NITROGEN DIOXIDE CONCENTRATION IN KAUNAS 2008-2009

The aim of the present study was to assess distribution of nitrogen dioxide concentration in Kaunas. A passive sampling method and triethanolamine as an absorbent was used. Sampling was carried out in 62 measurements points of Kaunas city during four different seasons in 2008-2009. According to measured concentration average seasonal and annual concentration of nitrogen dioxide was calculated. The study results showed that mean nitrogen dioxide concentration in Kaunas was 18.1 mu gm(-3) (2008) and 25.0 mu gm(-3) (2009). The highest mean seasonal concentration was found during spring seasons (30.7 mu gm(-3)), the lowest - during summer (16.0 mu gm(-3)). The highest nitrogen dioxide concentration was in Centras district (2008 - 32.8 mu gm(-3) and 2009 - 34.0 mu gm(-3)), lowest in Panemune (2008 - 9.7 mu gm(-3) and 2009 - 15.7 mu gm(-3)). We found a negative correlation between nitrogen dioxide concentration and precipitation (r=-0.543, p=0.000). Correlation between nitrogen dioxide concentration and wind speed and temperature was non significant. Using Arc GIS program maps of nitrogen dioxide concentration distribution were plotted. Nitrogen dioxide concentration interpoliation results revealed, that the highest pollution was in Centras, Zaliakalnis, Dainava districts, the lowest was found in areas where lower traffic flows and more green places.