1, first-class excellent (AQI is between 0 and 50): indicates that the color is green, and the health impact is: the air quality is satisfactory, and there is basically no air pollution.
2. Grade II is good (AQI is from 5 1 to 100): it means that the color is yellow, and the health impact is: the air quality is acceptable, but some pollutants may have a slight impact on the health of a very small number of abnormally sensitive people.
3. Grade III is light pollution (AQI is from 10 1 to 150): orange, and the health impact is that the symptoms of susceptible people are slightly aggravated, and the symptoms of healthy people are highly irritating.
4. The fourth grade is moderate pollution (AQI is 15 1 to 200): it means that the color is red, and the health impact is: further aggravating the symptoms of susceptible people.
Grade 5.5 is heavy pollution (AQI is between 20 1-300): it means purple, and its impact on health is that people with poor physical fitness have obvious symptoms, exercise tolerance is reduced, and healthy people generally have symptoms.
Grade 6.6 is serious pollution (AQI is above 300): it means that the color is reddish brown, and the impact on health is that the exercise tolerance of healthy people is reduced, with obvious strong symptoms.
air quality standards
Air refers to the gas around the earth, which maintains the survival of human beings and creatures. What plays an important role in human and biological survival is the air layer within 0/2 km from the ground, that is, the troposphere. Clean air consists of 78.06% nitrogen, 20.95% oxygen and 0.03% carbon dioxide, accounting for about 99.04% of the total air, and the sum of other gases is less than 1%.
A clean atmosphere is one of the necessary conditions for human survival. A person can live for five weeks without eating or drinking, but he will die if he doesn't breathe air for more than five minutes. The human body needs to inhale 10- 12 cubic meters of air every day. The atmosphere has a certain self-purification ability, and pollutants that enter the atmosphere due to natural processes are removed from the atmosphere through the self-purification process of the atmosphere, thus keeping the atmosphere clean.
The above contents refer to Baidu Encyclopedia-Air Quality.