Transference of potentially toxic elements from soils to plants in a derelict Pb-Zn mining area (San Quintín mine, South-Central Spain)

Background and aims: Abandoned mining areas represent critical environmental pollution hotspots due to the persistence of waste materials enriched in potentially toxic elements (PTEs). This study evaluates the transfer of PTEs from contaminated soils to six plant species in the vicinity of the San Quintín Pb-Zn mine (Ciudad Real, Spain), a site impacted by over a century of mining activity. Methods: The studied species include the tree Quercus ilex , the shrubs Retama sphaerocarpa and Scrophularia canina , and the annual herbaceous species Spergularia rubra , Rumex bucephalophorus , and Hirschfeldia incana . Soil and plant tissue samples were analysed using X-ray fluorescence and atomic absorption spectrometry to determine concentrations of Zn, Pb, Hg, Cu, and other PTEs. Results: Results revealed a high heterogeneity in the bioaccumulation of elements such as Zn, Pb, Hg, and Cu among the studied species, with Spergularia rubra and Rumex bucephalophorus emerging as effective bioindicators of soil contamination. Specific correlations between soil and plant concentrations were identified, and atmospheric uptake was found to significantly influence Hg accumulation in plant tissues. Conclusions: This work enhances our understanding of plant uptake mechanisms in contaminated environments and provides a foundation for ecological restoration and environmental monitoring strategies in decommissioned mining areas, emphasizing the role of both edaphic properties and species-specific physiological adaptations.