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Résultats 331-340 de 1,310
Distribution and bioaccumulation of steroidal and phenolic endocrine disrupting chemicals in wild fish species from Dianchi Lake, China Texte intégral
2011
Liu, Jingliang | Wang, Renmin | Huang, Bin | Lin, Zhan | Wang, Yu | Pan, Xuejun
The distribution and bioaccumulation of steroidal and phenolic endocrine disrupting chemicals (EDCs) were studied in various tissues of wild fish species from Dianchi Lake, China. In muscle tissue, 4-tert-octylphenol, 4-cumylphenol, 4-nonlyphenol and bisphenol A were detected in fish from each sampling site, with maximal concentrations of 4.6, 4.4, 18.9 and 83.5ng/g dry weight (dw), respectively. Steroids (estrone, 17β-estradiol 17α-ethynylestradiol and estriol) were found at lower levels (<11.3ng/g dw) and less frequently in muscle samples. The highest concentrations of steroids and phenols were found in liver, followed by those in gill and the lowest concentration was found in muscle. The field bioconcentration factors (BCFs) of phenols were calculated in fish species ranged from 18 to 97. Moreover, the measured tissue concentrations were utilized in order to estimate water concentration of steroids (4.4–18.0ng/L). These results showed that steroidal and phenolic EDCs were likely ubiquitous contaminants in wild fish.
Afficher plus [+] Moins [-]Annual and seasonal trends of ambient ozone concentration and its impact on forest vegetation in Mercantour National Park (South-eastern France) over the 2000–2008 period Texte intégral
2011
Sicard, Pierre | Dalstein-Richier, Laurence | Vas, Nicolas
In the South-Eastern French Mediterranean region, high ozone concentrations were measured since many years and specific symptoms like chlorotic mottles were detected on Arolla pines. We presented results for the 2000–2008 period concerning the trend analysis for ambient ozone concentrations and related forest damages, with the Mann and seasonal Kendall tests. Ozone precursor’s emissions from Europe have been reduced over the last 20 years. Decreases in annual averages, median, 25th and 98th percentiles and maxima values were found. The seasonal trend analysis for the high-lying stations showed a decreasing trend for the warm season, when main ozone production is the photochemistry, and an increase for the cold period, caused by a reduced ozone titration. Statistics on Arolla Pine reveal strong correlations between mottling intensity and the high ozone concentrations. Finally, decreases for the ozone concentrations, and associated statistics, AOT40 values and for the mottling intensity on conifers needles were observed.
Afficher plus [+] Moins [-]Polycyclic aromatic hydrocarbons in urban soils of Beijing: Status, sources, distribution and potential risk Texte intégral
2011
Peng, Chi | Chen, Weiping | Liao, Xiaolan | Wang, Meie | Ouyang, Z. (Zhiyun) | Jiao, Wentao | Bai, Yang
We studied the source, concentration, spatial distribution and health risk of 16 polycyclic aromatic hydrocarbons (PAHs) in urban soils of Beijing. The total mass concentration of 16 PAHs ranged from 93 to 13 141 μg kg⁻¹ with a mean of 1228 μg kg⁻¹. The contour map of soil PAH concentrations showed that the industrial zone, the historical Hutong district and the university district of Beijing have significantly higher concentrations than those in remainder of the city. The results of sources identification suggested that the primary sources of PAHs were vehicle exhaust and coal combustion and the secondary source was the atmospheric deposition of long-range transported PAHs. The incremental lifetime cancer risks (ILCRs) of exposing to PAHs in the urban soils of Beijing for adult were 1.77 × 10⁻⁶ and 2.48 × 10⁻⁵, respectively under normal and extreme conditions. For child, they were 8.87 × 10⁻⁷ and 6.72 × 10⁻⁶, respectively under normal and extreme conditions.
Afficher plus [+] Moins [-]Determination of PM₁₀ deposition based on antimony flux to selected urban surfaces Texte intégral
2011
Langner, Marcel | Kull, Martin | Endlicher, Wilfried R.
Deposition of PM₁₀ particles to several types of urban surfaces was investigated within this study. Antimony was chosen as a tracer element to calculate dry deposition velocities for PM₁₀, since antimony proved to be present almost exclusively in PM₁₀ particles in ambient urban air. During 18 months, eight sampling sites in Berlin and Karlsruhe, two cities in Germany, were operated. PM₁₀ concentrations and dry deposition were routinely sampled as two week averages. Additionally, leaf-samples were collected at three sites with tall vegetation. The obtained deposition velocities ranged from 0.8 to 1.3cms⁻¹ at roadside sites and from 0.4 to 0.5cms⁻¹ at the other sites. With reference to the whole canopy, additional deposition velocities of about 0.5cms⁻¹ were obtained for leaf surfaces. As a consequence, it can be concluded that vegetation-covered areas beside streets show the highest potential to capture particles in urban areas.
Afficher plus [+] Moins [-]Behavior of pharmaceuticals and drugs of abuse in a drinking water treatment plant (DWTP) using combined conventional and ultrafiltration and reverse osmosis (UF/RO) treatments Texte intégral
2011
Boleda, M(a) Rosa | Galceran, M(a) Teresa | Ventura, Francesc
The behavior along the potabilization process of 29 pharmaceuticals and 12 drugs of abuse identified from a total of 81 compounds at the intake of a drinking water treatment plant (DWTP) has been studied. The DWTP has a common treatment consisting of dioxychlorination, coagulation/flocculation and sand filtration and then water is splitted in two parallel treatment lines: conventional (ozonation and carbon filtration) and advanced (ultrafiltration and reverse osmosis) to be further blended, chlorinated and distributed. Full removals were reached for most of the compounds. Iopromide (up to 17.2 ng/L), nicotine (13.7 ng/L), benzoylecgonine (1.9 ng/L), cotinine (3.6 ng/L), acetaminophen (15.6 ng/L), erythromycin (2.0 ng/L) and caffeine (6.0 ng/L) with elimination efficiencies ≥94%, were the sole compounds found in the treated water. The advanced treatment process showed a slightly better efficiency than the conventional treatment to eliminate pharmaceuticals and drugs of abuse.
Afficher plus [+] Moins [-]Anatomy of an urban waterbody: A case study of Boston’s Muddy River Texte intégral
2011
Mathew, Miriam | Yao, Yifu | Cao, Yixing | Shodhan, Khyati | Ghosh, Indrani | Bucci, Vanni | Leitao, Christopher | Njoka, Danson | Wei, Irvine | Hellweger, Ferdi L.
The objective of this study was to characterize and understand the water quality of Boston’s Muddy River prior to restoration, to help guide those activities and evaluate their success. We use a combination of monitoring, data analysis and mathematical modeling. The seasonal pattern of temperature, pollutant signatures (identified using a principal component analysis), correlations with precipitation and spatial patterns all point to a significant wastewater input at one of the outfalls and suggest significant receiving water impact. However, a quantitative analysis using a mathematical model (QUAL2K) suggests this source is not significant. Rather, internal loading from algae, sediment bed and waterfowl dominate the spatial pattern of water quality. These results suggest significant improvement can be expected from planned sediment dredging. The paper provides a case study of water quality assessment in the context of urban river restoration, and it illustrates the utility of combining monitoring and data analysis with modeling.
Afficher plus [+] Moins [-]Thallium in the hydrosphere of south west England Texte intégral
2011
Law, Sin | Turner, Andrew
Thallium is a highly toxic metal whose environmental concentrations, distributions and behaviour are not well understood. In the present study we measure the concentrations of Tl in filtered and unfiltered samples of rain, tap, river, estuarine and waste waters collected from south west England. Dissolved Tl was lowest (<20 ng L⁻¹) in tap water, rain water, treated sewage and landfill effluents, estuarine waters, and rivers draining catchments of sandstones and shales. Concentrations up to about 450 ng L⁻¹ were observed in rivers whose catchments are partly mineralized and where metal mining was historically important, and the highest concentration (∼1400 ng L⁻¹) was measured in water abstracted directly from an abandoned mine. Compared with other trace metals measured (e.g. As, Cd, Co, Cr, Cu, Ni, Pb, Zn), Tl has a low affinity for suspended particles and undergoes little removal by conventional (hydroxide precipitation) treatment of mine water.
Afficher plus [+] Moins [-]The physiological, transcriptional and genetic responses of an ozone- sensitive and an ozone tolerant poplar and selected extremes of their F₂ progeny Texte intégral
2011
Street, Nathaniel Robert | James, Tallis Matthew | James, Tucker | Mikael, Brosché | Jaakko, Kangasjärvi | Mark, Broadmeadow | Taylor, Gail
Relatively little is known about the transcriptional response or genetic control of response and adaptation of trees to tropospheric ozone exposure. Such understanding is needed as up to 50% of forests, globally, may be subjected to phytotoxic concentrations of ozone. The physiological, transcriptional and genetic response to ozone was examined in Populus trichocarpa and P. deltoides, which show extreme sensitivity and tolerance to ozone, respectively. Using an inbred F₂ mapping population derived from these two species, we mapped quantitative trait loci (QTL) for traits associated with ozone response, examined segregation of the transcriptional response to ozone and co-located genes showing divergent responses between tolerant and sensitive genotypes with QTL. QTL were identified linking detrimental effects of ozone with leaf and biomass traits and differential responses were found for key genes involved in ethylene production and response.
Afficher plus [+] Moins [-]Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil Texte intégral
2011
Holmstrup, Martin | Sørensen, Jesper G. | Overgaard, Johannes | Bayley, Mark | Bindesbøl, Anne-Mette | Slotsbo, Stine | Fisker, Karina V. | Maraldo, Kristine | Waagner, Dorthe | Labouriau, Rodrigo | Asmund, Gert
Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel and zinc appeared to be regulated and kept at low internal concentrations compared to soil concentrations. Lead, cadmium and copper accumulation did not correlate with glycogen reserves of individual worms. In contrast, aluminium, nickel and zinc were negatively correlated with glycogen reserves. These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy.
Afficher plus [+] Moins [-]Environmental quality of mussel farms in the Vigo estuary: Pollution by PAHs, origin and effects on reproduction Texte intégral
2011
Ruiz, Y. | Suarez, P. | Alonso, A. | Longo, E. | Villaverde, A. | San Juan, F.
This work analyzes the influence of environmental and physiological parameters on PAHs accumulation in cultured mussels. Lipid content and reproductive stage are directly related with PAHs accumulation pattern. We observed a rapid accumulation and depuration of PAHs, mainly during periods of nutrients accumulation, spawns and gonadic restorations. Correlations between PAHs accumulation and physiological status indicate when mussels are more susceptible to adverse effects of these pollutants. A positive correlation between mutagenic congener’s accumulation and occurrence of gonadic neoplastic disorders is shown for the first time in mussels. Molecular indices were used to identify the origin of hydrocarbons accumulated by Mytilus, showing a chronic pyrolytic pollution and pollutant episodes by petrogenic sources and biomass combustion in the studied area. Multivariate analysis suggests the possibility of including physiological parameters of sentinel organisms in environmental biomonitoring programs, mainly in aquaculture areas, taking into account their two aspects: farms productivity and human food safety.
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