Availability of geogenic heavy metals in soils of Thiva town (central Greece)

Abstract

Potentially toxic metals in the urban chemical environment impose risks to both ecosystem and human health. Here, we evaluate the labile pools and availabilities of non-anthropogenic Ni, Cr, Co and Mn in soil samples from Thiva town (central Greece) and investigate their associations with common soil properties and geochemical data obtained by the aqua regia and single selective dissolutions. Experimental work included the initial application of the sequential extraction protocol proposed by the European Community Bureau of Reference and chemical extractions with ethylenediamine tetraacetic acid solution and a modified physiologically based extraction test with the aim to obtain the operationally defined fractions of plant availability and human bioaccessibility, respectively. The leachate results demonstrated that despite the significant contribution of residual metal species especially for Ni and Cr, the studied serpentine soils provide chemically labile pools for all the considered elements. Nickel was found to be the most available metal with the order being Ni > Cr ∼ Co ∼ Mn for plant uptake and Ni > Cr > Co ∼ Mn for human bioaccessibility. The aqua regia extractable concentrations are not predictors of elemental availabilities except for Ni bioaccessible data interpreting however only a moderate percentage of the total variance. The incorporation of basic soil properties (mostly total organic carbon), geochemical data for the major elements Ca, Mg and Fe and ammonium oxalate extractable Cr significantly improved the estimations for individual elements entailing the strong influence of the chemistry and mineralogy of soil materials to the release of focus metals from the soil matrix. This study provides for the first time bioaccessible data for serpentine-derived soils that are more realistic for evaluating potential adverse effects on the human health.

TOF-SIMS and FE-SEM/EDS to verify the heavy metal fractionation in serpentinite quarry soils

“…(Table 4). These results are in accordance with those of Bradl (2004) and Kelepertzis and Stathopoulou (2013), who indicated that, although the oxides, mainly of Mn, are present in the soils in very low concentrations, the oxides have a high affinity for Co. On the other hand, it has been found that the percentage of Co associated with Fe and Mn oxides is lower in soils with a low content of oxides (39% M1 and 31% M3), and over 50% (Table 2 and Fig. 2) in the other soils.…”

Weathering and transport of chromium and nickel from serpentinite in the Coast Range ophiolite to the Sacramento Valley, California, USA

“…The absence of Cr in the HA extraction and presence in the CBD extraction suggests Cr is incorporated into Fe oxides but is not associated with Mn oxides. Similar results were seen in HA extractions of serpentine soils in Greece (Kelepertzis and Stathopoulou, 2013) and is likely due to the oxidation of Cr(III) to Cr(VI) by Mn oxides (Bartlett and James, 1979;Fendorf, 1995) and the high solubility of Cr(VI). Nickel is released in both the HA and CBD, but is more concentrated in the CBD extraction suggesting it is more strongly associated with soluble Fe oxides.…”

“…Several studies have focused on the Cr chemistry and mineralogy of serpentinite and serpentine-derived soils (e.g., Becquer et al, 2003;Cheng et al, 2011;Fandeur et al, 2009;Hseu et al, 2007;Hseu and Iizuka, 2013;Kelepertzis and Stathopoulou, 2013;Kierczak et al, 2007;Oze et al, 2004a;. Elevated Cr(VI) concentrations in soil pore water and groundwater adjacent to serpentinite have been reported (Ball and Izbicki, 2004;Fantoni et al, 2002;Izbicki et al, 2008;Robertson, 1975;RoblesCamacho and Armienta, 2000;Wood et al, 2010).…”

Heavy Metals in Urban Park Soils From Athens, Greece

“…Potentially harmful elements (PHE's) including heavy metals and metalloids, are among the most tenacious soil pollutants because of their non-biodegradable nature and the long term toxicity (Ajmone-Marsan and Biasioli, 2010;Massas et al, 2013;Kelepertzis and Stathopoulou, 2013). Urban soils especially in public park areas may have an immediate impact on public health, mainly due to the direct contact with humans (Mielke et al, 1999).…”