of color live, on average, in more polluted neighborhoods than whites, according to new University of Minnesota research.

Researchers say thousands of deaths could be prevented each year if the racial disparity is reduced.

The University study, released earlier this month, found that non-whites are more likely to live in areas with higher concentrations of nitrogen dioxide, which increases the risk of respiratory illness, heart disease and other diseases. The pollutant comes mostly from vehicle exhaust and power plants.

Minnesota’s pollutant exposure gap between whites and non-whites is the 15th largest in the country, and researchers say the Twin Cities’ gap is wide as well.

“Even cities without high pollution can still have large gaps between demographic groups, and Minneapolis is one of those cities,” said Julian Marshall, environmental engineering associate professor and senior author of the study.

Researchers found that non-white Americans’ nitrogen dioxide exposure levels are 38 percent higher than whites’. About 7,000 people of color die of heart disease annually, according to the study.

While past studies have examined pollution disparities on regional levels, the new research was the first to look at the issue on a national scale. It also examined national pollution disparities for income, but it found that race-based gaps were much wider.

Measuring disparities in Minneapolis

The city of Minneapolis recently partnered with the Center for Earth, Energy and Democracy, a research center, to analyze air pollution levels in different neighborhoods.

“The disparity between whites and people of color is definitely an issue in Minneapolis, and it’s something that we’re working to address,” said Patrick Hanlon, the Minneapolis Health Department’s environmental initiatives supervisor.

The two-year study will track 72 different chemicals in 120 locations throughout Minneapolis to assess the problematic areas, Hanlon said.

With this information, he said, the city can increase its community outreach and education initiatives in the affected areas. He also said businesses in areas with low pollutant levels could advertise their ranking for marketing purposes.

A wide-reaching problem

About 131 million Americans — almost half of the nation’s population — live in areas with air pollution, according to the National Resources Defense Council.

Worldwide, about 3.7 million people died in 2012 from exposure to outdoor air pollution, according to the World Health Organization.

The University researchers chose to monitor nitrogen dioxide because the chemical’s concentration level varies widely throughout the country. It’s also one of six pollutants that the U.S. Environmental Protection Agency examines and regulates.

The University researchers drew demographic information from the U.S. Census and paired it with pollution data from a University-developed pollution estimate model, which used satellite and land usage measurements. Graduate student and researcher Lara Clark said they plan to study whether racial disparities change over time.

“Hopefully, this is a useful baseline so that we can compare these things over time to see where they’re getting better and where they’re getting worse,” Marshall said.