%0 Journal Article
%T Temporal Variations in Concentrations of Ozone, Nitrogen Dioxide, and Carbon Monoxide at Osijek, Croatia
%A Elvira Kova£¿-Andri£¿
%A Tatjana Radanovi£¿
%A Iva Topalovi£¿
%A Berislav Markovi£¿
%A Nikola Saka£¿
%J Advances in Meteorology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/469786
%X The purpose of this study was to investigate the ozone, carbon monoxide, and nitrogen dioxide variations and their correlation with meteorological parameters in Osijek (Eastern Croatia) during the summer seasons of 2002, 2007, and 2012. The measured data are discussed in relation to the EU guidelines (Directive 2002/3/EC, Directive 2008/50/EC). In order to characterize ambient air with respect to ozone photochemical pollution we calculated three photochemical pollution indicators. These indicators may also be a valid measure for harmful effects on living organisms. The influence of local meteorological parameters on the measured concentrations of ozone, carbon monoxide, and nitrogen dioxide was also investigated. We have attempted to establish correlations between measured pollutant concentrations and meteorological parameters using the technique of multivariate principal component analysis (PCA). 1. Introduction Air pollution is a common theme for the past decades because of it is growing source of general pollution and the most common source in urban areas being vehicle exhaust. The main pollutants from diesel fuel vehicles include carbon monoxide (CO) and nitrogen dioxide (NO2) from which secondary pollutant ozone (O3) is formed [1]. For a long time, ozone was fairly constant trace constituent of the air, but, in recent years, its concentration in the surface layer of the atmosphere shows a steady increase and at the present time it is greater than ever. Its volume fraction during the preindustrial period increased 2 to 4.5 times and it is still rising [2]. In urban areas or polluted atmosphere various reactions are carried out in which the formation of O3 depends on the ratio of nitrogen oxides ( ), while the effect of CO cycles is such that it slowly oxidizes nitrogen monoxide (NO) to nitrogen dioxide (NO2) and thus indirectly affects the concentration of ozone. Carbon monoxide molecules are entering the cycle of oxidation, and nitrogen monoxide (NO) is oxidized to nitrogen dioxide (NO2). Nitrogen oxides originate mainly from anthropogenic sources, and increased production of ozone in the lower layer is associated with the cycles of photochemical reactions involving volatile organic compounds (VOCs) [3]. Anthropogenic emissions of VOCs and induce changes in the natural sources of tropospheric ozone. If the mixture of and VOCs is irradiated with the visible light, ozone will be generated in the reaction vessel until all the VOCs are spent. The same process is taking place in the air to form large amounts of ozone by solar radiation in the presence
%U http://www.hindawi.com/journals/amete/2013/469786/