Modelling of motor transport exhaust gas influence on the atmosphere

Mobile pollutant sources, such as industry and energetics, are the basic Sources Of Pollutant emission to the atmosphere ill Lithuania. However, motor transport has the greatest share in the emission of mobile Pollutant sources. The carried out investigation revealed that in Vilnius Zirmunai district the highest concentration of pollutants is emitted during morning and afternoon rush hours when traffic is the heaviest. In 14 places of the streets in Zirmunai three types of cars were counted (lights, medium, heavy) and with COPERT program maximal emissions of CO, NOx. CHx, SO2 were fixed. Using these data, numerical modelling of transfer processes of these Pollutants was carried out. The research results indicate that the high amounts of emitted gaseous Pollutants are recorded 1-2 m away from the driving part and 4-6 m away the amounts of the exhaust sharply go down. It has been set that concentration of CO, NOx, CHx, SO2 directly depend oil motor transport's intensity. The amount of the substances goes evenly down receding from the driving part. In most cases maximum permitted concentration of these Pollutants was recorded.