Natural background values for heavy metals in the sediments of a contaminated Northern Adriatic lagoon environment: a geochemical perspective

Abstract

Abstract. Major and trace elements were determined in 14 sediment cores collected from the Marano and Grado Lagoon (northern Adriatic sea). The lagoon is contaminated by several harmful priority substances, heavy metals included, and it has also been declared a "polluted site of national interest" (SIN) mainly due to high Hg concentrations in sediments. Based on a normalization procedure involving predicted linear relationships for "metal vs Al" obtained from the core subsamples, background values for each metal were evaluated on a regional scale and according to the grain-size variability. Compared to Environmental Quality Standards reported in the Italian laws and regulations, the estimated background ranges show that bottom sediments are naturally "enriched" in some metals, such as Cr, Ni and Cd especially in sediments with a high percentage of the fine component. A correct evaluation on sediment quality status should be made on the basis of regional background values for each metal, taking into account local geochemical characteristics, i.e. mineralogical composition and grain-size variability of sediments.

Anthropogenically induced environmental changes in the northeastern Adriatic Sea in the last 400 years (Panzano Bay, Gulf of Trieste)

“…Similar vertical trends have been recorded in the Marano Lagoon, located 20 km west of Panzano Bay (Covelli et al, 2013). The Ni concentrations are almost the same in the two areas, while Pb values are slightly higher in Panzano Bay (starting from 1980 until today).…”

Anthropogenically induced environmental changes in the northeastern Adriatic Sea in the last 500 years (Panzano Bay, Gulf of Trieste)

“…The northern Adriatic Sea is densely urbanized and polluted (Lotze et al, 2006;Cozzi and Giani, 2011), and the areas around the Po River, the Venice Lagoon and in the Gulf of Trieste bear the highest pressure (Solis-Weiss et al, 2007;Raccanelli et al, 2009). Panzano Bay, located in the northeastern part of the Gulf of Trieste, is a shallow and sheltered embayment prone to the accumulation of pollutants, with recent anthropogenic pressure coming from agricultural, maricultural, mining and industrial activities (Horvat et al, 1999).…”

Trace metals and polycyclic aromatic hydrocarbons in the Eastern Mediterranean sediments: Concentration ranges as a tool for quality control of large data collections

“…Good Environmental Status (GES) with regard to chemical pollution can be assessed in relation to reference conditions, such as background concentrations (BC) of a compound in the pristine environment (European Commission, 2017). BCs of naturally occurring elements and compounds may show significant geographical variability in sediments, which pose an additional challenge for their assessments (Covelli et al, 2013;Ospar, 2006;Pérez-Fernández et al, 2019). The definition of BC in the Mediterranean is periodically revised, as new data become available (UNEP/MED, 2022).…”