Main components of smog in China

Sulfur dioxide, nitrogen oxides and inhalable particles are the main components of smog, the first two are gaseous pollutants, and the last is

A particulate matter is the chief culprit that aggravates smog weather pollution. They combine with fog and instantly turn the sky gray. The abbreviation of particulate matter is PM, and what Beijing monitors is fine particulate matter (PM2.5), that is, pollutant particles with a 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.

Extended data:

Haze weather is a state of air pollution, and smog 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" causing 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.

Haze is composed of particles such as dust, sulfuric acid, nitric acid and organic hydrocarbons in the air. It will also make the atmosphere turbid, blur the vision and worsen the visibility. If the horizontal visibility is less than 65,438+00,000 meters, the sight distance obstacle caused by this non-aqueous aerosol system is called haze or dust haze, and the Hong Kong Observatory calls it haze.

When smog occurs, the relative humidity is not large, but it is saturated in the fog (if there are a large number of condensation nuclei, the relative humidity may not reach 100%, and saturation may occur). Smog is caused by pollutants such as automobile exhaust. When the relative humidity is between 80% and 90%, the visibility deterioration caused by blurred vision is caused by the mixture of haze and fog.

When water vapor condensation intensifies and air humidity increases, haze will turn into fog. The difference between haze and fog is that the relative humidity is small when haze occurs, but it is saturated in fog (if there are a large number of condensation nuclei, the relative humidity may not reach 100%, and saturation may occur).

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