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Fate and effects of anthropogenic chemicals in mangrove ecosystems: A review Texte intégral
2011
Lewis, Michael | Pryor, Rachel | Wilking, Lynn
The scientific literature for fate and effects of non-nutrient contaminant concentrations is skewed for reports describing sediment contamination and bioaccumulation for trace metals. Concentrations for at least 22 trace metals have been reported in mangrove sediments. Some concentrations exceed sediment quality guidelines suggesting adverse effects. Bioaccumulation results are available for at least 11 trace metals, 12 mangrove tissues, 33 mangrove species and 53 species of mangrove-habitat biota. Results are specific to species, tissues, life stage, and season and accumulated concentrations and bioconcentration factors are usually low. Toxicity tests have been conducted with 12 mangrove species and 8 species of mangrove-related fauna. As many as 39 effect parameters, most sublethal, have been monitored during the usual 3 to 6 month test durations. Generalizations and extrapolations for toxicity between species and chemicals are restricted by data scarcity and lack of experimental consistency. This hinders chemical risk assessments and validation of effects-based criteria.
Afficher plus [+] Moins [-]Species- and age-related variation in metal exposure and accumulation of two passerine bird species Texte intégral
2011
Berglund, Å.M.M. | Koivula, M.J. | Eeva, T.
We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu–Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age.
Afficher plus [+] Moins [-]Combining polar organic chemical integrative samplers (POCIS) with toxicity testing to evaluate pesticide mixture effects on natural phototrophic biofilms Texte intégral
2011
Pesce, Stéphane | Morin, Soizic | Lissalde, Sophie | Montuelle, Bernard | Mazzella, Nicolas
Combining polar organic chemical integrative samplers (POCIS) with toxicity testing to evaluate pesticide mixture effects on natural phototrophic biofilms Texte intégral
2011
Pesce, Stéphane | Morin, Soizic | Lissalde, Sophie | Montuelle, Bernard | Mazzella, Nicolas
Polar organic chemical integrative samplers (POCIS) are valuable tools in passive sampling methods for monitoring polar organic pesticides in freshwaters. Pesticides extracted from the environment using such methods can be used to toxicity tests. This study evaluated the acute effects of POCIS extracts on natural phototrophic biofilm communities. Our results demonstrate an effect of POCIS pesticide mixtures on chlorophyll a fluorescence, photosynthetic efficiency and community structure. Nevertheless, the range of biofilm responses differs according to origin of the biofilms tested, revealing spatial variations in the sensitivity of natural communities in the studied stream. Combining passive sampler extracts with community-level toxicity tests offers promising perspectives for ecological risk assessment.
Afficher plus [+] Moins [-]Combining polar organic chemical integrative sampler (POCIS) with toxicity testing to evaluate pesticide mixture effects on natural phototrophic biofilms Texte intégral
2011
Pesce, Stéphane | Morin, Soizic | Lissalde, Sophie | Montuelle, Bernard | Mazzella, Nicolas | Milieux aquatiques, écologie et pollutions (UR MALY) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Réseaux épuration et qualité des eaux (UR REBX) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL) ; Institut National de la Recherche Agronomique (INRA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]) | Cemagref's "PestExpo" Research Program ; French National Office for the Aquatic Environment
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Afficher plus [+] Moins [-]Global gene expression profile induced by the UV-filter 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) in zebrafish (Danio rerio) Texte intégral
2011
Zucchi, Sara | Oggier, Daniela M. | Fent, Karl
Residues of the UV-filter 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) are ubiquitously found in aquatic biota but potential adverse effects in fish are fairly unknown. To identify molecular effects and modes of action of EHMC we applied a gene expression profiling in zebrafish using whole genome microarrays. Transcriptome analysis and validation of targeted genes were performed after 14 days of exposure of male zebrafish. Concentrations of 2.2 μg/L and 890 μg/L EHMC lead to alteration of 1096 and 1137 transcripts, respectively, belonging to many pathways. Genes involved in lipid metabolism and estrogenic pathway (vtg1), lipid biosynthesis (ptgds), vitamin A metabolic process (rbp2a), DNA damage and apoptosis (gadd45b), and regulation of cell growth (igfbp1a) were investigated by qRT-PCR analysis in whole body, liver, brain and testis. The analysis showed tissue-specific gene profiles and revealed that EHMC slightly affects the transcription of genes involved in hormonal pathways including vtg1, esr1, esr2b, ar, cyp19b and hsd17β3.
Afficher plus [+] Moins [-]Salting our landscape: An integrated catchment model using readily accessible data to assess emerging road salt contamination to streams Texte intégral
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.
Afficher plus [+] Moins [-]Effects of organic matter and ageing on the bioaccessibility of arsenic Texte intégral
2011
Meunier, Louise | Koch, Iris | Reimer, Kenneth J.
Arsenic-contaminated soils may pose a risk to human health. Redevelopment of contaminated sites may involve amending soils with organic matter, which potentially increases arsenic bioaccessibility. The effects of ageing on arsenic-contaminated soils mixed with peat moss were evaluated in a simulated ageing period representing two years, during which arsenic bioaccessibility was periodically measured. Significant increases (p = 0.032) in bioaccessibility were observed for 15 of 31 samples tested, particularly in comparison with samples originally containing >30% bioaccessible arsenic in soils naturally rich in organic matter (>25%). Samples where percent arsenic bioaccessibility was unchanged with age were generally poor in organic matter (average 7.7%) and contained both arsenopyrite and pentavalent arsenic forms that remained unaffected by the organic matter amendments. Results suggest that the addition of organic matter may lead to increases in arsenic bioaccessibility, which warrants caution in the evaluation of risks associated with redevelopment of arsenic-contaminated land.
Afficher plus [+] Moins [-]Avoidance tests with Folsomia candida for the assessment of copper contamination in agricultural soils Texte intégral
2011
Boiteau, Gilles | Lynch, D.H. | MacKinley, P.
The feasibility of assessing copper accumulation in agricultural soils using avoidance tests with a Canadian strain of Folsomia candida was investigated under laboratory conditions. The avoidance response to nominal copper sulfate concentrations of 0, 200, 800, 1600 and 3200 mg kg⁻¹ in OECD soil was inconsistent between trials with the standard plastic cup or a modified Petri dish method requiring less soil. However, combined results from three Petri dish trials decreased variability and provided a 75% avoidance level, close to the 80% criterion proposed for avoidance tests. A Copper avoidance EC₅₀ₛ of 18 mg kg⁻¹was obtained using the Petri dish method whether tests were conducted with or without light. While Petri dish tests have potential as a cheap tool to distinguish metal contaminated soils from uncontaminated soils they would be unsuitable for tracking or quantifying changes in metal concentrations. throughout remediation. Advantages and limitations of the method have been presented.
Afficher plus [+] Moins [-]Implementation of airborne trace element monitoring with devitalised transplants of Hypnum cupressiforme Hedw.: Assessment of temporal trends and element contribution by vehicular traffic in Naples city Texte intégral
2011
Adamo, P. | Giordano, S. | Sforza, A. | Bargagli, R.
A biomonitoring of airborne trace elements was performed in 2006 in Naples urban area through the exposure of devitalised Hypnum cupressiforme for 10 weeks at 4m height. In one street, the moss was exposed at different heights to assess vertical gradients of element concentrations. Results were compared with those of a 1999 biosurvey. Correlations among Al, Fe and Ti suggested a soil particles contribution to element uptake. Cu, Mo and Fe were related with traffic flows. Long-range transport contributed to Cd, Cu and Mo accumulation in moss at higher heights. As in 1999, the airborne element load was higher in coastal sites, more affected by marine aerosols and traffic. In all sites, contents of Cd, Fe, Pb, Ni and V in moss were remarkably lower than in 1999, indicating a positive effect of actions set up in recent years to reduce the traffic and to improve the city air quality.
Afficher plus [+] Moins [-]Photochemical processing of aldrin and dieldrin in frozen aqueous solutions under arctic field conditions Texte intégral
2011
Rowland, Glenn A. | Bausch, Alexandra R. | Grannas, Amanda M.
Organochlorine (OC) contaminants are transported to the Polar Regions, where they have the potential to bioaccumulate, presenting a threat to the health of wildlife and indigenous communities. They deposit onto snowpack during winter, and accumulate until spring, when they experience prolonged solar irradiation until snowmelt occurs. Photochemical degradation rates for aldrin and dieldrin, in frozen aqueous solution made from MilliQ water, 500 μM hydrogen peroxide solution or locally-collected melted snow were measured in a field campaign near Barrow, AK, during spring–summer 2008. Significant photoprocessing of both pesticides occurs; the reactions depend on temperature, depth within the snowpack and whether the predominant phase is ice or liquid water. The effect of species present in natural snowpack is comparable to 500 μM hydrogen peroxide, pointing to the potential significance of snowpack-mediated reactions. Aldrin samples frozen at near 0 °C were more reactive than comparable liquid samples, implying that the microenvironments experienced on frozen ice surfaces are an important consideration.
Afficher plus [+] Moins [-]Changes in photosynthesis, mesophyll conductance to CO₂, and isoprenoid emissions in Populus nigra plants exposed to excess nickel Texte intégral
2011
Velikova, Violeta | Tsonev, Tsonko | Loreto, Francesco | Centritto, Mauro
Poplar (Populus nigra) plants were grown hydroponically with 30 and 200 μM Ni (Ni₃₀ and Ni₂₀₀). Photosynthesis limitations and isoprenoid emissions were investigated in two leaf types (mature and developing). Ni stress significantly decreased photosynthesis, and this effect depended on the leaf Ni content, which was lower in mature than in developing leaves. The main limitations to photosynthesis were attributed to mesophyll conductance and metabolism impairment. In Ni-stressed developing leaves, isoprene emission was significantly stimulated. We attribute such stimulation to the lower chloroplastic [CO₂] than in control leaves. However chloroplastic [CO₂] did not control isoprene emission in mature leaves. Ni stress induced the emission of cis-β-ocimene in mature leaves, and of linalool in both leaf types. Induced biosynthesis and emission of isoprenoids reveal the onset of antioxidant processes that may also contribute to reduce Ni stress, especially in mature poplar leaves.
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