On the vulnerability of woody riparian vegetation during flood events

Environmental Fluid Mechanics - Wood is recognized as a key element of river ecosystem for a large number of positive feedbacks with biotic and abiotic components, both when it is present as large...     

Biosorbents for solid-phase extraction of toxic elements in waters

Some trace metals are highly toxic for the environment. There is therefore a need for reliable methods for the determination of metals at trace levels. To this end, new sample pretreatment methods such as separation, preconcentration and speciation prior to the determination of metal ions have developed rapidly. Biosorption has become a major tool for solid-phase extraction methods. This review covers selected biosorbents such as algae, bacteria, filamentous fungi and yeasts, as new sorbents used in the solid-phase extraction of metal ions from various water sample matrices. A survey of the literature over 2004-2014 shows possible applications of selected new sorbents available for use in trace metal analysis in waters using solidphase extraction. We highlight the preconcentration of the toxic elements prior to their determination by atomic spectrometry.     

A motley of possible therapies of the COVID-19: reminiscing the origin of the pandemic

Environmental Science and Pollution Research - The 2019 outbreak of corona virus disease began from Wuhan (China), transforming into a leading pandemic, posing an immense threat to the global...     

TiO2-NPs and cadmium co-exposure: in vitro assessment of genetic and genomic DNA damage on Dicentrarchus labrax embryonic cells

Environmental Science and Pollution Research - The increased titanium dioxide nanoparticles (TiO2-NPs) spread and their interaction with organic and inorganic pollutants arouses concern for the...     

The methane sink associated to soils of natural and agricultural ecosystems in Italy

In the present work, the CH4 sink associated to Italian soils was calculated by using a process-based model controlled by gas diffusivity and microbial activity, which was run by using a raster-based geographical information system. Georeferenced data included land cover CLC2000, soil properties from the European Soil Database, climatic data from the MARS-STAT database, plus several derived soils properties based on published algorithms applied to the above mentioned databases. Overall CH4 consumption from natural and agricultural sources accounted for a total of 43.3 Gg CH4 yr(-1), with 28.1 Gg CH4 yr(-1) removed in natural ecosystems and 15.1 Gg CH4 yr(-1) in agricultural ecosystems. The highest CH4 uptake rates were obtained for natural areas of Southern Apennines and islands of Sardinia and Sicily, and were mainly associated to areas covered by sclerophyllous vegetation (259.7+/-30.2 mg CH4 m(-2) yr(-1)) and broad-leaved forest (237.5 mg CH4 m(-2) yr(-1)). In terms of total sink strength broad-leaved forests were the dominant ecosystem. The overall contribution of each ecosystem type to the whole CH4 sink depended on the total area covered by the specific ecosystem and on its exact geographic distribution. The latter determines the type of climate present in the area and the dominant soil type, both factors which showed to have a strong influence on CH4 uptake rates. The aggregated CH4 sink, calculated for natural ecosystems present in the Italian region, is significantly higher than previously reported estimates, which were extrapolated from fluxes measured in other temperate ecosystems.     

Stigmastane and hopanes as conserved biomarkers for estimating oil biodegradation in a former refinery plant-contaminated soil

In the last decade, a refinery plant located in Lido Adriano, East Ravenna (Italy) has been subject to mineral oil contamination. The mineral crude oil, extracted from the offshore in Adriatic sea, consisted of 78% aliphatics, cyclic alkanes and saturated polycyclic hydrocarbons, 9% aromatics, polycyclic aromatic hydrocarbons (PAHs) and alkylated derivatives, and 13% of tars/asphaltenes. Analysis of soil after 10 years of natural attenuation revealed a complete depletion of linear (n-C(9)-C(24)), light aromatics (C1-C3/benzenes) and PAHs (C2/naphthalene, C1/phenanthrene); besides a substantial degradation of isoprenoids prystane and phytane, branched and cyclic alkanes. The remaining contaminants which withstood to natural degradation was saturated polycyclic hydrocarbons (perhydro-PAH derivatives), unsaturated polycyclic hydrocarbons (tetrahydro, dihydro-PAH derivatives), terpanes, steranes and unidentified compounds. Such residues resulted in 80% reduction of its concentration after two months of laboratory treatment. Samples were extracted by organic solvents, separated by silica/alumina gel column chromatography and analyzed by gas chromatography-mass selective detector (GC-MSD). Identification and quantification of aliphatic, cyclic alkanes, typical PAHs, terpanes and steranes were carried out to chromatograms of M/Z=85, 83, individual M/Zs, M/Z=191 and 217, respectively. The present work shows that, among numerous biomarkers present in the source oil, stigmastane and two isomers of hopane showed invariable concentrations after laboratory experiments that mimic natural biodegradation in the field, so they can be used as conserved internal biomarkers. These are very useful tools to assess alterations in less stable classes of saturated compounds contained in petroleum. Marked degradation of perhydro, tetrahydro, dihydro-PAH derivatives in the laboratory treatment has been evidenced.     

Vitellogenesis in the deep-sea shark Centroscymnus coelolepis

At present, information on the reproductive physiology of Centroscymnus coelolepis, which is one of most important and widespread deep-sea shark species, is completely lacking. In this study, we investigated vitellogenesis, a key step in the reproduction biology of fishes. Specimens of C. coelolepis were collected at 2850 m depth in the Western Mediterranean Sea. The size of the collected sharks (range: 35.5–65.0 cm TL) was much lower than those typically reported for the Atlantic and Pacific Oceans. The marked distinctiveness of Mediterranean and Atlantic/Pacific populations was reflected by the achievement of sexual maturity at a smaller size in Mediterranean specimens. The examination of cytoplasmatic components of oocytes indicated that vitellogenin uptake in the ovary started when oocytes reached 14 mm in diameter. Only reproductive females displayed a significant relationship between plasmatic vitellogenin and gonadal development, suggesting that vitellogenesis in C. coelolepis is a discontinuous process. Oestradiol levels were tightly coupled with gonadal development, underlining the importance of this hormone in controlling vitellogenesis. All these findings suggest that vitellogenesis in this yolk-sac viviparous shark might occur with similar mechanisms of oviparous vertebrates.     

Hydractinia echinata test system. II. SAR toxicity study of some anilide derivatives of Naphthol-AS type

In this paper, a toxicity study for a series of anilides of Naphthol-AS type is presented. The toxicity of the model compounds was determined by using the Hydractinia echinata (Hydrozoa) test system. Conformational analysis of Naphthol-AS derivatives was performed to elucidate the possible enzymatic hydrolysis mechanism of these compounds. This mechanism occurs with different rates and always leads to a stoichiometric mixture of reaction products, consisting in the substituted amine and the corresponding α-hydroxy-carboxylic acid. With one exception, the toxicities of the reaction products are subadditive. Quite similar measured toxicity values, log(1/MRC₅₀), led to their average calculated values, and thus to the establishment of class isotoxicity. This method represents a practical alternative useful for the reduction of experimental tests on animals to the lowest possible level, in accordance to the ‘3Rs’ (reduction, refinement and replacement) concept.     

Mutagenic properties of PM2.5 urban pollution in the Northern Italy: The nitro-compounds contribution

PM2.5 is the breathable fraction of the particulate matter and some adverse health effects, such as respiratory functionality, cardiological diseases and cancer, can be in some measure attributable to this risk factor exposure. Some of the most carcinogen compounds transported by PM2.5 are nitro-compounds. In this study, a strengthened in vitro bioassay — able to predict the mutagenic/carcinogenic activity of the environmental mixtures — was conducted on PM2.5 organic extracts to define the nitro-compounds burden. PM2.5 air pollution was daily monitored, during 2006, in three cities located in the Northern part of Italy (Torino, Pavia and Verona) and the mutagenic properties of the PM2.5 organic extracts were assessed with the Ames test. The bacterial used in this study were three Salmonella typhimurium strains: TA98, nitroreductase-less mutant TA98NR and YG1021 carrying a nitroreductase-producing plasmid. The annual PM2.5 mean level measured in Torino was 46.5 (± 31.6) μg/m³, in Pavia 34.8 (± 25.1) μg/m³, and in Verona 37.3 (± 27.8) μg/m³, while the mutagenicity expressed as TA98 net reverants/m³ was 28.0 (± 22.1), 28.3 (± 24.9), and 34.2 (± 30.9) respectively. Monthly pool bioassays, conducted with the three different strains, showed a greater mutagenic response of the YG1021 in each city. The relationship among the mutagenic answers for YG1021:TA98:TA98NR was about 6:3:1 (p < 0.001). Over nitroreductase activity enhanced the response of 2.2, 2.0 and 1.7 times for Torino, Pavia, and Verona (ANOVA Torino p < 0.05) respectively. Without nitroreductase activity the genotoxicity was limited. These biological findings are able to describe a relevant role played by the nitro compounds in the mutagenic properties of the urban PM2.5 in the Padana plain; moreover the bacterial nitroreductase plays a predominant role in DNA interaction primarily for Torino PM2.5 extracts.