In 2024, the annual PM2.5 concentration of Nantong was 25 mcg/m3, which was the lowest in history; the days with excellent or good air account for 86.1%, ranking 2nd in Jiangsu; the average ozone concentration was 156 mcg/m3, which reached the standard of national air quality level 2 for the first time in the past 3 years.Photo by Xu Congjun