Lithogenic and anthropogenic contributions of trace metal(oid)s in coastal sediments near the Port of Trieste (northern Adriatic Sea): A geochemical normalisation approach based on regional background values

Metal(oid) concentrations in coastal sediments are often due to the contribution of anthropogenic inputs to the local geochemistry. This study aims to assess the source (lithogenic or anthropogenic) of metal(oid)s in the surface sediments of the eastern sector of the Gulf of Trieste, which is the area most impacted by urban and industrial activities. A comparison with the environmental quality standards (EQSs) defined by the legislation showed that threshold levels were exceeded for Cr, Ni, Hg, Pb, As and Cd. Since the EQS values do not take into account the natural site-specific geochemical features of sediments, a normalisation procedure was applied to quantify the real anomaly. Aluminium (Al) was identified as an ideal proxy element due to its excellent correlation with the muddy fraction and regional functions for metal(oid)s were determined using sediments from a core collected in the central sector of the Gulf as a baseline in order to calculate enrichment factors (EFs). Negligib...