Nitrogen dioxide concentration in Kaunas 2008–2009

Abstract

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 μgm-3 (2008) and 25.0 μgm-3 (2009). The highest mean seasonal concentration was found during spring seasons (30.7 μgm-3), the lowest – during summer (16.0 μgm-3). The highest nitrogen dioxide concentration was in Centras district (2008 – 32.8 μgm-3 and 2009 – 34.0 μgm-3), lowest in Panemun÷ (2008 – 9.7 μgm-3 and 2009 – 15.7 μgm-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, Žaliakalnis, Dainava districts, the lowest was found in areas where lower traffic flows and more green places.