Ask a friend who uses ink weather, what is the weather quality index inside? For example, pm2.5 is 142, which is a quantitative understanding?

Air quality index (AQI) is an index to quantitatively describe air quality. The larger the value, the more serious the air pollution and the greater the harm to human health. The main pollutants involved in air quality assessment are fine particles (pm2.5), inhalable particles (pm 10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and carbon monoxide (CO). [ 1]

Air quality index (AQI) is defined as a dimensionless index that quantitatively describes air quality, and individual air quality index (IAQI) is also designated for individual pollutants. [2] Air quality index can be used to intuitively evaluate the quality of atmospheric environment and guide the control and management of air pollution.

According to the size of air quality index, air quality is divided into five grades, corresponding to six categories of air quality. The greater the index, the higher the grade, indicating the pollution situation. In the first half of 20 12, the original air pollution index (API) was changed to air quality index (AQI). AQI*** is divided into six grades, from excellent grade I, good grade II and light pollution grade III to heavy pollution grade V and heavy pollution grade VI. When the daily average concentration of PM2.5 reaches 150 μ g/m3, the AQI reaches 200; When the daily average concentration of PM2.5 reaches 250μ g/m3, the AQI reaches 300; When the daily average concentration of PM2.5 reaches 500 μ g/m3, the corresponding AQI index reaches 500.

The more serious the situation, the greater the harm to human health.

0 ~ 50 Ⅰ is excellent for normal activities.

51~100 Ⅱ is good

101~150 Ⅲ1The symptoms of susceptible people with mild pollution are slightly aggravated. Patients with heart disease and respiratory diseases in healthy population should reduce physical exertion and outdoor activities.

151~ 200 Ⅲ 2 light pollution

201~ 250 Ⅳ1The symptoms of patients with moderately polluted heart disease and lung disease are obviously aggravated, and their exercise tolerance is reduced. Generally, elderly people with symptoms of healthy people and patients with heart disease and lung disease should reduce physical activity.

251~ 300 Ⅳ 2 Moderately severe pollution

30 1 ~ 500ⅴ heavily polluted healthy people's exercise tolerance decreased, with obvious strong symptoms. The elderly and patients with certain diseases in advance should stay indoors to avoid physical exertion, and the general population should try to reduce outdoor activities. [2]