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Distributions and sources of volatile chlorocarbons and bromocarbons in the Yellow Sea and East China Sea Texto completo
2015
Yang, Bin | Yang, Gui-Peng | Lu, Xiao-Lan | Li, Li | He, Zhen
Six volatile halogenated organic compounds (VHOC), namely, chloroform, carbon tetrachloride, trichloroethylene, bromodichloromethane, dibromochloromethane, and bromoform, were studied in the Yellow Sea and East China Sea from April to May, 2009. The spatial variability of these VHOC was influenced by various factors, including anthropogenic inputs, biogenic production and complicated hydrographic features such as Changjiang Diluted Water, Yellow Sea Cold Water Mass, and Kuroshio Current. Diurnal study results showed that factors such as solar irradiation, biological activity, and tide affected the abundance of these VHOC. Correlation analyses revealed that bromodichloromethane was positively correlated with chlorophyll a in surface seawater. Principal component analysis suggested that chlorinated compounds like carbon tetrachloride originated from anthropogenic sources whereas brominated compounds such as bromodichloromethane originated from biogenic sources. Sources of other chlorinated and brominated compounds may not be governed by biological processes in the marine environment.
Mostrar más [+] Menos [-]Abundance, size and polymer composition of marine microplastics ≥10μm in the Atlantic Ocean and their modelled vertical distribution Texto completo
2015
Enders, Kristina | Lenz, Robin | Stedmon, Colin A. | Nielsen, Torkel G.
We studied abundance, size and polymer type of microplastic down to 10μm along a transect from the European Coast to the North Atlantic Subtropical Gyre (NASG) using an underway intake filtration technique and Raman micro-spectrometry. Concentrations ranged from 13 to 501itemsm−3. Highest concentrations were observed at the European coast, decreasing towards mid-Atlantic waters but elevated in the western NASG. We observed highest numbers among particles in the 10–20μm size fraction, whereas the total volume was highest in the 50–80μm range. Based on a numerical model size-dependent depth profiles of polyethylene microspheres in a range from 10–1000μm were calculated and show a strong dispersal throughout the surface mixed layer for sizes smaller than 200μm. From model and field study results we conclude that small microplastic is ubiquitously distributed over the ocean surface layer and has a lower residence time than larger plastic debris in this compartment.
Mostrar más [+] Menos [-]Sources, concentrations and risk factors of organochlorine pesticides in soil, water and sediment in the Yellow River estuary Texto completo
2015
Li, Jing | Li, Fadong | Liu, Qiang
The environmental occurrence, sources and risk factors of organochlorine pesticides (HCHs and DDTs) and their isomers or metabolites were studied using comprehensive surveys (including soil, surface water, groundwater and sediment sampling) conducted in the Yellow River Delta (YRD). HCHs and DDTs were all detected in multi environmental media. Compared with reported organochlorine pesticide values in China and abroad and with related environmental quality standards, the concentrations of HCHs and DDTs were generally at low levels in the YRD. Composition of OCPs (DDT metabolites and HCH isomers) showed that DDTs in the multiple environments of the YRD not only came from residues of dicofol but also from atmospheric deposition, while HCH pollution results from the historical usage of a mixture of technical HCH and lindane. Furthermore, the sum of Excess Lifetime Cancer Risk (∑ELCR) exposure to HCHs exceeded the generally acceptable risk level of 1.0E-06 recommended by the USEPA for carcinogenic chemicals.
Mostrar más [+] Menos [-]Intersex related gene expression profiles in clams Scrobicularia plana: Molecular markers and environmental application Texto completo
2015
Ciocan, Corina M. | Cubero-Leon, Elena | Langston, William J. | Pope, Nick | Cornelius, Keith | Hill, E.M. | Alvarez-Munoz, Diana | Indiveri, Paolo | Lerebours, Adelaide | Minier, Christophe | Rotchell, Jeanette M.
Intersex, the appearance of female characteristics in male gonads, has been identified in several aquatic species. It is a widespread phenomenon in populations of the bivalve, Scrobicularia plana, from the southwest coast of the U.K. Genes previously identified as differentially expressed (ferritin, testicular haploid expressed gene, THEG, proliferating cell nuclear antigen, PCNA; receptor activated protein kinase C, RACK; cytochrome B, CYB; and cytochrome c oxidase 1, COX1) in intersex clams relative to normal male clams, were selected for characterisation and an environmental survey of the Channel region. Transcripts were significantly differentially expressed at sites with varying intersex incidence and contaminant burdens. Significant correlations between specific gene expressions, key contaminants and sampling locations have been identified, though no single gene was associated with intersex incidence. The results highlight the difficulty in understanding the intersex phenomenon in molluscs where there is still a lack of knowledge on the control of normal reproduction.
Mostrar más [+] Menos [-]Emerging contaminants (pharmaceuticals, personal care products, a food additive and pesticides) in waters of Sydney estuary, Australia Texto completo
2015
Birch, G.F. | Drage, D.S. | Thompson, K. | Eaglesham, G. | Mueller, J.F.
The current investigation of marine water from 30 sites adjacent to stormwater outlets across the entire Sydney estuary is the first such research in Australia. The number of analytes detected were: 8/59 pharmaceutical compounds (codeine, paracetamol, tramadol, venlafaxine, propranolol, fluoxetine, iopromide and carbamazepine), 7/38 of the pesticides (2,4-dichlorophenoxyacetic acid (2,4-D), 3,4-dichloroaniline, carbaryl, diuron, 2-methyl-4-chlorophenoxyacetic acid (MCPA), mecoprop and simazine) and 0/3 of the personal care products (PCPs) analysed. An artificial sweetener (acesulfame) was detected, however none of the nine antibiotics analysed were identified. Sewage water is not discharged to this estuary, except infrequently as overflow during high-precipitation events. The presence of acesulfame (a recognised marker of domestic wastewater) and pharmaceuticals in water from all parts of the estuary after a dry period, suggests sewage water is leaking into the stormwater system in this catchment. The pesticides are applied to the environment and were discharged via stormwater to the estuary.
Mostrar más [+] Menos [-]Merits of partial shielding in dumping sediment spoils Texto completo
2015
Jensen, Jacob Hjelmager | Saremi, Sina | Jimenez, Carlos | Hadjioannou, Louis
The commonly adopted method of dumping dredge spoil at sea using split-hull barges leads to considerable sediment loss to the water column and a subsequent dispersion of fine material that can pose a risk to sensitive “downstream” habitats such as coral reefs. Containing sediment loads using stitched closed geotextile bags is practiced for minimizing loss of contaminated sediment, but is expensive in terms of operational efficiency. Following promising observations from initial laboratory trials, the plunging of partially shielded sediment loads, released on open sea, was studied. The partial shielding was achieved with rigid, open containers as well as flexible, open bags. The loss of sediment from these modes of shielding was measured, and it was observed that even limited and unstitched shielding can be effective in debilitating the entrainment of water into the descending load. In particular, long-sleeved flexible bags practically self-eliminated the exposure of the load and thus losses.
Mostrar más [+] Menos [-]Fringing reefs exposed to different levels of eutrophication and sedimentation can support similar benthic communities Texto completo
2015
Rouzé, H. | Lecellier, G. | Langlade, M.J. | Planes, S. | Berteaux-Lecellier, V.
Benthic communities are sensitive to anthropogenic disturbances which can result in changes in species assemblages. A spatio-temporal survey of environmental parameters was conducted over an 18-month period on four different fringing reefs of Moorea, French Polynesia, with unusual vs. frequent human pressures. This survey included assessment of biological, chemical, and physical parameters. First, the results showed a surprising lack of a seasonal trend, which was likely obscured by short-term variability in lagoons. More frequent sampling periods would likely improve the evaluation of a seasonal effect on biological and ecological processes. Second, the three reef habitats studied that were dominated by corals were highly stable, despite displaying antagonistic environmental conditions through eutrophication and sedimentation gradients, whereas the reef dominated by macroalgae was relatively unstable. Altogether, our data challenge the paradigm of labelling environmental parameters such as turbidity, sedimentation, and nutrient-richness as stress indicators.
Mostrar más [+] Menos [-]Current air quality plans in Europe designed to support air quality management policies Texto completo
2015
Miranda, Ana | Silveira, Carlos | Ferreira, Joana | Monteiro, Alexandra | Lopes, Diogo | Relvas, Helder | Borrego, C. | Roebeling, Peter
Current air quality plans in Europe designed to support air quality management policies Texto completo
2015
Miranda, Ana | Silveira, Carlos | Ferreira, Joana | Monteiro, Alexandra | Lopes, Diogo | Relvas, Helder | Borrego, C. | Roebeling, Peter
The intensification of the human activity in urban areas as a result of the increasing population has contributed to the air pollution worsening in cities. To reverse this trend, the European Commission established a legal framework to improve the air quality. Thereby the Member States need to develop air quality plans (AQP) for zones and agglomerations where air quality limit values are exceeded, in order to implement pollution control strategies and meet the legal requirements. Understanding the reasons for the levels of air quality non–compliance as well as evaluating available and commonly used tools to predict the air quality and their effects, is crucial for the decision–making process on air quality management policies. Based on a compilation of regional and local AQP, a review of assessment capabilities and used modeling tools to evaluate the effects of emission abatement measures on the air quality and health was performed. In most cases, models are applied to estimate emissions and to assess the resulting air quality from both reference and emission abatement scenarios. Air quality’s impacts on the health and environment are rarely quantified. Regarding the air quality assessment, beyond the modeling, monitored data for validation of simulations are also used. Some studies, however, do not include the use of air quality models, considering the monitoring network as spatially representative of the study domain (e.g. Lisbon Region, Riga, Malta). In order to overcome methodological limitations for quantifying the impacts of emission abatement measures, economic evaluation techniques or even Integrated Assessment Methodologies (IAM) have been developed. IAM, already applied in some AQP or case studies, namely for Antwerp and London, are used for assessing how reductions in emissions contribute to improve air quality, reduce exposure and protect human health.
Mostrar más [+] Menos [-]Current air quality plans in Europe designed to support air quality management policies Texto completo
2015
Miranda, Ana | Silveira, Carlos | Ferreira, Joana | Monteiro, Alexandra | Lopes, Diogo | Relvas, Hélder | Borrego, Carlos | Roebeling, Peter
The intensification of the human activity in urban areas as a result of the increasing population has contributed to the air pollution worsening in cities. To reverse this trend, the European Commission established a legal framework to improve the air quality. Thereby the Member States need to develop air quality plans (AQP) for zones and agglomerations where air quality limit values are exceeded, in order to implement pollution control strategies and meet the legal requirements. Understanding the reasons for the levels of air quality non–compliance as well as evaluating available and commonly used tools to predict the air quality and their effects, is crucial for the decision–making process on air quality management policies. Based on a compilation of regional and local AQP, a review of assessment capabilities and used modeling tools to evaluate the effects of emission abatement measures on the air quality and health was performed. In most cases, models are applied to estimate emissions and to assess the resulting air quality from both reference and emission abatement scenarios. Air quality’s impacts on the health and environment are rarely quantified. Regarding the air quality assessment, beyond the modeling, monitored data for validation of simulations are also used. Some studies, however, do not include the use of air quality models, considering the monitoring network as spatially representative of the study domain (e.g. Lisbon Region, Riga, Malta). In order to overcome methodological limitations for quantifying the impacts of emission abatement measures, economic evaluation techniques or even Integrated Assessment Methodologies (IAM) have been developed. IAM, already applied in some AQP or case studies, namely for Antwerp and London, are used for assessing how reductions in emissions contribute to improve air quality, reduce exposure and protect human health.
Mostrar más [+] Menos [-]Seasonal and interannual variations in whole-ecosystem isoprene and monoterpene emissions from a temperate mixed forest in Northern China Texto completo
2015
Bai, Jianhui | Guenther, Alex | Turnipseed, Andrew | Duhl, Tiffany
Contributed Measurements of BVOC emissions, meteorological parameters, and solar radiation were carried out in a temperate forest, China during the summer seasons in 2010 and 2011. Terpenoid emissions were measured using the Relaxed Eddy Accumulation (REA) technique on an above-canopy tower. Isoprene contributed 79.1% and 82.0% of terpenoid emissions in 2010 and 2011 summer. The monoterpene emissions were dominated by α–pinene, contributing 6.3% and 12.2% of the total terpenoid emissions in 2010 and 2011 summer. Terpenoid emissions exhibited strong diurnal variations. Isoprene and monoterpene emissions maxima typically occurred a few hours after the noon PAR peak and coincided with the daily temperature maximum. During 2011 summer, the mean isoprene emission flux (mg m–2 h–1) was 0.889, mean total monoterpene emission flux was 0.143. Emission factors, representing the emission expected at a temperature of 30 °C, for this site were 0.32mg m–2 h–1 for total monoterpenes and 4.3mg m–2 h–1 for isoprene. The observations were used to evaluate the isoprene and monoterpene emission magnitude and variability predicted by the MEGANv2.1 model. Canopy scale isoprene and monoterpene emission factors based on these observations fall within the range of emission factors assigned to locations within 50km of the site by the MEGANv2.1 emission model. When using the site specific landcover data for the site, the measured emission factors are 12% for isoprene and 20% for monoterpenes lower than the MEGANv2.1 emission factors. MEGANv2.1 predicts that variations in light intensity should result in significant changes in isoprene emissions during the study but this was not evident in the observations. Observed diurnal, seasonal and interannual variations in isoprene and monoterpene emissions were strongly correlated with air temperature which was the dominant driving variable for MEGANv2.1 during the study period. The observed temperature response for isoprene and monoterpenes is similar to the temperature sensitivity of the MEGANv2.1 response functions.
Mostrar más [+] Menos [-]Benthic foraminifera as indicators of habitat change in anthropogenically impacted coastal wetlands of the Ebro Delta (NE Iberian Peninsula) Texto completo
2015
Benito, Xavier | Trobajo, Rosa | Ibàñez, Carles | Cearreta, Alejandro | Brunet, Manola
Present-day habitats of the Ebro Delta, NE Iberian Peninsula, have been ecologically altered as a consequence of intensive human impacts in the last two centuries (especially rice farming). Benthic foraminiferal palaeoassemblages and sediment characteristics of five short cores were used to reconstruct past wetland habitats, through application of multivariate DCA and CONISS techniques, and dissimilarity coefficients (SCD). The timing of environmental changes was compared to known natural and anthropogenic events in order to identify their possible relationships. In deltaic wetlands under altered hydrological conditions, we found a decrease in species diversity and calcareous-dominated assemblages, and a significant positive correlation between microfaunal changes and organic matter content. Modern analogues supported palaeoenvironmental interpretation of the recent evolution of the Delta wetlands. This research provides the first recent reconstruction of change in the Ebro Delta wetlands, and also illustrates the importance of benthic foraminifera for biomonitoring present and future conditions in Mediterranean deltas.
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