Some cities beat targets for pollution

Others fall short of goals; three mayors told to make plans to correct problems

Beijing, Tianjin and surrounding areas dramatically exceeded their air pollution reduction targets through the fall and winter months, while the mayors of three cities were summoned after failing to meet their own targets, according to China's top environmental authority.

The Ministry of Ecology and Environment released the performance of 28 major cities in the Beijing-Tianjin-Hebei region on Thursday, showing PM2.5 levels from October to March.