Occurrence of Rare Earth Elements (REEs) and trace elements in in feathers of fledglings of Ichthyaetus melanocephalus (Mediterranean gull) and Chroicocephalus ridibundus (Black-headed gull) from the Venice Lagoon (Italy)

Abstract

Rare earth Elements (REEs) are emerging global pollutants due to their distinctive physical and chemical features that render them vital in a multitude of manufacturing apps. However, few researchers have been able to draw on any systematic study into REE’s presence and build up in the environment. So far, no previous study has investigated REE’s in the feathers of gulls using a non-invasive biomonitoring tool. The concentrations of 16 REEs and trace elements (Hg,Pb,Cd, Rb and Se) were analysed in the feathers of the Mediterranean gull (MG) (Ichthyaetus melanocephalus) and Black-headed gull (BHG) (Chroicocephalus ridibundus). The concentrations were ascertained by an Inductively Coupled Plasma-Mass Spectrometer subsequent to a microwave digestion of feathers. MG accumulated higher REEs and trace elements than BHG. All the 16 REEs were detected in each feather sample with a strong correlation to each element; only in the case of Ce, there were data below the Limit of Quantification (LoQ). Light rare earth elements (LREE) were found to be higher in concentration as compared to heavy rare earth elements (HREE). In the case of the trace elements, extreme concentrations of Cd and Rb were found in some bird species indicating a greater exposure. Most of the other trace elements (Hg, Pb and Se) were found below the LoQ.