Emissions of harmful pollutants in North Carolina have reached historic lows, according to a recent report by the N.C. Division of Air Quality.
Compared to previous decades, there have been major improvements in lowering criteria air pollutants like sulfur dioxide, carbon monoxide, nitrogen oxides, fine particulate matter and volatile organic compounds. The Clean Air Act requires regulation of those specific air pollutants.
For example, North Carolina had 94 percent fewer sulfur dioxide emissions from 1990 through 2020.
Shawn Taylor, the public information officer for the N.C. Division of Air Quality, said many of these declines occurred in the early 2000s, partially because of the state's 2002 Clean Smokestacks Act.
“It required coal power plants to reduce their emissions,” Taylor said. “As a result, North Carolina had, throughout the 2000s and 2010s, far less emissions of pollutants like nitrogen oxides and sulfur dioxides than surrounding states.”
Neil Alexis, a professor in UNC's Department of Pediatrics and the associate director of the Center of Environmental Medicine, Asthma and Lung Biology at UNC, said criteria pollutant levels trending downward is a good start, but there are still things people need to worry about.
He said other pollutants that induce health effects, such as wildfire smoke, have recently emerged. He also said that "clean" is a subjective term when describing air.
Levels are used to rate the concentration of air pollution, and while one level might be safe for someone who is healthy, it may be dangerous for those who are sensitive to air pollution — especially those with asthma, chronic obstructive pulmonary disease and other respiratory diseases.
“I'm not sure we truly know what that bottom level is to protect susceptible people,” Alexis said. “That's why we need to keep doing the work until we come up with a level that we think will protect everybody.”