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After decades of improvement, America's air may not be getting any cleaner.
Over the last two years the nation had more polluted air days than just a few years earlier, federal data shows. While it remains unclear whether this is the beginning of a trend, health experts say it's troubling to see air quality progress stagnate.
% - Days - Air - America - Year
There were 15% more days with unhealthy air in America both last year and the year before than there were on average from 2013 through 2016, the four years when America had its fewest number of those days since at least 1980.
President Donald Trump has repeatedly claimed just the opposite, saying earlier this month in Ireland: "We have the cleanest air in the world, in the United States, and it's gotten better since I'm president."
Case - Air - Days - Year - President
That's not quite the case. There were noticeably more polluted air days each year in the president's first two years in office than any of the four years before, according to new Environmental Protection Agency data analyzed by The Associated Press.
The Trump administration is expected to replace an Obama-era rule designed to limit emissions from electric power plants on Wednesday. Called the Clean Power Plan, it would have gradually phased out coal-burning power plants that emit both air pollutants and heat-trapping gases responsible for climate change.
Air - Quality - Mix - Factors - Regulations
Air quality is affected by a complex mix of factors, both natural and man-made. Federal regulations that limit the emissions of certain chemicals and soot from factories, cars and trucks have helped dramatically improve air quality over recent decades. In any given year, however, air quality can be affected by natural variations. That may be what's behind the stalled progress, scientists say.
"What you're seeing is a flattening off of progress as opposed to a major change in the wrong direction," said former deputy EPA administrator Bob Perciasepe,...
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