本轮污染区域传输占七成

Core Viewpoint - Beijing is currently experiencing air pollution, but conditions are expected to improve, leading to a return to good air quality levels by Saturday [1][2] Group 1: Air Quality Status - As of today, Beijing's air quality is at a light pollution level, with PM2.5 concentrations reaching 79 micrograms per cubic meter at 16:00 on the 17th, indicating light pollution [1] - On the 18th at 08:00, PM2.5 concentrations rose to 116 micrograms per cubic meter, entering moderate pollution levels, and further increased to 148 micrograms per cubic meter by 16:00 [1] Group 2: Contributing Factors - The increase in PM2.5 levels is attributed to regional transmission, with 70% of the pollution being influenced by external sources, particularly from coal burning [1] - During the pollution event, coal source tracers in PM2.5 components increased by 6.6 times, indicating significant contributions from regional coal sources [1] - Local pollution accounted for 28% of PM2.5 levels, while regional transmission pollution made up 72%, highlighting the combined impact of local generation and regional transport [1]