Data Source and Description
●Air quality data of mainland China, Hong Kong, Macao, and Taiwan obtained from local government agencies for ecological environment and environmental monitoring.
●Worldwide air quality data comes from aqicn, AirNow, OpenAQ and local environmental agencies.
●For the stations at mainland China, the Air Quality Index (AQI) value adopts the Chinese standards. Other stations adopt their local standards or U.S. standards.Annual National Environmental Data and Statistics