Phytoavailability Assessment of Cadmium and Lead in Polluted Soils and Accumulation by Matricaria Chamomilla (Chamomile)

Surface soil and chamomile plant samples from 26 locations affected by several anthropogenic sources (coal-burning power plant, traffic emissions, lead/zinc and iron factories) were collected in Bulgaria. The mobilizable (extracted by 0.11 mol/L acetic acid) and the phytoavailable (extracted by 0.05 mol/L EDTA) metal fractions were evaluated using the extraction protocols proposed by the Standards, Measurements and Testing Programme of the European Union (BCR). Cadmium accumulation in chamomile roots, stems and flowers correlated well with acetic acid/EDTA soluble Cd as well as with the total soil cadmium (r > 0.84). However, lead uptake was found to correlate significantly only with its content in the EDTA-soluble soil fraction (r > 0.82). The results reveal that single soil extraction with EDTA is an appropriate procedure for quick estimation of potential availability of Cd and Pb to chamomile plants from polluted soils.