Evaluating top soil trace element pollution in the vicinity of a cement plant and a former open-cast uranium mine in central Argentina

BERMUDEZ, GONZALO M.A.; MORENO, MÓNICA; INVERNIZZI, RODRIGO; PLÁ, RITA; PIGNATA, M.L

JOURNAL OF SOILS AND SEDIMENTS (PRINT)

SPRINGER HEIDELBERG

Año: 2010 p. 1 - 16

1439-0108

Purpose Heavy metals are especially dangerous because oftheir persistence and toxicity. Soil behaves as a sink ofheavy metals by aerial deposition of particles emitted bydifferent human activities. The aims of this work were toidentify the levels and sources of heavy metal and traceelements in agricultural and residential areas in Argentinaand to evaluate the enrichment of total and HCl-extractedheavy metals.Materials and methods Ninety-four topsoil samples werecollected in Córdoba, Argentina (0–10 cm). The majority ofthe samples were subject to agricultural practices. Thepossible metal pollution sources were a cement plant and anindustrial waste incinerator, a former open-cast uraniummine, petrochemical, and mechanical and metallurgicalindustries among others. The elements As, Ba, Ca, Ce,Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Se,Sm, Ta, Tb, Th, U, Yb, and Zn were measured by neutronactivation analysis, and Co, Cu, Fe, Mn, Ni, Pb, and Znwere partially extracted by 0.5-M HCl and measured usingatomic absorption spectroscopy. Several nonparametricstatistics were performed to the dataset in order toaccomplish the objectives of the study.Results and discussion The mean total Ba concentrationexceeded soil quality guidelines for residential areas, withthe maximum total As and Co concentrations surpassing theagricultural and residential limits stated in national andinternational legislations. The elements As and Ba werefound to be controlled by parent factors, whereas Ca, Co,Cr, Cu, Mn, Ni, Pb, and Zn were controlled by bothanthropogenic and pedogenic factors. A cement plant wasthe main source of Ca, Co, Cr, Cu, Mn, Ni, Pb, and Zn,whereas lanthanides, Fe, K, U, and also Zn were associatedwith a former open-cast operation uranium mine. Acorrelation analysis showed that soil organic matter andpH had strong associations with 0.5-M HCl-extracted Co,Cu, Mn, Ni, Pb, and Zn.Conclusions Fe-normalized enrichment factors calculated for0.5-M HCl-extracted heavy metals are potentially significantfor characterizing the element bioavailability, the anthropogeniccontamination, and the anomaly assessment. Accordingto soil quality guidelines for environmental health, the humanand wildlife populations in Córdoba Province might beexperiencing toxic As, Ba, Co, Cr, Ta, U, and Zn effects.Therefore, mitigation strategies should be performed on anabandoned mine (Schlagintweit Uranium Mine), Yocsina,Despeñaderos, and Oliva.