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Unravelling motor behaviour hallmarks in intoxicated adolescents: methylmercury subtoxic-dose exposure and binge ethanol intake paradigm in rats Texte intégral
2018
Oliveira, Aline Nascimento | Pinheiro, Alana Miranda | Belém-Filho, Ivaldo Jesus Almeida | Fernandes, Luanna Melo Pereira | Cartágenes, Sabrina Carvalho | Ribera, Paula Cardoso | Fontes-Júnior, Enéas Andrade | Crespo-Lopez, Maria Elena | Monteiro, Marta Chagas | Lima, Marcelo Oliveira | Maia, Cristiane Socorro Ferraz
Methylmercury (MeHg) is a hazardous environmental pollutant, affecting Amazon basin communities by anthropogenic activities. The exact safe level of MeHg exposure is unclear, despite the efforts of health international societies to avoid mercury (Hg) poisoning. Central nervous system is severely impacted by Hg intoxication, reflecting on motor impairment. In addition, alcohol has been associated to an overall brain damage. According to lifestyle of Amazon riverside communities, alcohol intake occurs frequently. Thus, we investigated if continuous MeHg exposure at low doses during adolescence displays motor deficits (experiment 1). In the experiment 2, we examine if the co-intoxication (i.e. MeHg plus ethanol exposure) during adolescence intensify motor damage. In the experiment 1, Wistar adolescent rats (31 days old) received chronic exposure to low dose (CELD) of MeHg (40 μg/kg/day) for 35 days. For the experiment 2, five sessions of alcohol binge drinking paradigm (3ON-4OFF; 3.0 g/kg/day) were employed associated to MeHg intoxication. Motor behaviour was evaluated by the open field, pole test, beam walking and rotarod paradigms. CELDS of MeHg display motor function damage, related to hypoactivity, bradykinesia-like behaviour, coordination deficits and motor learning impairment. Co-intoxication of MeHg plus ethanol reduced cerebellar Hg content, however also resulted in motor behavioural impairment, as well as additive effects on bradykinesia and fine motor evaluation.
Afficher plus [+] Moins [-]An extensive review on restoration technologies for mining tailings Texte intégral
2018
Sun, Wei | Ji, Bin | Khoso, Sultan Ahmed | Tang, Honghu | Liu, Runqing | Wang, Li | Hu, Yuehua
Development of mineral resources and the increasing mining waste emissions have created a series of environmental and health-related issues. Nowadays, the ecological restoration of mining tailings has become one of the urgent tasks for mine workers and environmental engineers all over the world. Aim of the present paper is to highlight the previous restoration techniques and the challenges encountered during the restoration of mine tailings. As it is a common practice that, before restoring of tailings, the site should be evaluated carefully. Studies showed that the mine tailings’ adverse properties, including excessive heavy metal concentration, acidification, improper pH value, salinization and alkalization, poor physical structure and inadequate nutrition, etc., are the major challenges of their restoration. Generally, four restoration technologies, including physical, chemical, phytoremediation, and bioremediation, are used to restore the mining tailings. The working mechanism, advantages, and disadvantages of these techniques are described in detail. In addition, selection of the suitable restoration techniques can largely be carried out by considering both the economic factors and time required. Furthermore, the ecosystem restoration is perceived to be a more promising technology for mine tailings. Therefore, this extensive review can act as a valuable reference for the researchers involved in mine tailing restoration.
Afficher plus [+] Moins [-]The effects of ozone on human health Texte intégral
2018
Nuvolone, Daniela | Petri, Davide | Voller, Fabio
Ozone is a highly reactive, oxidative gas associated with adverse health outcome, including mortality and morbidity. Data from monitoring sites worldwide show levels of ozone often exceeding EU legislation threshold and the more restrictive WHO guidelines for the protection of human health. Well-established evidence has been produced for short-term effects, especially on respiratory and cardiovascular systems, associated to ozone exposure. Less conclusive is the evidence for long-term effects, reporting suggestive associations with respiratory mortality, new-onset asthma in children and increased respiratory symptom effects in asthmatics. The growing epidemiological evidence and the increasing availability of routinely collected data on air pollutant concentrations and health statistics allow to produce robust estimates in health impact assessment routine. Most recent estimates indicate that in 2013 in EU-28, 16,000 premature deaths, equivalent to 192,000 years of life lost, are attributable to ozone exposure. Italy shows very high health impact estimates among EU countries, reporting 3380 premature deaths and 61 years of life lost (per 100,000 inhabitants) attributable to ozone exposure.
Afficher plus [+] Moins [-]A review on pesticide removal through different processes Texte intégral
2018
Marican, Adolfo | Durán-Lara, EstebanF.
The main organic pollutants worldwide are pesticides, persistent chemicals that are of concern owing to their prevalence in various ecosystems. In nature, pesticide remainders are subjected to the chemical, physical, and biochemical degradation process, but because of its elevated stability and some cases water solubility, the pesticide residues persist in the ecosystem. The removal of pesticides has been performed through several techniques classified under biological, chemical, physical, and physicochemical process of remediation from different types of matrices, such as water and soil. This review provides a description of older and newer techniques and materials developed to remove specific pesticides according to previous classification, which range from bioremediation with microorganisms, clay, activated carbon, and polymer materials to chemical treatment based on oxidation processes. Some types of pesticides that have been removed successfully to large and small scale include, organophosphorus, carbamates, organochlorines, chlorophenols, and synthetic pyrethroids, among others. The most important characteristics, advantages, and disadvantages of techniques and materials for removing pesticides are described in this work.
Afficher plus [+] Moins [-]Indoor air quality of everyday use spaces dedicated to specific purposes—a review Texte intégral
2018
Marć, Mariusz | Śmiełowska, Monika | Namieśnik, Jacek | Zabiegała, Bożena
According to literature data, some of the main factors which significantly affect the quality of the indoor environment in residential households or apartments are human activities such as cooking, smoking, cleaning, and indoor exercising. The paper presents a literature overview related to air quality in everyday use spaces dedicated to specific purposes which are integral parts of residential buildings, such as kitchens, basements, and individual garages. Some aspects of air quality in large-scale car parks, as a specific type of indoor environment, are also discussed. All those areas are characterized by relatively short time use. On the other hand, high and very high concentration levels of xenobiotics can be observed, resulting in higher exposure risk. The main compounds or group of chemical compounds are presented and discussed. The main factors influencing the type and amount of chemical pollutants present in the air of such areas are indicated.
Afficher plus [+] Moins [-]Chemical sensing platform for the Zn+2 ions based on poly(o-anisidine-co-methyl anthranilate) copolymer composites and their environmental remediation in real samples Texte intégral
2018
Khan, Aftab Aslam Parwaz | Khan, Anish | Alam, M.A. | Oves, Mohammad | Asiri, Abdullah M. | Rahman, Mohammed M. | Inamuddin,
A novel nanostructure of poly(o-anisidine-co-methyl anthranilate) (poly(Ani-Co-MA) copolymer has been synthesized by chemical oxidative in situ polymerization technique with equal molar proportion of monomers in the presence of sodium dodecylbenzene sulfonic acid (SDBS) surfactant. The synthesized copolymers were characterized by scanning electron microscope (SEM) and X-ray crystallography (XRD), Fourier transform infrared (FTIR), UV-Vis, thermo-gravimetric analysis (TGA), and simultaneous X-ray photoelectron spectroscopy (XPS) study. The ultraviolet visible spectrum shows the π to π∗ transition and n to π∗ transition. XRD diffraction pattern confirms the amorphous nature of poly(Ani-Co-MA)-SDBS composites. The scanning electron microscope image shows the morphology of the copolymer matrix. For the selective detection of Zn⁺² cation in neutral phosphate buffer, it was fabricated Zn⁺² cation sensor based on glassy carbon electrode (GCE) coated with poly(Ani-co-MA)-SDBS composites as a thin layer with conducting coating binders. The proposed cation sensor has been found to exhibit the inertness in air and chemical environment, long-term stability with good sensitivity, a broad linear dynamic range practically, a reliable reproducibility, short response time, and high electrochemical activity. The sensitivity (0.3560 μA μM⁻¹ cm⁻²) of Zn⁺² cation sensor has been calculated from the slope of the calibration curve. The linearity of the calibration curve is found over the linear dynamic range (LDR) 0.1 nM~0.01 M, and detection limit (DL) is 27.0 ± 1.35 pM at the signal to noise ratio of 3. This novel effort may be considered quite reliable and effective to detect Zn⁺² cation in environmental and biomedical sectors on a broad scale. Simultaneously, SDBS doped poly(o-anisidine-co-methyl anthranilate) copolymer composites were measured against medically important organisms Escherichia coli. E. ludwigi, and Bacillus subtilis. Graphical abstract ᅟ
Afficher plus [+] Moins [-]Application of UV-visible absorption spectroscopy combined with two-dimensional correlation for insight into DOM fractions from native halophyte soils in a larger estuarine delta Texte intégral
2018
Wei, Huaibin | Yu, Huibin | Pan, Hongwei | Gao, Hongjie
UV-visible absorption spectroscopy combined with principal component analysis (PCA) and two-dimensional correlation (2D correlation) is used to trace components of dissolved organic matter (DOM) extracted from soils in a larger estuarine delta and to investigate spatial variations of DOM fractions. Soil samples of different depths were collected from native halophyte soils along a saline gradient, i.e., Suaeda salsa Comm. (SSC), Chenopodium album Comm. (CAC), Phragmites australis Comm. (PAC), and Artemisia selengensis Comm. (ASC). Molecular weights of DOM within the SSC soil profile were the lowest, followed by the CAC, PAC, and ASC soil profiles. Humification degree of DOM within the ASC soil profile was the highest, followed by the PAC, SSC, and CAC soil profiles. DOM within the soil profiles mainly contained phenolic, carboxylic, microbial products, and aromatic and alkyl groups through the PCA, which presented the significant differentiation among the four native halophyte soil profiles. The 2D UV correlation spectra of DOM within the SSC soil profile indicated that the variations of the phenolic groups were the largest, followed by the carboxylic groups, microbial products, and humified organic materials according to the band changing order of 285 → 365 → 425 → 520 nm. The 2D UV correlation spectra of DOM within the CAC soil profiles determined that the decreasing order of the variations was phenolic groups > carboxylic groups > microbial products according the band changing order of 285 → 365 → 425 nm. The 2D UV correlation spectra of DOM within the PAC soil profile proved that the variations of the phenolic groups were larger than those of the carboxylic groups according to the band changing order of 285 → 365 nm. The 2D UV correlation spectra of DOM within the ASC soil profile demonstrated that the variations of the phenolic groups were larger than those of the other DOM fractions according to the broad cross-peak at 285/365–700 nm.
Afficher plus [+] Moins [-]A study on the causal effect of urban population growth and international trade on environmental pollution: evidence from China Texte intégral
2018
Boamah, KofiBaah | Du, Jianguo | Boamah, AngelaJacinta | Appiah, Kingsley
This study seeks to contribute to the recent literature by empirically investigating the causal effect of urban population growth and international trade on environmental pollution of China, for the period 1980–2014. The Johansen cointegration confirmed a long-run cointegration association among the utilised variables for the case of China. The direction of causality among the variables was, consequently, investigated using the recent bootstrapped Granger causality test. This bootstrapped Granger causality approach is preferred as it provides robust and accurate critical values for statistical inferences. The findings from the causality analysis revealed the existence of a bi-directional causality between import and urban population. The three most paramount variables that explain the environmental pollution in China, according to the impulse response function, are imports, urbanisation and energy consumption. Our study further established the presence of an N-shaped environmental Kuznets curve relationship between economic growth and environmental pollution of China. Hence, our study recommends that China should adhere to stricter environmental regulations in international trade, as well as enforce policies that promote energy efficiency in the urban residential and commercial sector, in the quest to mitigate environmental pollution issues as the economy advances.
Afficher plus [+] Moins [-]Artificial intelligence and regression analysis for Cd(II) ion biosorption from aqueous solution by Gossypium barbadense waste Texte intégral
2018
Fawzy, Manal | Nasr, Mahmoud | Nagy, Heba | Helmi, Shacker
In this study, batch biosorption experiments were conducted to determine the removal efficiency of Cd(II) ion from aqueous solutions by Gossypium barbadense waste. The biosorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) connected with energy dispersive X-ray (EDX). The sorption mechanism was described by complexation/chelation of Cd²⁺ with the functional groups of O–H, C=O, –COO–, and C–O, as well as, cation-exchange with Mg²⁺ and K⁺. At initial Cd(II) ion concentration (C ₒ), 50 mg/L, the adsorption equilibrium of 89.2% was achieved after 15 min under the optimum experimental factors of pH 6.0, biosorbent dosage 10 g/L, and particle diameter 0.125–0.25 mm. Both Langmuir and Freundlich models fitted well to the sorption data, suggesting the co-existence of monolayer coverage along with heterogenous surface biosorption. Artificial neural network (ANN) with a structure of 5–10–1 was performed to predict the Cd(II) ion removal efficiency. The ANN model provided high fit (R ² 0.923) to the experimental data and indicated that C ₒ was the most influential input. A pure-quadratic model was developed to determine the effects of experimental factors on Cd(II) ion removal efficiency, which indicated the limiting nature of pH and biosorbent dosage on Cd(II) adsorption. Based on the regression model (R ² 0.873), the optimum experimental factors were pH 7.61, biosorbent dosage 24.74 g/L, particle size 0.125–0.25 mm, and adsorption time 109.77 min, achieving Cd²⁺ removal of almost 100% at C ₒ 50 mg/L.
Afficher plus [+] Moins [-]Investigating the driving forces of China’s carbon intensity based on a dynamic spatial model Texte intégral
2018
Huang, Junbing
In extant literature on China’s carbon intensity, economic growth is considered an important determinant. However, the corresponding policy implications are slightly weak in subsequent practice because economic growth is an outcome of many economic activities, such as technological progress and capital stock accumulation. Furthermore, spatial spillover effects are ignored when using regional datasets. As a result, this study uses the dynamic spatial model to analyze the driving forces of China’s provincial carbon intensity over the period 2000–2014. Results indicate that both technological progress and capital stock accumulation are important measures to carbon intensity reduction. China’s current industrialization, urbanization, and special energy structure exert a negative effect on the decline in carbon intensity. In addition, China’s provincial carbon intensity also exhibits considerable spatiotemporal distribution characteristics. As such, the corresponding policy measures are presented.
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