China's smog 'environmental crisis': WHO

The smog that's affected much of northern China over the past week has been described as an "environmental crisis" by the World Health Organisation.

Beijing residents wearing face masks as air pollutions hits dangerous levels and smog blankets the city. (Getty)

With Beijing's official reading for PM 2.5 - small airborne particles which easily penetrate the lungs - standing at 501 micrograms per cubic metre on Wednesday (the WHO's recommended safe limit is 25), some scientists are saying the affect is like a nuclear winter.

But as the Chinese get richer, more and more attention is being paid to quality of life, with awareness of smog impact prompting protests across parts of China.

Chinese communist leaders, worried that protests will gain momentum, arranged for a rare public appearance of President Xi Jinping on Wednesday to show he too is breathing the same air. 

China's now dispatching teams to monitor emissions and says it will spend billions on a clean-up. 

The pollution is blamed on the use of coal for energy, dramatic economic development, increasing car use and climatic factors.