Bioaccumulation of heavy metals in herbal plants from areas not exposed to heavy anthropopressure

The aim of the study was to evaluate the content of Zn, Cu, Mn, Pb, Hg and Fe in sandy everlasting, yarrow and stinging nettle in relation to the concentration of metals in the soil. Samples of soils and plants were collected from natural habitats (edges of forests in the Kujawy-Pomerania Province). The total metal content and their available forms for plants in the soil samples were determined. The stinging nettle inhabited the richest environmental areas in which anthropogenic accumulation of metals in the surface of soils was determined. The investigated soils were not contaminated with heavy metals and the content of their plant-available forms was not harmful for a proper plants growth. The content of metals extracted with the diethylenetriaminepentaacetic acid was considerably higher than the concentration referred to as the deficit level for plants. Among the analyzed herbal plants, sandy everlasting contained the largest amounts of copper, manganese, and only concentration of lead in dry weight was higher than 10 mg⋅kg⁻¹, indicating that the plants harvested from the study areas should not be used in herbal medicine. Bioconcentration factor (BCF) values point clearly to the mercury and zinc accumulation in the aboveground parts of herbal plants.