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1.
Environmental Science and Pollution Research - The Fundão Dam collapsed, on November 5th, 2015, dumping more than 50 million/m3 of iron ore tailings, enriched with metals, into the Doce River...  相似文献   
2.
Phyllanthus niruri is a plant that is used to prevent calcium oxalate crystallisation and to block the stone formation in urolithiasis. Contaminants in the environment can be readily taken up by medicinal plants due to their ability to absorb chemicals into their tissues. If contaminated plants are ingested, they have the potential to negatively affect human and environmental health. The aim of this study was to assess contamination in the soil and the medicinal plant P. niruri by cadmium (Cd) in ceramic industrial areas of Monte Carmelo, Brazil. Soil samples and plant samples (divided in root, shoot and leaves) were collected from a contaminated monitoring site and from a rural area (which was used as a reference site for comparative purposes). The Cd concentrations of the samples were analysed with an atomic absorption spectrometer. P. niruri was found to be sensitive to soil contamination by Cd that was attributed to ceramic industrial emissions. The results revealed that Cd bioaccumulation in the roots and shoots of P. niruri was associated with a significant increase (p?<?0.05) in the concentration of active lignan compounds (phyllanthin and hypophyllanthin) in the leaves. The identification of high concentrations of Cd and active lignan compounds suggests a risk of contamination of the site and the risk of a high dose of Cd to people exposed at the site.  相似文献   
3.
A number of Mn-oxide minerals in soils from a farm in North Devon have been tentatively identified using a combination of advanced analytical techniques: scanning electron microscopy (SEM), scanning electron microprobe (SEMP), X-ray diffraction (XRD) and bulk chemical analysis by wet digestion followed by inductively-coupled plasma spectrometry (ICP). The minerals lithiophorite and hollandite are thought to occur throughout the study area although there is considerable geographical variation in the proportions of minerals present. Bimessite, vernadite, romanechite, todorokite and cryptomelane may also be present, although in smaller amounts. The use of SEMP, together with a simple sorption experiment, has allowed a study of the extent of uptake of Co and Cu by different Mn-oxide minerals. Lithiophorite appears to take up Co and Cu more effectively than hollandite within a pH range of 4–6.  相似文献   
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From the rudimentary data available on the domestic energy consumption of the urban and rural poor in developing countries it appears that consumption by the poor in much of the developing world is at bare subsistence levels. Despite generally higher incomes, the domestic energy consumption of the urban poor appears to be no higher in Btu terms than that of the rural poor due to the more thermally efficient fuel supplies used by the urban poor. A further tentative conclusion is that for similar reasons related to the changing efficiency of the fuel supply system, energy consumption measured in quantity terms rises within a given area by less than the rise in income at lower income levels. As incomes rise there is a tendency to switch to more efficient fuels in a manner analogous to the contrast in energy consumption patterns between urban and rural areas. Thus a rising demand for energy services can be accomodated by a less than proportionate gross input. En examinant les données rudimentaires dont on dispose sur la consommation domestique en énergie des classes urbaines et rurales défavorisées des pays en développement, il ressort que la consommation de ces classes dans la plupart de ces pays se situe à des niveaux de simple subsistence. Malgré des revenus généralement plus élevés, la consommation domestique en énergie des classes urbaines défavorisées ne semble pas étre supérieure en termes d'unités thermiques britanniques à celle des classes rurales défavorisées en raison d'approvisionnements en combustibles thermiques à meilleur rendement dans les villes. Une autre conclusion provisoire envisage que pour des raisons similaires ayant trait aux fluctuations de l'efficacité du système d'approvisionnement en combustibles, la consommation énergétique mesurée en termes quantitatifs augments dans une zone donnée moins rapidement que les revenus aux échelons inférieurs. Au fur et à mesure que les revenus progressent, la tendance à utiliser des combustibles a meilleur rendement reflète le même contraste existant dans les modes de consommation en énergie entre les zones urbaines et rurales. On peut donc satisfaire les besoins croissants en matière d'énergie par des coûts de production proportionnellement moins élevés. Por los datos rudimentarios disponibles sobre el consumo doméstico de energía de los estratos probres rural y urbano de los países en desarrollo, parece ser que dicho consumo está en los límites del nivel de subsistencia. A pesar del relativo mayor ingreso de los estratos pobres urbanos, el consumo de energía de éstos no parece ser, en términos fíisicos, mayor que la de los estratos pobres rurales debido a que aquellos emplean combustibles que pueden usarse con mayor eficiencia térmica. Otra conclusión tentativa es que debido a razones similares a esta disparidad de eficiencia, la cantidad de energía consumida en un sector pobre aumenta en una proporción menor que el aumento del ingreso. En forma análoga a la deferencia entre las tendencias de consumo entre grupos ru rales y urbanos, a mayores niveles de ingreso en una misma área hay una tendencia a usar combustibles más eficientes. Como resultado una demanda creciente de energía puede ser satisfecha con un amento proporcionalmente menor de suministrode combustible.  相似文献   
6.
A surface drinking water monitoring program for four corn (Zea mays L.) herbicides was conducted during 1995-2001. Stratified random sampling was used to select 175 community water systems (CWSs) within a 12-state area, with an emphasis on the most vulnerable sites, based on corn intensity and watershed size. Finished drinking water was monitored at all sites, and raw water was monitored at many sites using activated carbon, which was shown capable of removing herbicides and their degradates from drinking water. Samples were collected biweekly from mid-March through the end of August, and twice during the off-season. The analytical method had a detection limit of 0.05 microg L(-1) for alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)-acetamide] and 0.03 microg L(-1) for acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)-acetamide], atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine], and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)-acetamide]. Of the 16528 drinking water samples analyzed, acetochlor, alachlor, atrazine, and metolachlor were detected in 19, 7, 87, and 53% of the samples, respectively. During 1999-2001, samples were also analyzed for the presence of six major degradates of the chloroacetanilide herbicides, which were detected more frequently than their parent compounds, despite having higher detection limits of 0.1 to 0.2 microg L(-1). Overall detection frequencies were correlated with product use and environmental fate characteristics. Reservoirs were particularly vulnerable to atrazine, which exceeded its 3 microg L(-1) maximum contaminant level at 25 such sites during 1995-1999. Acetochlor annualized mean concentrations (AMCs) did not exceed its mitigation trigger (2 microg L(-1)) at any site, and comparisons of observed levels with standard measures of human and ecological hazards indicate that it poses no significant risk to human health or the environment.  相似文献   
7.
This in vitro study investigates the impact of silica-coated magnetite particles (Fe3O4@SiO2/SiDTC, hereafter called IONP; 2.5 mg L?1) and its interference with co-exposure to persistent contaminant (mercury, Hg; 50 μg L?1) during 0, 2, 4, 8, 16, 24, 48, and 72 h on European eel (Anguilla anguilla) brain and evaluates the significance of the glutathione (GSH) redox system in this context. The extent of damage (membrane lipid peroxidation, measured as thiobarbituric acid reactive substances, TBARS; protein oxidation, measured as reactive carbonyls, RCs) decreased with increasing period of exposure to IONP or IONP + Hg which was accompanied with differential responses of glutathione redox system major components (glutathione reductase, GR; glutathione peroxidase, GPX; total GSH, TGSH). The occurrence of antagonism between IONP and Hg impacts was evident at late hour (72 h), where significantly decreased TBARS and RC levels and GR and glutathione sulfo-transferase (GST) activity imply the positive effect of IONP + Hg concomitant exposure against Hg-accrued negative impacts [vs. early (2 h) hour of exposure]. A period of exposure-dependent IONP alone and IONP + Hg joint exposure-accrued impact was perceptible. Additionally, increased susceptibility of the GSH redox system to increased period of exposure to Hg was depicted, where insufficiency of elevated GR for the maintenance of TGSH required for membrane lipid and cellular protein protection was displayed. Overall, a fine-tuning among brain glutathione redox system components was revealed controlling IONP + Hg interactive impacts successfully.  相似文献   
8.
We analyze daily wintertime cyclone variability in the central and eastern Mediterranean during 1958–2001 and identify four distinct “cyclone states,” corresponding to the presence or absence of cyclones in each basin. Each cyclone state is associated with wind flows that induce characteristic patterns of cooling via turbulent (sensible and latent) heat fluxes in the eastern Mediterranean basin and Aegean Sea. The relative frequency of occurrence of each state determines the heat loss from the Aegean Sea during that winter, with largest heat losses occurring when there is a storm in the eastern but not central Mediterranean (eNOTc) and the smallest occurring when there is a storm in the central but not eastern Mediterranean (cNOTe). Time series of daily cyclone states for each winter allow us to infer Aegean Sea cooling for winters prior to 1985, the earliest year for which we have daily heat flux observations. We show that cyclone states conducive to Aegean Sea convection occurred in 1991/1992 and 1992/1993, the winters during which deepwater formation was observed in the Aegean Sea, and also during the mid-1970s and the winters of 1963/1964 and 1968/1969. We find that the eNOTc cyclone state is anticorrelated with the North Atlantic Oscillation (NAO) prior to 1977/1978. After 1977/1978, the cNOTe state is anticorrelated with both the NAO and the North Caspian Pattern, showing that the area of influence of large-scale atmospheric teleconnections on regional cyclone activity shifted from the eastern to the central Mediterranean during the late 1970s. A trend toward more frequent occurrence of the positive phase of the NAO produced less frequent cNOTe states since the late 1970s, increasing the number of days with strong cooling of the Aegean Sea surface waters.  相似文献   
9.
The servicising approach in vineyard protection is considered a valid alternative to achieve decoupling between the economic and environmental performance of viticulture. In this paper, a policy package is designed to promote the uptake of a servicised model of vineyard protection in an area of smallholding viticulture. In doing so, a specific methodology based on a step by step protocol has been followed that aims to come up with a package that is effective, implementable and socially as well as politically acceptable. The paper concludes on the importance of combining several policy instruments in a policy package to realise the political objective. The proposed viable policy package includes incentives that support the companies’ shift towards offering crop protection solutions, further development of IPM solutions and instruments that encourage farmers to reduce the use of pesticides and collectively hire crop protection services.  相似文献   
10.
Environmental Science and Pollution Research - In this study, the essential oil (EO) from leaves of Croton linearis Jacq was extracted and characterized by GC/MS. The EO hydrophilic-lipophilic...  相似文献   
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