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Aerosol and ozone observations during six cruise campaigns across the Mediterranean basin: temporal, spatial, and seasonal variability Full text
2014
Bencardino, Mariantonia M. | Pirrone, Nicola N. | Sprovieri, Francesca F.
The Mediterranean basin, because of its semi-enclosed configuration, is one of the areas heavily affected by air pollutants. Despite implications on both human health and radiative budget involving an increasing interest, monitoring databases measuring air pollution directly over this area are yet relatively limited. Owing to this context, concentrations of fine (PM₂.₅) and coarse (PM₂.₅–₁₀) particles along with other ancillary data, such as ozone levels and meteorological parameters, were measured during six cruise campaigns covering almost the whole Mediterranean basin. Elemental composition of both PM₂.₅and PM₂.₅–₁₀was also determined to identify specific tracers for different classes of particles that can be found in the Mediterranean atmosphere. Outcomes resulting from the integration of a preliminary qualitative examination with a more quantitative analysis, based on receptor modelling, suggested that European continental influence, Saharan dust outbreaks, wildfire events, sea spray and fossil fuel combustion were the leading causes of the aerosol-ozone variations within the Mediterranean basin. Shipping emissions, consisting in both local harbours and maritime traffic across the basin, were also tested using the marker ratio of V/Ni. Peak values observed for coarse fraction have shown to be driven by the occurrence of African dust events. Considering the major influence of Continental pollution and wildfire events, the spatial variability resulted in larger fine particle concentrations and higher ozone levels over the Eastern Mediterranean side in comparison to the Western one.
Show more [+] Less [-]An assessment of hematological and biochemical responses in the tropical fish Epinephelus stoliczkae of Chabahar Bay and Gulf of Oman under chromium exposure: ecological and experimental tests Full text
2014
Sadeghi, Parvin | Savari, Ahmad | Movahedinia, Abdolali | Safahieh, Alireza | Azhdari, Danial
The aim of this investigation was to evaluate the effect of chromium on hematological and biochemical parameters in Epaulet Grouper, Epinephelus stoliczkae of Chabahar Bay and Gulf of Oman by ecological and experimental tests. Spatial evaluation of ecological test results showed these parameters had significant difference among some sampling sites. Examination of hematological and biochemical profiles on Epaulet Grouper was performed after 0.5, 1, 7, 14, and 21 days of chromium exposure (3.6, 7.31 and 14.6 mg/L). Experimental test results of chromium induce indicated the significant decrease in MCV, MCH, neutrophils, basophils, plasma protein and significant increase in MCHC, lymphocytes, monocytes, eosinophils and a biphasic trend in Hb, Ht, RBC, WBC, and glucose (p < 0.05). Cellular and nuclear axis, cytoplasmic volume, cell and nuclear volume, and surface area were significantly different for ecological and experimental results (p < 0.05). It was concluded that these parameters are sensitive in monitoring the toxicity of chromium concentrations.
Show more [+] Less [-]Radionuclides in some edible and medicinal macrofungal species from Tara Mountain, Serbia Full text
2014
Rakić, Milana | Karaman, Maja | Forkapić, Sofija | Hansman, Jan | Kebert, Marko | Bikit, Kristina | Mrdja, Dušan
Edible and medicinal macrofungi used in human diet represent not only important sources of nutritive elements but toxic substances as well (heavy metals and radionuclides). Radioactivity levels of four radionuclides (⁴⁰K, ¹³⁷Cs, ²²⁶Ra, ²²⁸Ra) were determined in the basidiomata (fruiting bodies of a Basidiomycetes) of six lignicolous (Fomitopsis pinicola, Ganoderma applanatum, Hericium clathroides, Megacollybia platyphylla, Pluteus cervinus, Trametes gibbosa) and three mycorrhizal (Boletus luridus, Boletus sp. 1, Boletus sp. 2) species as well as their soil (wood) substrates by gamma spectrometry (high-resolution high-purity germanium (HPGe) detector). The aim was to investigate their ability for radionuclide absorption according to transfer factors (from soil and wood), to predict potential bioindicator species as well as species with potential risk for human use. Samples were taken during years 2011 and 2012, at two sites in forest ecosystem of Tara Mountain (Serbia). Observed concentration ranges per dry weight were as follows: 29–3,020 Bq/kg (⁴⁰K), 21.9–735 Bq/kg (¹³⁷Cs), 3–39 Bq/kg (²²⁶Ra), and 2.0–18 Bq/kg (²²⁸Ra). Obtained results indicate that the type of basidiome (fleshy/tough), most likely due to a different metabolic rate, has a very important role in radionuclide accumulation. The highest activity concentrations of all analyzed radionuclides were found in species with fleshy basidiomata—P. cervinus, H. clathroides, M. platyphylla, and Boletus species. A species-specific influence on radionuclide uptake was more prominent comparing to habitat differences and the role of fungal trophic mode. No significant variations were observed regarding radionuclide activity among the same fungal species from different sampling sites.
Show more [+] Less [-]Chromium (VI) remediation by a native strain: effect of environmental conditions and removal mechanisms involved Full text
2014
González, Paola S. | Ambrosio, Laura F. | Paisio, Cintia E. | Talano, Melina A. | Medina, María I. | Agostini, Elizabeth
A native bacterial strain with high capability for Cr (VI) removal was isolated from tannery sediments located in Elena (Córdoba Province, Argentina). The strain was characterized by amplification of 16S rRNA gene and identified as Serratia sp. C8. It was able to efficiently remove different Cr (VI) concentrations in a wide range of pHs and temperatures. The addition of different carbon sources as well as initial inoculum concentration were analyzed, demonstrating that Serratia sp. C8 could reduce 80 % of 20 mg/L Cr (VI) in a medium containing glucose 1 g/L, at pH 6–7 and 28 °C as optimal conditions, using 5 % inoculum concentration. The mechanisms involved in Cr (VI) removal were also evaluated. The strain was capable of biosorpting around 7.5–8.5 % of 20 mg/L Cr on its cell surface and to reduce Cr (VI). In addition, approximately a 54 and 46 % of total Cr was detected in the biomass and in the culture medium, respectively, and in the culture medium, Cr (III) was the predominant species. In conclusion, Serratia sp. C8 removed Cr (VI) and the mechanisms involved in decreasing order of contribution were as follows: reduction catalyzed by intracellular enzymes, accumulation into the cells, and biosorption to the microbial biomass. This strain could be a suitable microorganism for Cr (VI) bioremediation of tannery sediments and effluents or even for other environments contaminated with Cr.
Show more [+] Less [-]Molecular and ultrastructural insights into the earthworm Eisenia fetida of the assessment of ecotoxicity during colistin exposure Full text
2014
Guo, Ruizi | Ding, Xueyao | Zhong, Xiaoxia | Gao, Shangji | Sun, Yongxue
Colistin is a peptide antibiotic widely used as a feed additive in animal farming, especially in poultry and swine production, for treatment and prevention of gram-negative bacterial infections, as well as for growth promotion use. When orally ingested, colistin is poorly absorbed and is eliminated almost unaltered by the enteric canal into the environment. Thus, risk of environmental toxicity cannot be ignored. In the present study, we examined the effects of colistin on Heath Shock Protein (HSP) 70, metallothionein (MT) gene expressions, and the ultrastructure of intestinal cells, following treatment of the soil indicator earthworm Eisenia fetida with 10, 20, and 100 mg/kg colistin for 7, 14, and 21 days. The results showed that, compared with the control, the expressions of HSP70 and MT genes changed significantly. Colistin caused up-regulations of HSP70’s expression while inhibited the expression of MT gene. In addition, most mitochondria and endoplasmic reticulum were damaged in the group treated with high concentration. The investigation of gene expressions of HSP70 and MT, as well as pathological alterations in the intestinal cells, may provide important information in terms of ecotoxicity of colistin and can be used as early warning system.
Show more [+] Less [-]Oxidative stress—implications, source and its prevention Full text
2014
Rājabīra Kaura, | Jasmit Kaur, | Mahajan, Jyoti | Kumar, Rakesh | Arora, Saroj
Oxidative stress has been a major predicament of present day living. It has been the product of imbalance between the processes involved in free radical generation and their neutralization by enzymatic and non-enzymatic defence mechanisms. The oxidative stress has been contributed by numerous factors including heavy metals, organic compound-rich industrial effluents, air pollutants and changing lifestyle pattern focussing mainly on alcohol consumption, dietary habits, sun exposure, nuclear emissions, etc. The most common outcome of oxidative stress is the increased damage of lipid, DNA and proteins that resulted in the development of different pathologies. Among these pathologies, cancer is the most devastating and linked to multiple mutations arising due to oxidative DNA and protein damage that ultimately affect the integrity of the genome. The chemopreventive agents particularly nutraceuticals are found to be effective in reducing cancer incidences as these components have immense antioxidative, antimutagenic and antiproliferative potentials and are an important part of our dietary components. These secondary metabolites, due to their unique chemical structure, facilitate cell-to-cell communication, repair DNA damage by the downregulation of transcription factors and inhibit the activity of protein kinases and cytochrome P450-dependent mixed function oxidases. These phytochemicals, therefore, are most appropriate in combating oxidative stress-related disorders due to their tendency to exert better protective effect without having any distinct side effect.
Show more [+] Less [-]The short-term effects of a routine poisoning campaign on the movements and detectability of a social top-predator Full text
2014
Allen, Benjamin L. | Engeman, Richard M. | Leung, Luke K–P.
The short-term effects of a routine poisoning campaign on the movements and detectability of a social top-predator Full text
2014
Allen, Benjamin L. | Engeman, Richard M. | Leung, Luke K–P.
Top-predators can be important components of resilient ecosystems, but they are still controlled in many places to mitigate a variety of economic, environmental and/or social impacts. Lethal control is often achieved through the broad-scale application of poisoned baits. Understanding the direct and indirect effects of such lethal control on subsequent movements and behaviour of survivors is an important pre-requisite for interpreting the efficacy and ecological outcomes of top-predator control. In this study, we use GPS tracking collars to investigate the fine-scale and short-term movements of dingoes (Canis lupus dingo and other wild dogs) in response to a routine poison-baiting program as an example of how a common, social top-predator can respond (behaviourally) to moderate levels of population reduction. We found no consistent control-induced differences in home range size or location, daily distance travelled, speed of travel, temporal activity patterns or road/trail usage for the seven surviving dingoes we monitored immediately before and after a typical lethal control event. These data suggest that the spatial behaviour of surviving dingoes was not altered in ways likely to affect their detectability, and if control-induced changes in dingoes' ecological function did occur, these may not be related to altered spatial behaviour or movement patterns.
Show more [+] Less [-]The short-term effects of a routine poisoning campaign on the movements and detectability of a social top-predator Full text
2014
Allen, Benjamin L | Engeman, Richard M | Leung, Luke K–P
Top-predators can be important components of resilient ecosystems, but they are still controlled in many places to mitigate a variety of economic, environmental and/or social impacts. Lethal control is often achieved through the broad-scale application of poisoned baits. Understanding the direct and indirect effects of such lethal control on subsequent movements and behaviour of survivors is an important pre-requisite for interpreting the efficacy and ecological outcomes of top-predator control. In this study, we use GPS tracking collars to investigate the fine-scale and short-term movements of dingoes (Canis lupus dingo and other wild dogs) in response to a routine poison-baiting program as an example of how a common, social top-predator can respond (behaviourally) to moderate levels of population reduction. We found no consistent control-induced differences in home range size or location, daily distance travelled, speed of travel, temporal activity patterns or road/trail usage for the seven surviving dingoes we monitored immediately before and after a typical lethal control event. These data suggest that the spatial behaviour of surviving dingoes was not altered in ways likely to affect their detectability, and if control-induced changes in dingoes' ecological function did occur, these may not be related to altered spatial behaviour or movement patterns.
Show more [+] Less [-]Electrochemical advanced oxidation processes: today and tomorrow. A review Full text
2014
Sirés, Ignasi | Brillas, Enric | Oturan, Mehmet A. | Rodrigo, Manuel A. | Panizza, Marco
In recent years, new advanced oxidation processes based on the electrochemical technology, the so-called electrochemical advanced oxidation processes (EAOPs), have been developed for the prevention and remediation of environmental pollution, especially focusing on water streams. These methods are based on the electrochemical generation of a very powerful oxidizing agent, such as the hydroxyl radical (•OH) in solution, which is then able to destroy organics up to their mineralization. EAOPs include heterogeneous processes like anodic oxidation and photoelectrocatalysis methods, in which•OH are generated at the anode surface either electrochemically or photochemically, and homogeneous processes like electro-Fenton, photoelectro-Fenton, and sonoelectrolysis, in which•OH are produced in the bulk solution. This paper presents a general overview of the application of EAOPs on the removal of aqueous organic pollutants, first reviewing the most recent works and then looking to the future. A global perspective on the fundamentals and experimental setups is offered, and laboratory-scale and pilot-scale experiments are examined and discussed.
Show more [+] Less [-]Influence of microbial and synthetic surfactant on the biodegradation of atrazine Full text
2014
Singh, Anil Kumar | Cameotra, Swaranjit Singh
The present study reports the effect of surfactants (rhamnolipids and triton X-100) on biodegradation of atrazine herbicide by strain A6, belonging to the genus Acinetobacter. The strain A6 was able to degrade nearly 80 % of the 250-ppm atrazine after 6 days of growth. The bacterium degraded atrazine by de-alkylation process. Bacterial cell surface hydrophobicity as well as atrazine solubility increased in the presence of surfactant. However, addition of surfactant to the mineral salt media reduced the rate and extent of atrazine degradation by decreasing the bioavailability of herbicide. On the contrary, addition of surfactant to atrazine-contaminated soil increased the rate and extent of biodegradation by increasing the bioavailability of herbicide. As compared to triton X-100, rhamnolipids were more efficient in enhancing microbial degradation of atrazine as a significant amount of atrazine was removed from the soil by rhamnolipids. Surfactants added for the purpose of hastening microbial degradation may have an unintended inhibitory effect on herbicide degradation depending upon contiguous condition, thus highlighting the fact that surfactant must be judiciously used in bioremediation of herbicides.
Show more [+] Less [-]Cytotoxic effect of linear alkylbenzene sulfonate on human intestinal Caco-2 cells: associated biomarkers for risk assessment Full text
2014
Bradai, Mohamed | Han, Junkyu | El Omri, Abdelfatteh | Funamizu, Naoyuki | Sayadi, Sami | Isoda, Hiroko
Linear alkylbenzene sulfonate (LAS) is a synthetic anionic surfactant widely present in the environment due to its intensive production and use in the detergency field. Admitting that current procedure of risk assessment has limits in providing realistic risk assessment data and predicting the cumulative effect of the toxicant mixtures, the incorporation of information regarding the mode of action and cell response mechanism seems to be a potential solution to overcome these limits. In this regard, we investigated in this study the LAS cytotoxicity on human intestinal Caco-2 cells, trying to unveil the protein actors implicated in the cell response using proteomics approach in order to give a better understanding of the toxicological effect and allow the identification of appropriate biomarkers reflecting the mode of action associated with LAS. As results, we demonstrated that LAS induces a time- and dose-dependent cytotoxicity in Caco-2 cells accompanied by an induction of oxidative stress followed by an excessive increase of intracellular calcium level. Proteomics approach helped in discovering three informative biomarkers of effect associated with LAS cytotoxic effect, reported for the first time: calreticulin, thioredoxin, and heat shock cognate 71 (HSP7C), confirmed by real-time PCR and western blot analysis. These biomarkers could serve for more reliable future risk assessment studies that consider the toxicants mode of action in order to help in the prediction of potential cumulative effects of environmentally coexisting contaminants.
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