What are the main components of smog?

Three main components: sulfur dioxide, nitrogen oxides and inhalable particles.

I. Definition of Haze Fog is an aerosol system consisting of a large number of tiny water droplets or ice crystals suspended in the air near the ground.

Haze is a combination of fog and haze. The aerosol system composed of dust, sulfuric acid, nitric acid and other particles in the air causes visual impairment, which is called smog. Haze is haze.

Second, smog is ubiquitous in cities, which is the result of the interaction between specific climatic conditions and human activities.

The economic and social activities of high-density population will inevitably emit a large number of fine particles (PM 2.5). Once the emission exceeds the atmospheric circulation capacity and carrying capacity, the concentration of fine particles will continue to accumulate. At this time, if it is affected by calm weather, it is easy to have a wide range of smog.

Third, the components of smog are mainly composed of sulfur dioxide, nitrogen oxides and inhalable particles. The first two are gaseous pollutants, and the last particulate matter is the main reason for aggravating smog weather pollution. Together, they make the sky instantly gloomy.

The abbreviation of particulate matter is PM, and Beijing monitors fine particulate matter (PM2.5), that is, pollutant particles with aerodynamic equivalent diameter less than or equal to 2.5 microns. This particle itself is not only a pollutant, but also a carrier of toxic substances such as heavy metals and polycyclic aromatic hydrocarbons.

The distribution of haze particles is relatively uniform, and the size of haze particles is relatively small, ranging from 0.00 1 micron to 10 micron, with an average diameter of about 1 ~ 2 micron. Floating particles are invisible to the naked eye. Because the smog is composed of dust, sulfuric acid, nitric acid and other particles, the longer the scattering wavelength, the more the light ratio, so the smog looks yellow or orange-gray.

4. Smog weather Smog weather is a state of air pollution. Haze is a general term for all kinds of suspended particles in the atmosphere, especially PM2.5 (particles with aerodynamic equivalent diameter less than or equal to 2.5 microns) is considered as the "culprit" of haze weather.

With the deterioration of air quality, cloudy days are increasing and the harm is increasing. In many areas of our country, the smog weather phenomenon is combined with fog as an early warning and forecast of disastrous weather. Collectively referred to as "haze weather".