Mobility of heavy metals from polluted sediments of a semi-enclosed basin: in situ benthic chamber experiments in Taranto’s Mar Piccolo (Ionian Sea,Southern Italy)

In situ benthic flux experiments were conducted at two stations in the Mar Piccolo of Taranto (Italy), one of the most industrialised and contaminated coastal areas of the Mediterranean. Sediments of the two stations are notably different in their trace metal content, with a station closer to a Navy harbour showing higher mean concentrations of almost all investigated metals (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, V and Zn). Conversely, both stations are characterised by significant Hg contamination, compared to the local baseline. Results of a sequential extraction scheme on surface sediments suggest a relatively scarce mobility of the examined metals (Zn > Ni > Cr > As > Cu > Pb). A Hg-specific extraction procedure showed that most of the element (93.1 %) occurs in a fraction comprising Hg bound to Fe/Mn oxi-hydroxides. Reduction of these oxides may affect Hg remobilisation and redistribution. Porewater profiles of dissolved trace metals were quite similar in the two sites, although significant differences could be observed for Al, Cu, Fe and Hg. The highest diffusive fluxes were observed for As, Fe and Mn. Mobility rates of several trace elements (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, V and Zn) were directly measured at the sediment–water interface. Results from benthic in situ incubation experiments showed increasing dissolved metal concentrations with time, resulting in higher fluxes for Cu, Fe, Hg, V and Zn in the most contaminated site. Conversely, fluxes of Mn, Ni and Pb were comparable between the two stations. The estimated flux of Hg (97 μg m^?2 day^?1) was the highest observed among similar experiments conducted in other highly contaminated Mediterranean coastal environments. Benthic fluxes could be partially explained by considering rates of organic matter remineralisation, dissolution of Fe/Mn oxy-hydroxides and metal speciation in sediments. Seasonal and spatial variation of biogeochemical parameters can influence metal remobilisation in the Mar Piccolo area. In particular, metals could be promptly remobilised as a consequence of oxygen depletion, posing a serious concern for the widespread fishing and mussel farming activities in the area.     

Detection of Viruses in Coastal Seawater Using <Emphasis Type="Italic">Mytilus Galloprovincialis</Emphasis> as an Accumulation Matrix

The purpose of this study was to demonstrate that shellfish can be used to detect enteric viruses in marine waters where they are present at very low concentrations. Aqua-cultured mussels were placed in the sea just off the mouth of a drainage channel affected by human and animal faecal contamination. Samples were taken from the channel, the sea and the mussels at intervals over two 4-week periods. The samples were tested to verify the presence of both rotaviruses and E. coli. Rotaviruses were detected by Real Time-PCR, typed by multiplex PCR and subsequently sequenced. E. coli was enumerated in water matrices by a filtering method and in mussels by the MPN method. The presence of E. coli in the examined matrices demonstrates contamination of faecal origin throughout the studied environments. Rotaviruses were recorded in channel waters, but not in sea water. In both experiments, rotaviruses were detected in mussels 21 and 28 days after being placed in the sea water off the channel mouth. The use of mussels thus enabled the detection of rotaviruses in waters where the high dilution rendered direct investigation impossible. This study indicates that mussels can be used in marine virological surveillance programs.     

Identification of Quarries Rehabilitation Scenarios: A Case Study Within the Metropolitan Area of Bari (Italy)

This paper addresses quarries rehabilitation issue within a Metropolitan Area. Areas where mining activity is carried out have been subjected to physical and environmental degradation linked both to pursue the building materials extraction and to the city expansion continuously asking for new areas to be developed with residential and service functions. These changes also occurred where environmental and landscape values are present. It has been therefore pointed out the issue of such areas redevelopment that, to be functionally reintegrated, must be consistently linked to the activities and the territorial local contexts characteristics. In this paper the quarries reuse issue is carried out through parameters identification able to define the quarries relationship with the neighboring towns and with their surroundings besides to identify their physical, environmental and landscaping characteristics. Quarry reuse alternatives have been identified among those consistent with the rehabilitation goals, as defined by the planning sector and internationally approved, while their selection is derived from the application of a two-step methodology: a multi-criteria analysis related to punctual parameters at a "site-specific" level, followed by a further territorial indicators checking over the wide area. This application has led to socially accepted results identifying the examined quarries for reuses ranging from agricultural-forestry and urban to functional or naturalistic. The proposed method has also proved to be suitable to address the abandoned quarries reuse problem with a systemic and consultative approach, as it is able to correlate the many variables present in the social and spatial complexity of the Metropolitan Areas.     

Cleaning painted surfaces: evaluation of leaching phenomenon induced by solvents applied for the removal of gel residues

Cleaning is one of the most important, delicate, and at the same time controversial processes in the conservation treatment of paintings. Although a strict definition of cleaning would be the removal of dirt, grime, or other accretions (surface cleaning), in the conservation field, cleaning is used in the broader meaning to include thinning/removing altered or “unwanted layers” of materials without damaging or altering the physicochemical properties of the surfaces to be preserved. The cleaning of unvarnished paintings is one of the most critical issues that are currently discussed. Several studies exist regarding different cleaning tools, such as gels, soaps, enzymes, ionic liquids, and foams, as well as various dry methods and lasers, but only a few have been performed on the risk associated with the use of water and organic solvents for the cleaning treatments in relation to the original paint binder. The aim of the study is to verify analytically the behavior of water gelling agents during cleaning treatments and the interaction of the following elements: water or organic solvents applied for the removal of gel residues with the original lipid paint binder. For this purpose, the study was conducted on a fragment of canvas painting (sixteenth to seventeenth century) of Soprintendenza per i Beni Storici, Artistici ed Etnoantropologici del Friuli Venezia Giulia (Superintendence for the Historical, Artistic and Ethno-anthropological Heritage of Friuli Venezia Giulia), Udine by means of Fourier transform infrared spectroscopy, gas chromatography/mass spectrometry, and scanning electron microscopy.     

The quantitative real-time PCR applications in the monitoring of marine harmful algal bloom (HAB) species

In the last decade, various molecular methods (e.g., fluorescent hybridization assay, sandwich hybridization assay, automatized biosensor detection, real-time PCR assay) have been developed and implemented for accurate and specific identification and estimation of marine toxic microalgal species. This review focuses on the recent quantitative real-time PCR (qrt-PCR) technology developed for the control and monitoring of the most important taxonomic phytoplankton groups producing biotoxins with relevant negative impact on human health, the marine environment, and related economic activities. The high specificity and sensitivity of the qrt-PCR methods determined by the adequate choice of the genomic target gene, nucleic acid purification protocol, quantification through the standard curve, and type of chemical detection method make them highly efficient and therefore applicable to harmful algal bloom phenomena. Recent development of qrt-PCR-based assays using the target gene of toxins, such as saxitoxin compounds, has allowed more precise quantification of toxigenic species (i.e., Alexandrium catenella) abundance. These studies focus only on toxin-producing species in the marine environment. Therefore, qrt-PCR technology seems to offer the advantages of understanding the ecology of harmful algal bloom species and facilitating the management of their outbreaks.     

Significance of urinary arsenic speciation in assessment of seafood ingestion as the main source of organic and inorganic arsenic in a population resident near a coastal area

In order to characterize the different sources of exposure to arsenic (As), urinary excretion of total As, the sum of inorganic As+MMA+DMA determined by the hydride generation-atomic absorption spectrophotometry technique, and the species As(3), As(5), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and arsenobetaine were determined in 49 workers at a steel foundry, with presumed occupational exposure to As, and 50 subjects from the general population, all males. No evidence of occupational exposure to As resulted from environmental monitoring performed in the foundry, although the analysis of minerals used as raw materials showed the presence of As, particularly in fossils and fine ores. The urinary concentrations of As(3), MMA, DMA, the sum of inorganic As+MMA+DMA and total As were not different in the two groups, while arsenobetaine appeared significantly higher in the controls than in the workers. The different species of urinary As were all significantly correlated. Urinary excretion of As(3) was associated with the consumption of mineral water and with residence in an industrial zone, while MMA, DMA, arsenobetaine, the sum of inorganic As+MMA+DMA and total As urinary excretion were associated with the consumption of crustaceans and/or shellfish 3 days or less before urine collection. Multiple regression analysis confirmed these results. In conclusion, in populations with a high consumption of seafood, living in areas characterized by coastal/marine As pollution, only speciation of As can identify a prevalent role of environmental sources, like the consumption of seafood contaminated by As, in determining urinary As excretion, and exclude an occupational origin of the exposure.     

Protection of ash (Fraxinus excelsior) trees from ozone injury by ethylenediurea (EDU): roles of biochemical changes and decreased stomatal conductance in enhancement of growth

Treatments with ethylenediurea (EDU) protect plants from ozone foliar injury, but the processes underlying this protection are poorly understood. Adult ash trees (Fraxinus excelsior), with or without foliar ozone symptoms in previous years, were treated with EDU at 450ppm by gravitational trunk infusion in May-September 2005 (32.5ppmh AOT40). At 30-day intervals, shoot growth, gas exchange, chlorophyll a fluorescence, and water potential were determined. In September, several biochemical parameters were measured. The protective influence of EDU was supported by enhancement in the number of leaflets. EDU did not contribute its nitrogen to leaf tissue as a fertiliser, as determined from lack of difference in foliar N between treatments. Both biochemical (increase in ascorbate-peroxidase and ascorbic acid, and decrease in apoplastic hydrogen peroxide) and biophysical (decrease in stomatal conductance) processes regulated EDU action. As total ascorbic acid increased only in the asymptomatic trees, its role in alleviating O(3) effects on leaf growth and visible injury is controversial.