Emissions of harmful air pollutants like ozone and fine particles continue a long-running downward trend, the state Department of Environmental Quality Division reported today.

Today’s report is a latest update to DEQ’s Air Quality Trends in North Carolina.

DEQ attributes the decline of air pollution emissions to efforts by state leaders, regulatory agencies, electric utilities, industry and the public to significantly address air quality concerns over the last 50 years. 

Statewide emissions of carbon monoxide and sulfur dioxide, in particular, reached all-time lows in 2022, the latest year for which data are available from the U.S. Environmental Protection Agency.

“Even as our population and economy continue to grow, North Carolina’s air quality keeps getting better and better,” said DEQ Secretary Reid Wilson. “By controlling air pollution, we are giving every North Carolinian a cleaner, healthier future.”

Mike Abraczinskas, director of the Division of Air Quality, said, “Our air quality continues to improve thanks to tireless efforts by our dedicated staff, partners and a wide variety of stakeholders who have come together to implement sound environmental policies.”

According to the report, statewide emissions of the air pollutants regulated under the federal Clean Air Act have declined sharply from 1990 through 2022. 

Specifically, emissions fell: 

95 percent for sulfur dioxide 

74 percent for carbon monoxide

71 percent for nitrogen oxides 

48 percent for fine particles

67 percent for volatile organic compounds

North Carolina’s outdoor air quality has improved as emissions have fallen. 

Measured concentrations of those air pollutants have been below every federal health-based standard for more than a decade, DEQ said. 

Average concentrations of SO2, for example, are 95 percent below the federal standard; annual nitrogen dioxide concentrations are 89 percent below the standard.

North Carolina’s transition away from coal for power generation has been a major driver of these changes. 

More of the state’s power now comes from clean sources such as solar, wind and nuclear energy. Energy efficiency improvements in homes and buildings also reduce emissions from power plants.

Cars, trucks and other vehicles on North Carolina roads also emit far less pollution than older vehicles, thanks to improved engine and fuel standards and more advanced emissions controls. From 1990 through 2022, CO, NOx, and VOC emissions have declined by 81 percent, 72 percent and 85 percent, respectively, from these on-road sources of air pollution. 

The state expects to see further reductions from the transportation sector in the coming years due to the increasing adoption of electric vehicles.

High concentrations of air pollutants can harm public and environmental health. 

Ground-level ozone, formed from VOCs and NOx, and fine particles can worsen asthma and contribute to heart and lung conditions. 

Pollutants such as SO2 are associated with haze and acid rain. Greenhouse gases contribute to climate change, and various hazardous air pollutants are known carcinogens. North Carolina has seen reductions in emissions of each of these classes of pollutants.

Some additional findings of the updated report:

The number of ozone exceedance days statewide continues to be low. From 2015-2024, North Carolina recorded two days of Code Red or above for ozone in the state, compared to 83 such days from 2005-2014.

Visibility in the state’s national and state parks has improved noticeably in the last three decades, due to reductions in emissions of SO2, NOx and other air pollutants that scatter light. For example, in 2023, visitors could see as far as 119 miles at Great Smoky Mountains National Park during an average clear day, compared with just 54 miles in 1996.

Net greenhouse gas emissions from fossil fuel combustion have decreased by 38 percent from 2005 to 2020 due to both a shift in fuel use and increased energy efficiency. 

During this same period, North Carolina’s population and real Gross State Product grew by 20 percent and 23 percent, respectively.

From 1993-2022, combined emissions of federally designated Hazardous Air Pollutants and state-designated Toxic Air Pollutants have fallen by more than 108 million pounds, an 82 percent drop.