Mercury Content in Central and Southern Adriatic Sea Sediments in Relation to Seafloor Geochemistry and Sedimentology

Abstract

Mercury contents were determined in surface sediments from the Central and Southern Adriatic Sea to gain insight into the processes, factors, and variables affecting its distribution. Mercury concentration was measured by thermal decomposition amalgamation atomic absorption spectrometry in samples collected by box-corer from Ancona to Santa Maria di Leuca during the CNR-PERTRE cruise (16/9-4/10/2016). Sediments were also evaluated for chemical-physical parameters (pH, Eh), biogeochemical composition (total carbon, inorganic carbon, total organic carbon, organic matter) and grain size. The average mercury concentration in the Adriatic Sea sediment was 0.053 mg/Kg (d.w.), range 0.011–0.12 mg/Kg (d.w.). Mercury content was mainly affected by grain size and organic matter (OM) distribution, whereas anthropic factors exerted a limited influence. Concentrations followed the distribution of sediment types (clay > silt > sand) due to Adriatic Sea hydrodynamics and were well below the regulatory limits in all samples.

Sources and Metal Pollution of Sediments from a Coastal Area of the Central Western Adriatic Sea (Southern Marche Region, Italy)

“…The coarser fractions were dry-sieved over the range 2 mm down to 0.063 mm by a stack of sieves ISO 3310 in accordance with UKAS Traceability Test Sieve LAB22-1. Bioclast component (>2 mm fraction) was separated by sands (2 mm < sands > 0.063 mm), while the finer fractions were analyzed by X-ray sedigraph (Micrometrics 5000D) [45].…”

“…The statistical approach allowed the determination of compositional facies, that is, areas with common geochemical, mineralogical, and sedimentological properties. Previous studies have investigated the sedimentological and geochemical processes and recognized the main source area of sediments as well as anthropic heavy metal inputs in different offshore areas of the Adriatic Sea [4,13,[44][45][46] but little is known about the present study area that instead shows a specific role as consequence of the coastal morphology on the Adriatic Sea circulation [47].…”

Hg Levels in Marine Porifera of Montecristo and Giglio Islands (Tuscan Archipelago, Italy)

“…Atmospheric inputs of Hg have tripled during the last 150 years, being two-thirds of its actual concentration from anthropogenic sources [2,3]. Traces of mercury have been found in all the compartments of the ecosphere (atmosphere, hydrosphere, lithosphere and biosphere) [4][5][6]. In aquatic environments, it is transformed by chemical and biological reactions in organomercury compounds, as methylmercury (MeHg), the most toxic mercury species, which can be bioaccumulated more than other trace elements along the trophic chain [6].…”

“…Traces of mercury have been found in all the compartments of the ecosphere (atmosphere, hydrosphere, lithosphere and biosphere) [4][5][6]. In aquatic environments, it is transformed by chemical and biological reactions in organomercury compounds, as methylmercury (MeHg), the most toxic mercury species, which can be bioaccumulated more than other trace elements along the trophic chain [6]. Mercury can have many different effects on a wide range of organisms, both vertebrates, e.g., References [7][8][9], and invertebrates, e.g., References [10][11][12].…”

MH-ICP-MS Analysis of the Freshwater and Saltwater Environmental Resources of Upolu Island, Samoa

“…We enter into this study knowing that many elements, such as sodium, calcium, and selenium [ 19 , 20 ], are essential to life, but also that many heavy metals have no biological function and are harmful to life in even relatively moderate concentrations. Cadmium (Cd), lead (Pb), and mercury (Hg), for instance, are particularly egregious to life, and their distributions and concentrations are typically a result of industrial and human activity [ 21 , 22 , 23 ]. However, we also know that excessively high amounts of some essential elements in the body can be toxic.…”