China News Service, Beijing, January 25 (Reporter Ruan Yulin) Affected by poor diffusion conditions, China's Beijing, Tianjin, Hebei, Shanxi, Shandong, Henan and other places experienced moderate to heavy pollution on the 25th.
Since January 20, the cold air force across the country has been weak, and heavy PM2.5 (fine particulate matter) pollution has occurred in many areas such as the Beijing-Tianjin-Hebei and surrounding areas, the north-central Yangtze River Delta, the Fenwei Plain, and southern Liaoning.
The China Environmental Monitoring Station showed that at 12:00 on January 25, the air quality in Jinzhou, Yingkou, Jiuquan and other cities was seriously polluted; the air quality in Shijiazhuang, Baoding, Handan, Hengshui, Taiyuan, Linfen, Changchun, Harbin, Jinan, Zibo and other cities Severe pollution has occurred; air quality in Beijing, Tianjin, Tangshan, Qinhuangdao, Xingtai, Cangzhou, Shenyang, Zhengzhou, Luoyang and other cities has experienced moderate pollution.
China Environmental Monitoring Center issued a reminder of the process of severe and above pollution. On the 25th, the ground in Beijing-Tianjin-Hebei and surrounding areas was controlled by weak atmospheric pressure, with low wind speed, high humidity, poor diffusion conditions, and continuous accumulation of pollutants. The southern part, central and southern Shanxi, Shandong and most of Henan are mainly polluted moderately to severely, and some cities in Shandong and Henan are at risk of serious pollution.
Analyzing the causes of pollution, experts from the National Air Pollution Prevention and Control Center said that recently the conditions of atmospheric diffusion across the country are generally unfavorable. Due to factors such as snow melting, the relative humidity near the ground is relatively high, which is likely to cause the accumulation and continuous transformation of pollutants; Discharge of air pollutants, superimposed on unfavorable weather conditions, cause pollution processes.
Analysis believes that in this process, the pollution level in Beijing-Tianjin-Hebei and surrounding areas is relatively prominent, and nitrate, sulfate ions and organic matter are the main components of PM2.5.
It shows that the secondary conversion of gaseous pollutants such as nitrogen oxides and sulfur dioxide makes an important contribution to the increase of PM2.5 concentration, and the organic particulate matter emitted from sources such as coal combustion and biomass combustion cannot be ignored.
Experts said that although the composition of PM2.5 in the region is dominated by secondary inorganic ions, there are exceptions in individual cities.
In Dezhou City, during the period when the PM2.5 concentration continued to increase, the concentration of organic matter, elemental carbon and PM2.5 increased simultaneously, of which organic matter accounted for up to about 70%, indicating that the primary emission of combustion sources dominated the increase in local PM2.5 concentration.
The China Environmental Monitoring Station predicts that on the 26th, affected by the weak cold air, the diffusion conditions in the northern part of the Beijing-Tianjin-Hebei region will improve slightly, the southern part of the Beijing-Tianjin-Hebei region will be affected by pollution transmission, and the southern part of Hebei, western Shandong and most of Henan will remain moderate to severe Pollution.
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