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Physiological basis of differential zinc and copper tolerance of Verbascum populations from metal-contaminated and uncontaminated areas Full text
2016
Morina, Filis | Jovanović, Ljubinko | Prokić, Ljiljana | Veljović-Jovanović, Sonja
Metal contamination represents a strong selective pressure favoring tolerant genotypes and leading to differentiation between plant populations. We investigated the adaptive capacity of early-colonizer species of Verbascum recently exposed to Zn- and Cu-contaminated soils (10–20 years). Two Verbascum thapsus L. populations from uncontaminated sites (NMET1, NMET2), one V. thapsus from a zinc-contaminated site (MET1), and a Verbascum lychnitis population from an open-cast copper mine (MET2) were exposed to elevated Zn or Cu in hydroponic culture under glasshouse conditions. MET populations showed considerably higher tolerance to both Zn and Cu than NMET populations as assessed by measurements of growth and net photosynthesis, yet they accumulated higher tissue Zn concentrations in the shoot. Abscisic acid (ABA) concentration increased with Zn and Cu treatment in the NMET populations, which was correlated to stomatal closure, decrease of net photosynthesis, and nutritional imbalance, indicative of interference with xylem loading and divalent-cation homeostasis. At the cellular level, the sensitivity of NMET2 to Zn and Cu was reflected in significant metal-induced ROS accumulation and ion leakage from roots as well as strong induction of peroxidase activity (POD, EC 1.11.1.7), while Zn had no significant effect on ABA concentration and POD activity in MET1. Interestingly, MET2 had constitutively higher root ABA concentration and POD activity. We propose that ABA distribution between shoots and roots could represent an adaptive mechanism for maintaining low ABA levels and unaffected stomatal conductance. The results show that metal tolerance can occur in Verbascum populations after relatively short time of exposure to metal-contaminated soil, indicating their potential use for phytostabilization.
Show more [+] Less [-]Disruption of steroidogenesis after dimethoate exposure and efficacy of N-acetylcysteine in rats: an old drug with new approaches Full text
2016
Jallouli, Manel | El Bini Dhouib, Ines | Dhouib, Hanène | Lasram, Montassar | Gharbi, Najoua | El Fazaa, Saloua
Organophosphates (OPs) like dimethoate (DMT), are pesticides used worldwide, which can affect both animals and human. Whereas their toxicity is due to acetylcholinesterase inhibition, their secondary toxic effects have been related to free oxygen radical biosynthesis. The present study was designed to investigate the reprotoxic effects of DMT and the protective role of N-acetylcysteine (NAC) in male rat. DMT (20 mg/ kg/body weight) was administered daily to rats via gavage in corn oil and NAC (2 g/l) was added to drinking water for 30 days. Rats were sacrificed on the 30th day, 2 h after the last administration. Markers of testis injury (steroidogenesis impairment) and oxidative stress (lipid peroxidation, reduced glutathione, and antioxidant status) were assessed. In DMT-exposed rats, the serum level of testosterone was decreased. Further, a significant increase in lipid peroxidation level and a significant decrease in the activities of antioxidant enzymes were observed in the testis of rats during DMT intoxication. Real-time PCR (RT-PCR) analysis demonstrated a decrease in messenger RNA (mRNA) levels for testicular steroidogenic acute regulatory StAR protein, cytochrome P450scc, 3β-hydroxysteroid dehydrogenase (3β-HSD), and 17β hydroxysteroid dehydrogenase (17β-HSD) in the testis after DMT exposure. No significant changes in the oxidative stress status and selected reproductive variables were observed on CTN group, whereas NAC restored the oxidative stress and the steroidogenesis on NAC group. Dimethoate induces reprotoxicity and oxidative stress. N-acetylcysteine showed therapeutic recovery effects against dimethoate toxicity.
Show more [+] Less [-]Gas permeability of biochar-amended clay: potential alternative landfill final cover material Full text
2016
Wong, James Tsz Fung | Chen, Zhongkui | Ng, Charles Wang Wai | Wong, Ming Hung
Compacted biochar-amended clay (BAC) has been proposed as an alternative landfill final cover material in this study. Biochar has long been proposed to promote crop growth, mitigate odor emission, and promote methane oxidation in field soils. However, previous studies showed that soil-gas permeability was increased upon biochar application, which will promote landfill gas emission. The objective of the present study is to investigate the possibility of using compacted BAC as an alternative material in landfill final cover by evaluating its gas permeability. BAC samples were prepared by mixing 425-μm-sieved peanut shell biochar with kaolin clay in different ratios (0, 5, 10, and 15 %, w/w) and compacting at different degrees of compactions (DOC) (80, 85, and 90 %) with an optimum water content of 35 %. The gas permeability of the BACs was measured by flexible wall gas permeameter and the microstructure of the BACs was analyzed by SEM with energy-dispersive x-ray spectroscopy (EDX). The results show that the effects of biochar content on BAC gas permeability is highly dependent on the DOC. At high DOC (90 %), the gas permeability of BAC decreases with increasing biochar content due to the combined effect of the clay aggregation and the inhibition of biochar in the gas flow. However, at low DOC (80 %), biochar incorporation has no effects on gas permeability because it no longer acts as a filling material to the retard gas flow. The results from the present study imply that compacted BAC can be used as an alternative final cover material with decreased gas permeability when compared with clay.
Show more [+] Less [-]Volcano-related materials in concretes: a comprehensive review Full text
2016
Cai, Gaochuang | Noguchi, Takafumi | Degée, Hervé | Zhao, Jun | Kitagaki, Ryoma
Massive volcano-related materials (VRMs) erupted from volcanoes bring the impacts to natural environment and humanity health worldwide, which include generally volcanic ash (VA), volcanic pumice (VP), volcanic tuff (VT), etc. Considering the pozzolanic activities and mechanical characters of these materials, civil engineers propose to use them in low carbon/cement and environment-friendly concrete industries as supplementary cementitious materials (SCMs) or artificial/natural aggregates. The utilization of VRMs in concretes has attracted increasing and pressing attentions from research community. Through a literature review, this paper presents comprehensively the properties of VRMs and VRM concretes (VRMCs), including the physical and chemical properties of raw VRMs and VRMCs, and the fresh, microstructural and mechanical properties of VRMCs. Besides, considering environmental impacts and the development of long-term properties, the durability and stability properties of VRMCs also are summarized in this paper. The former focuses on the resistance properties of VRMCs when subjected to aggressive environmental impacts such as chloride, sulfate, seawater, and freezing–thawing. The latter mainly includes the fatigue, creep, heat-insulating, and expansion properties of VRMCs. This study will be helpful to promote the sustainability in concrete industries, protect natural environment, and reduce the impacts of volcano disaster. Based on this review, some main conclusions are discussed and important recommendations regarding future research on the application of VRMs in concrete industries are provided.
Show more [+] Less [-]Evaluating genotoxic risks in Brazilian public health agents occupationally exposed to pesticides: a multi-biomarker approach Full text
2016
This is the first study demonstrating genotoxic effects and whole transcriptome analysis on community health agents (CHAs) occupationally exposed to pesticides in Central Brazil. For the transcriptome analysis, we found some genes related to Alzheimer’s disease (LRP1), an insulin-like growth factor receptor (IGF2R), immunity genes (IGL family and IGJ), two genes related to inflammatory reaction (CXCL5 and CCL3), one gene related to maintenance of cellular morphology (NHS), one gene considered to be a strong apoptosis inductor (LGALS14), and several transcripts of the neuroblastoma breakpoint family (NBPF). Related to comet assay, we demonstrated a significant increase in DNA damage, measured by the olive tail moment (OTM), in the exposed group compared to the control group. Moreover, we also observed a statistically significant difference in OTM values depending on GSTM1 genotypes. Therefore, Brazilian epidemiological surveillance, an organization responsible for the assessment and management of health risks associated to pesticide exposure to CHA, needs to be more proactive and considers the implications of pesticide exposure for CHA procedures and processes.
Show more [+] Less [-]Chemical characteristics of rainwater in Sichuan basin, a case study of Ya’an Full text
2016
Li, Yun-Chun | Zhang, Meng | Shu, Man | Ho, Steven Sai Hang | Liu, Zi-Fang | Wang, Xian-Xiang | Zhao, Xiao-Qing
Rainwater chemistry was investigated at a semi-rural site in Ya’an, Sichuan basin with rain samples collected from May 2013 to July 2014. The rainwater pH values ranged from 3.25 to 6.86, with an annual volume-weighted mean (VWM) of 4.38, and the acid rain frequency was 74 %. Such severe acidification, 15 % of the total events showed a pH below 4.0, attributed to the deficiency of Ca²⁺, significant anthropogenic pollution contribution, and rainy pattern to this area. The annual VWM of total ions concentration was 477.19 μeq/L. NH₄ ⁺ was the most abundant ionic species, followed by SO₄ ²⁻, NO₃ ⁻, Ca²⁺, Cl⁻, Na⁺, K⁺, Mg²⁺, and F⁻ in a descending order. The total ionic concentrations presented a seasonal trend of lower values in autumn and summer but higher ones in winter and spring. Based on enrichment factor, correlation analysis and principle component analysis, three factors were identified: factor 1 (NH₄ ⁺, SO₄ ²⁻, NO₃ ⁻, K⁺, and Cl⁻, 47.45 % of the total variance) related to anthropogenic sources (coal/fuel combustion, biomass burning and agriculture), factor 2 (Ca²⁺, Mg²⁺, Na⁺, and Cl⁻, 34.01 % of the total variance) associated with natural sources, and factor 3 (H⁺, 11.78 % of the total variance) related to free acidity. Back trajectory analysis indicates that the rainwater chemistry in Ya’an was mainly affected by regional air masses from Sichuan basin. Long-range transported air masses from southwest with heavy anthropogenic pollution increased the total ion concentration and acidity of rainwater. Considering its special topography, anthropogenic emissions from regional and long-range transport (especially from southwest) must be controlled effectively to improve the acid rain condition of non-urban areas in Sichuan basin.
Show more [+] Less [-]Biochemical and lysosomal biomarkers in the mussel Mytilus galloprovincialis from the Mar Piccolo of Taranto (Ionian Sea, Southern Italy) Full text
2016
Moschino, Vanessa | Da Ros, Luisa
Biomarkers are internationally recognized as useful tools in marine coastal biomonitoring, in particular, as early-warning signals at the level of individual organisms to assess biological effects of pollutants and other stressors. In the present study, Mytilus galloprovincialis has been employed as a sentinel organism to assess biological pollution effects in the Mar Piccolo of Taranto (Southern Italy), a coastal lagoon divided into two small inlets, connected to the open sea through one natural and one artificial narrow openings. Mussels were collected in June 2013 at three sites located within each of the two inlets of the Mar Piccolo. Biological effects were investigated through a suite of biomarkers suitable to reflect effects and/or exposure to contaminants at biochemical and cellular levels. Biochemical biomarkers included glutathione-S-transferase (GST) and acetylcholinesterase (AChE) enzyme activities; as histochemical biomarkers, lysosomal membrane stability, lipofuscin and neutral lipid accumulation, and lysosomal structural changes were considered. As a whole, results highlighted differences among the three study sites, particularly for GST, AChE, and lipofuscins, which are consistent with the variations of the chemical pollutants in sediments. The applied biomarkers showed that a stress syndrome likely to be ascribed to environmental pollutants is occurring in mussels living in the Mar Piccolo of Taranto, in particular, the ones inhabiting the first inlet.
Show more [+] Less [-]Scenario of organophosphate pollution and toxicity in India: A review Full text
2016
The present study on organophosphate deals with the reports on pollution and toxicity cases throughout India. The use of pesticides was introduced in India during the 1960s which are now being used on a large scale and represents the common feature of Indian agriculture. Use of organophosphates as a pesticide came as an alternative to chlorinated hydrocarbons due to their easy degradability. Although these xenobiotics degrade under natural condition, their residues have been detected in soil, sediments, and water due to their non-regulated usage practice. The over-reliance on pesticides has not only threatened our environment but contaminations of organophosphate residues have been also detected in certain agricultural products like tea, sugars, vegetables, and fruits throughout India. This paper highlights many of the cases where different organophosphates have been detected exceeding their respective MRL values. Some organophosphates detected are so hazardous that even WHO has listed them in class 1a and class 1b hazardous group. Presence of their residues in blood, milk, honey, and tissues of human and animals revealed their excessive use and bioaccumulating capabilities. Their intentional or unintentional uptake is causing thousands of deaths and severity each year. Most of the toxicity cases presented here are due to their uptake during a suicidal attempt. This shows how easily these harmful substances are available in the market.
Show more [+] Less [-]Comparison of PAHs uptake by selected Monocotyledones and Dicotyledones from municipal and industrial sewage sludge Full text
2016
Gworek, Barbara | Klimczak, Katarzyna | Kijeńska, Marta | Gozdowski, Dariusz
The study was focused on two goals: (i) the confirmation of the existence of a general relation between the content of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and in plants growing in it, regardless of the type and content of sewage sludge, and (ii) if so, the answer to the question whether the uptake of PAHs by plants depends on their type. To realize the set aims, the contents of PAHs in four differentiated plant species were measured, two belonging to the Monocotyledones and two belonging to Dicotyledones group, growing in municipal and industrial sewage sludge in two locations. All the investigations were carried out during the period of 3 years. The results clearly demonstrated that the uptake of PAHs by a plant depended on polyaromatic hydrocarbon concentration in the sewage sludge. The relation between accumulation coefficient of PAHs in plant material vs. the content of PAH in sewage sludge was of exponential character. The results indicate that in case of four- and five-ring PAHs, the root uptake mechanism from soil solution occurs, regardless of the type and origin of sewage sludge and the type of plant. For three-ring PAHs, we can assume for Monocotyledones that the root uptake mechanism occurs because we observe a significant correlation between the content of fluorene, phenanthrene, and anthracene in plant material and in the sewage sludge. For Dicotyledones, the correlation is insignificant, and in this case probably two mechanisms occur—the uptake by roots and by leaves.
Show more [+] Less [-]Predicting seasonal fate of phenanthrene in aquatic environment with a Markov chain Full text
2016
Sun, Caiyun | Ma, Qiyun | Zhang, Jiquan | Zhou, Mo | Chen, Yanan
Phenanthrene (Phe) with carcinogenicity is ubiquitous in the environment, especially in aquatic environment; its toxicity is greater. To help determine toxicity risk and remediation strategies, this study predicted seasonal fate of Phe in aquatic environment. Candidate mechanisms including biodegradation, sorption, desorption, photodegradation, hydrolysis and volatility were studied; the results for experiments under simulated conditions for normal, wet and dry seasons in the Yinma River Basin indicated that biodegradation in sediment, sorption, desorption, and volatility were important pathways for elimination of Phe from aquatic environment and showed seasonal variations. A microcosm which was used to mimic sediment/water system was set up to illustrate seasonal distribution and transport of Phe. A Markov chain was applied to predict seasonal fate of Phe in air/water/sediment environment, the predicted results were perfectly agreed with results of microcosm experiments. Predicted results with a Markov chain suggested that volatility and biodegradation in sediment were main elimination pathways, and contributions of elimination pathways showed seasonal variations; Phe was eliminated from water and sediment to negligible levels over around 250 h in August and over 1000 h in May; in November, Phe was eliminated from water to a negligible level while about 31 % of Phe amount still remained in sediment over 1000 h.
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