خيارات البحث
النتائج 4081 - 4090 من 4,924
Quantitative ecotoxicological impacts of sewage treatment plant effluents on plankton productivity and assimilative capacity of rivers
2019
Karrasch, Bernhard | Horovitz, Omer | Norf, Helge | Hillel, Noa | Hadas, Ora | Beeri-Shlevin, Yaron | Laronne, Jonathan B.
Sewage treatment plants are sources of inorganic and organic matter as well as contaminants for the receiving watercourses. We analyzed the ecological consequences of such effluents by following a holistic and synecological ecotoxicological approach based on quantifying extracellular enzyme activities (EEA), primary production and bacterial cell, and biomass production rates. Samples were obtained at three locations at the Rivers Holtemme and Elbe, Germany and Lower Jordan River, Israel and West Bank, as well as from their adjacent sewage treatment plants. Blending river samples with sewage treatment plant effluents mainly resulted in a stimulation of EEAs, which was diminished in blends with 0.2-μm filtered sewage treatment plant effluents. Stimulation for primary production and bacterial cell and biomass production of River Holtemme and Elbe samples was observed, and inhibition of these rates for Lower Jordan River samples probably linked to generally high turbidity. The quantified bacterial biomass versus cell production rates showed almost unbalanced (≫ 1) growth. Very high biomass to cell production ratios were found for sewage and sewage-containing samples, which provides a semi-quantitative indicator function for high quantities of microbial easy utilizable dissolved organic matter as nutrition source. The presented approach enables the simultaneous quantification of inhibitory and stimulating toxic responses as well as supplying ecosystem-based data for policy decision-making, and for direct incorporation in models to derive management and remediation strategies.
اظهر المزيد [+] اقل [-]Zinc-lysine prevents chromium-induced morphological, photosynthetic, and oxidative alterations in spinach irrigated with tannery wastewater
2019
Zaheer, Ihsan Elahi | Ali, Shafaqat | Rizwan, Muhammad | Bareen, Firdaus-e- | Abbas, Zohaib | Bukhari, Syed Asad Hussain | Wijaya, Leonard | Alyemeni, Mohammed Nasser | Ahmad, Parvaiz
Anthropogenic activities have resulted in severe environmental degradation. Untreated wastewater from tanneries is hazardous to all kinds of life on earth. Effluent from tanning industries, containing large amount of Cr, is used to irrigate the crops in Pakistan. The current experiment was carried out to study the effects of tannery wastewater on spinach and the role of lysine-Zn in mitigating the severity of stress. The plants were grown in soil and the following treatments were used: irrigation with 0%, 33%, 66%, and 100% wastewater (ww) along with two doses (0 mM, 10 mM) of Zn-lysine. Foliar application of zinc-lysine enhanced the plant growth, biomass, Zn contents, photosynthesis, and enzyme activities in different tissues of plant. Zinc-lysine (10 mM) considerably decreased the Cr content in roots and shoots, along with ameliorating the oxidative stress by enhancing the activities of antioxidant enzymes in plants. Addition of Zn-lys (10 mM) improved the plant height by 19%, root length by 57%, leaf dry weight by 19%, and root dry weight by33% under 100% Cr treatment. Zn-lys significantly reduces the oxidative stress and concentration of Cr as compared with the Cr treatments alone. Application of Zn-lys (10 mM) reduced the Cr contents in roots by 27 and 22 under 33 and 66% Cr treatment, respectively. Taken together, Zn-lys chelates efficiently ameliorated the toxic effects of chromium. Zn-lysine has the extravagant potential of mitigating the heavy metal toxicity without harming the normal growth and development of the plants.
اظهر المزيد [+] اقل [-]Spermidine application reduces fluoride uptake and ameliorates physiological injuries in a susceptible rice cultivar by activating diverse regulators of the defense machinery
2019
Banerjee, Aditya | Singh, Ankur | Roychoudhury, Aryadeep
The manuscript illustrates the ameliorative effects of exogenously applied higher polyamine (PA), spermidine (Spd) in the susceptible indica rice cultivar IR-64 subjected to prolonged fluoride stress. The Spd treatment drastically reduced fluoride bioaccumulation by restricting entry of the anions through chloride channels and enabled better maintenance of the proton gradient via accumulation of P-H⁺/ATPase, thereby improving the root and shoot lengths, fresh and dry weights, RWC, chlorophyll content and activities of pyruvate dehydrogenase (PyrDH), α-amylase, and nitrate reductase (NR) in the Spd-treated, stressed plants. Expression of RuBisCo, PyrDH, α-amylase, and NR was stimulated. Spd supplementation reduced the molecular damage indices like malondialdehyde, lipoxygenase, protease activity, electrolyte leakage, protein carbonylation, H₂O₂, and methylglyoxal (detoxified by glyoxalase II). Mitigation of oxidative damage was facilitated by the accumulation and utilization of proline, glycine-betaine, total amino acids, higher PAs, anthocyanin, flavonoids, β-carotene, xanthophyll, and phenolics as verified from the expression of genes like P5CS, BADH1, SAMDC, SPDS, SPMS, DAO, PAO, and PAL. Spd treatment activated the ascorbate-glutathione cycle in the stressed seedlings. Expression and activities of enzymatic antioxidants showed that GPOX, APX, GPX, and GST were the chief ROS scavengers. Exogenous Spd promoted ABA accumulation by upregulating NCED3 and suppressing ABA8ox1 expression. ABA-dependent osmotic stress-responsive genes like Osem, WRKY71, and TRAB1 as well as ABA-independent transcription factor encoding gene DREB2A were induced by Spd. Thus, Spd treatment ameliorated fluoride-mediated injuries in IR-64 by restricting fluoride uptake, refining the defense machinery and activating the ABA-dependent as well as ABA-independent stress-responsive genes.
اظهر المزيد [+] اقل [-]Sorption of 14C-carbofuran in Austrian soils: evaluation of fate and transport of carbofuran in temperate regions
2019
Cáceres, Tanya | Maestroni, Britt | Islam, Marivil | Cannavan, Andrew
Carbofuran is an anticholinesterase carbamate commonly used as an insecticide, nematicide and acaricide in agricultural practice throughout the world. However, data on its sorption in temperate soils from Europe is limited. Laboratory studies were conducted to determine the adsorption of carbofuran on three distinct Austrian soils using batch experiments and radiometric techniques. Carbofuran adsorption capacity of the soils was found to be low in the three soils tested and showed to be related to the soils clay and organic carbon contents. The pesticide presented linear adsorption isotherms in all of the three soils. Due to the low sorption of carbofuran in the soils tested and to its high water solubility, there is a risk of migration to water bodies through run off and consequent negative effects on aquatic organisms and soil biota.
اظهر المزيد [+] اقل [-]Bidens pilosa L. hyperaccumulating Cd with different species in soil and the role of EDTA on the hyperaccumulation
2019
Dou, Xuekai | Dai, Huiping | Skuza, Lidia | Wei, Shuhe
Investigating whether the same hyperaccumulator shows a high accumulation potential for different species of the same heavy metal in the soil has rarely been considered until now. In this experiment, Cd accumulation by a hyperaccumulator Bidens pilosa L. from soils spiked with 3 and 9 mg Cd kg⁻¹ in the form of Cd(NO₃)₂, CdCl₂, CdBr₂, CdI₂, CdSO₄, CdF₂, Cd(OH)₂, CdCO₃, Cd₃(PO₄)₂, and CdS and effect of soil amendment with EDTA were determined. The results showed that the Cd concentrations in B. pilosa for high-solubility species were basically higher. But the enrichment factors (EFs) (shoot to soil Cd concentration ratio) and translocation factors (TFs) (shoot to root Cd concentration ratio) of low-solubility Cd species were all greater than 1, either indicating that there was a high Cd hyperaccumulative potentials of B. pilosa without considering on Cd species in soil. EDTA significantly improved B. pilosa Cd hyperaccumulation, especially for low-solubility Cd forms in soils. These results can perfectly explain the accumulation properties of one hyperaccumulator to different species of the same heavy metal. Phytoremediation may be applied for a wide scope for different Cd species–contaminated soil. Moreover, the total amount of Cd in soil was important when assessing the risk of Cd-contaminated soils.
اظهر المزيد [+] اقل [-]Acute effect of daily fine particulate matter pollution on cerebrovascular mortality in Shanghai, China: a population-based time series study
2019
Leepe, Khadija Akter | Li, Mei | Fang, Xin | Hiyoshi, Ayako | Cao, Yang
Numerous studies have investigated the impacts of ambient fine particulate matter (PM₂.₅) on human health. In this study, we examined the association of daily PM₂.₅ concentrations with the number of deaths for the cerebrovascular disease on the same day, using the generalized additive model (GAM) controlling for temporal trend and meteorological variables. We used the data between 2012 and 2014 from Shanghai, China, where the adverse health effects of PM₂.₅ have been of particular concern. Three different approaches (principal component analysis, shrinkage smoothers, and the least absolute shrinkage and selection operator regularization) were used in GAM to handle multicollinear meteorological variables. Our results indicate that the average daily concentration of PM₂.₅ in Shanghai was high, 55 μg/m³, with an average daily death for cerebrovascular disease (CVD) of 62. There was 1.7% raised cerebrovascular disease deaths per 10 μg/m³ increase in PM₂.₅ concentration in the unadjusted model. However, PM₂.₅ concentration was no longer associated with CVD deaths after controlling for meteorological variables. The results were consistent in the three modelling techniques that we used. As a large number of people are exposed to air pollution, further investigation with longer time period including individual-level information is needed to examine the association.
اظهر المزيد [+] اقل [-]The use of vegetation, bees, and snails as important tools for the biomonitoring of atmospheric pollution—a review
2019
The continuous discharge of diverse chemical products in the environment is nowadays of great concern to the whole world as some of them persist in the environment leading to serious diseases. Several sampling techniques have been used for the characterization of this chemical pollution, although biomonitoring using natural samplers has recently become the technique of choice in this field due to its efficiency, specificity, and low cost. In fact, several living organisms known as biomonitors could accumulate the well-known persistent environmental pollutants allowing their monitoring in the environment. In this work, a review on environmental biomonitoring is presented. The main sampling techniques used for monitoring environmental pollutants are first reported, followed by an overview on well-known natural species used as passive samplers and known as biomonitors. These species include conifer needles, lichen, mosses, bees and their byproducts, and snails, and were widely used in recent research as reliable monitors for environmental pollution.
اظهر المزيد [+] اقل [-]Experimental characterization of multi-nozzle atomization interference for dust reduction between hydraulic supports at a fully mechanized coal mining face
2019
To analyze the distribution pattern concerning multi-nozzle interference spray particle granularity between hydraulic supports, the present study conducts atomization interference experimental characterization for three types of nozzles used in coal mines based on a Doppler laser interference spray dust suppression simulation experimental system. The results indicate that for single-nozzle atomization, the impact of spray pressure on spray droplet size is gradually subdued, and a spray pressure of 8 MPa yields the best result; compared with single-nozzle spray, the multi-nozzle atomization interference effect can downsize the spray field overlapping zone, leading to an improved uniformity of overall spray particle distribution. As the spray field overlapping coefficient k increases, the particle size of the interference spray field decreases first and then increases. As the spray field overlapping coefficient reaches 0.4, the distribution of spray droplet size is most concentrated, corresponding to the optimal atomized dust suppression effect. Practical testing indicates that the optimal spray field overlapping coefficient measured at a fully mechanized mining face agrees well with the experimental result. Under the optimal parameters, the average total dust and respirable dust suppression rates measured at various measuring points on the downwind side during support relocation reach 78.93% and 80.53%, respectively.
اظهر المزيد [+] اقل [-]Sub-chronic exposure to Tris(1,3-dichloro-2-propyl) phosphate induces sex-dependent hepatotoxicity in rats
2019
As the application and environmental release of tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) are being increased rapidly, serious concerns have been raised regarding its adverse effects on human health. Exposure to TDCIPP has been implicated in hepatotoxicity, but the molecular mechanisms remain unclear. Here, both male and female Sprague Dawley rats were administered TDCIPP with 125, 250, or 500 mg/kg/day for 12 weeks. Then the ultrastructure of liver, biochemical indicators in serum and liver, and hepatic gene expression were analyzed to reveal molecular mechanisms of hepatotoxicity induced by TDCIPP. Continuous TDCIPP exposure decreased body weight, particularly in 500 mg/kg/day TDCIPP-exposed males, and dose dependently increased the ratio of liver to body weight in both genders. The decreased levels of triglyceride, cholesterol, and transaminase in the serum and livers were observed in both genders after TDCIPP exposure, which indicated dysfunction in the hepatic metabolism. Liver histopathology revealed hepatocellular damages in males and females after TDCIPP exposure. The transcriptomic analysis indicated that TDCIPP exposure significantly changed pathways of bile acid metabolism, inflammatory response, oxidative phosphorylation and carcinogenicity in 250 and 500 mg/kg/day TDCIPP-exposed males and 500 mg/kg/day TDCIPP-exposed females, and there was no statistical significance in any other TDCIPP-exposed groups. The transcriptional analysis showed that TDCIPP exposure led to oxidative stress in the livers of rats, thereby increasing the inflammatory response and promoting mechanisms of carcinogenesis in both genders. Finally, TDCIPP led to more severe adverse phenotypic effects in male than female rats.
اظهر المزيد [+] اقل [-]An evaluation of the levels of organochlorine compounds (OCPs and PCBs) in cultured freshwater and wild sea fish eggs as an exposure biomarker for environmental contamination
2019
Atmaca, Enes | Das, Yavuz Kursad | Yavuz, Oguzhan | Aksoy, Abdurrahman
In this study, the eggs of 30 wild Black Sea whiting (Merlangius merlangus euxinus, Nordmann, 1840) and 30 farmed freshwater rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) collected from Samsun Province in Turkey were analyzed to determine the level of contamination by nine organochlorine pesticides (OCPs), namely α-hexachlorocyclohexane (α-HCH), β-HCH, γ-HCH (lindane), hexachlorobenzene (HCB), aldrin, 2,4′-dichlorodiphenyltrichloroethane (DDT), 4,4′-DDT, 2,4′-dichlorodiphenyldichloroethylene (DDE), 4,4′-DDE, and 15 polychlorinated biphenyls (PCBs) (PCB-28, -70, -74, -81, -99, -101, -118, -138, -153, -156, -170, -180, -183, -187, and -208), and their potential use as biomarkers to monitor levels of environmental contamination. OCPs and PCBs in the fat of fish eggs were extracted cryogenically and their concentrations were determined with a gas chromatography-electron capture detector (GC-ECD). The whiting eggs showed high OCP and PCB levels compared to the rainbow trout eggs. The median ∑ DDT values for whiting and rainbow trout eggs were 1601.62 ng g⁻¹ fat (range 824.87–5049.81) and 406.49 ng g⁻¹ fat (range 199.88–588.82); median ∑Indicator PCBs were 1264.24 ng g⁻¹ fat (range 520.05–6140.32) and 82.11 ng g⁻¹ fat (range 2.85–215.97); and median ∑ HCHs were 155.66 ng g⁻¹ fat (range 35.45–330.40) and 13.48 ng g⁻¹ fat (range 4.44–66.44), respectively. In the whiting eggs, the ∑Indicator PCB level was above the maximum residue limit (MRL) of 200 ng g⁻¹ fat stated in the European Commission Regulation (EC) and Turkish Food Codex (TFC). In addition, there was a significant difference between the contamination levels of the eggs of the two species. In conclusion, it appears that fish eggs can serve as a valuable biomarker for the level of contamination of persistent organochlorine contaminants in different aquatic environments.
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