engleski

Distribution of trace metals in soils from areas impacted by war activities in Croatia

Soil samples were collected in 8 areas which were most affected by the war in Croatia. These areas are (with number of collected samples given in parentheses): Banovina (26), Pokuplje + Kordun (30), Eastern Lika (4), Posavina (17), Western Slavonija (29), Osijek soils region (20), Vukovar region (20) and Šibenik region (8). A total of 150 soil samples were collected and analyzed for the content of about 30 metals, including toxic metals which can originate from explosions of ammunition and ordnance (Cd, Pb, Cu, Zn, Ni, Co, Cr, Sb, As, U). Soil samples were air dried under laminar flow and the fraction <2mm was separated for analysis by sieving. This fraction was further milled in order to obtain fine homogenous material for analysis. Acid digestion of soils was done using concentrated nitric acid in a closed microwave digestion system. About 30 elements were determined in the digestion extracts by HR ICPMS. Mercury was measured in undigested soils by an AMA solid mercury analyzer. A soil CRM (GBW 07410) was used for quality control purposes and to determine the recovery of the extraction for analyzed metals by the digestion method employed. In addition, 6 soil samples were analyzed both at the Norwegian Institute for Water Research - NIVA (HNO3 and total digestion) and at the Rudjer Bošković Institute - RBI. Comparison with certified values and total sediment digestion revealed that for the majority of elements more than 90% of metals were extracted by the HNO3 digestion in closed MW system. Lower recoveries were obtained for elements incorporated in the sediment matrix, such as Al, Ba, K, Sr and Ti. The obtained results indicate that in about half of the analyzed soil samples concentration of two or more toxic metals was higher than the MPC (Maximal Permissible Concentration) for agricultural soils in Croatia (Narodne Novine, Legal Bulletin 15/92). In majority of these samples concentrations were up to 2 times higher than the MPC, but at few locations highly polluted soils with 5 to 100 times higher concentrations of As, Cd, Cu, Hg, Pb, Sb, Zn and U were detected. For some of these samples mixed industrial-war origin of contamination must be suspected (locations Galdovo in Sisak, Ražine in Šibenik etc), but for some samples, especially in the region of Western Slavonija, the most probable origin of the very high concentrations of Zn, Pb, Cu and Sb is ammunition used for destroying electric transformer stations (ETS) around which samples were collected. The region where levels of numerous metals (especially Cu, Pb and Zn) were also highly elevated, were soils collected in the unexploded ordonanance (UXO) destruction area on the military shooting range near the town of Slunj. Obtained results showed that the war impact on the environment, although limited in some areas, can be identified by analyses of soils even after more than 10 years after the war activities ceased.

Soil; war-realted contamination; Croatia

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