A third of Beijing's soaring air pollution comes from outside city.

Reuters: “Around one-third of the air pollution in China‘s smog-hit capital comes from outside the city, official media reported on Wednesday, citing a pollution watchdog.”
“Chen Tian, chief of the Beijing Environmental Protection Bureau, said that 28-36% of hazardous airborne particles known as PM2.5 came from surrounding provinces like Hebei, home to seven of China’s 10 most polluted cities in 2013, according to official data.
The central government has identified the heavily industrialised Beijing-Hebei-Tianjin region as one of the main fronts in its war against pollution, and it is under pressure to cut coal consumption and industrial capacity.
….The city plans to cut coal consumption by 13 million tonnes by 2017, down from about 23m tonnes in 2013. Hebei province used about 280m tonnes of coal last year and aims to cut the total by 40m tonnes over the same period.
Beijing also plans to limit the number of cars on its roads to 5.6m this year, with the number allowed to rise to 6m by 2017. It is also trying to enforce a ban on old vehicles with lower fuel standards.
The city government said in a report last week it failed to meet national standards in four of the six major controlled pollutants in 2013. It said its PM2.5 concentrations stood at a daily average of 89.5 micrograms per cubic metre, 156% higher than national standards.
In 2013, PM2.5 concentrations in 74 cities monitored by authorities stood at an average of 72 micrograms per cubic metre (cu m), more than twice China’s recommended national standard of 35 mg/cu m.”