Evaluation methods of the impact of motorization on the quality of the atmospheric air

The automotive industry is one of the fastest developing branches in the world. From year to year on the roads appear more and more cars. In the modern vehicles, better and more efficient technologies reducing exhaust emission are applied. However, the cars are still the leading source of air pollution, especially in towns and cities. Car exhaust gases have adverse effect on the human health, because they form so-called “low emission”. It means that they are released into the troposphere at the people living height. As a result, people are exposed to the direct and long-lasting contact with the fumes. Therefore, precise assessment is very important to the vehicles’ impact on the quality of the atmospheric air. The review of the evaluation methods of the impact of vehicles on the air quality was presented in the paper, with special regard to the mathematical dispersion modelling of the exhaust gases. In particular, NOx emission by sector in Poland, changing NOx emissions from road transport in Poland in the years 2000-2009 with regard to the change in the number of cars, vertical cross-section of a typical symmetric urban street canyon are presented in the paper.