Plants accumulating heavy metals in the Danube River wetlands

Background: we present herein our results regarding the accumulation of four heavy metals (copper, cadmium,lead, and zinc) in four aquatic species plants (ceratophyllum demersum, potamogeton pectinatus, potamogetonlucens, potamogeton perfoliatus) collected from the danube river, south-western part of romania and their possibleuse as indicators of aquatic ecosystems pollution with heavy metals.methods: elements concentration from the vegetal material was determined through inductively coupled plasma –mass spectrometry.results: the species were chosen based on their previous use as bioindicators in aquatic ecosystems and due tothe fact they are one of the most frequent aquatic plant species of the danube river ecosystems within the irongates natural park. highest amounts are recorded for ceratophyllum demersum (3.52 ?g/g for cd; 22.71 ?g/g for cu;20.06 ?g/g for pb; 104.23 ?g/g for zn). among the potamogeton species, the highest amounts of heavy metals arerecorded in potamogeton perfoliatus (1.88 ?g/g for cd; 13.14 ?g/g for cu; 13.32 ?g/g for pb; 57.96 ?g/g for zn). thesequence for the bioconcentration factors (bcfs) calculated in order to describe the accumulation of the fourmetals is cd > > zn > pb > cu. increase of the zinc concentration determines an increase of the cadmiumconcentration (spearman rho=0.40, p=0.02).conclusions: despite the low ambiental levels of heavy metals, the four aquatic plants have the ability toaccumulate significant amounts, which make them useful as biological indicators. bcf value for ceratophyllumdemersum indicated this species as a cadmium hyperaccumulator.