Flawed studies and ignorance about North Carolina air quality have given lawmakers and the general public an inaccurate picture of trends in ground-level ozone, or “smog,” in some cases exaggerating public exposure by a factor of 10. This study reexamines air-quality data from monitors across the state, concluding that exposure to dangerous ozone levels is surprisingly rare — and is dropping even without passage of the proposed “Clean Smokestacks” legislation.