In 2011, haze, PM2.5 and other professional terms came into the public view. People began to pay attention to this substance. Haze is a phenomenon of air turbidity caused by a large number of suspended particles (PM2.5) in the atmosphere.
What is the haze in Beijing?
The results show that there are two main types of particles in Beijing haze. One is primary particulate matter, which is produced by direct discharge of pollution sources. The second is the secondary particles, which are the main particles to form haze. In nature, the gases produced by plant respiration and human activities enter into the atmosphere, produce chemical reactions, and generate secondary fine particles. The main components are organic matters and inorganic salts, which are mainly nitrates.
The proportion of nitrate remained unchanged in Beijing haze increased significantly
According to the winter observation data in 2017 and 2008, organic matter has always been the main component of PM1 in Beijing atmosphere. In winter 2017, the proportion of nitrate in PM1 increased significantly, 11 percentage points higher than that in winter 2008, while the proportion of sulfate decreased by 6 percentage points. This is related to the growth of motor vehicles and the reduction of sulfur dioxide emissions from coal and industry in Beijing.
Vehicle is still the main source of PM2.5, and the contribution rate of coal combustion plummeted
According to the latest analysis of PM2.5 sources in Beijing, local emissions accounted for two-thirds of the main sources of PM2.5 in 2017, and regional transmission accounted for one-third. Among the local emissions, mobile sources account for 45% of the total. Compared with the main sources of PM2.5 in 2013, the contribution rate of mobile sources and dust sources increased significantly in 2017, while the contribution rate of coal and industrial sources decreased.
PM2.5 and other major pollutants in Beijing decrease year by year
After air pollution control in recent years, the proportion of main components and main contribution sources of PM2.5 in Beijing have changed. At the same time, the concentration of PM2.5, sulfur dioxide, PM10 and other pollutants in the air of Beijing decreased year by year with the continuous growth of regional GDP, total energy consumption and vehicle ownership. In 2017, the concentration of PM2.5 in Beijing was 58 μ g / m3, which exceeded ten National Atmospheric targets.
The blue sky defense war in Beijing continues
In the past 10 years, haze, PM2.5 and other professional words have become well-known terms for women and children from scientific research terms; in the past 5 years, Beijing's air quality has generally improved. But it will be hard to say goodbye to haze in the next few years. In June 2018, the State Council issued the three-year action plan to win the blue sky defense war, and continued to implement air pollution prevention and control actions.
The sources and causes of haze in Beijing are complex, both man-made and natural. Everyone living in this sky is the victim of air pollution, as well as the producer and controller. The governance of haze in Beijing is a long-term, difficult and complex process. Only with the joint efforts of the government, enterprises and individuals can the blue sky and white clouds be expected.