To interpret the trends in urban air quality of Prague, Czech capital, monthly averages of PM10, SO2 , NO2, NO, O3 and CO concentrations from the national network of automated monitoring stations were analyzed together with long term trends in fuel consumption and number of vehicles registered in Prague within a period of 1992–2005. The results showed that concentrations of SO2 dropped significantly during the period of concern.
Similarly NOX and PM10 concentrations decreased significantly in the first half of the nineties, but remained rather stable or increased after 2000, presumably reflecting rapid increase of traffic density.