A methodological approach to evaluate arsenic speciation and bioaccumulation in different plant species from two highly polluted mining areas

► Terrestrial plants from abandoned mine sites accumulated extremely high arsenic contents in their tissues. ► A new method achieved quantitatively extraction of arsenic species from highly polluted plants without alteration of original speciation. ► Inorganic arsenic species, mainly As (V), were predominant, regardless the plant tissue or the plant species. ► Soil-to-plant transfer factors, based on total and available arsenic in soils, were evaluated. ► Arsenic uptake and accumulation by plants depended on both the site pollution and the plant species.