Paola Rivaro

Temporal distribution of trace metals in Antarctic coastal waters

Abstract In the framework of the Italian Research Programme in Antarctica, a nearshore station positioned inside the Gerlache Inlet (Terra Nova Bay, Western Ross Sea) was regularly sampled during the Austral Spring 1997/1998, from November to February. In order to evaluate the physical, chemical and biological variations along the water column, measurements of a large number of parameters were performed at a suitable frequency: temperature, salinity, fluorescence, suspended particulate matter, concentration of dissolved and particulate Fe, Cu and Mn, concentration of nutrients and phytoplankton pigments. Samples of pack ice and marine microlayer were also collected and analysed. Elaboration of data with regards to temporal and vertical components provided a good description of temporal distribution of trace metals in the coastal waters of Terra Nova Bay, in relation to the physical and biological processes. Concerning the surface layer, it was found that concentrations are mainly affected by the dynamic of the pack ice melting and phytoplankton activity. The first process influences both the input of metals from meltwaters and the covering of the seawater surface, allowing atmospheric dust input only when all ice has been melted or removed. Direct release from ice of particulate Fe and Cu were clearly shown by surface concentration peaks and by the high concentrations of suspended particulate matter and particulate metals detected in the ice core section interfaced with the seawater. Moreover, a quite complex dynamic dissolved/particulate partitioning was found, which can account for the temporal uncoupling between the maximum values of particulate and dissolved metals. In absence of pack ice, there is evidence of a further input of Fe and Mn due to atmospheric dust brought into the water column through the marine microlayer. This picture is complicated by phytoplankton activity, which removes micronutrients like Fe and Cu from water, incorporating them into organic particulate matter. The dynamic of metal uptake follows that of primary production which, in the studied area, shows a specific trend characterised by two distinct blooms: the first in the second half of December and the second in late summer. In intermediate and deep waters, the vertical distribution of Fe and Mn was characterised by a substantial constant profile until January; then, an increase of particulate metal concentration with depth was observed along with a corresponding decrease of the dissolved concentrations. This trend is typical of these scavenging-type elements which are removed by particulate matter during the sinking process, in the absence of well-defined water column stratification.

An optimum multiparameter mixing analysis of the shelf waters in the Ross Sea

The analysis of the mixing processes involving water masses on the Ross Sea continental shelf is one of the goals of the CLIMA project (Climatic Long-term Interactions for the Mass balance in Antarctica). This paper uses extended Optimum MultiParameter analysis (OMP), which is applied to four datasets collected during the cruises of 1994/95, 1995/96, 1997/98 and 2000/01 in the Ross Sea (Antarctica). Data include both hydrological, (temperature, salinity, and pressure; T, S, and P, respectively) and chemical parameters (O2, Si(OH)4, PO4, and NO3+NO2). The OMP analysis is based on the assumption that the mixing is a linear process which affects all parameters equally so that each sample shows physical/chemical properties that are the result of the mixing of some properly selected Source Water Types (SWTs). OMP thus evaluates the best set of contributions by all SWTs to each sample, and allows the spatial distribution and structure of the water masses in a basin to be evaluated. Ocean circulation may subsequently be inferred by means of a deeper analysis of the spreading of the water mass. In this study, the “real” Redfield ratios observed in the Ross Sea were used to correct the equations referring to the chemical parameters in accordance with the extended version of OMP. The solutions include some physically realistic constraints. The results allow a detailed description of the water mass distribution, validated through comparison with some “canonical” thermohaline characteristics of the Ross Sea hydrology. In particular our results verify the spreading of the HSSW over the entire continental shelf and emphasize the key role it plays in the ventilation of the deep waters outside the Ross Sea. In addition a description is given of the intrusion of relatively warm waters coming from the open ocean and flowing at some specific locations at the continental shelf break.

Trace metals in Adriatic coastal sediments: Distribution and speciation pattern

Abstract In the framework of the Italian National Project for the safeguard of Adriatic Sea (PRISMA 2), distribution of trace metals in surface coastal sediments of two areas influenced by river Po freshwaters (Ancona and Chioggia) was studied. A sequential extraction technique was used to determine the chemical association of heavy metals (Pb, Cu, Cd, Fe, Hg, Sn, Co and Zn) with major sedimentary phases (exchangeable ions and carbonates, Mn and Fe oxides, sulphides and organic matter and residual minerals). The relationship between the metals content and the grain‐size composition of the sediments was studied: all the elements resulted associated principally with the fine fraction. The considered sediments are not particularly polluted and speciation revealed that the major part of the heavy metals present are not easily mobilizable and bioavailable.

Determination of organotin compounds in marine mussel samples by using high-performance liquid chromatography–hydride generation inductively coupled plasma atomic emission spectrometry

HPLC–hydride generation-ICP-AES for the determination of organotin compounds is described. A detection limit of 7 ng for tin was obtained and the organotin species were completely separated within 7 min. The system has been used for the determination of organometallic compounds in marine mussel samples. Preliminary results obtained in laboratory experiments are presented.

Emerging pollutants in aquatic environments: monitoring of UV filters in urban wastewater treatment plants

Six UV filters – benzophenone-3 (BP-3), octocrylene (OC), ethylhexyl dimethyl p-aminobenzoate (OD-PABA), ethylhexyl methoxycinnamate (EHMC), ethylhexyl salicylate (EHS) and homosalate (HMS) – with endocrine disrupting potential were monitored in different wastewater treatment plants (WWTPs) located in Genoa, Italy. The influent and effluent samples were collected once a month from April to September 2011. The analytes were determined by stir bar sorptive extraction followed by liquid desorption (SBSE-LD) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Quantitative analysis was performed in triggered MRM (tMRM), which allowed improvement of specificity without compromising sensitivity. In the inlet samples four analytes were detected; in particular BP-3, OC, EHMC, and OD-PABA were in the range of 4–163, 12–390, 23–68, and 2–4 ng L−1, respectively. Measured concentrations indicated variability of UV filter inputs to WWTPs, with higher loads during the warmer months. A highly positive correlation was found between air temperature and the measured concentration of OC and BP-3. Only BP-3 and OC were detected in some effluent samples, with considerably lower concentrations. The removal efficiencies of the plants were in the range of 64 to >99% and 94 to >99% for BP-3 and OC, respectively.

Heavy Metals Distribution in Suspended Particulate Matter and Sediment Collected from Vlora Bay (Albania): A Methodological Approach for Metal Pollution Evaluation

Abstract Heavy metals (Al, Fe, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn) content was evaluated in suspended particulate matter and sediment samples collected from Vlora Bay (Albania) in the framework of Centro Internazionale di Scienze del Mare (CISM) Project activities. The trend of the metals (in general, overlapping that showed by the suspended particulate matter distribution), together with the linear correlation values found between metals, suggested the pivotal role of the Vjosa River and of the inner circulation scheme of Vlora Bay on their distribution. The geoaccumulation index, Igeo, was calculated as a criterion to assess if a metal concentration found in the sediment represents contamination level or can be considered as background level. The results show that metals concentrations in sediments can be considered near the background levels found in the Mediterranean Sea, even if some accumulation was found in several stations. The data were compared to Sediment Quality Guidelines considering the ERL (effects range low) and ERM (effects range medium) values, to evaluate the potential effects of sediment-associated metals on aquatic organisms. The Ni value for all samples was above the ERM value, while Cr and As values were in between ERL and ERM. Metal speciation was also evaluated in some sediment samples. Generally, the metals found were associated with the refractory phases, which constitute up to 80% of the total concentration. Moreover, the sampling strategies and the adopted analytical methods were compared to those recommended by national and international regulations.

Biogeochemistry, grain size and mineralogy of the central and southern Adriatic Sea sediments: a review

This review aims to present the current status of studies on geochemical (major minor and trace elements), biochemical (total organic carbon, total nitrogen, isotopic carbon composition, Bacteria, Archaea, phytopigments, proteins, carbohydrates, lipids, humic and fulvic acids), mineralogical (light and heavy minerals, clay minerals) and pollutant (trace metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, pesticides, organic stannic compounds) parameters, grain-size composition and sediment–water interactions (early diagenesis and benthic fluxes) for the bottom sediments of the central and southern Adriatic Sea. The review highlighted gaps in or completeness of the parameters needed for research, of areas in which the parameters were investigated, as well as the interdisciplinary nature of the studies. In general, biogeochemical, mineralogical, grain-size and pollutant studies in the central and southern Adriatic Sea are restricted to limited areas, consider only single parameters without an interdisciplinary approach and, except for some more recent projects, are predominatly out of date. On the whole, there is a lack of an organised study concerning the various parameters for the entire central and southern Adriatic Sea and their evolution over time.

Seasonal variations in levels of butyltin compounds in mussel tissues sampled in an oil port

Abstract The aim of the present study has been to follow the seasonal variations of organotin compounds in the mussel ( Mytilus galloprovincialis Lam.), under natural conditions in the Genoa oil port. To this purpose, mussels were sampled at one month intervals between 1994 and 1995 and the organotins were extracted from the whole body, the gills and the digestive glands. The determinations were carried out by using a HPLC-hydride generation-ICP-AES system. The results were analyzed by a multivariate statistical method, such as the principal component analysis, an useful support in the data elaboration. Dibutyltin showed the highest concentrations among the considered compounds. Both tributyltin and dibutyltin showed seasonal variations in their concentrations, while monobutyltin did not in all the tissues sampled, during the considered period.

Heavy metals distribution in the Eolian Basin (South Tyrrhenian Sea)

The concentration and distribution of heavy metals in the Eolian Basin are discussed. The data concern sediment and particulate matter samples and are correlated with the environmental parameters. In the sediments the measurements indicate that the elements (Zn, Pb, Co, Ni, Cr, Cu, Cd, Mn, Fe) display characteristics which seem not to be influenced by the various water masses circulating in the archipelago. In the particulate matter, the distribution of heavy metals (Pb, Cd, Cu, Mn, Fe) shows interesting correlations with the environmental characteristics of the zone.

Heavy metals in albanian coastal sediments

Heavy metals (Fe, Mn, Cr, Ni, Cu, Cd, Pb, Sn) concentration has been determined on 39 coastal sediment samples collected in Albania. The relationship between the heavy metals content and the grain size has been considered. All metals, except Cu and Cd, resulted accumulated in the finest fraction, which constituted up to 95% of most of the considered sediments. A good correlation has been found for Ni, Cr, Fe, Zn, Cu in the entire area, indicating a common origin for these metals in the analyzed sediments. Concentration values fall in the range reported for Dinaric chain derived sediments, revealing, generally, a natural origin of the metal contents. Though in some selected areas such as the Drin and the Skumbin Bay, an antropogenic input of Cr, Fe, Ni and Cu can be observed, as the result of discharging of mines and smelter activities.