African Americans are exposed to 38% higher levels of nitrogen dioxide air pollution than whites, a new study shows.
Nitrogen dioxide comes from sources such as power plants and car exhausts, and this type of air pollution is associated with asthma and heart disease, the researchers said.
They examined nitrogen dioxide levels in cities across the nation and used US Census data as well.
Race more important than income
They found that in most areas, lower-income African Americans have higher exposure than higher-income whites. On average, race is more important than income in explaining differences in nitrogen dioxide exposure, study authors report.
Read: Air pollution tied to appendicitis
The investigators also found that the largest white/others differences in exposure to nitrogen dioxide in descending order were in New York, Pennsylvania, Illinois, Michigan and New Jersey.
The urban areas with the largest differences were New York/Newark, Philadelphia and Bridgeport/Stamford, Connecticut, Boston and Providence, Rhode Island.
The impact of breathing air heavier with nitrogen dioxide could amount to an estimated 7000 extra deaths from heart disease each year among non-whites, the researchers estimated.
The findings were published in the journal PLoS One.
A shocking finding
"We were quite shocked to find such a large disparity between whites and others related to air pollution," study co-author Julian Marshall, a civil engineering associate professor in University of Minnesota's College of Science and Engineering, said in a university news release.
Read: Air pollution hurts sperm
"Our study provides a great baseline to track over time on important issues of environmental injustice and inequality in our country," he added.
"Our findings are of broad interest to researchers, policymakers and city planners," study co-author Lara Clark, a civil engineering PhD student in the College of Science and Engineering, said in the news release. "The next step in the research would be to look at why this disparity occurs and what we can do to solve it."
Plants clean air pollution
Air pollution shortening lives in China
Air pollution speeds hardening of arteries