China News Agency, Beijing, January 23 (Reporter Ruan Yulin) A large-scale pollution process has occurred in central and eastern China on the 20th, with heavy PM2.5 (fine particulate matter) pollution in many places.
As of January 22, 15 cities across the country have activated red warnings and 34 cities have activated orange warnings, and have taken corresponding emergency emission reduction measures.
Monitoring shows that since January 20, the cold air force across the country has been weak, with heavy PM2.5 pollution in Beijing-Tianjin-Hebei and surrounding areas, central and northern Yangtze River Delta, Fenwei Plain and southern Liaoning.
As of 16:00 on January 22, 29 of the 337 cities at prefecture-level and above in the country had severely polluted days of PM2.5. Among them, Henan Province had more severely polluted days (14); 83 cities had PM2. The 5-hour concentration exceeded 150 micrograms per cubic meter, and the hourly PM2.5 concentration in 15 cities including Huludao and Shangqiu exceeded 250 micrograms per cubic meter.
Analyzing the causes of pollution, experts from the National Air Pollution Prevention and Control Center said that in recent days, atmospheric diffusion conditions 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.
At the same time, high-intensity air pollutant emissions are superimposed on unfavorable weather conditions and cause pollution processes.
Experts say that from January 20 to 22, most of the country’s surface wind speeds were below 2 meters per second, with obvious static and stable characteristics. Convergence also occurred in southern Hebei, most of Henan, and western Shandong, which could easily cause pollutants to migrate to this area. Convergence; Some cities in Beijing-Tianjin-Hebei are affected by snow melting and the relative humidity is around 80%. Since the morning of the 22nd, strong fog with visibility of less than 200 meters has appeared in central and western Shandong, and local strong fog with visibility of less than 50 meters has appeared. The relative humidity is close to saturation, accelerating the conversion of gaseous pollutants, and continuously pushing up the PM2.5 concentration.
In response to this pollution process, provinces and cities in key regions actively adopted early warning and emergency measures.
As of January 22, 15 cities across the country have activated red warnings and 34 cities have activated orange warnings. All localities have adopted corresponding emergency emission reduction measures based on the warning levels of heavy pollution weather.
China National Environmental Monitoring Station predicts that from the 23rd to the 25th, the diffusion conditions will be poor, with moderate to severe pollution in central and southern Hebei, central and southern Shanxi, western Shandong, and most of Henan.
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