According to the Beijing Environmental Protection Bureau, during the daytime from October 13 to 14, the ground in Beijing was controlled by the pressure equalization field, the wind speed was small, the weather situation continued to be stable, and the pollution diffusion conditions were unfavorable, which was affected by local pollution accumulation and regional transportation. The concentration of PM2.5 rises from good to moderate to severe pollution.

In response to the air pollution process, the relevant departments have further increased law enforcement at all times.

In terms of fixed source law enforcement, the first is to use the automatic monitoring system to monitor the emission of pollutants from elevated sources in real time, and to find out the problems in a timely manner; second, to use hotspot grid technology to concentrate on law enforcement forces to accurately investigate and deal with fixed-source atmospheric environmental problems, and seriously investigate and punish food and beverage.

Environmentally-friendly facilities such as auto repair and other key industries in the atmosphere have not installed environmental violations such as environmental protection facilities, abnormal operation of environmental protection facilities, and non-point source pollution such as “three burns and three dusts”.

According to the Beijing Municipal Environmental Protection Bureau, on the 14th, more than 240 pollution sources (points) were inspected at the urban level, and more than 40 environmental problems were found. Law enforcement officers stopped and ordered corrections. Anyone involved in the dust on the construction site will be transferred to the  relevant departments for handling. If the environment is illegal, it will be further investigated and dealt with according to law.

In terms of mobile sources, the environmental protection department issued a combination punch for heavy-duty diesel vehicles, strictly checked the excessive standard vehicles; implemented the law enforcement mode of “environmental forensics and public security punishment”, focusing on the road inspection and night inspection at the junction of Jingjing and the city.

First, in 38 major entrances to Jingkou and comprehensive checkpoints, especially for 18 key entrances to Beijing, 24 hours of law enforcement has been implemented. Others have implemented 24-hour mobile enforcement at Jingkou. In the 32 key roads, focusing on the heavy duty of heavy diesel vehicles, the fixed law enforcement points were combined with the mobile law enforcement points to carry out inspections.

The second is to further strengthen the law enforcement of households, carry out comprehensive inspections on a number of emission pollutants and emission control devices for motor vehicles and non-road mobile machinery, and deepen the use of more than 2,000 heavy-duty diesel vehicles in centralized parking places and dynamically grasp the use of non-road mobile machinery. Conduct household inspections. The inspection contents include smoke, OBD on-board diagnostic system, post-emission treatment device inspection, and diesel vehicle NOx emission inspection, which basically achieved comprehensive supervision of heavy-duty diesel vehicle emissions.

The third is to implement closed-loop management, and to include the foreign-funded heavy-duty diesel vehicles that have exceeded the standard in the law enforcement in the “blacklist” database, and will not go through the formalities of going to Beijing before passing the re-examination. The city's heavy-duty diesel vehicles with excessive emissions exceeded the accuracy of the law enforcement, and severe punishment.

According to the statistics of the Beijing Municipal Environmental Protection Bureau, as of now, the city's environmental protection department has inspected more than 6,000 vehicles per day, and investigated and dealt with more than 900 heavy-duty diesel vehicles.