Dandelion (Taraxacum officinale) and Agrimony (Agrimonia eupatoria) as Indicators of Geogenic Contamination of Flysch Soils in Eastern Slovakia.

Contents of potentially toxic elements Fe, Mn, Cr, Ni, Co, V, Cu, and Mo were determined in common dandelion (Taraxacum officinale) and agrimony (Agrimonia eupatoria) to show their usefulness as bioindicators of geogenic soil pollution. Both plants were collected on geochemically anomalous soils developed on flysch sedimentary rocks (Paleogene) of Eastern Slovakia, which also are composed of weathered detritus of some ultramafic rocks. Generally, contents of the investigated association of potentially toxic elements are highly increased in these "serpentine"-like soils. Elevated concentrations were detected in both shoots and roots of the plants. The highest values, which exceed world average values for plants, were observed for Ni content. They ranged from 1.7 to 16.3 mg kg(-1) in dandelion and from 1.6 to 22.6 mg kg(-1) in agrimony. Essential elements, such as Mo, Cu, and Mn, were the most concentrated in plants, whereas Co, V, and Cr were the least concentrated. Although the bioindication value of the common dandelion for anthropogenic soil pollution is well known, it is not mentioned for agrimony in literature, and no data exist to indicate the geogenic pollution for both plants. Dandelion and agrimony are widely used as herbal drugs; therefore, our intention also was to point out another fact, namely, possible high uptake of potentially toxic elements by herbal plants growing on similar soils.