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Metal contamination in quail meat: residues, sources, molecular biomarkers, and human health risk assessment Texte intégral
2018
Darwish, Wageh Sobhy | Atia, Amira Samir | Khedr, Mariam H. E. | Eldin, Walaa Fathy Saad
Quail meat is an emerging source of high-quality animal protein. Quails are exposed to a wide range of xenobiotics such as heavy metals. In this study, residual concentrations of four toxic metals, of significant public health importance, including cadmium (Cd), lead (Pb), arsenic (As), and nickel (Ni), were determined in edible tissues of quails. In addition, metal loads were measured in water, feed, and litter samples collected from same quail farms as possible sources for quail exposure to heavy metals. The possible use of metallothionein (MT) and heat shock protein 70 (Hsp70) as molecular biomarkers of exposure to heavy metals was further investigated. Furthermore, the dietary intake and the potential risk assessment of the examined heavy metals among children and adults were calculated. The edible tissues of quails contained high concentrations of four heavy metals (contents (ppm/ww) ranging from 0.02 to 0.32 in Cd, 0.05 to 1.96 in Pb, 0.002 to 0.32 in As, and 1.17 to 3.94 in Ni), which corresponded to the high contents of these metals in the feeds, water, and litter. MT and Hsp70 mRNA expressions showed positive correlations with the concentrations of heavy metals in tissues indicating the possibility to use these proteins as biomarkers for quail’s exposure to toxic metals. Dietary intake of quail meat and risk assessment revealed potential risks especially for children after prolonged exposure to the examined metals. Thus, legislations should be established and continuous screening of metal residues should be adopted in order to reduce the toxic metal concentrations in feeds and drinking water for quails. Reduction of exposure to heavy metals subsequently would lead to minimization of exposure of such toxicants through consumption of quail meat.
Afficher plus [+] Moins [-]Is the informal economic activity a determinant of environmental quality? Texte intégral
2018
Imamoglu, Hatice
This study aims to investigate whether the size of the informal economic activity is a determinant of the environmental quality in the case of Turkey. First, the MIMIC model approach will be used to estimate the size of the informal economic activity. Second, time series analysis will be conducted for the period from 1970 to 2014, in order to examine the effect of the size of the informal economic activity on the environmental quality by conducting Carrion-i-Silvestre et al. (Economet Theor 25:1754, 2009) unit root tests, Bound test and Maki (Econ Model 29:2011–2015, 2012) cointegration tests that allow structural breaks will be employed prior to the DOLS, FMOLS, and ARDL approaches for long-run and short-run models. The results suggest that informal economic activity is a positively significant determinant on the environmental quality. Moreover, this paper suggests that both formal and informal economies have significant impact on environmental quality. However, formal economy exerts positively higher effects on the environmental quality compared to informal economy. Turkish authorities need to pay more attention on both formal and informal economic activities to prevent environmental degradation in Turkey.
Afficher plus [+] Moins [-]Biocontrol of the wheat pathogen Zymoseptoria tritici using cyclic lipopeptides from Bacillus subtilis Texte intégral
2018
Mejri, Samara | Siah, Ali | Coutte, François | Magnin-Robert, Maryline | Randoux, Béatrice | Tisserant, Benoit | Krier, François | Jacques, Philippe | Reignault, Philippe | Halama, Patrice
Innovation toward ecofriendly plant protection products compatible with sustainable agriculture and healthy food is today strongly encouraged. Here, we assessed the biocontrol activity of three cyclic lipopeptides from Bacillus subtilis (mycosubtilin, M; surfactin, S; fengycin, F) and two mixtures (M + S and M + S + F) on wheat against Zymoseptoria tritici, the main pathogen on this crop. Foliar application of these biomolecules at a 100-mg L⁻¹ concentration on the wheat cultivars Dinosor and Alixan, 2 days before fungal inoculation, provided significant reductions of disease severity. The best protection levels were recorded with the M-containing formulations (up to 82% disease reduction with M + S on Dinosor), while S and F treatments resulted in lower but significant disease reductions. In vitro and in planta investigations revealed that M-based formulations inhibit fungal growth, with half-maximal inhibitory concentrations of 1.4 mg L⁻¹ for both M and M + S and 4.5 mg L⁻¹ for M + S + F, thus revealing that the observed efficacy of these products may rely mainly on antifungal property. By contrast, S and F had no direct activity on the pathogen, hence suggesting that these lipopeptides act on wheat against Z. tritici as resistance inducers rather than as biofungicides. This study highlighted the efficacy of several lipopeptides from B. subtilis to biocontrol Z. tritici through likely distinct and biomolecule-dependent modes of action.
Afficher plus [+] Moins [-]Using carbonized low-cost materials for removal of chemicals of environmental concern from water Texte intégral
2018
Weidemann, Eva | Niinipuu, Mirva | Fick, Jerker | Jansson, Stina
Adsorption on low-cost biochars would increase the affordability and availability of water treatment in, for example, developing countries. The aim of this study was to identify the precursor materials and hydrochar surface properties that yield efficient removal of compounds of environmental concern (CEC). We determined the adsorption kinetics of a mixture containing ten CECs (octhilinone, triclosan, trimethoprim, sulfamethoxasole, ciprofloxacin, diclofenac, paracetamol, diphenhydramine, fluconazole, and bisphenol A) to hydrochars prepared from agricultural waste (including tomato- and olive-press wastes, rice husks, and horse manure). The surface characteristics of the hydrochars were evaluated via diffuse reflectance infrared spectroscopy (DRIFTS), X-ray photoelectron spectroscopy (XPS), and N₂-adsorption. Kinetic adsorption tests revealed that removal efficiencies varied substantially among different materials. Similarly, surface analysis revealed differences among the studied hydrochars and the degree of changes that the materials undergo during carbonization. According to the DRIFTS data, compared with the least efficient adsorbent materials, the most efficient hydrochars underwent more substantial changes during carbonization.
Afficher plus [+] Moins [-]Characterization of particulate matter and black carbon over Bay of Bengal during summer monsoon: results from the OMM cruise experiment Texte intégral
2018
Prijith, Sudhakaran Syamala | Moorthy, Krishnaswamy Krishna | Babu, Surendran Nair Suresh | Satheesh, Sreedharan Krishnakumari
Total and size-segregated particulate matter (PM) and black carbon (BC) concentrations over the Bay of Bengal (BoB) have been measured in the summer monsoon (August–September 2014) onboard a scientific cruise conducted as a part of the Ocean Monsoon and Mixing (OMM) experiment. Role of long-range transport and prevailing meteorology in producing the observed spatio-temporal features is inferred by synthesizing the results of in situ observations in conjunction with the wind components from Modern Era Retrospective Analysis for Research and Applications (MERRA), rainfall data from Tropical Rainfall Measuring Mission (TRMM), surface BC concentration and BC Aerosol Optical Thickness (AOTBC) from MERRA2 and HYSPLIT back trajectory and dispersion model analysis. Mean values of total PM and BC mass concentrations are observed to be ~ 21.4 μgm⁻³ and ~ 393ngm⁻³ respectively. The study has revealed significant influence of monsoon rainfall (over the measurement locations and regions through which transport occurred) on the concentration of both PM and BC over northern BoB. Results also indicate transport of aerosols with significant anthropogenic fraction, from the land regions at west to the BoB. A comprehensive analysis showed that while an eastward wind (westerly) from the Indian mainland produced an increase in PM₂.₅ over northern BoB, a southerly wind, mostly from the Indian Ocean, caused a decrease in concentration of PM₂.₅. Spectral variation of absorption coefficients of aerosols reveals that most of the BC over BoB is associated with fossil fuel combustion. Prevailing strong surface-level convergence (associated with a low-level anticyclone) resulted in accumulation and consequent enhancement of aerosol concentration over central and northern BoB during the study period. In addition, horizontal flow rates estimated across western boundary of BoB using AOTBC from MERRA2 for 10 years revealed an increasing trend in BC transport from the mainland leading to a gradual buildup in BC concentration over the regions of BoB.
Afficher plus [+] Moins [-]The impact of occupational exposure to traffic-related air pollution among professional motorcyclists from Porto Alegre, Brazil, and its association with genetic and oxidative damage Texte intégral
2018
Carvalho, Roseana Böek | Carneiro, Maria Fernanda Hornos | Barbosa, Fernando Jr | Batista, Bruno Lemos | Simonetti, Júlia | Amantéa, Sergio Luis | Rhoden, Cláudia Ramos
Vehicles play an important role in modern life; however, they also generate hazards. Occupational exposed subjects are in long-term contact with harmful products, which sets these professionals in a susceptible group to air pollutant damage. The aims of this study were to quantify individual exposure to pollutant gases and chemical elements and to evaluate oxidative and genetic damage in professional motorcyclists and office workers. We recruited professional motorcyclists and office workers from Porto Alegre, Brazil, between January and December 2016. Individual exposure to air pollutants was assessed by passive monitoring. Fingernail trace elements were determined by using inductively coupled plasma mass spectrometry. Oxidative stress biomarkers were quantified spectrophotometrically, and genotoxicity was evaluated by micronuclei assay. Individual exposure to NO₂ and O₃, trace element content (Sb, Pt, As, Cd, V, Mn, and Co), oxidative stress factors, and genetic damage were statistically higher in professional motorcyclists (p < 0.05). Moreover, NO₂ and O₃ levels showed very strong positive correlation with plasmatic lipid peroxidation (p < 0.001 and r = 0.8849 and 0.8995) and strong positive correlation with micronuclei frequency (p < 0.001 and r = 0.7683 and 0.7280). Results suggest that professional motorcyclists are at high risk due to long-term air pollution exposure, which implies in the onset of several harmful effects and worsening of pre-existent diseases.
Afficher plus [+] Moins [-]Conversion of Eragrostis plana Nees leaves to activated carbon by microwave-assisted pyrolysis for the removal of organic emerging contaminants from aqueous solutions Texte intégral
2018
Cunha, Mariene R. | Lima, Eder C. | Cimirro, Nilton F. G. M. | Thue, Pascal S. | Dias, Silvio L. P. | Gelesky, Marcos A. | Dotto, Guilherme L. | dos Reis, Glaydson S. | Pavan, Flávio A.
Eragrostis plana Nees leaves, abundant lignocellulosic biomass, was used as carbon source for preparation of activated carbon, by using microwave-assisted pyrolysis and chemical activation. The novel activated carbon (MWEPN) was characterised by FTIR, CHN elemental analysis, Boehm’s titration method, TGA, SEM, N₂ adsorption/desorption curves and pH of the point of zero charge (pHₚzc). Afterwards, the adsorbent was successfully employed for adsorption of the two emerging contaminants (caffeine and 2-nitrophenol). The results indicated that MWEPN had a predominantly mesoporous structure with a high surface area of 1250 m² g⁻¹. FTIR analysis indicated the presence of carbonyl, hydroxyl and carboxylic groups on the surface of MWEPN. The Boehm analysis showed the existence of the high amount of acid moieties on the surface of activated carbon. Adsorption kinetic indicated that the system followed the Avrami fractional order at the optimal pH of 7. The equilibrium time was attained at 30 min. The Liu isotherm model better described the isothermal data. Based on the Liu isotherm, the maximum sorption capacities (Qₘₐₓ) of caffeine and 2-nitrophenol adsorbed onto activated carbon at 25 °C were 235.5 and 255.8 mg g⁻¹, respectively.
Afficher plus [+] Moins [-]Properties and effects of organic additives on performance and emission characteristics of diesel engine: a comprehensive review Texte intégral
2018
Kumar, Chandan | Rana, Kunj Bihari | Tripathi, Brajesh | Nayyar, Ashish
Fast depletion of conventional automobile fuels and environmental pollution due to exhaust emission are the issues of great importance. Improvement in engine performance and emission control is quite difficult to handle simultaneously. The fuel properties can be improved substantially by incorporation of additives in different proportions to get better emission standard without deteriorating the engine performance. The aim of current study is to review/summarize the effects of various organic additives on the engine performance (i.e., brake thermal efficiency, brake specific fuel consumption, volumetric efficiency, etc.) and emissions (i.e., carbon dioxide, carbon monoxide, nitrogen oxides, hydrocarbons, particulate matter, and other harmful compounds). The physico-chemical and combustion properties (i.e., density, latent heat, dynamic viscosity, flash point, boiling point, cetane number, oxygen content, lower heating value, auto-ignition temperature, etc.) of various additives were also discussed to check the suitability of additives with diesel. Finally, limitations and opportunities using organic additives with respect to engine performance and combustion were discussed to guide future research and improvement in this field.
Afficher plus [+] Moins [-]QSAR modeling in ecotoxicological risk assessment: application to the prediction of acute contact toxicity of pesticides on bees (Apis mellifera L.) Texte intégral
2018
Hamadache, Mabrouk | Benkortbi, Othmane | Hanini, Salah | Amrane, Abdeltif
Despite their indisputable importance around the world, the pesticides can be dangerous for a range of species of ecological importance such as honeybees (Apis mellifera L.). Thus, a particular attention should be paid to their protection, not only for their ecological importance by contributing to the maintenance of wild plant diversity, but also for their economic value as honey producers and crop-pollinating agents. For all these reasons, the environmental protection requires the resort of risk assessment of pesticides. The goal of this work was therefore to develop a validated QSAR model to predict contact acute toxicity (LD₅₀) of 111 pesticides to bees because the QSAR models devoted to this species are very scarce. The analysis of the statistical parameters of this model and those published in the literature shows that our model is more efficient. The QSAR model was assessed according to the OECD principles for the validation of QSAR models. The calculated values for the internal and external validation statistic parameters (Q ² and [Formula: see text] are greater than 0.85. In addition to this validation, a mathematical equation derived from the ANN model was used to predict the LD₅₀ of 20 other pesticides. A good correlation between predicted and experimental values was found (R ² = 0.97 and RMSE = 0.14). As a result, this equation could be a means of predicting the toxicity of new pesticides.
Afficher plus [+] Moins [-]Effects of pollution and bioleaching process on the mineral composition and texture of contaminated sediments of the Reconquista River, Argentina Texte intégral
2018
Tufo, Ana E. | Porzionato, Natalia F. | Curutchet, Gustavo
In this work, we report on the structural and textural changes in fluvial sediments from Reconquista River´s basin, Argentina, due to processes of contamination with organic matter and remediation by bioleaching. The original uncontaminated matrix showed quartz and phyllosilicates as the main primary mineral constituents and phases of interstratified illite-montmorillonite as secondary minerals. It was found that in contaminated sediments, the presence of organic matter in high concentration causes changes in the specific surface area, particle size distribution, size and distribution of micro and meso, and the morphology of the particles with respect to the uncontaminated sediment. After the bioleaching process, there were even greater changes in these parameters at the level of secondary mineral formation and the appearance of nanoparticles, which were confirmed by SEM. Especially, we found the formation of cementing substances such as gypsum, promoting the formation of macroporous aggregates and the weathering of clay components. Our results indicate that the bioleaching not only decreases the content of metals but also favors the formation of a material with improved characteristics for potential future applications.
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