Nowadays, everyone is often discussing PM2.5. Does anyone know the particle size distribution of the main components of the air in haze weather?

There are several reasons for the formation of haze weather.

1. The main factor is when the atmospheric air pressure is low and the air is not flowing. Due to the stagnant air flow, tiny particles in the air gather and float in the air.

2. The ground is dusty and the air humidity is low. People and traffic on the ground stir up the dust.

3. Car exhaust is the main pollutant emission. In recent years, there have been more and more cars in cities, and the car exhaust is a factor in smog.

4. Secondary pollution caused by factories.

5. CO2 and other pollutants emitted by heating in winter. Particulate matter PM2.5 is a relatively large part of the inhalable particulate matter PM10, accounting for about 50% to 80% of PM10. It is particulate matter with an aerodynamic equivalent diameter of less than or equal to 2.5 μm, also known as fine particulate matter, of which dust accounts for 1/5 and salts generated by the conversion of gaseous pollutants account for 1/3. The chemical composition of fine particulate matter is very complex. The chemical composition of fine particulate matter is different in different time and space. The impact of particulate matter with different chemical components on human health and atmospheric visibility is also different. These effects are also related to the chemical composition inside and outside the particulate matter. related to the surface state of existence. In addition, the chemical composition of particulate matter from different sources is different, so the chemical composition of particulate matter can be used to analyze the source of particulate matter. The chemical components of fine particulate matter include inorganic components, organic components, trace metal elements, elemental carbon (EC), biological substances (bacteria, germs, molds, etc.), etc. Carbon-containing particles in the atmosphere are composed of organic carbon (OC) and light-absorbing elemental carbon (EC). The chemical structure of elemental carbon is similar to impure graphite. Organic carbon is the most abundant component in fine particles.