ORIGINAL RESEARCH
Risk Elements in Soils of Burdened Areas
of Eastern Slovakia
Jozef Vilček1, Ondrej Hronec2, Ján Tomáš3
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1Faculty of Humanities and Natural Sciences University of Prešov in Prešov,
Soil Science and Conservation Research Institute Prešov, Raymanova 1, 080 01 Prešov, Slovakia
2Institute of Environment and Regional Development, University of Central Europe in Skalica, Slovakia
3Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Slovakia
Pol. J. Environ. Stud. 2012;21(5):1429-1436
KEYWORDS
ABSTRACT
Areal or pointed extension of soil contamination by risk elements was determined in samples from 47
locatoins of agricultural soils in “pollution-loaded” regions of eastern Slovakia during 2006 and 2008. These
regions were primarily the areas of middle Spiš and northern Gemer, where soils were under long-term contamination
by solid polluting elements containing risk elements. A source of contamination was metallurgical
plants located in the broken terrain with unfavorable dispersion conditions. Risk elements Cd, Pb, Cu, Zn,
Ni, Cr, and As were determined in the lixivium of Aqua regia and their accessible (mobile) forms in the lixivium
of 1 mol·dm-3 NH4HNO3. To consider the solubility of the risk elements the lixivium of 0.05 mol·dm-3 EDTA (mobile and mobilizable forms) and the lixivium of 2 mol·dm-3 HNO3 (potentially releasable contents)
was used. Ascertained contents of the risk elements in the lixivium of Aqua regia correspond with the
results regarding risk elements that were obtained by reduction in the mixture of inorganic acids before 1990.
Then values of the solid polluting elements containing risk elements were the highest. The results confirm
the large areal character of soil contamination by Hg and As in the emission areals of metallurgical plants
where the natural endegeneous geochemical abnormalities now exist. Extremely high values of Pb, Zn, and
Cd in close proximity to the former shaft-furnace (without any possibility of dispersion) are the result of solid
polluting elements from Pb, Sn, alloys and ZnSO4 production facilities. A considerably larger area of contaminated
soils by Cu is connected to refined flame furnace copper production and convertors and its dispersion
into the wider areas. Some isolated locations with Cd, Cu, Ni, Hg, and As excesses are connected to geological-
petrographical conditions where polymetallic mineralizing of old environmental loads is characteristic.
In the samples with high contents of risk elements in Aqua regia, there were also over limit values for
accessible plant risk elements. In the sum of mobile and mobilizable forms with relatively the highest content
of Cd (36.57%) and the lowest Cr (0.36%) were determined in the following decreasing order Cd > Pb
> Cu > Ni > Zn > Cr. The relevant prevalence of risk elements in residual fractions is apparently connected
to their emission origin from thermic processes as predominantly insoluble risk element oxids.