%0 Article %A Makra László %D 2001 %G English %B Acta climatologica %@ 0563-0614 %T Analysis of air quality parameters in Csongrád county %U http://acta.bibl.u-szeged.hu/16859/1/climatologica_034_035_023-044.pdf %X The aim of the study is to determine partly spatial and temporal characteristics, partly statistical interrelationships concerning contaminating parameters at the town of Szeged and in Csongrád county. We also fit extreme-value models to the N0 2 and S02 concentrations observed at some stations and calculate return levels, which are about to be exceeded once in a given period, based on these models. Monthly averages for N0 2 and S0 2 concentrations and monthly totals for deposited particulates at given sites are analysed in this paper. Data have been available, depending on the pollutants, since at least 1985. Local trend analysis does not show a clear spatial structure among the sites since signs of significant periods are different and significant periods of the same sign are not similar among the sites. A special case of the two-sample t-test developed by Makra is also applied. This test makes it possible to determine whether or not averages of non-independent variables differ significantly. By using this test we made a so called tear analysis, according to which it was found that monthly totals of deposited dust tore considerably with negative signs at the end of the data sets. Spatial relations are analysed by factor analysis with the intention to determine objective subregions by applying data sets of N0 2 , S0 2 and deposited dust. Ratios of pollutants refer definitely to the role of motor vehicle traffic. Variation of traffic contributes mostly to the change in daily air quality.