Which air quality APP indicator is reliable?

The source is different. In China, the authoritative data of air quality index comes from two sources, one is the environmental monitoring station in China, including the monitoring substations in various places, and the other is the monitoring data of the American Embassy. The former data are mainly evaluated according to the standards formulated by China, while the latter data are mainly based on the standards used internationally and in the United States. The data of American Embassy is mainly used to serve American residents who work and live in China.

China's air quality evaluation standard is relatively low in the world. Foreign countries define 0-35 as high-quality air quality, and the domestic standard is 0-50. In the process of calculating air quality index, when the concentration is the same, the ambient air quality standards are different, and the AQI calculation results are also different. For example, the 24-hour average concentration limit of PM2.5 is 35 μ g/m3 in the United States and 75 μ g/m3 in China. With the same pollutant concentration, the calculated AQI index is nearly twice as different.

Some weather applications use data from China monitoring station, while others use data from the United States, which leads to different weather applications playing different data.

The value point is different. The air quality index has different values. According to the national standard, we should refer to the data of each point and adopt the daily average. However, some applications use the hourly value or the maximum value of the unit point, which will lead to "data fighting" in weather applications.

The basis is different. According to the analysis of the relevant personnel of the Environmental Monitoring Center, some applications release AQI index mainly based on PM2.5 value, which is only one of the index evaluation criteria, so when the concentration of other pollutants such as ozone (O3) exceeds the standard, the data released by the environmental protection department will inevitably be inconsistent.

Which is more reliable?

According to the above analysis, no application is accurate, and the data of each application will be biased. Want to refer to the most accurate data, directly pay attention to the real-time data published by China National Environmental Monitoring Center, or pay attention to the data published by the US Consulate.

China National Environmental Monitoring Center has launched an official App, but it is not as "humanized" as other commercial apps, which have more perfect functions and can give users a better experience. Therefore, when using weather App to understand air quality, it is advisable to put two or three applications together to confirm each other and get more accurate data.