Seventy of 74 monitored China's cities have suffered from air pollution in the third quarter of this year, according to the Ministry of Environmental Protection.

Haze shrouds Changsha, capital of central China's Hunan Province, Oct. 22, 2013. Air pollution monitors in Changsha showed that the AQI (air quality index) hit level 5 in the 11:00 a.m. this morning. And the air pollution is caused by PM2.5 primarily. (Xinhua/Li Ga)

Among the most polluted 10 cities, 7 of them are near the capital, Beijing. Air pollution readings in Beijing as well as neighboring Tianjin Municipality and Hebei Province have been worse than in other parts of the country.

The monitored cities in the region failed to meet the required standards during an average of 62.5 percent of the time, or about 58 days, while the national average stood at around 29 days. PM2.5, is airborne particles less than 2.5 microns diameter, together with ozone, are the major pollutants in the region.

East China’s Yangtze River Delta and South China’s Pearl River Delta had more clear days than other parts of the country.