By Greg Barnes

Decades ago, state regulators began using color-coded bars to warn people about high levels of ozone trapped in the Earth’s lower atmosphere.

The warning colors ranged from green for good, yellow for moderate, orange for unhealthy for sensitive groups, red for unhealthy for almost everyone and purple for very unhealthy.

In the 1990s and early 2000s, summers in North Carolina were dominated by red or orange ozone days from the mountains to the coast. Back then, more than 30 North Carolina counties failed to meet the U.S. Environmental Protection Agency’s air quality standards.

Not anymore.

March 1 marked the start of the 2019 ozone season, which runs through Oct. 31. As in the past, the state Department of Environmental Quality’s Division of Air Quality and its partner groups will issue daily ozone forecasts, using the same color codes.

But don’t expect to see any red days or more than a smattering of orange days. Between 2013 and 2017, the state recorded only one red day — compared with a high of 51 red days in 2002.

In large part, the reductions are due to much stricter federal vehicle emission requirements and a 2002 North Carolina law called the Clean Smokestacks Act, which imposed limits on the emissions of certain pollutants from coal-burning power plants.

Increased energy efficiency and the large-scale conversion from coal to natural gas in power plants are also credited with reducing ozone in the atmosphere. Common pollutants from new cars today have been reduced by about 99 percent from what they were in 1970.

The reductions have been so great that the U.S. Environmental Protection Agency in November 2017 designated North Carolina as attaining the 2015 ozone standard statewide, despite the agency’s lowering of the pollutant level needed to comply from 75 parts per billion to 70 parts per billion.

“It’s a great accomplishment,” said Mike Abraczinskas, director of the Division of Air Quality.

shows bar graphs with the number of days for "red" ozone dropping off over time
Chart courtesy: NC DEQ/ Air Quality Trends in North Carolina

But not everyone sees it the same way. Kym Hunter, a senior attorney with the Southern Environmental Law Center, said the state is focusing too much attention on building new highways and not enough on funding and developing other forms of transportation that would create less pollution.

When it comes to ozone, Hunter said, North Carolina’s biggest issue is no longer pollutants from coal-burning power plants but from motor vehicles. While improvements have been made to decrease vehicle emissions, she said, the number of miles being driven has skyrocketed.

What is ozone?

Ozone is a gas made up of three oxygen atoms that occurs naturally in the upper atmosphere and protects life from the sun’s ultraviolet rays. But in the lower atmosphere, near the Earth’s surface, ozone is created by man-made chemical reactions — air pollutants from vehicles, power plants, gasoline vapors and other emissions — and can be toxic to people and plants. The primary source of ground-level pollutants is nitrogen oxides and volatile organic compounds.

According to the EPA, exposure to ozone levels of greater than 70 parts per billion for 8 hours or longer is unhealthy. The harmful effects can include throat and lung irritation or aggravation of asthma or emphysema.

The EPA says children are at greatest risk from exposure to ozone because their lungs are still developing and they are more likely to be active outdoors when ozone levels are high, which increases their exposure. Children are also more likely than adults to have asthma.

According to the DEQ, emissions of nitrogen oxides from coal-burning power plants fell 97 percent after the Clean Smokestacks Act. Sulfur dioxide levels dropped by 81 percent between 2002 and 2017. Most of the major power plants in the state are now using natural gas, which is cleaner and cheaper than coal.

Reducing the level of contaminants in the ozone layer is believed to have saved lives. A study published in 2014 by the University of North Carolina-Chapel Hill found that premature deaths in the state dropped by 1,700 — or 63 percent — between the time the Clean Smokestacks Act was passed in 2002 through 2012.

Also in 2014, Duke University researchers published a study that found improved health of North Carolinians since the 1990s because of state and federal measures to reduce air pollution. The study found lower death rates from emphysema, asthma and pneumonia.

Meeting the standard

Today, Abraczinskas said, every area of the state meets the EPA’s air-quality standard, though he acknowledged that the Charlotte area is borderline, largely because of vehicle emissions. Abraczinskas said the state is working with a partner agency, Air Quality – Mecklenburg County, to lower ozone contaminants in the Queen City. A spokesman for the group could not be reached for comment.

YouTube video

Sponsored video

Abraczinskas said he is confident that new EPA regulations will significantly reduce ozone in Charlotte and throughout the state and the country. The regulations, known as Tier 3 standards, started in 2017 and will be fully phased in by 2025. Tier 3 sets new vehicle emission standards and lowers the sulfur content of gasoline.

Ozone could be further reduced by a settlement with Volkswagen, which was found to have unlawfully cheated on vehicle emissions. North Carolina has been awarded $92 million in the February 2018 settlement and plans to use the money in three equal phases The first phase calls for replacement of school and transit buses and heavy-duty equipment.

Fewer roads, more rail

While reducing vehicle emissions helps, said Hunter of the Southern Environmental Law Center, the state has been focusing on building major highways and not on light-rail and other transportation systems that would get people to drive less.

A proposed light-rail line between downtown Durham and Chapel Hill is projected to provide service to more than 26,000 people a day, removing thousands of cars from congested roads in the rapidly growing area. The line would also connect with Duke University, UNC-Chapel Hill and UNC Health Care, three of the top-10 employers in the state.

The light-rail system, first proposed in 1999 and now besieged by escalating costs, hit another snag late last month when Duke University decided not to sign a cooperative agreement with GoTriangle, the group spearheading the effort. Without Duke, the rail system may not advance.

Hunter questioned whether Gov. Roy Cooper’s administration has done all it can to support the project.

Meanwhile, she said, the state keeps building highways, including toll roads and other upgrades in Charlotte and $2.2 billion for the Interstate-540 loop around Raleigh.

“Overall, the state is spending at least 94 percent of its transportation funding on highway construction, and we would rather they put more money in other forms of transportation,” Hunter said.

Correction: The article originally stated DEQ was working with Clean Air Carolina in Mecklenburg County, not Air Quality – Mecklenburg County. Also the article stated that the Trump administration proposed rolling back Tier 3 standards, but the administration had looked to roll back CAFE emissions standards.

Creative Commons License

Republish our articles for free, online or in print, under a Creative Commons license.

Greg Barnes retired in 2018 from The Fayetteville Observer, where he worked as senior reporter, editor, columnist and reporter for more than 30 years. Contact him at: gregbarnes401 at