SO2 Pollution in Double-Control Zones In the 341 cities of the statistics (including county level municipality), 64 of them are located in SO2 Pollution Control Zone and 118 belong to Acid Rain Control Zone.

• “两控区”二氧化硫污染情况 统计的341个城市中(包括县级市)，有64个城市属于二氧化硫污染控制区，118个城市属于酸雨控制区。