SHANGHAI, Dec 24 (SMM) – All aluminium rod plants in Jiaozuo of China's top aluminium-producing province Henan have been required to halt production after the city escalated smog alert to the highest level from 18: 00 CST December 23, according to sources. 

Under the red alert for heavy air pollution, industrial enterprises have to cut pollutant emission by no less than 30%. 

It remains unclear when the anti-smog measures will be lifted.