Thick smog returns to Beijing

Smog shrouding Beijing on Sunday (February 16) morning highlighted the struggle China faces in controlling persistent and often dangerous air pollution.

Sunday was the third day that the Chinese capital saw hazardous levels of air pollution.

An index measuring PM2.5, or particulate matter with a diameter of 2.5 micrometers (PM2.5), reached 400 in much of the capital overnight, Beijing Municipal Environmental Monitoring Center said.

The previous night, it had exceeded 500, the highest level measured by the country's monitoring system.

A level above 300 is considered hazardous, while the World Health Organisation recommends a daily level of no more than 20.

Pollution is a rising concern for China's stability-obsessed leaders, keen to douse potential unrest as affluent city dwellers turn against a growth-at-all-costs economic model that has tainted much of the country's air, water and soil.

The stone walls and moat of the forbidden city, former residenc