What is air quality?

Air quality depends on the overall level of air pollution in a certain area, and it interacts with meteorological conditions (such as humidity, temperature and wind) to form the overall atmospheric conditions. Poor air quality can be expressed aesthetically (such as unpleasant smell), and it can do harm to plants, animals, people and even some objects. The atmosphere is a gas shell around the earth, and most of it is permanently attached to the earth by gravity. The atmosphere is mainly composed of nitrogen (78% by volume) and oxygen (2 1%). There are also a small amount of argon, carbon dioxide and water vapor, and a small amount of other gases and particles.

The gas composition of the atmosphere is very important in its function. Ozone accounts for two millionths of the average composition of the atmosphere, but it is concentrated in the stratosphere. Stratospheric ozone is very important for the survival of life on earth. Particulate matter is another important trace component. The change of sol content and trace carbon dioxide composition in the atmosphere can cause obvious changes in climate.