The air quality index is usually divided into six grades.
1, Grade I: excellent, and the air quality index is 0 to 50. The air quality is good, there is basically no air pollution, and all kinds of people can move normally.
2. Grade II: Good, with air quality index of 5 1 to 100. The air quality is acceptable, but some pollutants may have a slight impact on the health of a very small number of extremely sensitive people, and such people should reduce outdoor activities.
3. Grade III: light pollution, air quality index 10 1 to 150. The symptoms of susceptible people are slightly aggravated, and the symptoms of healthy people are aggravated. Children, the elderly and patients with heart disease and respiratory diseases should reduce long-term and moderate outdoor exercise.
It is recommended to open the window frequently to keep the air unobstructed and breathe more fresh air.
Classification of air pollution index
Grade I: the air pollution index is ≤50, the air quality grade is Grade I, and the air quality status is excellent.
There is no air pollution problem and no harm to public health.
Grade II: air pollution index ≤ 100, air quality grade II, and air quality is in good condition.
Air quality is considered acceptable, and it is harmless to public health except for a few people who are particularly sensitive to certain pollutants.
Grade III: air pollution index ≤ 150, air quality grade III (1), and air quality is slightly polluted.
People who are sensitive to pollutants will have an impact on their health, but basically have no impact on healthy people.
Level 4: air pollution index ≤200, air quality level 3 (2), and air quality status is light pollution.
Almost everyone's health will be affected, especially sensitive people.
Grade 5: the air pollution index is ≤ 300, and the air quality grade is Grade 4, and the air quality status belongs to moderate and severe pollution.
Everyone's health will be seriously affected.
Level 6: air pollution index > 300, air quality level is V, and air quality status belongs to severe pollution.
Everyone's health will be seriously affected.
legal ground
Article 10 of the Law of People's Republic of China (PRC) on the Prevention and Control of Air Pollution shall organize experts to review and demonstrate the formulation of atmospheric environmental quality standards and air pollutant discharge standards, and solicit opinions from relevant departments, trade associations, enterprises and institutions and the public.