What is the air pollution index?

The air pollution index is divided into seven grades.

1, the air pollution index is 0-50, the air quality is Grade I, excellent, there is basically no air pollution, and all kinds of people can move normally.

2. The air pollution index is 5 1- 100, and the air quality is Grade II, which is good and acceptable, but some pollutants may have a slight impact on the health of a very small number of abnormally sensitive people.

3. The air pollution index is 10 1- 150, and the air quality is Grade III, which belongs to mild pollution. The symptoms of susceptible people are slightly aggravated, and the symptoms of healthy people are irritating.

4. The air pollution index is 15 1-200, and the air quality is Grade 4, which is moderate pollution, further aggravating the symptoms of susceptible people and possibly affecting the heart and respiratory system of healthy people.

5. The air pollution index is 20 1-300, and the air quality is Grade 5, which belongs to severe pollution. The symptoms of patients with heart disease and lung disease are obviously aggravated, and their exercise tolerance is reduced. Healthy people generally have symptoms.

6. The air pollution index is 30 1-500, and the air quality is Grade 6, which is seriously polluted. Healthy people have decreased exercise tolerance, strong symptoms, and some diseases appear in advance.

7. The air pollution index is greater than 50 1, and the air quality is Grade 7, which is extremely (dangerously) heavily polluted. The exercise tolerance of healthy people is greatly reduced, and the symptoms are obviously strong, which is also the high incidence period of acute symptoms.