How to judge the quality of air?
Air pollution index
The air quality of API shows the influence of color on health. The suggested measures are 0-50: excellent and normal activities 5 1- 100: good and 100-200: the symptoms of people vulnerable to mild pollution are slightly aggravated, and patients with heart disease and respiratory diseases in healthy people should reduce physical exertion and outdoor activities. The symptoms of patients with moderate pollution heart disease and lung disease are obviously aggravated, and their exercise tolerance is reduced. 300 heavily polluted healthy people have decreased exercise tolerance and obvious strong symptoms. The elderly and patients with certain diseases in advance should stay indoors to avoid physical exertion, and the general population should avoid outdoor activities.