Black, Asian and Latino Americans have been exposed to more harmful pollution than white people in the last 10 years - leading to more than 5,000 avoidable deaths, an unprecedented study reveals.
While most reports say overall exposure has dropped, research by the University of Washington shows that is not the case for ethnic minorities.
They found disparities in nitrogen dioxide exposure were larger by race and ethnicity than by income, age or education - and persisted across the decade.
Analyzing county-level data of nitrogen dioxide, the researchers concluded non-whites still suffered 37 percent more toxic exposure than whites in 2010, an insignificant drop from 40 percent in 2000.
The study concludes that if people of color had breathed the lower NO2 levels experienced by whites in 2010, it would have prevented an estimated 5,000 premature deaths from heart disease among the nonwhite group.
The groundbreaking study led by the University of Washington estimated exposure to outdoor concentrations of a transport-related pollutant in 2000 and 2010, based on neighborhoods
This includes exposure to harmful air pollution emitted by cars, trucks, power plants, and other combustion sources.
'Everyone benefited from clean air regulations and less pollution; that's the good news,' said lead author and UW civil and environmental engineering doctoral student Lara Clark.
'But the fact that there is a pervasive gap in exposure to NO2 by race - and that the relative gap was more or less preserved over a decade - is the bad news.'
To investigate the racial disparities, the researchers developed a first-of-its-kind model that combines satellite and regulatory measurements with land use data to predict pollution at a neighborhood level throughout the United States.
Considering relative differences, nonwhites experienced 40 percent higher exposures than whites in 2000; in 2010, that gap shrunk only slightly, to 37 percent.
Furthermore, in 2000, concentrations of NO2 in neighborhoods with the highest proportion of nonwhite residents were 2.5 times higher than in neighborhoods with the lowest proportion of nonwhite residents.
In 2010, that value increased slightly, to 2.7 times higher.
'The finding that shocks us is that when it comes to how much NO2 a person breathes,