What are the factors that affect air quality?

The factors that affect air quality are: Man-made pollutant emissions from fixed pollution sources and mobile pollution sources are one of the most important factors that affect air quality, including tail gas from cars, ships and airplanes, industrial pollution, residents' living and heating, and garbage incineration. Urban development density, topography and meteorology are also important factors affecting air quality.

Particles with aerodynamic equivalent diameter less than or equal to 2.5 microns in ambient air. It can be suspended in the air for a long time, and the higher its concentration in the air, the more serious the air pollution. Although PM2.5 is only a small part of the composition of the earth's atmosphere, it has an important impact on air quality and visibility.

Extended data:

Air quality is not only related to the quality of human life, but also deeply affects other creatures on the earth. Therefore, we should consciously safeguard the obligation of environmental protection, strive to improve the living standards of human beings and continuously improve air quality.

The air pollution index (API) adopted in China is divided into five grades, and the API value is less than or equal to 50, which means that the air quality is excellent, which is equivalent to reaching the first-class national air quality standard and meeting the air quality requirements of nature reserves, scenic spots and other areas that need special protection. The API value is greater than 50 and less than or equal to 100, which means that the air quality is good, which is equivalent to reaching the second-class national air quality standard.

The API value is greater than 100 and less than or equal to 200, indicating that the air quality is slightly polluted, which is equivalent to reaching the national air quality third-class standard; After long-term contact, the symptoms of susceptible people are slightly aggravated, and healthy people have irritating symptoms. The API value is greater than 200, indicating that the air quality is poor, which exceeds the national air quality level 3 standard and is harmful to human body after exposure for a certain period of time.

Baidu encyclopedia-air quality