Breathe easy. Air quality in the United States is actually getting better. Visualizations of data from NASA’s Aura satellite show that overall, air quality in the United States is improving.
The satellite measures nitrogen dioxide pollution levels across the United States. Nitrogen dioxide is a common air pollutant, originating from combustion of gasoline or coal, and NASA says that it is a good proxy for air pollution in general. For particular cities, NASA researchers looked at pollution levels between 2005 and 2007 and compared it to pollution levels in the air between 2009 and 2011. They found that in New York, nitrogen dioxide pollution levels dropped 32 percent. In Atlanta, the drop was even steeper, at 42 percent.
Reasons for the improvement are varied, but researchers have speculated that a variety of factors contributed to the decline, including more efficient technology and stricter regulations.
This year’s State of the Air from the American Lung Association came to similar conclusions. Their report looked at more varied pollutants, and found that while overall, air quality was improving, ozone levels had risen slightly from the previous year’s report.
There’s still a lot of work yet to be done. Both reports say that over 140 million people in the United States are living in areas with unhealthy amounts of air pollution.
"While our air quality has certainly improved over the last few decades, there is still work to do – ozone and particulate matter are still problems," Bryan Duncan, an atmospheric scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a press release.