Air quality level

Air quality is divided into six grades, corresponding to the air quality index of the six grades. The greater the index, the greater the grade, indicating the more serious the pollution.

1, Grade I: excellent; Air quality index 0-50; The air quality is satisfactory and there is basically no air pollution; All kinds of people can move normally.

2. Level 2: Good; Air quality index 51-100; The air quality is acceptable, but some pollutants may have a weak impact on the health of a very small number of abnormally sensitive people; Such people should reduce outdoor activities.

3. Grade III: light pollution; Air quality index101-150; The symptoms of susceptible people are slightly aggravated, and healthy people have irritating symptoms; Children, the elderly and patients with heart disease and respiratory diseases should reduce long-term and high-intensity outdoor sports.

4, level 4: moderate pollution; Air quality index151-200; Further aggravating the symptoms of susceptible people may have an impact on the heart and respiratory system of healthy people; Children, the elderly and patients with heart disease and respiratory diseases should avoid long-term and high-intensity outdoor sports, and the general population should moderately reduce outdoor sports.

Grade 5 and 5: heavy pollution; Air quality index 201-300; Symptoms of patients with heart disease and lung disease are obviously aggravated, exercise tolerance is reduced, and symptoms are common in healthy people; Children, the elderly and patients with heart disease and lung disease should stay indoors and stop outdoor sports. Ordinary people should reduce outdoor sports.

6, level 6: serious pollution; Air quality index > 300; The exercise tolerance of healthy people is reduced, the symptoms are obviously strong, and some diseases appear in advance; Children, the elderly and patients should stay indoors to avoid physical exertion, and the general population should avoid outdoor activities.

legal ground

Notice of the Ministry of Environmental Protection on Implementing Ambient Air Quality Standard (GB 3095-2012)

Article 1 The implementation of the Ambient Air Quality Standard is an objective requirement for strengthening atmospheric environmental governance in the new period. With the rapid development of China's economy and society, the energy consumption dominated by coal has risen sharply, the number of motor vehicles has increased sharply, the emissions of nitrogen oxides (nitrogen oxides) and volatile organic compounds (VOCs) have increased significantly in economically developed areas, and the pollution of ozone (O3) and fine particles (PM2.5) has intensified. In the case that the pollution of inhalable particulate matter (PM 10) and total suspended particulate matter (TSP) has not been completely solved, the pollution of PM2.5 and O3 in Beijing-Tianjin-Hebei, Yangtze River Delta, Pearl River Delta and other areas is aggravated, and the smog is frequent, and the visibility is reduced. It is urgent to implement new environmental air quality standards, increase pollutant monitoring items and tighten some pollutant limits, so as to objectively reflect China's environmental air quality and promote air pollution prevention and control.