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Resultados 2261-2270 de 62,508
Occurrence and assessment of perfluoroalkyl acids (PFAAs) in commonly consumed seafood from the coastal area of Bangladesh Texto completo
2017
Habibullah-Al-Mamun, Md. | Ahmed, Md. K. | Raknuzzaman, M. | Islam, Md. S. | Ali, M.F. | Tokumura, M. | Masunaga, S.
This study reports the first evidence of the occurrence of perfluoroalkyl acids (PFAAs) in commonly consumed seafood from the coastal area of Bangladesh. Fifteen target PFAAs in 48 seafood samples (5 finfish and 2 shellfish species) were measured by HPLC-MS/MS. The results were comparable with other studies worldwide, particularly from China, Spain, Sweden, and USA. The majority of monitored PFAAs did not show clear seasonal variation. However, seafood from the southeast area (Coxs Bazar and Chittagong) showed relatively higher levels of PFAAs. Moreover, the dietary exposure assessment revealed that the daily intakes of PFAAs via seafood consumption were far less than the health-based guidelines, indicating low health risk for the Bangladeshi coastal residents."
Mostrar más [+] Menos [-]Trace element concentrations in the apex predator swordfish (Xiphias gladius) from a Mediterranean fishery and risk assessment for consumers Texto completo
2017
Gobert, Sylvie | Pasqualini, Vanina | Dijoux, Jessica | Lejeune, Pierre | Durieux, Eric Dominique Henry | Marengo, Michel | FOCUS - Freshwater and OCeanic science Unit of reSearch - ULiège | Stareso
peer reviewed | Swordfish (Xiphias gladius L., 1758) is an apex predator, highly migratory meso-pelagic fish widely distributed in the Atlantic Ocean and Mediterranean. As top predators, this fish may be the end reservoir of the bioaccumulation of trace elements in a food chain because they occupy higher trophic levels and are an important food source, causing them to be potentially hazardous to consume. This study aims to investigate the concentration of 18 trace elements of Swordfish, caught in the Mediterranean Sea and to discuss human exposure risks. The mean element levels in the fish muscles were clearly below the maximum allowable concentrations established by International food safety regulations. The data suggested that the risk is minor and acceptable for human health. The findings of this study amplify the scarce database on contaminants available, especially new data on “emerging elements”, for this species from the Mediterranean Sea. | Transpolmed Et Post Doc de Michel Marengo
Mostrar más [+] Menos [-]Environmental effects of the Deepwater Horizon oil spill: A review Texto completo
2016
Beyer, Jonny | Trannum, Hilde C. | Bakke, Torgeir | Hodson, Peter V. | Collier, Tracy K.
The Deepwater Horizon oil spill constituted an ecosystem-level injury in the northern Gulf of Mexico. Much oil spread at 1100–1300 m depth, contaminating and affecting deepwater habitats. Factors such as oil-biodegradation, ocean currents and response measures (dispersants, burning) reduced coastal oiling. Still, > 2100 km of shoreline and many coastal habitats were affected. Research demonstrates that oiling caused a wide range of biological effects, although worst-case impact scenarios did not materialize. Biomarkers in individual organisms were more informative about oiling stress than population and community indices. Salt marshes and seabird populations were hard hit, but were also quite resilient to oiling effects. Monitoring demonstrated little contamination of seafood. Certain impacts are still understudied, such as effects on seagrass communities. Concerns of long-term impacts remain for large fish species, deep-sea corals, sea turtles and cetaceans. These species and their habitats should continue to receive attention (monitoring and research) for years to come. | acceptedVersion
Mostrar más [+] Menos [-]Modelling of cadmium uptake by plant roots in agricultural soil: construction and sensitivity analysis of the model Texto completo
2012
Zhongbin, Lin | Nguyen, Christophe | Schneider, Andre
Emission factors and detailed chemical characterization of PM and VOCs from 4 in-use petrol and diesel passenger cars Texto completo
2012
Polo, L. | Goriaux, M. | Jaffrezo, J.L. | Besombes, Jean-Luc | André, M. | Charron, A.
Environmental and welfare friendly housing for pigs
2010
Aarnink, A.J.A. | Groenestein, C.M. | Ogink, N.W.M.
Carbon isotope composition, macronutrient concentrations, and carboxylating enzymes in relation to the growth of Pinus halepensis mill. when subject to ozone stress Texto completo
2010
Inclan , Rosa (Ecotoxicology of Air Pollution, Madrid(Espagne).) | Gimeno , Benjamin S. (Ecotoxicology of Air Pollution, Madrid(Espagne).) | Peñuelas , Josep (Universitat Autónoma de Barcelona, Barcelone(Espagne).) | Gerant , Dominique (INRA , Champenoux (France). UMR 1137 Ecologie et Ecophysiologie Forestières) | Querido , Alberto (Ecotoxicology of Air Pollution, Madrid(Espagne).)
Carbon isotope composition, macronutrient concentrations, and carboxylating enzymes in relation to the growth of Pinus halepensis mill. when subject to ozone stress Texto completo
2010
Inclan , Rosa (Ecotoxicology of Air Pollution, Madrid(Espagne).) | Gimeno , Benjamin S. (Ecotoxicology of Air Pollution, Madrid(Espagne).) | Peñuelas , Josep (Universitat Autónoma de Barcelona, Barcelone(Espagne).) | Gerant , Dominique (INRA , Champenoux (France). UMR 1137 Ecologie et Ecophysiologie Forestières) | Querido , Alberto (Ecotoxicology of Air Pollution, Madrid(Espagne).)
We present here the effects of ambient ozone (O3)-induced decline in carbon availability, accelerated foliar senescence, and a decrease in aboveground biomass accumulation in the Aleppo pine (Pinus halepensis Mill.). Aleppo pine seedlings were continuously exposed in open-top chambers for 39 months to three different types of O3 treatments, which are as follows: charcoal-filtered air, nonfiltered air (NFA), and nonfiltered air supplemented with 40 ppb O3 (NFA+). Stable carbon isotope discrimination (Δ) and derived time-integrated ci/ca ratios were reduced after an accumulated ozone exposure over a threshold of 40 ppb (AOT40) value from April to September of around 20,000 ppb·h. An AOT40 of above 67,000 ppb·h induced reductions in ribulose-1, 5-biphosphate carboxylase/oxygenase activity, aboveground C and needle N and K concentrations, the C/N ratio, Ca concentrations in twigs under 3 mm, and the aerial biomass, as well as increases in needle P concentrations and phosphoenolpyruvate carboxylase (PEPC) activity and the N and K concentrations in twigs under 3 mm. Macronutrients losses, the limitations placed on carbon uptake, and increases in catabolic processes may be the causes of carbon gain diminution in leaves which was reflected as a reduction in aboveground biomass at tree level. Stimulation of PEPC activity, the consequent decreased Δ, and compensation processes in nutrient distribution may increase O3 tolerance and might be interpreted as part of Aleppo pine acclimation response to O3.
Mostrar más [+] Menos [-]Carbon isotope composition, macronutrient concentrations, and carboxylating enzymes in relation to the growth of Pinus halepensis mill. when subject to ozone stress Texto completo
2010
Inclan, Rosa | Gimeno, Benjamin S. | Peñuelas, Josep | Gerant, Dominique | Querido, Alberto
We present here the effects of ambient ozone (O3)-induced decline in carbon availability, accelerated foliar senescence, and a decrease in aboveground biomass accumulation in the Aleppo pine (Pinus halepensis Mill.). Aleppo pine seedlings were continuously exposed in open-top chambers for 39 months to three different types of O3 treatments, which are as follows: charcoal-filtered air, nonfiltered air (NFA), and nonfiltered air supplemented with 40 ppb O3 (NFA+). Stable carbon isotope discrimination (Δ) and derived time-integrated ci/ca ratios were reduced after an accumulated ozone exposure over a threshold of 40 ppb (AOT40) value from April to September of around 20,000 ppb·h. An AOT40 of above 67,000 ppb·h induced reductions in ribulose-1, 5-biphosphate carboxylase/oxygenase activity, aboveground C and needle N and K concentrations, the C/N ratio, Ca concentrations in twigs under 3 mm, and the aerial biomass, as well as increases in needle P concentrations and phosphoenolpyruvate carboxylase (PEPC) activity and the N and K concentrations in twigs under 3 mm. Macronutrients losses, the limitations placed on carbon uptake, and increases in catabolic processes may be the causes of carbon gain diminution in leaves which was reflected as a reduction in aboveground biomass at tree level. Stimulation of PEPC activity, the consequent decreased Δ, and compensation processes in nutrient distribution may increase O3 tolerance and might be interpreted as part of Aleppo pine acclimation response to O3.
Mostrar más [+] Menos [-]Metallophytes: The unique biological resource, its ecology and conservational status in Europe, central Africa and Latin America Texto completo
2010
Baker, A. J. M. | Ernst, W. H. O. | van der Ent, A. | Malaisse, François | Ginocchio, R.
peer reviewed | Metalliferous soils provide very restrictive habitats for plants due to phytotoxicity, resulting in severe selection pressures. Species comprising heavy-metal plant communities are genetically altered ecotypes with specific tolerances to, e.g., cadmium, copper, lead, nickel, zinc and arsenic, adapted through microevolutionary processes. Evolution of metal tolerance takes place at each specific site (Ernst 2006). A high degree of metal tolerance depends on the bioavailable fraction of the metal(loids) in the soil and the type of mineralization. At extremely high soil metal concentrations, especially on polymetallic soils, even metal-tolerant genotypes are not able to evolve extreme tolerances to several heavy metals simultaneously. Adapted genotypes are the result of the Darwinian natural selection of metal-tolerant individuals selected from surrounding non-metalliferous populations (Antonovics et al. 1971; Baker 1987; Ernst 2006). Such selection can lead ultimately to speciation and the evolution of endemic taxa. Heavy-metal tolerance was first reported by Prat (1934) in Silene dioica and demonstrated experimentally in grasses by Bradshaw and co-workers in Agrostis spp. and by Wilkins in Festuca ovina in the late 1950s and 1960s (see Antonovics et al. 1971) and from the early 1950s onwards in the herb Silene vulgaris by Baumeister and co-workers (see Ernst 1974). Metal-tolerant plants avoid intoxication by an excess of heavy metals by means of special cellular mechanisms, as long as the soil metal levels do not exceed the levels of metal tolerance (Ernst 1974; Ernst et al. 2004). They can thus thrive on soils that are too toxic for non-adapted species and ecotypes.
Mostrar más [+] Menos [-]Occurrence of anthropogenic and naturally-produced organohalogenated compounds in tissues of Black Sea harbour porpoises Texto completo
2010
Weijs, Liesbeth | Das, Krishna | Neels, Hugo | Blust, Ronny | Covaci, Adrian
peer reviewed | Harbour porpoises are one of the three cetacean species inhabiting the Black Sea. This is the first study to report on polybrominated diphenyl ethers (PBDEs) and naturally-produced compounds, methoxylated PBDEs (MeO-PBDEs) and polybrominated hexahydroxanthene derivatives (PBHDs), in tissues (kidney, brain, blubber, liver, muscle) of male harbour porpoises (11 adults, 9 juveniles) from the Black Sea. Lipid-normalized concentrations decreased from muscle > blubber > liver > kidney > brain for the sum of polychlorinated biphenyls (PCBs) and for the sum of PBDEs. Among the naturally-produced compounds, levels of PBHDs were higher than of MeO-PBDEs, with tri-BHD and 6-MeO-BDE 47 being the dominant compounds for both groups, respectively. Concentrations of naturally-produced compounds decreased from blubber to brain, similarly to the sum of DDT and metabolites (DDXs). Concentrations of DDXs were highest, followed by PCBs, HCB, PBHDs, PBDEs and MeO-PBDEs. Levels of PCBs and PBDEs in blubber were lower than concentrations reported for harbour porpoises from the North Sea, while concentrations of DDXs were higher.
Mostrar más [+] Menos [-]Thermodynamics and kinetic processes at coal interface for CO2 geological storage Texto completo
2008
Charriere, Delphine | Pokryszka, Zbigniew | Behra, Philippe
Currently, the geological storage of CO2 is heavily studied around the world in order to limit global warming due to the greenhouse effect. The atmospheric CO2, which has been steadily increasing for more than a century, is assumed to be in a large part responsible of this warming. Nowadays, various options have been considering to store CO2 in an underground environment for periods covering several centuries. Among the options, one is to inject it in unexploited coal seams. The objective of our work is to characterise the interactions between CO2 ans coal interfaces from two French coal seams. This will contribute to identify the most adapted coal basin which could be used for storing CO2 in France.
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