NASA satellite data shows that, at least by one measure, air pollution has decreased recently
Saturday, June 28, 2014, 8:24 -
Dramatic new satellite pictures from NASA are dialing back doom-and-gloom predictions about our air quality.
The progression-map (seen in video above) shows by at least one measure, the air in the United States has improved. Over the last decade, nitrogen dioxide has decreased in cities across the U.S. -- red and orange are the worst areas; green and blue are better. The difference is especially striking along the densely-populated I-95 corridor in the Northeast.
"We have much lower levels of [nitrogen dioxide]," said NASA Atmospheric Scientist Bryan Duncan. "Levels have gone down by about 40 percent since 2005."
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Nitrogen dioxide is a yellow-brown smog that comes mostly from vehicles, and coal-burning power plants. It forms ozone -- the gas in the atmosphere that burns our lungs.
So why is the air getting better, even though the number of cars on the road has increased?
"Our pollutant levels are going down, and that's because cars are becoming more fuel-efficient," said Duncan.
Newer coal-burning power plants now scrub much of the pollution out before it can get to our lungs. The World Health Organization says in 2012, about 3.7-million people around the world died from the effects of outdoor air-pollution -- most of them in Asia.
Experts say the people who smog has hit the hardest- are the ones who can really feel this improvement in our air.
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"People who have asthma, they definitely can tell that they're breathing easier," continued Duncan. "And it's easier when we're looking at it on a long-term basis or looking at hospital records or other medical records."
Nitrogen dioxide levels are also a good indicator of how other pollution is trending. But experts say, it's not all good news. There are other pollutants causing harm.
"We have about half the nation who lives in counties that have unhealthy levels of air-pollution."
Click here to check the air quality in your area.Files from CNN