Assessment of air pollution due to ozone in the north-east region Romania

The results of air quality monitoring in automatic stations in the North-East Region-Romania (RNER) region in the period 2009 - 2020 indicated that the declared ozone concentration values were generally lower than those regulated by law - information threshold > 180 μg/m3 as required by Directive 2008/50/EC and Law 104/2011. Air quality in RNER relative to ozone concentration was good, with only one exceeding of the information threshold (NT1 - 28 April 2009, 12:00 - 180,28 μg/m3). The highest multi-annual averages (2009 – 2020) were calculated for IS 4 stations (59,5 μg/m3), EM 3 (53,4 μg/m3) and SV 1 (50,3 μg/m3). High values were generally recorded at urban-type stations, where urban characteristics, heavy road transport and the presence of airports generated high ozone concentrations. The lowest multi-annual ozone concentrations were calculated for stations VS 1 (41,5 μg/m3), BC 2 (41,9 μg/m3), IS 3 (42,0 μg/m3) and BC 3 (42,7 μg/m3). Low values were generally registered at industrial stations, where the atmospheric calm and the frequency of urban haze favored the accumulation of pollutants on the soil surface, limiting the formation of ozone. Ozone pollution is viewed with concern by environmental specialists in RNER, due to the fact that this element has a negative impact on people and the environment.