Hexavalent Chromium Contamination in Groundwaters of Thiva Basin, Central Greece
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Hexavalent Chromium Contamination in Groundwaters of Thiva Basin, Central Greece Evangelos Tziritis • Efstratios Kelepertzis George Korres • Dimitrios Perivolaris • Stella Repani
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Received: 11 June 2012 / Accepted: 12 September 2012 / Published online: 21 September 2012 Ó Springer Science+Business Media New York 2012
Abstract There is an increasing concern regarding elevated levels of Cr(VI) in the environment due to its higher mobility and toxicity compared to the trivalent form. Anomalous hexavalent chromium concentrations (up to 212 lg/L) were determined in irrigated groundwaters from the wider area of Thiva Basin (central Greece), frequently exceeding the permissible limit for human consumption (50 lg/L for total Cr). Based on the spatial distribution of Cr(VI) values, two groups of groundwater samples were distinguished, possibly reflecting different natural and/or anthropogenic factors that govern the levels of contamination. The first group is spatially located northwards of Thiva town and is consisted of concentrations that range from 13 to 212 lg/L (median 58 lg/L), while the second group is located near Mouriki village and Cr(VI) values range from \9 to 14 lg/L. The Cr(VI) chemical anomalies represent an important social problem because the agricultural products of this region are a major vegetable supply for Greece, bringing up the urgent need to evaluate the health effects associated with Cr(VI) exposure by ingesting the potentially contaminated foods. Keywords Hexavalent chromium Groundwater contamination Thiva Central Greece
E. Tziritis Land Reclamation Institute, Hellenic Agricultural Organization ‘‘Demeter’’, Sindos, Greece E. Kelepertzis (&) G. Korres D. Perivolaris S. Repani Department of Geology and Geoenvironment, University of Athens, Athens, Greece e-mail: [email protected]
Chromium is an essential micronutrient for plant and animal metabolism (glucose metabolism, amino- and nucleic acid synthesis). However, when accumulated at high levels, it can generate serious trouble and diseases (nausea, skin ulcerations and lung cancer) and, as concentration reaches 0.1 mg/g body weight, it can ultimately become lethal (Ajmal et al. 1984). In groundwater systems, Cr is chiefly present in two oxidation states: Cr(III) and Cr(VI), depending on the redox conditions. The hexavalent form is considered to be the most toxic and is highly mobile and soluble compared to the trivalent one (Nikolaidis et al. 1999; Hellerich and Nikolaidis 2005); the latter is strongly adsorbed or precipitates as a solid (oxy)-hydroxide phase over the pH range of most natural waters (Peterson et al. 1996). According to Peterson et al. (1996), the background concentrations of Cr in unpolluted groundwater are expected to be \10 lg/L, whereas in contaminated areas concentrations up to several hundred mg/L have been reported (Loyaux-Lawniczak et al. 2001). Due to the adverse health effects that may cause, there is an increasing concern regarding the presence of Cr(VI) in aquifers, where relatively high levels have be
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