The cities with serious SO2 pollution are mainly located in Shanxi,Hebei,Guizhou,Chongqing and parts of Gansu,Shaanxi,Sichuan,Hubei,Guangxi and Inner Mongolia.

• 二氧化硫污染严重的城市主要分布在山西、河北、贵州、重庆及甘肃、陕西、四川、湖南、广西、内蒙古的部分地区。