空气质量数据提供者: the Czech Hydrometeorological Institute (Český hydrometeorologický ústav) (portal.chmi.cz)
Note that the measurement for SO2 (sulfur dioxide) are taken from the station: Kamenny Ujezd, Plzensky and the measurement for O3 (ozone) are taken from the station: Kocelovice, Jihocesky