Metais pesados em solos e vegetação espontânea da área de uma mina de chumbo, mina de Barbadalhos, Centro de Portugal Heavy metals in soil and spontaneous flora in a lead mine area, Barbadalhos mine, Central Portugal

The present study aims to assess contamination and distribution of heavy metals in soil around an abandoned Pb mine (Barbadalhos mine, Central Portugal) and assess phytoremedial potential of flora growing on metal enriched soils. Samples from soils and 49 species of the native flora along the two line transects were evaluated. Line transect 1 is perpendicular to the mineralized veins. Line transect 2 is in nearby non mineralized zone. Significant accumulation of heavy metals in both soils and native wild flora suggests that metal contamination especially that of Pb (up to 9330 mg kg -1 in soil) is a matter of great concern in the Barbadalhos area. However, metal concentrations higher than toxic level in some species like Cistus salvifolius (for Pb), Digitalis purpurea (for Pb, Zn, and Fe), Lonicera periclymenum, Anarrhinum bellidifolium, Phytolacca americana (for Pb and Zn); Andryala integrifolia and Ruscus aculeatus (for Fe) as well as Mentha suaveolens and Rubus ulmifolius (for Ag) indicate that internal detoxification metal tolerance mechanisms might also exist; therefore, their utility for phytoremediation is possible.