FIGURE 1.

Concentrations of potentially toxic elements on leaf surfaces of four different plant species. Mean ± standard deviation (n = 5). Leaves samples collected from mine residues (MR) or non-contaminated control site (NC) of four plant species: Brickellia veronicifolia (Bv), Allionia choisyi (Ac), Flaveria trinervia (Ft), and Gnaphalium sp. (G sp.). According to the Mann–Whitney U test, (^∗) means significant and (ns) means non-significant difference (p < 0.05). A = Zn, B = Cu, C = Cd, D = Pb, E = As, F = Sb.