CHARLOTTE, N.C. - For the first time in six years, the air quality in Charlotte may finally meet the national standard set by the EPA.
Previously, the city had been ranked among the top 10 worst polluters in the country.
Meteorologist John Ahrens is taking a look at how the city has made such a huge improvement.
In the past, Severe Weather Center 9 has discussed ozone alert days.
That's when the air quality is so bad from pollutants from cars and buses that if a person has emphysema or asthma, they shouldn’t step outside.
Charlotte has not seen one of those days in two years and experts said that's because the word is out to keep the air clean
Air quality expert Shelley Lanham said the standard set in 2008 was for ozone levels to not go over 75 parts per billion.
When the number gets higher than that, people could start having health issues.
The highest it's been in Charlotte so far this year is 72.
"We think there are just fewer of those high ozone pollutants," Lanham said.
There are two big players that make ozone -- heat and pollution.
Charlotte has seen the heat with the number of 90 degree days has jumped from last year so that leaves pollution.
"We've seen an 80 percent reduction in nitrogen-dioxide and sulfur-dioxide throughout the state," Lanham said. "Clean commuting, taking (Charlotte Area Transit System), the Blue Line, walking – Yea, I think we're getting the message out.”
But Charlotte is still playing catch up.
It is the only place in the state that hasn't met the federal air-quality standard and there is still a long way to go to get there.
Ozone season doesn't end until October and starting Thursday, 90 degree temperatures are returning.
The state announced Wednesday that all cities in North Carolina have met the standard for another pollutant called particle pollution.
High levels of that can go deep into the lungs and have been responsible for heart and lung disease.
North Carolina has taken several legal steps to clean the air since the standard was raised in 2012.
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