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Ni adsorption and Ni–Al LDH precipitation in a sandy aquifer: An experimental and mechanistic modeling study Texte intégral
2011
Mining activities and industries have created nickel (Ni) contaminations in many parts of the world. The objective of this study is to increase our understanding of Ni adsorption and Nickel–Aluminium Layered Double Hydroxide (Ni–Al LDH) precipitation to reduce Ni mobility in a sandy soil aquifer. At pH ≥7.2 both adsorption and Ni–Al LDH precipitation occurred. In batch experiments with the sandy soil up to 70% of oxalate-extractable Al was taken up in LDH formation during 56 days. In a long term column experiment 99% of influent Ni was retained at pH 7.5 due to Ni adsorption (≈34%) and Ni–Al LDH precipitation (≈66%) based on mechanistic reactive transport modeling. The subsequent leaching at pH 6.5 could be largely attributed to desorption. Our results show that even in sandy aquifers with relatively low Al content, Ni–Al LDH precipitation is a promising mechanism to immobilize Ni.
Afficher plus [+] Moins [-]Ecotoxicological assessment of TiO₂ byproducts on the earthworm Eisenia fetida Texte intégral
2011
Bigorgne, Emilie | Foucaud, Laurent | Lapied, Emmanuel | Labille, Jérôme | Botta, Céline | Sirguey, Catherine | Falla, Jaïro | Rose, Jerome | Joner, Erik J. | Rodius, François | Nahmani, Johanne
Ecotoxicological assessment of TiO₂ byproducts on the earthworm Eisenia fetida Texte intégral
2011
Bigorgne, Emilie | Foucaud, Laurent | Lapied, Emmanuel | Labille, Jérôme | Botta, Céline | Sirguey, Catherine | Falla, Jaïro | Rose, Jerome | Joner, Erik J. | Rodius, François | Nahmani, Johanne
The increasing production of nanomaterials will in turn increase the release of nanosized byproducts to the environment. The aim of this study was to evaluate the behaviour, uptake and ecotoxicity of TiO₂ byproducts in the earthworm Eisenia fetida. Worms were exposed to suspensions containing 0.1, 1 and 10 mg/L of byproducts for 24 h. Size of TiO₂ byproducts showed aggregation of particles up to 700 μm with laser diffraction. Only worms exposed at 10 mg/L showed bioaccumulation of titanium (ICP-AES), increasing expression of metallothionein and superoxide dismutase mRNA (Real-time PCR) and induction of apoptotic activity (Apostain and TUNEL). TiO₂ byproducts did not induce cytotoxicity on cœlomocytes, but a significant decrease of phagocytosis was observed starting from 0.1 mg/L. In conclusion, bioaccumulation of byproducts and their production of reactive oxygen species could be responsible for the alteration of the antioxidant system in worms.
Afficher plus [+] Moins [-]Ecotoxicological assessment of TiO2 byproducts on the earthworm Eisenia fetida Texte intégral
2011
Bigorgne, Emilie | Foucaud, Laurent | Emmanuel, Lapied | Labille, Jérôme | Botta, Céline | Sirguey, Catherine | Falla, Jaïro | Rose, Jérôme | Joner, Erik J. | Rodius, François | Nahmani, Johanne | Laboratoire des Interactions Ecotoxicologie, Biodiversité, Ecosystèmes (LIEBE) ; Université Paul Verlaine - Metz (UPVM)-Centre National de la Recherche Scientifique (CNRS) | Bioforsk Soil and Environment | Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE) ; Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) | International Consortium for the Environmental Implications of Nanotechnology (iCEINT), Aix en Provence, France | Laboratoire Sols et Environnement (LSE) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | French Environment and Energy Management Agency (ADEME); Region Lorraine
International audience | The increasing production of nanomaterials will in turn increase the release of nanosized byproducts to the environment. The aim of this study was to evaluate the behaviour, uptake and ecotoxicity of TiO2 byproducts in the earthworm Eisenia fetida. Worms were exposed to suspensions containing 0.1, 1 and 10 mg/L of byproducts for 24 h. Size of TiO2 byproducts showed aggregation of particles up to 700 mu m with laser diffraction. Only worms exposed at 10 mg/L showed bioaccumulation of titanium (ICP-AES), increasing expression of metallothionein and superoxide dismutase mRNA (Real-time PCR) and induction of apoptotic activity (Apostain and TUNEL). TiO2 byproducts did not induce cytotoxicity on ccelomocytes, but a significant decrease of phagocytosis was observed starting from 0.1 mg/L In conclusion, bioaccumulation of byproducts and their production of reactive oxygen species could be responsible for the alteration of the antioxidant system in worms. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
Afficher plus [+] Moins [-]Sorption of simazine to corn straw biochars prepared at different pyrolytic temperatures Texte intégral
2011
Zhang, Guixiang | Zhang, Qing | Sun, Ke | Liu, Xitao | Zheng, Wenjuan | Zhao, Ye
Simazine sorption to corn straw biochars prepared at various temperatures (100–600 °C) was examined to understand its sorption behavior as influenced by characteristics of biochars. Biochars were characterized via elemental analysis, BET-N₂ surface area (SA), FTIR and ¹³C NMR. Freundlich and dual-mode models described sorption isotherms well. Positive correlation between log Kₒc values and aromatic C contents and negative correlation between log Kₒc values and (O + N)/C ratios indicate aromatic-rich biochars have high binding affinity to simazine (charge transfer (π–π*) interactions) and hydrophobic binding may overwhelm H-bonding, respectively. Dual-mode model results suggest adsorption contribution to total sorption increases with carbonization degree. Positive correlation between amounts of adsorption (Qₐd) and SA indicates pore-filling mechanism. Comparison between our results and those obtained with other sorbents indicates corn straw biochars produced at higher temperature can effectively retain simazine. These observations will be helpful for designing biochars as engineered sorbents to remove triazine herbicides.
Afficher plus [+] Moins [-]Impacts of atmospheric pollution on the plant communities of British acid grasslands Texte intégral
2011
Payne, Richard J. | Stevens, Carly J. | Dise, Nancy B. | Gowing, David J. | Pilkington, Michael G. | Phoenix, Gareth K. | Emmett, Bridget A. | Ashmore, Michael R.
Impacts of atmospheric pollution on the plant communities of British acid grasslands Texte intégral
2011
Payne, Richard J. | Stevens, Carly J. | Dise, Nancy B. | Gowing, David J. | Pilkington, Michael G. | Phoenix, Gareth K. | Emmett, Bridget A. | Ashmore, Michael R.
Air pollutants are recognised as important agents of ecosystem change but few studies consider the effects of multiple pollutants and their interactions. Here we use ordination, constrained cluster analysis and indicator value analyses to identify potential environmental controls on species composition, ecological groupings and indicator species in a gradient study of UK acid grasslands. The community composition of these grasslands is related to climate, grazing, ozone exposure and nitrogen deposition, with evidence for an interaction between the ecological impacts of base cation and nitrogen deposition. Ozone is a key agent in species compositional change but is not associated with a reduction in species richness or diversity indices, showing the subtly different drivers on these two aspects of ecosystem degradation. Our results demonstrate the effects of multiple interacting pollutants, which may collectively have a greater impact than any individual agent.
Afficher plus [+] Moins [-]Impacts of atmospheric pollution on the plant communities of British acid grasslands Texte intégral
2011 | 2013
Payne, Richard | Stevens, Carly J | Dise, Nancy B | Gowing, David J | Pilkington, Michael G | Phoenix, Gareth K | Emmett, Bridget A | Ashmore, Michael R | Biological and Environmental Sciences | Lancaster University | Manchester Metropolitan University | The Open University | University of Sheffield | University of Sheffield | Centre for Ecology & Hydrology (CEH) | University of York
Air pollutants are recognised as important agents of ecosystem change but few studies consider the effects of multiple pollutants and their interactions. Here we use ordination, constrained cluster analysis and indicator value analyses to identify potential environmental controls on species composition, ecological groupings and indicator species in a gradient study of UK acid grasslands. The community composition of these grasslands is related to climate, grazing, ozone exposure and nitrogen deposition, with evidence for an interaction between the ecological impacts of base cation and nitrogen deposition. Ozone is a key agent in species compositional change but is not associated with a reduction in species richness or diversity indices, showing the subtly different drivers on these two aspects of ecosystem degradation. Our results demonstrate the effects of multiple interacting pollutants, which may collectively have a greater impact than any individual agent.
Afficher plus [+] Moins [-]The definition of species richness used by species sensitivity distributions approximates observed effects of salinity on stream macroinvertebrates Texte intégral
2011
Kefford, Ben J. | Marchant, Richard | Schäfer, Ralf B. | Metzeling, Leon | Dunlop, Jason E. | Choy, S. C. (Satish C.) | Goonan, Peter
The risk of chemicals for ecological communities is often forecast with species sensitivity distributions (SSDs) which are used to predict the concentration which will protect p% of species (PCₚ value). However, at the PCₚ value, species richness in nature would not necessary be p% less than at uncontaminated sites. The definition of species richness inherent to SSDs (contaminant category richness) contrasts with species richness typically measured in most field studies (point richness). We determine, for salinity in eastern Australia, whether these definitions of stream macroinvertebrate species richness are commensurable. There were strong relationships (r²≥0.87) between mean point species, family and Ephemeroptera, Trichoptera and Plecoptera species richness and their respective contamination category richness. Despite differences in the definition of richness used by SSDs and field biomonitoring, their results in terms of relative species loss from salinity in south-east Australia are similar. We conclude that in our system both definitions are commensurable.
Afficher plus [+] Moins [-]Plant communities in relation to flooding and soil contamination in a lowland Rhine River floodplain Texte intégral
2011
Schipper, Aafke M. | Lotterman, Kim | Leuven, Rob S.E.W. | Ragas, Ad M.J. | Kroon, Hans de | Hendriks, A Jan
Using canonical correspondence analysis (CCA), relationships were investigated between plant species composition and flooding characteristics, heavy metal contamination and soil properties in a lowland floodplain of the Rhine River. Floodplain elevation and yearly average flooding duration turned out to be more important for explaining variation in plant species composition than soil heavy metal contamination. Nevertheless, plant species richness and diversity showed a significant decrease with the level of contamination. As single heavy metal concentrations seemed mostly too low for causing phytotoxic effects in plants, this trend is possibly explained by additive effects of multiple contaminants or by the concomitant influences of contamination and non-chemical stressors like flooding. These results suggest that impacts of soil contamination on plants in floodplains could be larger than expected from mere soil concentrations. In general, these findings emphasize the relevance of analyzing effects of toxic substances in concert with the effects of other relevant stressors.
Afficher plus [+] Moins [-]Bisphenol A induces a rapid activation of Erk1/2 through GPR30 in human breast cancer cells Texte intégral
2011
Dong, S. | Terasaka, S. | Kiyama, R.
Bisphenol A (BPA) has been considered as an endocrine disruptor due to its ability to interact with estrogen receptors (ERs). While G protein-coupled receptor 30 (GPR30) is a novel estrogen receptor, its role in BPA-induced activation of Erk1/2 remains unknown. Human breast cancer cell lines, MCF-7, MDA-MB-231 and SKBR3, were used as experimental models to discriminate between ERs-dependent, putative ERs-independent and/or GPR30-associated effects. BPA induced a rapid activation of Erk1/2 in both ERα/β-positive and negative breast cancer cells, and this effect was not blocked with an ER antagonist, ICI 182,780. A small interfering RNA assay revealed that the expression of GPR30 was necessary for BPA-induced activation of Erk1/2 and transcriptional regulation of c-fos. In addition, BPA regulates the expression of c-fos likely through an AP1-mediated pathway. As a conclusion, GPR30 plays an important role in the BPA-induced activation of Erk1/2 in a manner distinguishable from that in ERα-mediated signaling.
Afficher plus [+] Moins [-]Habitat-specific bioaccumulation of methylmercury in invertebrates of small mid-latitude lakes in North America Texte intégral
2011
Chételat, John | Amyot, Marc | Garcia, Edenise
We examined habitat-specific bioaccumulation of methylmercury (MeHg) in aquatic food webs by comparing concentrations in pelagic zooplankton to those in littoral macroinvertebrates from 52 mid-latitude lakes in North America. Invertebrate MeHg concentrations were primarily correlated with water pH, and after controlling for this influence, pelagic zooplankton had significantly higher MeHg concentrations than littoral primary consumers but lower MeHg than littoral secondary consumers. Littoral primary consumers and pelagic zooplankton are two dominant prey for fish, and greater MeHg in zooplankton is likely sufficient to increase bioaccumulation in pelagic feeders. Intensive sampling of 8 lakes indicated that habitat-specific bioaccumulation in invertebrates (of similar trophic level) may result from spatial variation in aqueous MeHg concentration or from more efficient uptake of aqueous MeHg into the pelagic food web. Our findings demonstrate that littoral–pelagic differences in MeHg bioaccumulation are widespread in small mid-latitude lakes.
Afficher plus [+] Moins [-]Indoor metallic pollution related to mining activity in the Bolivian Altiplano Texte intégral
2011
Fontúrbel, Francisco E. | Barbieri, Enio | Herbas, Cristian | Barbieri, Flavia L. | Gardon, Jacques
The environmental pollution associated with mining and metallurgical activities reaches its greatest extent in several Andean cities and villages. Many locations in this area have accumulated through centuries a large amount of mining wastes, often disregarding the magnitude of this situation. However, in these naturally mineralized regions, there is little information available stating the exact role of mining and metallurgical industries in urban pollution. In this study, we demonstrated that the various metallic elements present in indoor dust (As, Cd, Cu, Pb, Sb, Sn, Zn) had a common origin and this contamination was increased by the proximity to the mines. Lead dust concentration was found at concerning levels for public health. In addition, wrong behaviors such as carrying mining workwear home contributed to this indoor dust pollution. Consequently, the constant exposure of the population could represent a potential health hazard for vulnerable groups, especially children.
Afficher plus [+] Moins [-]Temporal genetic variability and host sources of Escherichia coli associated with fecal pollution from domesticated animals in the shellfish culture environment of Xiangshan Bay, East China Sea Texte intégral
2011
Fu, Ling-Lin | Shuai, Jiang-Bing | Wang, Yanbo | Ma, Hong-Jia | Li, Jian Rong
This study was conducted to analyze the genetic variability of Escherichia coli from domesticated animal wastes for microbial source tracking (MST) application in fecal contaminated shellfish growing waters of Xiangshan Bay, East China Sea. (GTG)₅ primer was used to generate 1363 fingerprints from E. coli isolated from feces of known 9 domesticated animal sources around this shellfish culture area. Jackknife analysis of the complete (GTG)₅-PCR DNA fingerprint library indicated that isolates were assigned to the correct source groups with an 84.28% average rate of correct classification. Based on one-year source tracking data, the dominant sources of E. coli were swine, chickens, ducks and cows in this water area. Moreover, annual and spatial changes of E. coli concentrations and host sources may affect the level and distribution of zoonotic pathogen species in waters. Our findings will further contribute to preventing fecal pollution in aquatic environments and quality control of shellfish.
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