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Are plants useful as accumulation indicators of metal bioavailability? 全文
2013
Remon, E. | Bouchardon, J.-L. | Le Guédard, M. | Bessoule, J.-J. | Conord, C. | Faure, O.
The use of accumulation bioindicator to assess metal bioavailability has mainly concerned individual species. This work addresses this issue at the plant community level. Metal content within different species from plant communities found at three contaminated and one uncontaminated site was compared. Results showed that for two contaminated sites, leaf metals concentrations were comparable to those in plants from control site, i.e. approx (mg/kg) 0.1 Cd, 0.2 Cr, 9.2 Cu, 1.8 Ni, 0.5 Pb and 42 Zn. Only plants from the third site showed higher metal contents, ranging from 1.5- to 8-fold those of the control community. This contrasted with ammonium acetate–EDTA extractions, which indicated a very high “availability” of metals at the three sites, as compared to the control site. Thus, metal content in plant communities provided accurate information on actual transfer toward the ensemble of vegetation, which could be used to establish site-specific “fingerprints” of metal bioavailability.
显示更多 [+] 显示较少 [-]Photosynthetic traits of Siebold's beech and oak saplings grown under free air ozone exposure in northern Japan 全文
2013
Watanabe, Makoto | Hoshika, Yasutomo | Inada, Naoki | Wang, Xiaona | Mao, Qiaozhi | Koike, Takayoshi
We set up a free-air ozone (O3) exposure system for determining the photosynthetic responses of Siebold's beech (Fagus crenata) and oak (Quercus mongolica var. crispula) to O3 under field conditions. Ten-year-old saplings of beech and oak were exposed to an elevated O3 concentration (60 nmol mol−1) during daytime from 6 August to 11 November 2011. Ozone significantly reduced the net photosynthetic rate in leaves of both species in October, by 46% for beech and 15% for oak. In beech there were significant decreases in maximum rate of carboxylation, maximum rate of electron transport in photosynthesis, nitrogen content and photosynthetic nitrogen use efficiency, but not in oak. Stomatal limitation of photosynthesis was unaffected by O3. We therefore concluded photosynthesis in beech is more sensitive to O3 than that in oak, and the O3-induced reduction of photosynthetic activity in beech was due not to stomatal closure, but to biochemical limitation.
显示更多 [+] 显示较少 [-]Titanium distribution in swimming pool water is dominated by dissolved species 全文
2013
David Holbrook, R. | Motabar, Donna | Quiñones, Oscar | Stanford, Ben | Vanderford, Brett | Moss, Donna
The increased use of titanium dioxide nanoparticles (nano-TiO2) in consumer products such as sunscreen has raised concerns about their possible risk to human and environmental health. In this work, we report the occurrence, size fractionation and behavior of titanium (Ti) in a children's swimming pool. Size-fractionated samples were analyzed for Ti using ICP-MS. Total titanium concentrations ([Ti]) in the pool water ranged between 21 μg/L and 60 μg/L and increased throughout the 101-day sampling period while [Ti] in tap water remained relatively constant. The majority of [Ti] was found in the dissolved phase (<1 kDa), with only a minor fraction of total [Ti] being considered either particulate or microparticulate. Simple models suggest that evaporation may account for the observed variation in [Ti], while sunscreen may be a relevant source of particulate and microparticule Ti. Compared to diet, incidental ingestion of nano-Ti from swimming pool water is minimal.
显示更多 [+] 显示较少 [-]Chronic exposure to volcanogenic air pollution as cause of lung injury 全文
2013
Camarinho, Ricardo | Garcia, Patrícia Ventura | Rodrigues, Armindo Santos
Few studies were made regarding the pulmonary effects of exposure to volcanogenic air pollution, representing an unrecognized health risk for humans inhabiting non-eruptive volcanically active areas (10% of world human population). We tested the hypothesis whether chronic exposure to air pollution of volcanogenic origin causes lung injury, using wild mice (Mus musculus) as model. Lung injury was determined using histological morphometric parameters, inflammatory status (InfS) and the amount of black silver deposits (BSD). Mice exposed to volcanogenic air pollution have decreased percentage of alveolar space, alveolar perimeter and lung structural functionality (LSF) ratio and, increased alveolar septal thickness, amount of BSD and InfS. For the first time it is evidenced that non-eruptive active volcanism has a high potential to cause lung injury. This study also highlights the usefulness of M. musculus as bioindicator species, and of the developed biomarker of effect LSF ratio, for future animal and/or human biomonitoring programs.
显示更多 [+] 显示较少 [-]An SPE LC–MS/MS method for the analysis of human and veterinary chemical markers within surface waters: An environmental forensics application 全文
2013
Fenech, Cecilia | Nolan, Kieran | Rock, Luc | Morrissey, Anne
In this study, the use of co-occurring discriminators of sewage and manure was assessed as a potential way to disentangle sewage and manure sources. A suite of human and veterinary derived chemical markers, which includes pharmaceuticals and compound such as food additives, has been identified for this purpose. The suite was selected in such a manner as to provide additional source characterisation, e.g. differentiating raw versus treated sewage inputs. An SPE–LC–MS/MS method was developed and validated for the determined suite of chemical markers with a detection limit of up to 50 pg L−1. This represents one of the lowest limits of detection for pharmaceuticals reported in literature. To illustrate the suitability of the proposed method to differentiate sewage and manure inputs to surface water bodies, results from surface water samples collected at monitoring sites corresponding to specific land use types within Ireland are discussed.
显示更多 [+] 显示较少 [-]Carbon storage and sequestration by trees in urban and community areas of the United States 全文
2013
Nowak, David J. | Greenfield, Eric J. | Hoehn, Robert E. | Lapoint, Elizabeth
Carbon storage and sequestration by urban trees in the United States was quantified to assess the magnitude and role of urban forests in relation to climate change. Urban tree field data from 28 cities and 6 states were used to determine the average carbon density per unit of tree cover. These data were applied to statewide urban tree cover measurements to determine total urban forest carbon storage and annual sequestration by state and nationally. Urban whole tree carbon storage densities average 7.69 kg C m−2 of tree cover and sequestration densities average 0.28 kg C m−2 of tree cover per year. Total tree carbon storage in U.S. urban areas (c. 2005) is estimated at 643 million tonnes ($50.5 billion value; 95% CI = 597 million and 690 million tonnes) and annual sequestration is estimated at 25.6 million tonnes ($2.0 billion value; 95% CI = 23.7 million to 27.4 million tonnes).
显示更多 [+] 显示较少 [-]Low concentrations, potential ecological consequences: Synthetic estrogens alter life-history and demographic structures of aquatic invertebrates 全文
2013
Souza, María Sol | Hallgren, Per | Balseiro, Esteban | Hansson, Lars-Anders
Contraceptive drugs are nowadays found in aquatic environments around the globe. Particularly, 17α-ethinylestradiol (EE2) may act even at low concentrations, such as those recorded in natural ecosystems. We evaluated the physiological effects of EE2 on cyclopoids and calanoids, common copepods in both marine and freshwater communities. We used three EE2 concentrations and assessed its impact on activity of different physiological endpoints: Acetylcholinesterase (neurotransmission), Glutathione S-transferase (detoxifying system), and Caspase-3 (apoptosis). While EE2 exerts, distinctive effect on detoxifying and apoptotic systems, no effect on AChE was observed at environmental doses. Our results show that EE2 exposure affects differently copepod physiology endpoints, altering moulting process, adult recruitment in calanoids and calanoid to cyclopoid ratio. The ecological consequences of this underlying physiological process may affect since life history to population and community structures, and this represent a new aspects of this xenobiotic in natural systems.
显示更多 [+] 显示较少 [-]Environmental concentrations of engineered nanomaterials: Review of modeling and analytical studies 全文
2013
Gottschalk, Fadri | Sun, TianYin | Nowack, Bernd
Scientific consensus predicts that the worldwide use of engineered nanomaterials (ENM) leads to their release into the environment. We reviewed the available literature concerning environmental concentrations of six ENMs (TiO2, ZnO, Ag, fullerenes, CNT and CeO2) in surface waters, wastewater treatment plant effluents, biosolids, sediments, soils and air. Presently, a dozen modeling studies provide environmental concentrations for ENM and a handful of analytical works can be used as basis for a preliminary validation. There are still major knowledge gaps (e.g. on ENM production, application and release) that affect the modeled values, but over all an agreement on the order of magnitude of the environmental concentrations can be reached. True validation of the modeled values is difficult because trace analytical methods that are specific for ENM detection and quantification are not available. The modeled and measured results are not always comparable due to the different forms and sizes of particles that these two approaches target.
显示更多 [+] 显示较少 [-]Distributions, sources and pollution status of 17 trace metal/metalloids in the street dust of a heavily industrialized city of central China 全文
2013
Li, Zhonggen | Feng, Xinbin | Li, Guanghui | Bi, Xiangyang | Zhu, Jianming | Qin, Haibo | Dai, Zhihui | Liu, Jinling | Li, Qiuhua | Sun, Guangyi
A series of representative street dust samples were collected from a heavily industrialized city, Zhuzhou, in central China, with the aim to investigate the spatial distribution and pollution status of 17 trace metal/metalloid elements. Concentrations of twelve elements (Pb, Zn, Cu, Cd, Hg, As, Sb, In, Bi, Tl, Ag and Ga) were distinctly amplified by atmospheric deposition resulting from a large scale Pb/Zn smelter located in the northwest fringe of the city, and followed a declining trend towards the city center. Three metals (W, Mo and Co) were enriched in samples very close to a hard alloy manufacturing plant, while Ni and Cr appeared to derive predominantly from natural sources. Other industries and traffic had neglectable effects on the accumulation of observed elements. Cd, In, Zn, Ag and Pb were the five metal/metalloids with highest pollution levels and the northwestern part of city is especially affected by heavy metal pollution.
显示更多 [+] 显示较少 [-]Role of arbuscular mycorrhizal fungus Rhizophagus custos in the dissipation of PAHs under root-organ culture conditions 全文
2013
Aranda, Elisabet | Scervino, José Martín | Godoy, Patricia | Reina, Rocío | Ocampo, Juan Antonio | Wittich, Regina-Michaela | García-Romera, Inmaculada
Role of arbuscular mycorrhizal fungus Rhizophagus custos in the dissipation of PAHs under root-organ culture conditions 全文
2013
Aranda, Elisabet | Scervino, José Martín | Godoy, Patricia | Reina, Rocío | Ocampo, Juan Antonio | Wittich, Regina-Michaela | García-Romera, Inmaculada
Polycyclic aromatic hydrocarbons (PAHs) are one of the most common contaminants in soil. Arbuscular mycorrhizal (AM) fungi make host plants resistant to pollutants. This study aims to evaluate the impact of anthracene, phenanthrene and dibenzothiophene on the AM fungus Rhizophagus custos, isolated from soil contaminated by heavy metals and PAHs, under monoxenic conditions. We found a high level of tolerance in R. custos to the presence of PAHs, especially in the case of anthracene, in which no negative effect on AM-colonized root dry weight (root yield) was observed, and also a decrease in the formation of anthraquinone was detected. Increased PAH dissipation in the mycorrhizal root culture medium was observed; however, dissipation was affected by the level of concentration and the specific PAH, which lead us to a better understanding of the possible contribution of AM fungi, and in particular R. custos, to pollutant removal.
显示更多 [+] 显示较少 [-]Role of arbuscular mycorrhizal fungus Rhizophagus custos in the dissipation of PAHs under root-organ culture conditions 全文
2013
Aranda, Elisabet | Scervino, Jose Martin | Godoy, Patricia | Reina, Rocío | Ocampo, Juan Antonio | Wittich, Regina Michaela | García Romera, Inmaculada
Polycyclic aromatic hydrocarbons (PAHs) are one of the most common contaminants in soil. Arbuscular mycorrhizal (AM) fungi make host plants resistant to pollutants. This study aims to evaluate the impact of anthracene, phenanthrene and dibenzothiophene on the AM fungus Rhizophagus custos, isolated from soil contaminated by heavy metals and PAHs, under monoxenic conditions. We found a high level of tolerance in R. custos to the presence of PAHs, especially in the case of anthracene, in which no negative effect on AM-colonized root dry weight (root yield) was observed, and also a decrease in the formation of anthraquinone was detected. Increased PAH dissipation in the mycorrhizal root culture medium was observed; however, dissipation was affected by the level of concentration and the specific PAH, which lead us to a better understanding of the possible contribution of AM fungi, and in particular R. custos, to pollutant removal. | Fil: Aranda, Elisabet. Consejo Superior de Investigaciones Científicas; España | Fil: Scervino, Jose Martin. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentina | Fil: Godoy, Patricia. Consejo Superior de Investigaciones Científicas; España | Fil: Reina, Rocío. Consejo Superior de Investigaciones Científicas; España | Fil: Ocampo, Juan Antonio. Consejo Superior de Investigaciones Científicas; España | Fil: Wittich, Regina Michaela. Consejo Superior de Investigaciones Científicas; España | Fil: García Romera, Inmaculada. Consejo Superior de Investigaciones Científicas; España
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