People of color breathe in more nitrogen dioxide, an air pollutant, than whites, according to a new national study released Tuesday.
The study, by the University of Minnesota, was published Tuesday in the journal PLOS ONE.
It found that on average, minority populations are exposed to 38 percent more of the pollutant, and that eliminating the environmental disparity could prevent thousands of heart disease deaths each year.
The study was the first to look nationally at this air pollution disparity in such detail, comparing demographic Census to nitrogen dioxide data developed at the U of M, the Star Tribune reports.
Nitrogen dioxide does not dissolve easily, and therefore doesn’t produce early warning signs of exposure, such as irritation of the nose and eyes, and is more likely to be inhaled deeply into the lungs.
The gas can lead to conditions including inflammation of the small airways or bronchitis, or lead to fluid accumulation in the lungs, pulmonary edema.
Nitrogen dioxide is one of six air pollutants for which the U.S. Environmental Protection Agency has set limits and requires monitoring by states. Cars, trucks and factories like power plants are its largest sources, the Star Tribune reports.
Researchers say income mattered less than race in explaining the disparity.
Lead study author Julian Marshall says he was surprised by the findings, MPR News reports.
"Even in a relatively clean air city and a clean air state, we still have these relatively large disparities," Marshall said. "That's an important finding. That's not something I expected."
Of the 15 states with the largest exposure gaps between whites and nonwhites, Minnesota ranked 15th.
MPR News reports Commissioner of Health Ed Ehlinger says people of color tend to be more exposed to many environmental pollutants.
"In this case they live closer to highways, they live closer to places where transportation is much denser, and oftentimes live closer to places where they have pollution being generated from garbage burners or power plants," Ehlinger says.
Studies show that vehicle emissions are highest in the immediate vicinity of a busy freeway, major roadway or downtown area.
MPR reports the Minnesota Pollution Control Agency is monitoring nitrogen dioxide levels at the intersection of Interstate 94 and Interstate 35W in downtown Minneapolis to obtain a clearer picture of how the pollutant might be affecting people who live near the roadways.