National and state-based clean air policies, including reducing pollution from coal-fired power plants, are helping improve air quality in Colorado.
The annual "State of the Air" report, released Wednesday by the American Lung Association, also found that six of the 10 cities with the worst air pollution were in California.
That's according to the latest "State of the Air" report from the American Lung Association.
Compared to the 2016 report, Fairfield County, the most polluted county in the New York City metro area, had a weighted average of 24.0 days with unhealthful levels of ozone in 2013-2015, fewer than the 24.3 days in 2012-2014. "[The county] continues to get a grade of F for ozone smog and continues to get a grade of F for the daily measure of fine particle pollution".
In addition, Hartford County continued to be one of 82 USA counties with the lowest level of short-term particle pollution.
There is some good news. From 2013 to 2015, Luzerne County had 0.7 days per year with unhealthy, elevated levels of ozone.
The State of the Air Report shows the annual progress counties in all 50 states make toward improving air quality.
Still, the state's notorious traffic congestion left it one of most ozone-polluted areas in the nation.
But the association and other clean-air advocacy groups worry that under the Trump Administration - which wants to loosen regulations on industry and has already repealed certain Obama-era waterway protections - the clean air movement may suffer setbacks.
"The bottom line is that SC isn't doing the worst, but there's certainly room for improvement to become a leader as one of the cleanest states overall", said Emily Cedzo, the air, water and public health projects director for the Coastal Conservation League. "Air travels from one state to another, so only federal protections can help protect the air we all breathe". Too much ozone, however, can cause serious health complications. Particulates are also linked to lung cancer, heart attacks and strokes.
For this reason, residents of poor communities within these cities tend to be exposed to greater levels of pollution than communities in other parts of these cities. "Even with the drought and wildfires of recent years, we still enjoy the Lake County clean air".
While Milwaukee is not considered one of the cleanest cities in the US, it does have a good track record when it comes to clean air.
The American Lung Association's national report card found 7 out of 10 counties in MA have improved ozone quality.
Look up the air quality of your city and county here. Ground-level ozone, a main ingredient of smog, has harmful effects, especially on children, older adults, people with respiratory illnesses, and those who work outdoors.
Particle pollution is the mix of solids and liquid droplets floating in the air, which may include dust, dirt, soot and smoke from fires of business and vehicle emissions, according to the Centers for Disease Control and Prevention.