Bioavailability of Heavy Metals in the Soil from Different Locations of Medicinal Herbs

Medicinal herbs and their mixtures, which are widely used for prevention and treatment of some disease, can also present health risks due to the presence of toxic metals such as Pb and Cd. The application of different agrotechnical practices during plant growing season, as well as the process of circulation of substances in nature, may be the cause of plant contamination. The aim of this study was to determine the content of lead, cadmium and copper from soil which are bioavailable for absorption by plant, as well as the total content of these metals in some medicinal herbs that were cultivated in two different locations. The presence of these metals in the samples was detected using highly sensitive microanalytical technique potentiometric stripping analysis (PSA). The mean value of lead total content in the analyzed samples of medicinal herbs Chamimillae flos, Urticae folium, Menthae folium, Altheae radix and Basilici herba, which were grown at the sites near the industrial zone, was about 1.55 mu g/g, 1.82 mu g/g, 1.90 mu g/g, 1.99 mu g/g and 2.74 mu g/g, respectively. Contrary to this, the total content of this toxic metal in the analyzed plant samples grown on rural areas was detected only on some sites. Based on the results of this study, it can be concluded that medicinal herbs contained a certain amount of lead and that its content varied depending on the location at which the plant species were grown as well as on plant affinity to certain metal. Cadmium and copper were not detected in the tested plant material.