Much of the Chinese capital shut down on Tuesday after Beijing's city government issued its first red alert for pollution -- closing schools and construction sites and restricting the number of cars on the road.
Beijing's Municipal Bureau of Environmental Protection warned that severe pollution would cloak the Chinese capital for several days, starting Tuesday morning.
According to the US Embassy in Beijing, the air quality index stood at 250, classed as "very unhealthy" and 10 times higher than World Health Organization recommended levels.
Gao Yuanli, 35, told CNN that the smog frequently made her life difficult. She wears face masks during most winter days and bought an air purifier two years ago. "I can't go out on weekends now if the air is bad, and I don't go to outdoor markets anymore," she said. The alert means extra measures will be enforced.
Car use is being halved by allowing only odd or even numbered licence plates on the road at one time and heavy vehicles including garbage trucks are banned from the streets. Other polluting industrial activity has been curbed, as have fireworks and outdoor barbecuing.
The red alert -- the highest level in the system -- is due to be in force until noon Thursday local time. The city's roads and sidewalks were much quieter than usual and small businesses owners like Jia Xiaojiang, who makes egg pancakes, complained of fewer customers.
Jia doesn't wear face masks, but says the pollution has brought her respiratory issues."The smog is like toxic gas," she said. "I never had a sore throat before. Starting from last year, my throat hurts once I speak."