What’s the weather like?

Urban air quality levels are pollution index classifications and corresponding pollutant concentration limits determined based on urban air environmental quality standards and the ecological environmental effects of various pollutants and their impact on human health. At present, the grading standards for urban air quality pollution index are:

①Air pollution index (API) 0 to 50, which is the national first-level standard for daily average air quality. The air quality is excellent and is in line with nature reserves, Air quality requirements for scenic spots and other areas requiring special protection.

② (API) 51 to 100, which is the national second-level standard for daily average air quality. The air quality is good and meets the air quality requirements in residential areas, commercial areas, cultural areas, general industrial areas and rural areas.

③ (API) 101 to 200, which is the third level standard, and the air quality is lightly polluted. If exposed to this level of air for a long time, the symptoms of susceptible people will be slightly aggravated, and healthy people will have irritation symptoms. Comply with air quality requirements for specific industrial areas.

④ (API) 201~300, which is the fourth level standard, and the air quality is moderately polluted. After being exposed to this level of air for a certain period of time, the symptoms of patients with heart disease and lung disease will be significantly aggravated, their exercise tolerance will be reduced, and symptoms are common among healthy people.

⑤ (API) is greater than 300, which is the fifth level standard, and the air quality is severely polluted. Healthy people have reduced exercise tolerance, have obvious symptoms and develop certain diseases.

This classification standard is the implementation standard for urban air quality forecasting and the main basis for urban environmental functional zoning and air quality evaluation.