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Seasonal variation and source estimation of organic compounds in urban aerosol of Augsburg, Germany Full text
2011
Pietrogrande, Maria Chiara | Abbaszade, Gülcin | Schnelle-Kreis, Jürgen | Bacco, Dimitri | Mercuriali, Mattia | Zimmermann, Ralf
This study reports a general assessment of the organic composition of the PM₂.₅ samples collected in the city of Augsburg, Germany in a summer (August–September 2007) and a winter (February–March 2008) campaign of 36 and 30 days, respectively. The samples were directly submitted to in-situ derivatisation thermal desorption gas chromatography coupled with time of flight mass spectrometry (IDTD–GC–TOFMS) to simultaneously determine the concentrations of many classes of molecular markers, such as n-alkanes, iso- and anteiso-alkanes, polycyclic aromatic hydrocarbons (PAHs), oxidized PAHs, n-alkanoic acids, alcohols, saccharides and others. The PCA analysis of the data identified the contributions of three emission sources, i.e., combustion sources, including fossil fuel emissions and biomass burning, vegetative detritus, and oxidized PAHs. The PM chemical composition shows seasonal trend: winter is characterized by high contribution of petroleum/wood combustion while the vegetative component and atmospheric photochemical reactions are predominant in the hot season.
Show more [+] Less [-]Arsenic and Mn levels in Isaza (Gymnogobius isaza) during the mass mortality event in Lake Biwa, Japan Full text
2011
Hirata, Sawako Horai | Hayase, Daisuke | Eguchi, Akifumi | Itai, Takaaki | Nomiyama, Kei | Isobe, Tomohiko | Agusa, Tetsuro | Ishikawa, Toshiyuki | Kumagai, Michio | Tanabe, Shinsuke
The present study measured the concentrations of 25 elements (Li, Mg, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb and Bi) in the whole body of Isaza which is an endemic fish species to Lake Biwa, Japan, and compared the values in the specimens from the mass mortality Isaza (MMI) and normal fresh Isaza (NFI). The mean levels of Mn and total As (T-As) were relatively higher in MMI than in NFI. In the T-As, highly toxic inorganic As was detected in MMI. Moreover we found Mn and As concentrations in surface sediment were extremely high and temporally increased. From all these results, we could infer that the dissolution of Mn and As from surface sediment of Lake Biwa might have been one of the cause for the mass mortality of Isaza.
Show more [+] Less [-]Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment Full text
2011
Ochoa-Hueso, Raúl | Allen, Edith B. | Branquinho, Cristina | Cruz Mínguez, Cristina | Dias, Teresa | Fenn, Mark E. | Manrique, Esteban | Pérez-Corona, M Esther | Sheppard, Lucy J. | Stock, William D.
Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment Full text
2011
Ochoa-Hueso, Raúl | Allen, Edith B. | Branquinho, Cristina | Cruz Mínguez, Cristina | Dias, Teresa | Fenn, Mark E. | Manrique, Esteban | Pérez-Corona, M Esther | Sheppard, Lucy J. | Stock, William D.
We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains. Decoupling between N flushes and plant demand promotes losses via leaching and gas emissions. Differences in P availability may control the response to N inputs and susceptibility to exotic plant invasion. Invasive grasses accumulate as fuel during the dry season, altering fire regimes. California and the Mediterranean Basin are the most threatened by N deposition; however, there is limited evidence for N deposition impacts outside of California. Consequently, more research is needed to determine critical loads for each region and vegetation type based on the most sensitive elements, such as changes in lichen species composition and N cycling.
Show more [+] Less [-]Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment Full text
2011
Ochoa Hueso, Raúl | Allen, Edith B. | Branquinho, Cristina | Cruz, Cristina | Dias, Teresa | Fenn, Mark E. | Manrique, Esteban | Pérez-Corona, M. Esther | Sheppard, Lucy J. | Stock, William D. | Biología
Revisamos las consecuencias ecológicas de la deposición de N en las cinco regiones mediterráneas del mundo. La estacionalidad de las precipitaciones y los incendios regulan el ciclo del N en estos ecosistemas con escasez de agua, donde domina la deposición seca de N. La acumulación de nitrógeno en los suelos y en las superficies de las plantas produce picos de disponibilidad con las primeras lluvias invernales. El desacoplamiento entre los flujos de N y la demanda de la planta promueve pérdidas por lixiviación y emisiones de gases. Las diferencias en la disponibilidad de P pueden controlar la respuesta a los aportes de N y la susceptibilidad a la invasión de plantas exóticas. Los pastos invasores se acumulan como combustible durante la estación seca, alterando los regímenes de incendios. California y la cuenca mediterránea son las más amenazadas por la deposición de N; sin embargo, existe evidencia limitada de los impactos de la deposición de N fuera de California. En consecuencia, se necesita más investigación para determinar las cargas críticas para cada región y tipo de vegetación en función de los elementos más sensibles, como los cambios en la composición de las especies de líquenes y el ciclo del N.
Show more [+] Less [-]Identifying genes and gene networks involved in chromium metabolism and detoxification in Crambe abyssinica Full text
2011
Zulfiqar, Asma | Paulose, Bibin | Chhikara, Sudesh | Dhankher, Om Parkash
Chromium pollution is a serious environmental problem with few cost-effective remediation strategies available. Crambe abyssinica (a member of Brassicaseae), a non-food, fast growing high biomass crop, is an ideal candidate for phytoremediation of heavy metals contaminated soils. The present study used a PCR-Select Suppression Subtraction Hybridization approach in C. abyssinica to isolate differentially expressed genes in response to Cr exposure. A total of 72 differentially expressed subtracted cDNAs were sequenced and found to represent 43 genes. The subtracted cDNAs suggest that Cr stress significantly affects pathways related to stress/defense, ion transporters, sulfur assimilation, cell signaling, protein degradation, photosynthesis and cell metabolism. The regulation of these genes in response to Cr exposure was further confirmed by semi-quantitative RT-PCR. Characterization of these differentially expressed genes may enable the engineering of non-food, high-biomass plants, including C. abyssinica, for phytoremediation of Cr-contaminated soils and sediments.
Show more [+] Less [-]Long-chain perfluorinated chemicals in digested sewage sludges in Switzerland Full text
2011
Sun, Hongwen | Gerecke, Andreas C. | Giger, W. (Walter) | Alder, Alfredo C.
This study focused on the occurrence of long-chain perfluorinated chemicals (PFCs) in anaerobically stabilized sewage sludges from 20 municipal WWTPs using current and historic samples to evaluate the levels of PFCs and to identify the relative importance of commercial and industrial sources. A quantitative analytical method was developed based on solvent extraction of the analytes and a LC-MS/MS system. For total perfluoralkyl carboxylates (PFCAs), the concentrations ranged from 14 to 50μg/kg dry matter. Concentrations of perfluorooctane sulfonic acid (PFOS) ranged from 15 to 600μg/kg dry matter. In three WWTPs, the PFOS levels were six to nine times higher than the average values measured in the other plants. These elevated PFOS concentrations did not correlate with higher levels of PFCAs, indicating specific additional local sources for PFOS at these WWTPs. Average concentrations in selected samples from the years 1993, 2002, and 2008 did not change significantly.
Show more [+] Less [-]Salting our landscape: An integrated catchment model using readily accessible data to assess emerging road salt contamination to streams Full text
2011
Jin, Li | Whitehead, Paul | Siegel, Donald I. | Findlay, Stuart
A new integrated catchment model for salinity has been developed to assess the transport of road salt from upland areas in watersheds to streams using readily accessible landscape, hydrologic, and meteorological data together with reported salt applications. We used Fishkill Creek (NY) as a representative watershed to test the model. Results showed good agreement between modeled and measured stream water chloride concentrations. These results suggest that a dominant mode of catchment simulation that does not entail complex deterministic modeling is an appropriate method to model salinization and to assess effects of future applications of road salt to streams. We heuristically increased and decreased salt applications by 100% and results showed that stream chloride concentrations increased by 13% and decreased by 7%, respectively. The model suggests that future management of salt application can reduce environmental concentrations, albeit over some time.
Show more [+] Less [-]Identification of magnetic particulates in road dust accumulated on roadside snow using magnetic, geochemical and micro-morphological analyses Full text
2011
Bućko, Michał S. | Magiera, Tadeusz | Johanson, Bo | Petrovský, Eduard | Pesonen, Lauri J.
The aim of this study is to test the applicability of snow surveying in the collection and detailed characterization of vehicle-derived magnetic particles. Road dust extracted from snow, collected near a busy urban highway and a low traffic road in a rural environment (southern Finland), was studied using magnetic, geochemical and micro-morphological analyses. Significant differences in horizontal distribution of mass specific magnetic susceptibility (χ) were noticed for both roads. Multi-domain (MD) magnetite was identified as the primary magnetic mineral. Scanning electron microscope (SEM) analyses of road dust from both roads revealed: (1) angular-shaped particles (diameter ∼1–300 μm) mostly composed of Fe, Cr and Ni, derived from circulation of motor vehicles and (2) iron-rich spherules (d ∼ 2–70 μm). Tungsten-rich particles (d < 2 μm), derived from tyre stud abrasion were also identified. Additionally, a decreasing trend in χ and selected trace elements was observed with increasing distance from the road edge.
Show more [+] Less [-]Characterization of mercury species in brown and white rice (Oryza sativa L.) grown in water-saving paddies Full text
2011
Rothenberg, Sarah E. | Feng, Xinbin | Dong, Bin | Shang, Lihai | Yin, Runsheng | Yuan, Xiaobo
In China, total Hg (HgT) and methylmercury (MeHg) were quantified in rice grain grown in three sites using water-saving rice cultivation methods, and in one Hg-contaminated site, where rice was grown under flooded conditions. Polished white rice concentrations of HgT (water-saving: 3.3±1.6ng/g; flooded: 110±9.2ng/g) and MeHg (water-saving 1.3±0.56ng/g; flooded: 12±2.4ng/g) were positively correlated with root-soil HgT and MeHg contents (HgT: r²=0.97, MeHg: r²=0.87, p<0.05 for both), which suggested a portion of Hg species in rice grain was derived from the soil, and translocation of Hg species from soil to rice grain was independent of irrigation practices and Hg levels, although other factors may be important. Concentrations of HgT and other trace elements were significantly higher in unmilled brown rice (p<0.05), while MeHg content was similar (p>0.20), indicating MeHg infiltrated the endosperm (i.e., white rice) more efficiently than inorganic Hg(II).
Show more [+] Less [-]Expression of mtc in Folsomia candida indicative of metal pollution in soil Full text
2011
Nota, Benjamin | Vooijs, Riet | Straalen, N. M. van | Roelofs, Dick
The soil-living springtail Folsomia candida is frequently used in reproduction bioassays to assess soil contamination. Alternatively, the response of genes to contamination is assessed. In this study the expression of F. candida’s gene encoding the deduced metallothionein-like motif containing protein (MTC) was assessed, using quantitative PCR, in response to six different metals, each at two concentrations in soil. The expression of mtc was induced after exposure to all metals, except for one chromium concentration. Exposure to soil originating from metal-contaminated field sites also induced mtc, while the expression did not change in response to a polycyclic aromatic hydrocarbon. Since this transcript is induced by most of the tested metals, it may potentially be a good indicator of metal contamination. The presented gene expression assay might become a useful tool to screen potentially polluted sites, in order to identify the ones that need further ecotoxicological investigation.
Show more [+] Less [-]Toxicity of dispersant application: Biomarkers responses in gills of juvenile golden grey mullet (Liza aurata) Full text
2011
Milinkovitch, Thomas | Godefroy, Joachim | Théron, Michaël | Thomas-Guyon, Hélène
Dispersant use in nearshore areas is likely to increase the exposure of aquatic organisms to petroleum. To measure the toxicity of this controversial response technique, golden grey mullets (Liza aurata) were exposed to mechanically dispersed oil, chemically dispersed oil, dispersant alone in seawater, water-soluble fraction of oil and to seawater as a control treatment. Several biomarkers were assessed in the gills (enzymatic antioxidant activities, glutathione content, lipid peroxidation) and in the gallbladder (polycylic aromatic hydrocarbons metabolites). The significant differences between chemically dispersed oil and water soluble fraction of oil highlight the environmental risk to disperse an oil slick when containment and recovery can be conducted. The lack of significance between chemically and mechanically dispersed oil suggests that dispersant application is no more toxic than the natural dispersion of the oil slick. The results of this study are of interest in order to establish dispersant use policies in nearshore areas.
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