Greenpeace, a non-governmental environmental organization, released a list on Jan. 10 of the average annual PM2.5 density in 2013 in 74 major Chinese cities.

Not surprisingly, seven of the ten most polluted cities are located in north China’s Hebei Province. However, the PM2.5 density of 92 percent of the 74 cities failed to reach the national standard in 2013, and in 43 percent of them air quality is twice as bad as the standard. In the top 10 cities on the list, the air is nearly three times as bad.

Haikou on Hainan Island had the best air quality among the 74 cities, with an annual PM2.5 density of 25.6, followed by Lhasa in Tibet and Xiamen in southeast Fujian Province.

The Greenpeace list was based on data from China's Environmental Protection Ministry website as well as environmental protection bureaus in the 74 cities.

 

Zhengzhou

 

Buildings are seen amid heavy smog in Zhengzhou, capital of central China's Henan Province. [File photo]

Province: Henan

Average annual PM2.5 density: 102.4