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Emili A.,University of Trieste | Carrasco L.,CSIC - Institute of Environmental Assessment And Water Research | Carrasco L.,International Atomic Energy Agency | Acquavita A.,Environmental Protection Agency of Friuli Venezia Giulia | Covelli S.,University of Trieste
Environmental Science and Pollution Research | Year: 2014

Mercury (Hg) mobility at the sediment-water interface was investigated during a laboratory incubation experiment conducted with highly contaminated sediments (13 μg g-1) of the Gulf of Trieste. Undisturbed sediment was collected in front of the Isonzo River mouth, which inflows Hg-rich suspended material originating from the Idrija (NW Slovenia) mining district. Since hypoxic and anoxic conditions at the bottom are frequently observed and can influence the Hg biogeochemical behavior, a redox oscillation was simulated in the laboratory, at in situ temperature, using a dark flux chamber. Temporal variations of several parameters were monitored simultaneously: dissolved Hg (DHg) and methylmercury (MeHg), O2, NH4 +, NO3 - + NO2 -, PO4 3-, H2S, dissolved Mn2+, dissolved inorganic and organic carbon (DIC and DOC). Under anoxic conditions, both Hg (665 ng m2 day-1) and MeHg (550 ng m2 day-1) fluxed from sediments into the water column, whereas re-oxygenation caused concentrations of MeHg and Hg to rapidly drop, probably due to re-adsorption onto Fe/Mn-oxyhydroxides and enhanced demethylation processes. Hence, during anoxic events, sediments of the Gulf of Trieste may be considered as an important source of DHg species for the water column. On the contrary, re-oxygenation of the bottom compartment mitigates Hg and MeHg release from the sediment, thus acting as a natural "defence" from possible interaction between the metal and the aquatic organisms. © 2013 Springer-Verlag Berlin Heidelberg.

Emili A.,University of Trieste | Koron N.,Slovenian National Institute of Biology | Covelli S.,University of Trieste | Faganeli J.,Slovenian National Institute of Biology | And 3 more authors.
Applied Geochemistry | Year: 2011

Coastal areas in the northernmost part of the Adriatic Sea (Gulf of Trieste and the adjacent Grado Lagoon) are characterized by high levels of Hg, both in sediments and in the water column, mainly originating from the suspended material inflowing through the Isonzo/Soča River system, draining the Idrija (NW Slovenia) mining district, into the Gulf of Trieste. Hypoxic and anoxic conditions at the sediment-water interface (SWI) are frequently observed in the Gulf of Trieste and in the lagoon, due to strong late summer water stratification and high organic matter input. Mercury mobility at the SWI was investigated at three sampling points located in the Gulf of Trieste (AA1, CZ) and in the Grado Lagoon (BAR). Experiments were conducted under laboratory conditions at in situ temperature, using a dark flux chamber simulating an oxic-anoxic transition. Temporal variations of dissolved Hg and methylmercury (MeHg) as well as O2, NH4+, NO3-+NO2-, PO43-, H2S, dissolved Fe and Mn, dissolved inorganic C (DIC) and dissolved organic C (DOC) were monitored simultaneously. Benthic Hg fluxes were higher under anoxic conditions than in the oxic phase of the experiment. Methyl Hg release was less noticeable (low or absent) in the oxic phase, probably due to similar methylation and demethylation rates, but high in the anoxic phase of the experiment. The MeHg flux was linked to SO4 reduction and dissolution of Fe (and Mn) oxyhydroxides, and formation of sulphides. Re-oxygenation was studied at sampling point CZ, where concentrations of MeHg and Hg dropped rapidly probably due to re-adsorption onto Fe (Mn) oxyhydroxides and enhanced demethylation. Sediments, especially during anoxic events, should be, hence, considered as a primary source of MeHg for the water column in the northern Adriatic coastal areas. © 2010 Elsevier Ltd.

Tassan-Mazzocco F.,Environmental Protection Agency of Friuli Venezia Giulia | Felluga A.,Environmental Protection Agency of Friuli Venezia Giulia | Verardo P.,Environmental Protection Agency of Friuli Venezia Giulia
Aerobiologia | Year: 2015

Wind-carried pollen is universal outdoor and indoor components and is recognized as sources of respiratory allergies. Pollen information is important for determining clinical strategies in allergic patients, and several studies aim to forecast the presence of pollen in the atmosphere in order to reduce the risk of exposure for allergic patients. Forecasting models described in the literature are based on meteorological parameters requiring long historical series of coupled meteorological and pollen monitoring data as well as needing local calibration to produce reliable results. For this study, three different forecasting methods have been developed: two of them have shown to be suitable for foreseeing onset, abundance and duration of pollen presence in the atmosphere for the Gramineae and the Urticaceae families of allergenic plants being monitored in the Friuli Venezia Giulia region (north-eastern Italy). © 2015, Springer Science+Business Media Dordrecht.

Pezzetta E.,Environmental Protection Agency of Friuli Venezia Giulia | Lutman A.,Environmental Protection Agency of Friuli Venezia Giulia | Martinuzzi I.,Environmental Protection Agency of Friuli Venezia Giulia | Viola C.,Environmental Protection Agency of Friuli Venezia Giulia | And 2 more authors.
Environmental Earth Sciences | Year: 2011

High amounts of iron, up to 14 mg/L, were found in groundwater samples from Marano Lagoon in the Friuli Venezia Giulia Plain (northeast Italy). In order to characterize groundwater hydrochemistry in the area, an investigation has been conducted on 35 wells that were monitored since 2006. Leaching tests were performed (under anaerobic conditions with deionized and saline waters) on two core samples in the area to study the iron release from soils to groundwater. Collected data indicated the main role of salinity in metal leaching and highlighted spatial correspondence between high levels of chloride and iron. To understand the mechanism of groundwater salinization, sulphate/chloride ratio has been investigated and a statistical relation between salinity, pH and iron was found. These data do not show any relation between past activities and high iron groundwater contents. High iron concentrations are diffuse in the whole area and therefore comparable to background values. Consequently, the study states that no remediation plan should have been made for iron concentrations in this area. © 2010 Springer-Verlag.

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