Pollution is nothing new in China. But right now, the situation is perhaps more dangerous than it's ever been.
On the weekend, air pollution in Beijing went beyond hazardous levels as set out by the World Health Organization.
Today, Chinese media are candidly speaking out - calling on the government to do something about it.
The official Communist party newspaper the People's Daily ran a front-page editorial with the headline "How can we get out of this suffocating siege of pollution?"
It called on the government to deal with environmental pollution with "a sense of urgency."
The state-run China Daily said the country had to learn to balance development with quality of life.
The Global Times referred to China as the "biggest construction site in the world", saying it needs to do more to prevent pollution and move away from its "fixation on economic growth."
The China Youth Daily had a front-page opinion piece entitled "More suffocating than the haze is the weakness in response."
Thick smog is hovering over Beijing and about 30 other cities in northern and eastern China. In some places, visibility is reportedly down to 100 metres (300 feet).
The air is so bad authorities are advising people to stay inside (especially children and the elderly) and avoid doing anything strenuous.
Many stores are sold out of masks and air purifiers. Some construction sites have been ordered to shut down. Factories have cut back production. And authorities are keeping some government cars off the road.
Hospitals say the number of people showing up with trouble breathing is up 30%. With this kind of pollution, doctors say people can pick up respiratory infections more easily.
Over the long term, it can potentially lead to illnesses such as lung cancer and heart disease.
On Saturday, pollution levels in Beijing went well above 600 and may have hit 900. More than 100 is said to be unhealthy. 25 is considered safe by the World Health Organization.
Today, officials in Beijing said levels had dropped to around 350. But officials don't expect the air to clear until Wednesday, when the forecast is calling for high winds.
Retirees practice Taichi during a morning exercise routine in central China
Chinese officials say the weather is to blame for the build up of smog, not a rise in emissions or pollutants.
But the China Daily suggested it's not that simple. It says the government has to do a better job with urban planning.
"In the middle of a rapid urbanisation process, it is urgent for China to think about how such a process can press forward without compromising the quality of urban life with an increasingly worse living environment," the paper wrote.
The editorial went on to say "The air quality in big cities could have been better, had more attention been paid to the density of the high rises, had more trees been planted in proportion to the number of residential areas, and had the number of cars been strictly controlled. These are the lessons China should learn for its further urbanization."