engleski

Chlorinated hydrocarbons in the atmosphere and surface soil in the areas of the city of Zadar and Mt. Velebit - Croatia

The results of the analysis of the polychlorinated biphenyls in the soil from a number of points at the 110/35 kV Electrical Transformer Station in Zadar indicate significant contamination. Because there is some speculation about the possibilities of the inflow of spilled contaminants from the karstic soil of the city of Zadar to the coastal sea from other sources inside the city of Zadar, investigations of the chlorinated hydrocarbons in the atmosphere and soil of several parts of the city of Zadar were performed and are presented in this paper. Air sampling and analysis were performed by RECETOX - TOCOEN & Associates, Brno, CZ, May 13 to 23, 2003. Four samplers were in the city of Zadar and one was 150 km north on Mt. Velebit. Two phases were collected - particles using quartz filter Whatmann (fraction dae < 50 &#61549; m), and gas phase which was collected by the solid adsorbent trap - polyurethane foam (Gumotex Břeclav, density 0.03 g.m-3). All field samples and field blanks were extracted with dichloromethane in Büchi System B-811 automatic extractor. Volume of extracts was reduced and fractionation achieved on sulphuric acid modified silica gel column. Samples were analysed on GC-ECD HP 5890. Soil samples were air dried at the Rudjer Boskovic Institute, CMER and extracted at 24 hours with n-hexane by Soxhlet extraction The analytical method used for the analysis of extracts included filtration through a column of Na2SO4 anh., cleaning on an alumina column and the separation of the PCB's from organochlorine insecticides on a miniature silica gel column. Results of determination include 7 PCB congeners (PCB 28, PCB 52, PCB 101, PCB 118, PCB 153, PCB 138, PCB 180) and the sum of 7 congeners. The highest values were observed at ETS Zadar with the range from 1.111 to 5.147 ngm-3 of air. At the same position ranges of PCBs in the dried soil are from 30.8 to 17780 ngg-1 Levels of PCBs determined in the air and soil samples in the Zadar area were compared with the same from other European countries. Distribution of investigated pollutants between particulate phase and aerosol are also discussed. Positive correlations statistically significant for the sum of 7 PCB congeners were observed when comparing levels of PCBs in the soil and air of investigated locations.

PCB; war waste; atmosphere; Zadar; Croatia

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