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Embryotoxic and genotoxic effects of heavy metals and pesticides on early life stages of Pacific oyster (Crassostrea gigas)
2012
Mai, Hong Ngoc | Cachot, J. | Brune, J. | Geffard, Olivier | Belles, A. | Budzinski, H. | Morin, Brice | Environnements et Paléoenvironnements OCéaniques (EPOC) ; Observatoire aquitain des sciences de l'univers (OASU) ; Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) | Milieux aquatiques, écologie et pollutions (UR MALY) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA | International audience | This study evaluated embryotoxicity and genotoxicity of two dissolved metals copper and cadmium (Cu and Cd) and two pesticides (metolachlor and irgarol) occurring in Arcachon Bay (SW France) in Pacific oyster (Crassostrea gigas) larvae and investigated the relationship between those two endpoints. Embryotoxicity was measured by calculating the percentage of abnormal D-shaped larvae and genotoxicity was evaluated with DNA strand breaks using the comet assay. After 24 h exposure, significant increases of the percentage of abnormal D-larvae and the DNA strand breaks were observed from 0.1µg/L for Cu, 10 µg/L for Cd and 0.01 µg/L for both irgarol and metolachlor in comparison with the controls. A strong positive relationship between embryotoxicity and genotoxicity was recorded for Cu, Cd and metolachlor. The current study suggests that copper, irgarol and metolachlor can induce larval abnormalities and DNA damage in a population of exposed oysters at environmentally relevant concentrations.
Afficher plus [+] Moins [-]Bioacumulation and ultrastructural effects of Cd, Cu, Pb and Zn in the moss Scorpiurum circinatum (Brid.) Fleisch. & Loeske
2012
Basile, A. | Sorbo, S. | Pisani, T. | Paoli, L. | Munzi, S. | Loppi, S.
This paper tested if culturing the moss Scorpiurum circinatum (Brid.) Fleisch. & Loeske with metal solutions (Cd, Cu, Pb and Zn) for 30 days causes metal bioaccumulation and ultrastructural changes. The results showed that despite the high heavy metal concentrations in treatment solutions, treated samples did not show severe ultrastructural changes and cells were still alive and generally well preserved. Bioaccumulation highlighted that moss cells survived to heavy metal toxicity by immobilizing most toxic ions extracellularly, likely in binding sites of the cell wall, which is the main site of metal detoxification.
Afficher plus [+] Moins [-]Insights into aquatic toxicities of the antibiotics oxytetracycline and ciprofloxacin in the presence of metal: Complexation versus mixture
2012
Zhang, Yu | Cai, Xiyun | Lang, Xianming | Qiao, Xianliang | Li, Xuehua | Chen, Jingwen
Co-contamination of ligand-like antibiotics (e.g., tetracyclines and quinolones) and heavy metals prevails in the environment, and thus the complexation between them is involved in environmental risks of antibiotics. To understand toxicological significance of the complex, effects of metal coordination on antibiotics' toxicity were investigated. The complexation of two antibiotics, oxytetracycline and ciprofloxacin, with three heavy metals, copper, zinc, and cadmium, was verified by spectroscopic techniques. The antibiotics bound metals via multiple coordination sites and rendered a mixture of various complexation speciations. Toxicity analysis indicated that metal coordination did modify the toxicity of the antibiotics and that antibiotic, metal, and their complex acted primarily as concentration addition. Comparison of EC₅₀ values revealed that the complex commonly was highest toxic and predominately correlated in toxicity to the mixture. Finally, environmental scenario analysis demonstrated that ignoring complexation would improperly classify environmental risks of the antibiotics.
Afficher plus [+] Moins [-]Induction of mouthpart deformities in chironomid larvae exposed to contaminated sediments
2012
Di Veroli, Alessandra | Goretti, Enzo | Paumen, Miriam Leόn | Kraak, Michiel H.S. | Admiraal, Wim
The aim of the present study was to improve the cause–effect relationship between toxicant exposure and chironomid mouthpart deformities, by linking induction of mouthpart deformities to contaminated field sediments, metal mixtures and a mutagenic polycyclic aromatic compound metabolite (acridone). Mouthpart deformities in Chironomus riparius larvae were induced by both the heavy metal mixture and by acridone. A clear correlation between metal concentrations in the sediment and deformities incidence was only observed when the contaminated field sediments were left out of the analysis, probably because these natural sediments contained other toxic compounds, which could be responsible for a higher incidence of deformities than predicted by the measured metal concentrations only. The present study clearly improved the cause–effect relationship between toxicant exposure and the induction of mouthpart deformities. It is concluded that the incidence of mouthpart deformities may better reflect the potential toxicity of contaminated sediments than chemical analysis.
Afficher plus [+] Moins [-]Long-term biological monitoring of environmental quality around a solid waste landfill assessed with lichens
2012
Paoli, L. | Corsini, A. | Bigagli, V. | Vannini, J. | Bruscoli, C. | Loppi, S.
The diversity of epiphytic lichens and the accumulation of selected trace elements in the lichen Flavoparmelia caperata L. (Hale) were used as indicators of pollution around a landfill in central Italy along 14 years of waste management. Lichens revealed an increased deposition for some elements (i.e., Cd, Cr, Fe and Ni) and a decrease of the lichen diversity at sites facing the landfill after an enlargement of the dumping area. However, the results allowed to exclude a significant increase in heavy metal depositions in the surrounding area and suggested that successful waste management may be associated with environmental quality. It is concluded that lichen monitoring might provide essential information to enhance the implementation of ecological impact assessment, supporting industrial regulatory procedures, also when waste management is concerned.
Afficher plus [+] Moins [-]Metal resistance in populations of red maple (Acer rubrum L.) and white birch (Betula papyrifera Marsh.) from a metal-contaminated region and neighbouring non-contaminated regions
2012
Kirkey, Fallon M. | Matthews, Jennifer | Ryser, Peter
Metal resistance in populations of Acer rubrum and Betula papyrifera in the industrially contaminated region of Sudbury, Ontario, was compared with resistance in populations from neighbouring uncontaminated regions. In two one-season experiments, seedlings were grown outdoors on contaminated (mainly Cu, Ni) and uncontaminated substrates. Sudbury populations of both species responded less to contamination than populations from uncontaminated regions. In A. rubrum this difference was small. For both species, Sudbury plants were smaller when grown on uncontaminated substrate. B. papyrifera from Sudbury grew better on contaminated substrate than the other populations. There is indication of variation in metal resistance within the populations from the non-contaminated regions. The data shows that trees may develop adaptive resistance to heavy metals, but the low degree of resistance indicates that the development of such resistances are slower than observed for herbaceous species with shorter generation times.
Afficher plus [+] Moins [-]Formation and stability of Pb-, Zn- & Cu-PO₄ phases at low temperatures: Implications for heavy metal fixation in polar environments
2012
White, D. A. (Duanne A.) | Hafsteinsdóttir, Erla G. | Gore, Damian B. | Thorogood, Gordon | Stark, Scott C.
Low temperatures and frequent soil freeze–thaw in polar environments present challenges for the immobilisation of metals. To address these challenges we investigated the chemical forms of Pb, Zn and Cu in an Antarctic landfill, examined in vitro reaction kinetics of these metals and orthophosphate at 2 and 22 °C for up to 185 days, and subjected the products to freeze–thaw. Reaction products at both temperatures were similar, but the rate of production varied, with Cu-PO₄ phases forming faster, and the Zn- and Pb-PO₄ phases slower at 2 °C. All metal-orthophosphate phases produced were stable during a 2.5 h freeze–thaw cycle to −30 °C. Metal immobilisation using orthophosphate can be successful in polar regions, but treatments will need to consider differing mineral stabilities and reaction rates at low temperatures.
Afficher plus [+] Moins [-]Temperature dependence of ofloxacin fluorescence quenching and complexation by Cu(II)
2012
Pan, Bo | Han, Xuejiao | Wu, Min | Peng, Hongbo | Zhang, Di | Li, Hao | Xing, Baoshan
The coexistence of heavy metals and antibiotics is common in the environment, and their interactions may mutually alter their environmental behaviors and risks. This study investigated ofloxacin (OFL)–Cu(II) interaction using fluorescence quenching experiments. The possible artifacts were excluded and OFL quenching was attributed to static quenching as suggested by the linear Stern–Volmer plot and decreased quenching with increased temperature. The OFL–Cu(II) interaction was quantitatively described using a stoichiometry equation. The calculation suggested that OFL–Cu(II) association was the mixture of 1:1 and 1:2 complexes. The negative ΔG values and the negative ΔH values suggested that the complexation is a spontaneous and exothermic process. Cation-π binding and electrostatic interaction were excluded and the complexation of Cu(II) with OFL ketonic and carboxyl groups was proposed through UV–visible spectrum characterization, pH dependent complexation, and thermodynamic analysis.
Afficher plus [+] Moins [-]Contrasting levels of heavy metals in the feathers of urban pigeons from close habitats suggest limited movements at a restricted scale
2012
Frantz, Adrien | Pottier, Marie-Anne | Karimi, Battle | Corbel, Hélène | Aubry, Emmanuel | Haussy, Claudy | Gasparini, Julien | Castrec-Rouelle, Maryse
Despite restrictions in emissions, heavy metals may remain a major environmental issue due to their numerous sources and their persistence. Here, we assessed current levels of 4 metals (Copper, Cadmium, Lead, Zinc) in the feathers of 91 feral pigeons (Columba livia) from 7 sites in the urbanized region of Paris. Elements were detected in all pigeons, indicating that metals persist in urbanized areas. The ratio between metal concentrations in the feathers vs. in the environment calculated using data from other studies was 2–90 times higher for cadmium than for other metals, underlying its ecological importance. Concentrations in the feathers depended on locality, suggesting that pigeons remain in local habitats at this restricted scale, as expected from previous observations. Overall, our study suggests that urban feral pigeons may represent a good model system for metal biomonitoring.
Afficher plus [+] Moins [-]The adaptive response of lichens to mercury exposure involves changes in the photosynthetic machinery
2012
Nicolardi, Valentina | Cai, Giampiero | Parrotta, Luigi | Puglia, Michele | Bianchi, Laura | Bini, Luca | Gaggi, Carlo
Lichens are an excellent model to study the bioaccumulation of heavy metals but limited information is available on the molecular mechanisms occurring during bioaccumulation. We investigated the changes of the lichen proteome during exposure to constant concentrations of mercury. We found that most of changes involves proteins of the photosynthetic pathway, such as the chloroplastic photosystem I reaction center subunit II, the oxygen-evolving protein and the chloroplastic ATP synthase β-subunit. This suggests that photosynthesis is a target of the toxic effects of mercury. These findings are also supported by changes in the content of photosynthetic pigments (chlorophyll a and b, and β-carotene). Alterations to the photosynthetic machinery also reflect on the structure of thylakoid membranes of algal cells. Response of lichens to mercury also involves stress-related proteins (such as Hsp70) but not cytoskeletal proteins. Results suggest that lichens adapt to mercury exposure by changing the metabolic production of energy.
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