Urumqi was found to be the most polluted city in China during the first half of this year, a Ministry of Environment report said concerning air pollution in major Chinese cities.

Starting from January, the ministry monitored the air quality in 113 cities for three major pollutants, including SO2, NO2 and inhalable particles (PM10), over the course of six months. All the three pollutants pose health hazards to urban residents.

The coastal city Haikou in China’s southernmost province Hainan is the only city to have Grade 1, or excellent, air quality, while 79 cities including Shanghai, Guangzhou and Chongqing reached Grade 2 level, meaning the air quality is good, and 33 cities received a Grade 3 reading meaning their air is slightly polluted.

The ministry identified PM10 as the major pollutant as 26 cities it monitored failed PM10 standard while no cities exceeded the NO2 standard and only 12 has excessive S02.

PM10 are inhalable particles less than 10 microns in diameter, or one-fifth of the diameter of human hair and their major sources are vehicle exhaust emission and burning solid fuels.

During the survey period, SO2, N02 and PM10 concentration fell year on year by 9.1 percent, 2.7 percent and 5.5 percent respectively to 0.04, 0.036 and 0.086 milligrams per cubic meter.

Following are the 10 cities which have most PM10 particles in their air.

  Xining

PM10 concentration/cubic meter:0.110 milligrams