engleski

OZONE CONCENTRATIONS IN DIFFERENT PARTS OF ZAGREB AND ITS SURROUNDINGS

Ozone is a secondary pollutant formed through photochemical reactions between nitrogen dioxide and volatile organic compounds. In the cities, its summer concentrations are usually high. In this study, we measured ozone concentrations at three sites in Zagreb in the summer of 2005. The first site was in a residential part with low traffic density. The second site was in the city center with high traffic density. The third measuring site was in a rural area about 30 km south from the center. Ozone concentrations were measured using automatic devices based on UV absorption. At the same time we recorded temperature, relative humidity, wind velocity and direction for all three sites. Based on these data we calculated daily, hourly and eight-hourly ozone averages. In the northern, residential part of the town, hourly averages ranged between 8 μ g/m3 and 209 μ g/m3. In the center, hourly ozone concentrations ranged between 9 μ g/m3 and 183 μ g/m3. In the southern, rural area ozone concentrations were between 1 μ g/m3 and 121 μ g/m3. Average concentrations were the lowest in the rural area, even though we occasionally recorded elevated concentrations. All results were analyzed with regard to the meteorological conditions.

ambient air; meteorological conditions; rural area; traffic; urban area

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