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The mercury (Hg) pollution of sediments is the main carrier of Hg for the biota and, subsequently, for the local fish consumers in Augusta Bay area (SE Sicily, Italy), a coastal marine system affected by relevant sewage from an important chlor-alkali factory. This relationship was revealed by the determination of Mass Dependent (MDF) and Mass Independent Fractionation (MIF) of Hg isotopes in sediment, fish and human hair samples. Sediments showed MDF but no MIF, while fish showed MIF, possibly due to photochemical reduction in the water column and depending on the feeding habitat of the species. Benthic and demersal fish exhibited MDF similar to that of sediments in which anthropogenic Hg was deposited, while pelagic organisms evidenced higher MDF and MIF due to photoreduction. Human hair showed high values of δ 202 Hg (offset of +2.2‰ with respect to the consumed fish) and Δ 199 Hg, both associated to fish consumption. [ABSTRACT FROM AUTHOR]

Abstract: Concentrations of rare earth elements (REE), Y, Th and Sc were recently determined in marine sediments collected using a box corer along two onshore–offshore transects located in the Strait of Sicily (Mediterranean Sea). The REE+Y were enriched in offshore fine-grained sediments where clay minerals are abundant, whereas the REE+Y contents were lower in onshore coarse-grained sediments with high carbonate fractions. Considering this distribution trend, the onshore sediments in front of the southwestern Sicilian coast represent an anomaly with high REE+Y concentrations (mean value 163.4μgg−1) associated to high Th concentrations (mean value 7.9μgg−1). Plot of shale-normalized REE+Y data of these coastal sediments showed Middle REE enrichments relative to Light REE and Heavy REE, manifested by a convexity around Sm–Gd–Eu elements. These anomalies in the fractionation patterns of the coastal sediments were attributed to phosphogypsum-contaminated effluents from an industrial plant, located in the southern Sicilian coast. [ABSTRACT FROM AUTHOR]

Abstract: The analysis of 90 surficial sediments from three docks of the Naples Harbour (Levante, Granili, and Diaz) permits to compare the distribution modes of heavy metals with grain sizes, total organic carbon content (TOC) and distribution patterns of benthic foraminifera. Foraminiferal density and species richness decrease with the increasing toxic elements concentrations from the Levante to the Diaz dock. Median concentrations of Ni, Pb, Zn, and Hg (medians of 21.43mg/kg, 270.24mg/kg, 489.65mg/kg, and 1.18mg/kg, respectively) were reported for the Diaz dock where foraminifera are absent, thus suggesting a possible impact of toxic elements on the benthic ecosystem balance. Compared to the unpolluted marine sediments of the Granili dock, the Levante area shows higher heavy metals levels and a quasi-oligotypic benthic assemblage. This is dominated by the tolerant species Ammonia tepida that may be used as bio-indicator of pollution of anthropised marine sediments. [Copyright &y& Elsevier]