4. Study of Air Pollution in Lanzhou City in 2003–2012

The data of the air pollutants used in this chapter are the monitoring data of the three SO₂, NO₂, and PM₁₀ pollutants commonly used by the EPA. They are three pollutant indicators of monitoring data. According to the Chinese National Ambient Air Quality Standard (CNAAQS) GB3095–1996, as NAAQS GB3095–2012 was adopted in 2012, the study of the period 2003–2012 was using NAAQS GB3095–1996. The daily average concentration of major air pollutants of SO₂, NO₂, and PM₁₀ and the air pollution index (API) during 2003-2012 were obtained from the Lanzhou Environmental Monitoring Center. Data on dust in the period 2003-2007 were obtained on the basis of monthly averages from automatic air quality monitoring stations located in the city. In addition, along with the “Lanzhou Environmental Quality Report” (2003–2007) and Ministry of Environmental Protection of the People’s Republic of China, the data center published daily air quality data for key cities and other resources. The China Meteorological Administration Lanzhou ground weather station used meteorological data, including temperature data, air pressure data, 6 h precipitation data, wind speed data, visibility data, and dew-point temperature data, as well as it used the conventional surface meteorological observation data daily eight times at the same time.