Air pollution by nitrogen dioxide in Kiev city

In the article main nitrogen dioxide emissions sources in a big cities was analysed. Shown the temporal dynamics of average annual concentrations of nitrogen dioxide in Kiev city for time period 1985 - 2012, analyzed concentration of this pollutant in different part of the city and frequency of cases of maximum allowable concentration (MAC) exceeding. The highest concentrations of nitrogen dioxide observed in the central part of the city in some months the warm season. The frequency of cases exceeding of MAC in the air usually exceeds 50% and in the warm season 2012 average concentration of NO2 in the air has been very high and frequency of exceeding of MAC reached 100% in almost all monitoring stations. Studies show that in the warm season in the air of Kyiv regularly observed abnormally high concentrations of nitrogen dioxide, which is a precursor of photochemical smog, and under favorable meteorological conditions will result in the formation of this negative phenomenon in the atmosphere of the city.