A cold front will bring wind, rain and snowfall to northern China starting from Wednesday and, along with a temperature drop, is expected to disperse the week-long smog that has been choking the region.

The thick layer of smog shrouding Beijing and its surrounding areas has become heavier as the capital raised its four-tiered alert system to "orange." The smog has covered some 1.4 million square kilometers across central and east China since last Friday.

Outdoor air pollution ranked fourth both in the mortality and in overall burden on health rates across China, where it contributed to 1.2 million deaths and 25 million healthy years of life lost in 2010, according to the 2010 Global Burden of Disease (GBD) report.

Many inhabitants of the suffering areas are now rushing to buy air purifiers, facial masks and so on, to prevent over-exposure to the health-undermining air. Here we have listed the 10 biggest businesses set off by smog:

Real Estate

Chinese people who live in big cities are trying to escape from the heavy-polluted air by moving to places where they can enjoy blue skies and much-needed sunshine such as Hainan and Yunnan.