Lead accumulation in plants grown in polluted soils. Screening of native species for phytoremediation

Abstract

In the present work, we focused on soils contaminated with elevated lead concentrations in an agricultural and residential area surrounding a lead smelter plant in Bouwer, province of Córdoba, Argentina. The aim of this research work was to assess the phytoextraction suitability of native plant species growing in the vicinity of a former lead smelter. The lead concentration in leaves, stems and roots was determined in ten species collected at ten sampling sites along a lead concentration gradient in soil. It was found that at circa 1,600 μg g-1 Pb HCl 0,5 M extractable concentration in soil two native species, Tagetes minuta L. and Bidens pilosa L. accumulated high values of Pb concentration in leaves (380.5 μg g-1 DW and 100.6 μg g-1 DW, respectively). Therefore, Tagetes minuta L. and Bidens pilosa L. have a considerable phytoremediation potential for lead polluted soils. At the same sampling site, Sorghum halepense (L.) Pers., a non-native species, only bioconcentrate lead in roots (1,406.8 μg g-1 DW) showing a phytostabilization potential. The results of this study should be further developed in order to confirm the potential use of these species in soil remediation programs.