Determination of polychlorobiphenyls in Venice Lagoon sediments

Polychlorinated biphenyl (PCBs) congeners were measured in 14 sediment samples collected at five sites in the Venice Lagoon selected on the basis of a supposed diversity of inputs and of pollution levels. The PCBs were determined after a sonication assisted extraction by gas chromatography mass spectrometry (GCMS). The sum of the congener concentrations determined in the samples range from 4.05 to 239.15 ng/g on a dry weight basis. The concentration values are very variable both comparing the sites and comparing different samples from the same site and can be connected to the sand percentage in the sediment samples. The correlation matrix obtained from data matrix using the congener concentrations as variables shows high values, mostly between 0.964 and 1, suggesting that the pattern of the PCB congeners and the ratios among the concentrations in Venice Lagoon sediments are more or less constant; the samples differ only in the concentration level.     

Airborne concentrations of SARS-CoV-2 in indoor community environments in Italy

Environmental Science and Pollution Research - COVID-19 pandemic raised a debate regarding the role of airborne transmission. Information regarding virus-laden aerosol concentrations is still...     

An evaluation of the PM2.5 trace elemental composition in the Venice Lagoon area and an analysis of the possible sources

Global emissions reported by many authors have shown as natural and anthropic sources can contribute to the principal aerosol classes, but values change according the local scenario. The Venice Lagoon is exposed to different anthropic source emissions like vehicular traffic, industrial thermoelectric power plant, petrochemical plant, incinerator plant, domestic heating, ship traffic, glass factories and airport. Samplings of PM_2.5 were daily performed between March and November 2007 in Sacca San Biagio island (Venice), and values of PM_2.5 concentration and element concentration were obtained. Monthly average concentrations (μg m^?3) during this period show higher values during the spring and the autumn. A good relationship between data obtained and concentration values from environmental local agencies is evidenced, both for PM_2.5 from urban area (Venezia Mestre), and for PM₁₀ sampled in the same area, as well as the influence of some meteorological parameters on PM_2.5 concentration sampled. Trace elements samples were measured by an Inductively Coupled Plasma-Quadrupole Mass Spectrometry (ICP-QMS), and values (ng m^?3 and μg g^?1) for elements regulated by European directives (As, Cd, Ni, Pb), as well as, other elements (Na, Al, K, Ti, V, Mn, Fe, Co, Zn, Se, Ag) are also reported. Data analysis by mean of Principal Component Analysis (PCA) and Positive Matrix Factorization (PMF) pointed out four principal groups of elements like Mn–Fe–K, As–Se–Cd, V–Co, and Pb that could be assigned to specific sources of the Venetian wetland basin.     

Polychlorinated biphenyls in sediments of the Tam Giang-Cau Hai Lagoon, Central Vietnam

The Tam Giang-Cau Hai Lagoon, the largest in south east Asia, suffers from a great anthropogenic pressure and appears subject to a process of progressive environmental deterioration. To establish causes, history and trends of lagoon contamination, sediment samples representing three major parts of the systems were sampled and analysed for porosity, organic carbon, total nitrogen, delta(13)C, grain size, radiotracers and PCBs. PCB surficial concentrations range from 10.2 to 24.5 microg kg(-1), and maximum values are close to NOAA ERL guidelines. The downcore distribution of PCBs shows two well defined peaks in the core from Tam Giang (25.5 and 16.2 microg kg(-1)), whereas the sediment from Cau Hai is characterised by a maximum at the surface. Therefore, present trends indicate that contamination is still increasing or slightly decreasing. The prevailing congeners are 3-CB and 4-CB, hence recent PCBs appear to be mostly originated by Aroclor 1016- and 1242-like mixtures, with some samples influenced also by Aroclor 1248. Present sources seem to be similar everywhere and probably they are widespread all over the territory of the Thua Thien-Hue province.     

Contribution of harbour activities and ship traffic to PM2.5, particle number concentrations and PAHs in a port city of the Mediterranean Sea (Italy)

In this work, an assessment of the impact of ship traffic and related harbour activities (loading/unloading of ships and hotelling in harbour) on PM 2.5 and particle number concentrations (PNC) separating the contribution associated to ship traffic from that of harbour-related activities is reported. Further, an assessment of the impact and environmental risks associated to polycyclic aromatic hydrocarbon (PAH) concentrations was performed. Results refer to the city of Brindisi (88,500 inhabitants) in the south-eastern part of Italy and its harbour (with yearly 9.5 Mt of goods, over 520,000 passengers and over 175,000 vehicles). PM2.5 and PNC concentrations show a clear daily pattern correlated with daily ship traffic pattern in the harbour. High temporal resolution measurements and correlations with wind direction were used to estimate the average direct contribution to measured concentrations of this source. The average relative contribution of ship traffic was 7.4 % (±0.5 %) for PM2.5 and 26 % (±1 %) for PNC. When the contribution associated to harbour-related activities is added, the percentages become 9.3 % (±0.5 %) for PM2.5 and 39 % (±1 %) for PNC. In the site analysed, air coming from the harbour/industrial sector was richer in PAHs (5.34 ng/m³) than air sampled from all directions (3.89 ng/m³). The major compounds were phenanthrene, fluoranthene and pyrene, but the congener profiles were different in the two direction sectors: air from the harbour/industrial sector was richer in phenanthrene and fluorene, which are the most abundant PAHs in ship emissions. Results showed that lighter PAHs are associated to the gas phase, while high molecular weight congeners are mostly present in the particulate phase. The impact on the site studied of the harbour/industrial source to PAHs was 56 % (range, 29–87 %).     

Trace elements in size-segregated urban aerosol in relation to the anthropogenic emission sources and the resuspension

Size segregated particulate samples of atmospheric aerosols in urban site of continental part of Balkans were collected during 6 months in 2008. Six stages impactor in the size ranges: Dp?≤?0.49 μm, 0.49?2?≈?30 %) followed by traffic (PC2, σ²?≈?20 %) that are together contributing around 50 % of elements in the investigated urban aerosol. The EF model shows that major origin of Cd, K, V, Ni, Cu, Pb, Zn, and As in the fine mode is from the anthropogenic sources while increase of their contents in the coarse particles indicates their deposition from the atmosphere and soil contamination. This approach is useful for the assessment of the local resuspension influence on element’s contents in the aerosol and also for the evaluation of the historical pollution of soil caused by deposition of metals from the atmosphere.     

Gas-particle concentration and distribution of n-alkanes and polycyclic aromatic hydrocarbons in the atmosphere of Prato (Italy)

Air samples were collected in an urban and industrialised area of Prato (Italy) during 2002, as part of a study to identify and measure aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs). Total concentrations of aliphatic hydrocarbons ranged between 170 and 282ngm(-3) in the gas phase and from 48.9 to 276ngm(-3) in the particulate phase. The average total PAH concentrations (gas+particulate) were 59.4+/-26.5ngm(-3), and both gas and particulate phase PAH concentrations decreased with increasing temperature. Source identification using diagnostic ratios and principal component analysis identified automobile traffic, in particular, the strong influence of diesel fuel burning, as the major PAH source. Gas-particle partition coefficients (K(p)'s) of n-alkane and PAHs were well correlated with the sub-cooled liquid vapour pressure (P(L)(0)) and indicate stronger sorption of PAHs to aerosol particles compared with n-alkanes.     

Experimental evidence of biomass burning as a source of atmospheric 137Cs,puy de Dôme (1465 m a.s.l.), France

The presence of cesium-137 (¹³⁷Cs) in the environment is mainly due to past nuclear tests and accidental reactor releases. Due to the half-life of ¹³⁷Cs (30.2 y), amounts of this radionuclide releases are in fact still detectable in soils, and at trace levels in the vegetation and the atmosphere. Since the middle of the 1990’s, the presence of ¹³⁷Cs in the atmosphere has long been attributed to the resuspension of terrestrial dust. Recently, modelling studies have demonstrated that an additional and possibly dominant source of this anthropogenic radionuclide is biomass burning. Here, we report the variations of atmospheric ¹³⁷Cs activity levels over a 2-year period at the puy de Dôme (1465 m a.s.l.), France in combination with measurements of the aerosol chemical composition, in particular with indicators for biomass burning (levoglucosan and potassium) and soil dust (calcium). Temporal co-variations of these chemical compounds in addition to back-trajectories are used to identify common source emissions. Significant correlation is found between these compounds. Hence, we experimentally confirm the modelling study highlighting the fact that the atmospheric ¹³⁷Cs is partly released by biomass burning. In addition, we observed that the correlations between the ¹³⁷Cs concentrations and levoglucosan and biomass burning K⁺ differ according to the season. This is in agreement with the temporal evolution of levoglucosan concentration, which has maxima in winter and minima in summer.     

Trace metals in aerosol at Terra Nova Bay, Antarctica

Atmospheric particulate with an aerodynamic diameter <10 microm (PM10) was sampled continuously during the austral summers of 2000-2001 and 2001-2002 at a coastal site near to the Italian base of Terra Nova, Antarctica. Li, Pb, Cd, U, Ba, Bi, Cs, Rb, Tl, Sr, Al, V, Fe, Cu, Mn, Zn, Co, Ag were determined by inductively coupled sector field mass spectroscopy (ICP-SFMS) after sample digestion by a combination of HF, HNO3, and H2O2 in ultraclean conditions. Quality control of the analytical procedure was carried out by blank control, by evaluating the limits of detection, recoveries and repeatability. Concentrations found are extremely low for most metals, confirming the high purity of Antarctic aerosol. Principal Component Analysis (PCA) highlights high correlations among Pb, Cr, Bi, Cu and Zn concentration values and among Li, U, Ba, Cs, Rb, Al, V, Fe, Mn, Co concentration values permitting the identification of two principal source groups, namely crustal dust and human emission activities. Elements of anthropogenic origins (Pb, Cr, Cu, Zn) were highly enriched with respect to their crustal composition.